Friday, September 23, 2011
Air Races, Air Shows, and Risks
The recent fatal crash of the modified World War 2 P-51 “Galloping Ghost” at the Reno air races is a horrible incident. Lots of things have been said on the news and on the internet about it, but all of this is speculation based on incomplete information.
The National Transportation Safety Board (NTSB) will investigate this and determine its cause. They will use all the available information, including stuff not yet reported or on the internet. Until they publish their findings, perhaps a year from now, all else is mere speculation.
That being said, some speculators are more informed than others. I would place more trust in the speculations of an actual aircraft engineer over the speculations of most other members of the public. Being such an engineer, here are my speculations:
Facts
“Galloping Ghost” suddenly pitched up and climbed, rolled over inverted, and dove to the ground, all in a matter of scant seconds. Impact was not directly upon, but was immediately adjacent to, spectators, many of whom were killed by pieces thrown from the wreck. There was no post crash fire.
The left trim tab was photographed departing from the airplane’s horizontal tail before impact. The pilot’s head was not visible in the canopy before impact. The retractable tail wheel was seen extended before impact.
This aircraft was modified in several ways from its World War 2 configuration to compete in the races. Most notable were “clipped wings” reducing span (and aileron size) by 5 feet each side, and removal of the belly air scoop and radiator in favor of a sacrificial coolant system. These enable higher top speed, at the cost of higher landing speed and perhaps a reduced maximum roll rate, not a loss of basic stability.
Less obvious were changes to canopy size, wing fillet size, and smoothing of protuberances, for drag reduction. The race speeds significantly exceed 500 mph, when the original level-flight top speed for the P-51 during World War 2 was 435 mph.
I do not know what the original “never exceed” speed was for the P-51, but these race speeds would be approaching or exceeding that limit. Flying too fast risks structural failures of wing and tail components by a phenomenon called flutter.
Similar Previous Incident
About a decade ago, a similarly-modified P-51 named “Voodoo-5” experienced a very similar incident: sudden high speed pitch-up (at high acceleration) into a climb, with the pilot losing consciousness briefly due to excessive gee forces. He woke up, with no memory of events, at 9000 feet altitude, and regained control, landing successfully.
“Voodo-5” was found to have lost the same left trim tab as “Galloping Ghost”. Loss of the tab at high speed caused failure of part of the elevator control linkage, leaving only the right elevator for pitch control. Aerodynamic flutter was blamed for loss of the trim tab.
At 400+ mph, P-51's exhibit a relatively unusual nose-up tendency that you fight with down trim and down stick. Other aircraft exhibit high-speed nose-down "tuck", or no trim-change tendencies at all.
In the P-51 with that nose-up tendency, sudden loss of half your elevator effectiveness at very high speed causes the aircraft to suddenly and violently pitch up, at something near 10-15 gees. The pilot passes out, or can even be killed with a broken neck, depending on helmet weight and head restraints, or the lack thereof.
Speculations Regarding “Galloping Ghost”
“Galloping Ghost” lost the same left trim tab, and pitched up similarly at high gee. Some on the internet say telemetry from the aircraft indicated 11.5 gees. The differences between “Voodoo-5” and “Galloping Ghost” are (1) “Galloping Ghost” also experienced a roll, and (2) it appears her pilot never woke up, or was perhaps already dying of a broken neck.
It also appears that the high pitch-up gee level forced deployment of her tail wheel. The roll motion on the way up caused her to peak in inverted flight, as photographed. I think I see a light-colored helmet on the dark dashboard in that internet inverted-flight photo, but I could be wrong. She then continued her pitch-roll motion into a dive-to-impact.
There has been speculation that the pilot’s seat failed in “Galloping Ghost”, which might explain why his head was not visible in the canopy. I would be surprised at seat failure in a fighter plane at only 10-15 gees, but I guess it could happen. It did not in “Voodoo-5”, though.
Waiting for the Truth
The NTSB will opine officially maybe a year from now, but I'd almost bet they say that P-51 trim tabs are vulnerable to flutter-induced departure at race speeds beyond the original design's never-exceed speed. Few designers provide aerodynamic or mass balancing, or any other anti-flutter structural treatment, to a trim tab. Maybe they should. If so, the NTSB will say so.
Inappropriate Fear-Mongering
The public safety issue raised by some reporters has less to do with any given aircraft being "pushed too far", or being modified "too radically", and more to do with simple spectator crowd placement. The wording in those reports seems deliberately chosen to inflame fears, and is a disservice to the public, much like yelling “fire” in a crowded theater when there isn’t one.
At air shows, spectators may not legally be located beneath expected aircraft flight paths. At the Reno air races, they can be (and are) located under flight paths. Perhaps they should not be, similar to the air show restrictions. While these are the first spectator deaths at Reno since the 1950's, that risk has always been there.
There was a fatal crash at an air show the day following the “Galloping Ghost” incident. No one but the pilot was killed, because no one was underneath the falling plane.
Tuesday, September 6, 2011
Mars Mission Second Thoughts Illustrated
As I said in a previous posting (8-9-11), I had some second thoughts about the back-up propulsion for my fast trip Mars mission paper, presented at the Mars Society convention in Dallas, Texas, August 4-7, 2011. My backup had been the VASIMR electric propulsion scheme, thinking it a breakthrough in thrust for the power consumption. Based on what I saw at the meeting, it is no breakthrough, and is really mostly unsuitable for fast trips to Mars.
My second thoughts centered around an alternative slow-traveling vehicle requiring artificial gravity, because the manned mission duration would exceed the 1 year known to be tolerable. This vehicle would be powered by the same solid-core nuclear thermal technology I assumed in my landers, derived from the NERVA tested successfully 4 decades ago. I planned this alternative around simple minimum-energy Hohmann transfer orbits, because it is easy.
That still leaves the gas-core nuclear thermal-powered fast trip vehicle, which is still my baseline. I took a closer look at the orbits and the near-straight line “shots” across the solar system at the higher travel speeds. This verified my earlier crude ballpark estimate of the fast trip velocity requirements. All of this is illustrated here, at a level of analysis no deeper than is required to confirm the concepts and their feasibility. For example, I used circles to approximate the actually slightly-elliptical orbits of the planets. To first order for a feasibility check, this is “good enough”.
Baseline Trajectories
The baseline “fast trip mission” sends a fleet of three unmanned ships to Mars parking orbit ahead of the manned ship. This fleet is propelled by the landers themselves, and comprises all the propellant required to support the landing operations, plus enough to send these assets one-way to Mars by Hohmann transfer. Figure 1 shows the initial Hohmann transfer for these unmanned assets. Note that there is an opposition during the unmanned flight to Mars.
I looked for ways to center my manned fast trip about that first opposition, without adding too much extra time in orbit to the manned mission. This did not prove feasible, so that the manned fast trip is centered about a second opposition some 779 days after the first one. The mission calls for 16 weeks at Mars making landings, which would be 56 days to either side of the opposition. A little time spent making rough calculations gave me an “optimal” one-way flight time pretty near 83 days for the “average” mission these approximations represent. This is shown in Figure 2.
Baseline Vehicles
The total mission time (for the men) is under 9 months, so no artificial gravity is required. Note that the total time the propellant tanks sent unmanned must maintain the liquid hydrogen is well over two years – rather challenging! The vehicle designs are as shown in Figure 3, and are essentially unchanged from my paper. The direct launch costs are pretty much as I estimated in the original paper.
Guessing that total program costs are about 6 times the direct launch costs gives something like $50 billion to mount this mission, given the right team. Those figures are similar to the ones in the original paper. That “right team” issue is also discussed in more detail in that paper. See the 7-25-11 posting for an on-line version of that original paper.
Backup “Slowboat” Trajectories
If the manned vehicle is comprised of the same basic modules, but with solid core nuclear engines instead of the gas core engines, then single stage two-way flight, even on a Hohmann transfer, is not possible. But, a single stage transfer to Mars can be flown, and the empty tanks left there at Mars. In this way, a single stage return to Earth can be made, without relying on propellant already sent unmanned to Mars. This is a safety issue: what if rendezvous should fail in Mars orbit? The crew needs a way to return anyway.
The Hohmann transfer to Mars is identical to that in Figure 1. All four ships travel together as a single fleet: 3 unmanned and the one manned vessel. It is not possible to return by Hohmann transfer until the second opposition approaches, as illustrated in Figure 4. These oppositions are separated by 779 days, which leads to the timelines shown for the return in Figure 4. Thus, total manned mission duration is about 2.66 years, requiring the use of artificial gravity to protect the health of the crew, and considerably more packed supplies for the longer mission. Time at Mars about doubles, allowing for 16 2-week landings instead of 16 1-week landings, as in the baseline.
Backup “Slowboat” Vehicles
The unmanned vehicles are unchanged from my paper. The manned vehicle is necessarily bigger than the baseline design, driven by the substantially lower performance of solid core nuclear thermal rockets (SC-NTR) vs. gas core nuclear thermal rockets (GC-NTR). The solid core vehicle is substantially longer and about twice as heavy as the baseline gas core vehicle. The “payload” is larger, too, driven by the need to pack about 3 times as much supplies, with some of that bulky, heavy frozen food. These are depicted in Figure 5.
The return vehicles, command module (also the radiation shelter), habitat module, and supply storage modules are the same, I just needed 3 storage modules instead of one. I did take a closer look at the habitat module, since more space is needed for the longer mission to maintain psychological health. The easiest way to do that was to make the habitat an inflatable, along the lines of the Bigelow Aerospace modules already in experimental flight test now. Equipment and floor structure would be stowed along the axis for launch, and folded out into position once the module is inflated, as illustrated in Figure 6.
The same module could be used on the baseline fast trip vehicle, there is no need to build two different designs. It is imperative not to mount equipment on module walls, as they need to be accessible for very rapid meteoroid puncture repairs. (The same is true of non-inflatable modules.)
I wrestled with several ideas on how to provide adequate radius at acceptable spin rates for artificial gravity, at the one gee level which we already know would be adequate. The breakthrough was to spin the long ship end-over-end, using the long module stack as its own spin diameter. For the trip to Mars, the propellant stack is 34 modules long, each figured as 5.2 m diameter and 13.9 m long, based on the payload shroud dimensions for the SpaceX Falcon-heavy launch vehicle. Spinning end-over-end at only 1.2 rpm provides right about 1 gee at the forward end of the inflatable habitat (at its lower deck as illustrated). The stack is shorter returning to Earth, but should be long enough to provide close to 1 gee at no more than the acceptable limit of 4 rpm.
About Radiation
The original paper covers solar flare radiation shielding in the command module. This is done by surrounding the flight deck with water and wastewater tanks, plus perhaps a little steel plate. One provides space in there for all 6 crew, and a day or two of supplies to outlast the typical solar storm. This enables critical maneuvers to be flown, no matter what the solar weather, a major flight safety issue.
A little research since then provided credible dose estimates for the cosmic ray background radiation, composed of particles so energetic that ordinary shielding is more-or-less impractical. The dose varies between 22 and 60 REM per year in a steady “drizzle”, depending upon the strength of the solar wind, which tends to deflect some of it. The original radiation dose limits for astronauts was set to 25 REM/year, which was the World War 2-vintage max dose for civilian adults. It has since been revised to 50 REM/year, based on what I can find on the internet. The actual dosage rate only sometimes exceeds the newer limits, and then only by a small amount. Trips to Mars thus appear quite feasible without incurring any immediate health risks from cosmic rays, or even any significant prospect of long-term effects.
The Program As Revised
Changing to SC-NTR backup propulsion puts the artificial gravity and frozen food storage issues into the design mix. This has to be made to work, and they are things we have never before done. Using the baseline GC-NTR propulsion puts that very propulsion into the mix as something we never did do before, excepting some feasibility experiments. Those are the two development items to be worked in parallel, so that one or the other is ready in time to fly. (This is the same basic parallel path development idea that was in the original paper, where the baseline was GC-NTR, and the backup was VASIMR and its power plant.) All the other items are simple design / build / checkout efforts based on known technologies, and that includes the SC-NTR. The high-level program plan is just a bunch of parallel paths, as illustrated in Figure 7.
So, we are looking at somewhere in the vicinity of $53 B to $70 B to send 6 men to Mars to make 16 widely-separated landings all over the planet, in the one trip, with maximum safety and self-rescue capability designed-in at every step, and with all-reusable assets left in space to be refueled and reused by subsequent missions. The whole thing could be done for prices like that, in only 5-10 years, given the right kind of contractor teams, and the right kind of an agency to lead them. That is one incredible amount of “bang for the buck”!
As I said in my original paper, right now we do not have that agency, and only a couple of the right kind of contractors, at best. But, if we fix those lacks, we could really do this. The numbers show it is definitely feasible.
The last time we as a nation embarked on a mission to explore another world (the moon), we had nearly two decades of sustained economic boom, from all the jobs created just to get the mission done. That may not be causal, but it is definitely correlated. Why not do it again?
Figure 1 – “Slowboat” Transfer to Mars, Baseline and Backup
Figure 2 – “Fast Trip” Transfer To and From Mars, Baseline
Figure 3 – Baseline Manned and Unmanned Vehicles
Figure 4 – “Slowboat” Transfers to Earth, Backup
Figure 5 – Backup Manned and Unmanned Vehicles
Figure 6 – Inflatable Habitat Module, Baseline and Backup Vehicles
Figure 7 – Program Outline Plan
My second thoughts centered around an alternative slow-traveling vehicle requiring artificial gravity, because the manned mission duration would exceed the 1 year known to be tolerable. This vehicle would be powered by the same solid-core nuclear thermal technology I assumed in my landers, derived from the NERVA tested successfully 4 decades ago. I planned this alternative around simple minimum-energy Hohmann transfer orbits, because it is easy.
That still leaves the gas-core nuclear thermal-powered fast trip vehicle, which is still my baseline. I took a closer look at the orbits and the near-straight line “shots” across the solar system at the higher travel speeds. This verified my earlier crude ballpark estimate of the fast trip velocity requirements. All of this is illustrated here, at a level of analysis no deeper than is required to confirm the concepts and their feasibility. For example, I used circles to approximate the actually slightly-elliptical orbits of the planets. To first order for a feasibility check, this is “good enough”.
Baseline Trajectories
The baseline “fast trip mission” sends a fleet of three unmanned ships to Mars parking orbit ahead of the manned ship. This fleet is propelled by the landers themselves, and comprises all the propellant required to support the landing operations, plus enough to send these assets one-way to Mars by Hohmann transfer. Figure 1 shows the initial Hohmann transfer for these unmanned assets. Note that there is an opposition during the unmanned flight to Mars.
I looked for ways to center my manned fast trip about that first opposition, without adding too much extra time in orbit to the manned mission. This did not prove feasible, so that the manned fast trip is centered about a second opposition some 779 days after the first one. The mission calls for 16 weeks at Mars making landings, which would be 56 days to either side of the opposition. A little time spent making rough calculations gave me an “optimal” one-way flight time pretty near 83 days for the “average” mission these approximations represent. This is shown in Figure 2.
Baseline Vehicles
The total mission time (for the men) is under 9 months, so no artificial gravity is required. Note that the total time the propellant tanks sent unmanned must maintain the liquid hydrogen is well over two years – rather challenging! The vehicle designs are as shown in Figure 3, and are essentially unchanged from my paper. The direct launch costs are pretty much as I estimated in the original paper.
Guessing that total program costs are about 6 times the direct launch costs gives something like $50 billion to mount this mission, given the right team. Those figures are similar to the ones in the original paper. That “right team” issue is also discussed in more detail in that paper. See the 7-25-11 posting for an on-line version of that original paper.
Backup “Slowboat” Trajectories
If the manned vehicle is comprised of the same basic modules, but with solid core nuclear engines instead of the gas core engines, then single stage two-way flight, even on a Hohmann transfer, is not possible. But, a single stage transfer to Mars can be flown, and the empty tanks left there at Mars. In this way, a single stage return to Earth can be made, without relying on propellant already sent unmanned to Mars. This is a safety issue: what if rendezvous should fail in Mars orbit? The crew needs a way to return anyway.
The Hohmann transfer to Mars is identical to that in Figure 1. All four ships travel together as a single fleet: 3 unmanned and the one manned vessel. It is not possible to return by Hohmann transfer until the second opposition approaches, as illustrated in Figure 4. These oppositions are separated by 779 days, which leads to the timelines shown for the return in Figure 4. Thus, total manned mission duration is about 2.66 years, requiring the use of artificial gravity to protect the health of the crew, and considerably more packed supplies for the longer mission. Time at Mars about doubles, allowing for 16 2-week landings instead of 16 1-week landings, as in the baseline.
Backup “Slowboat” Vehicles
The unmanned vehicles are unchanged from my paper. The manned vehicle is necessarily bigger than the baseline design, driven by the substantially lower performance of solid core nuclear thermal rockets (SC-NTR) vs. gas core nuclear thermal rockets (GC-NTR). The solid core vehicle is substantially longer and about twice as heavy as the baseline gas core vehicle. The “payload” is larger, too, driven by the need to pack about 3 times as much supplies, with some of that bulky, heavy frozen food. These are depicted in Figure 5.
The return vehicles, command module (also the radiation shelter), habitat module, and supply storage modules are the same, I just needed 3 storage modules instead of one. I did take a closer look at the habitat module, since more space is needed for the longer mission to maintain psychological health. The easiest way to do that was to make the habitat an inflatable, along the lines of the Bigelow Aerospace modules already in experimental flight test now. Equipment and floor structure would be stowed along the axis for launch, and folded out into position once the module is inflated, as illustrated in Figure 6.
The same module could be used on the baseline fast trip vehicle, there is no need to build two different designs. It is imperative not to mount equipment on module walls, as they need to be accessible for very rapid meteoroid puncture repairs. (The same is true of non-inflatable modules.)
I wrestled with several ideas on how to provide adequate radius at acceptable spin rates for artificial gravity, at the one gee level which we already know would be adequate. The breakthrough was to spin the long ship end-over-end, using the long module stack as its own spin diameter. For the trip to Mars, the propellant stack is 34 modules long, each figured as 5.2 m diameter and 13.9 m long, based on the payload shroud dimensions for the SpaceX Falcon-heavy launch vehicle. Spinning end-over-end at only 1.2 rpm provides right about 1 gee at the forward end of the inflatable habitat (at its lower deck as illustrated). The stack is shorter returning to Earth, but should be long enough to provide close to 1 gee at no more than the acceptable limit of 4 rpm.
About Radiation
The original paper covers solar flare radiation shielding in the command module. This is done by surrounding the flight deck with water and wastewater tanks, plus perhaps a little steel plate. One provides space in there for all 6 crew, and a day or two of supplies to outlast the typical solar storm. This enables critical maneuvers to be flown, no matter what the solar weather, a major flight safety issue.
A little research since then provided credible dose estimates for the cosmic ray background radiation, composed of particles so energetic that ordinary shielding is more-or-less impractical. The dose varies between 22 and 60 REM per year in a steady “drizzle”, depending upon the strength of the solar wind, which tends to deflect some of it. The original radiation dose limits for astronauts was set to 25 REM/year, which was the World War 2-vintage max dose for civilian adults. It has since been revised to 50 REM/year, based on what I can find on the internet. The actual dosage rate only sometimes exceeds the newer limits, and then only by a small amount. Trips to Mars thus appear quite feasible without incurring any immediate health risks from cosmic rays, or even any significant prospect of long-term effects.
The Program As Revised
Changing to SC-NTR backup propulsion puts the artificial gravity and frozen food storage issues into the design mix. This has to be made to work, and they are things we have never before done. Using the baseline GC-NTR propulsion puts that very propulsion into the mix as something we never did do before, excepting some feasibility experiments. Those are the two development items to be worked in parallel, so that one or the other is ready in time to fly. (This is the same basic parallel path development idea that was in the original paper, where the baseline was GC-NTR, and the backup was VASIMR and its power plant.) All the other items are simple design / build / checkout efforts based on known technologies, and that includes the SC-NTR. The high-level program plan is just a bunch of parallel paths, as illustrated in Figure 7.
So, we are looking at somewhere in the vicinity of $53 B to $70 B to send 6 men to Mars to make 16 widely-separated landings all over the planet, in the one trip, with maximum safety and self-rescue capability designed-in at every step, and with all-reusable assets left in space to be refueled and reused by subsequent missions. The whole thing could be done for prices like that, in only 5-10 years, given the right kind of contractor teams, and the right kind of an agency to lead them. That is one incredible amount of “bang for the buck”!
As I said in my original paper, right now we do not have that agency, and only a couple of the right kind of contractors, at best. But, if we fix those lacks, we could really do this. The numbers show it is definitely feasible.
The last time we as a nation embarked on a mission to explore another world (the moon), we had nearly two decades of sustained economic boom, from all the jobs created just to get the mission done. That may not be causal, but it is definitely correlated. Why not do it again?
Figure 1 – “Slowboat” Transfer to Mars, Baseline and Backup
Figure 2 – “Fast Trip” Transfer To and From Mars, Baseline
Figure 3 – Baseline Manned and Unmanned Vehicles
Figure 4 – “Slowboat” Transfers to Earth, Backup
Figure 5 – Backup Manned and Unmanned Vehicles
Figure 6 – Inflatable Habitat Module, Baseline and Backup Vehicles
Figure 7 – Program Outline Plan
Monday, September 5, 2011
Surprise, Surprise: Oil Boom in the Williston Basin (“the Bakken”)
Resources on the internet about this formation have been revised recently. There appears to be an oil drilling boom going on in eastern Montana and western North Dakota. They are horizontal-drilling and hydro-fracturing for light crude (meaning low viscosity liquid). One of the descriptions says the crude they can recover seems to be just about the same gross physical properties as diesel (density, viscosity).
That's a surprise to me. Two years ago I researched this formation as a "shale unit, very low porosity and microscopic permeability", and everything I read about the hydrocarbons in it said a consistency more like tar. Hydro-fracturing simply would not work on a near-solid resource like that. It would have to be mined, like coal.
What I read now says the Bakken comprises a dolomite layer around 100-140 feet thick, bounded above and below by shale layers. Typically, the shale is the “original” source for the hydrocarbons. The dolomite is listed as 5% porosity and microscopic permeability (1-10 microdarcy's, just almost impermeable). It is in the dolomite layer (not the shale) that they are horizontal-drilling and hydro-fracturing. Estimates vary about how much of the total resource they might possibly recover this way, by over an order of magnitude, depending upon who made the estimate and what agenda they have.
For the Burgess Shale natural gas hydro-fracturing here in Texas, the estimate is that about 3% of the gas down there is actually recoverable. For the liquid in the Bakken dolomite layer, I'd simply guess that factor as 3% or less, which is nearer the 1% end of the estimate range of 1% to 50% that I saw on-line yesterday. Almost-nil permeability just has that effect, hydro-fracturing notwithstanding.
I suspect that there are residual tars left behind in both of the shale units in the Bakken formation, and that the source for the light fractions in the sandwiched dolomite layer is the lower shale member. Somehow, I don't see light fractions migrating downward from the upper shale member, so its lighter fractions are most likely now lost to us.
So, how much recoverable light oil might there be, and how much good might it do, if we can recover around 2% of it?
Oil in the Dolomite Layer:
If you guess that there's something like 500 x 500 statute miles of this formation, averaging 100 ft thick, at 5% porosity, then there might be as many as 6 trillion barrels of light oil down there.
500 mile dimension x 5280 ft per mile = 2.64E6 ft. 500 mi x 500 mi is then 6.97E12 sq ft. Multiply by 100 ft thick to obtain 6.97E14 cu.ft of dolomite rock. The hydrocarbon volume equals the pore space volume at 5% of rock volume, assuming the pores are 100% full. That's 3.48E13 cu.ft of hydrocarbons. Cu.ft volume of hydrocarbons x 7.48 gal per cu.ft is 2.61E14 gal hydrocarbons; divide that by 42 gal/barrel. That's 6.2E12 (about 6 trillion) barrels of hydrocarbon volume down there in the pores of the dolomite layer, supposedly all hydro-fracturable, very light crude.
Assume we can recover 2% of it. That's about 1.24E11 barrels of light oil that could be recovered, or about 124 billion barrels in ordinary terms. That's quite significant. I could be off by a factor of 2-3 in rock volume assumptions, more likely toward the smaller than the larger, so these figures are rather optimistic.
At our 7-8 billion barrels / year consumption in the USA, then potentially, this could power us for about 16-17 years. That really is significant, even if it is optimistic by a factor of 2-3. If it is all light oil. If we really can recover 2% of it. If the rock pores are really full. Lots of "ifs".
Let's say this oil boom lasts 20-30 years (typical for a very large field). The average production rate from the mature field (which takes several years to achieve) might be as much as around 4-6 billion barrels a year, again possibly optimistic by factor of 2-3. That's still a lot, optimistic or otherwise.
Replacing Foreign Imports:
About 1/3 of our consumption is domestic production, about 1/3 comes from Mexico and Canada, and about 1/3 comes from OPEC (which includes Venezuela, along with that idiot running it; and our “friend” Iran, with that insane group of religious fanatics running it). That's about 2.5 billion barrels per year from each source. We might very well be able to replace much of the OPEC oil with domestic from the Bakken dolomite layer, even as the other sources decline. For a little while.
But, no matter how politically expedient, it is still clearly not at all wise to count on it “ending” our dependence on foreign oil. Although, you can bet more than one GOP/Tea Party candidate will run on "why not save ourselves from oil dependence with the Bakken, if the environmentalists and Democrats would just get out of the way?" They did exactly that in '08: remember “drill, baby, drill?”
Even with the new oil boom that I did not expect to see, it’s still a comic-opera puppet-theater issue intended to distract the public from the real truths that threaten us. It’s still just a fake electioneering issue for a bunch of comic-opera buffoon candidates. Beware! I warned you!
About the Tar Shale Layers:
I saw no thickness figures on the two shale units, in the new data that I found this year. I bet they're quite thick, though. You'd have to deep strip mine it, and what I saw said it averages 2 miles down. Figure shale at 0.5% or less porosity, for maybe another handful of trillions of barrels of potentially-recoverable hydrocarbon. This tar shale stuff would be very hard to extract and process, though, and so it would be a supremely expensive product.
And, we would get it for the environmental cost of a permanent crater some 500x500x2 miles in size, which is bigger by far than the volume of Lake Superior. That shale tar is what I was thinking about when I posted what I did about "the Bakken" last year (the 3-14-10 article). That’s still true, oil boom notwithstanding.
Conclusions:
Yep, we need to go get the hydro-fracturable light oil.
Yep, it’ll surely help with imports.
Nope, it will not “save” us.
There is no permanent answer among depletable (fossil) fuels, and never will be.
Update 6-5-2016: here is an updated curve of US oil production versus time obtained from the US EIA website. I have sketched upon it the Hubbert curve for conventional oil production. It is clear the fracking technology is a new effect. How tall this could go, and how wide this will be over time, are things that are completely unclear as of yet.
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That's a surprise to me. Two years ago I researched this formation as a "shale unit, very low porosity and microscopic permeability", and everything I read about the hydrocarbons in it said a consistency more like tar. Hydro-fracturing simply would not work on a near-solid resource like that. It would have to be mined, like coal.
What I read now says the Bakken comprises a dolomite layer around 100-140 feet thick, bounded above and below by shale layers. Typically, the shale is the “original” source for the hydrocarbons. The dolomite is listed as 5% porosity and microscopic permeability (1-10 microdarcy's, just almost impermeable). It is in the dolomite layer (not the shale) that they are horizontal-drilling and hydro-fracturing. Estimates vary about how much of the total resource they might possibly recover this way, by over an order of magnitude, depending upon who made the estimate and what agenda they have.
For the Burgess Shale natural gas hydro-fracturing here in Texas, the estimate is that about 3% of the gas down there is actually recoverable. For the liquid in the Bakken dolomite layer, I'd simply guess that factor as 3% or less, which is nearer the 1% end of the estimate range of 1% to 50% that I saw on-line yesterday. Almost-nil permeability just has that effect, hydro-fracturing notwithstanding.
I suspect that there are residual tars left behind in both of the shale units in the Bakken formation, and that the source for the light fractions in the sandwiched dolomite layer is the lower shale member. Somehow, I don't see light fractions migrating downward from the upper shale member, so its lighter fractions are most likely now lost to us.
So, how much recoverable light oil might there be, and how much good might it do, if we can recover around 2% of it?
Oil in the Dolomite Layer:
If you guess that there's something like 500 x 500 statute miles of this formation, averaging 100 ft thick, at 5% porosity, then there might be as many as 6 trillion barrels of light oil down there.
500 mile dimension x 5280 ft per mile = 2.64E6 ft. 500 mi x 500 mi is then 6.97E12 sq ft. Multiply by 100 ft thick to obtain 6.97E14 cu.ft of dolomite rock. The hydrocarbon volume equals the pore space volume at 5% of rock volume, assuming the pores are 100% full. That's 3.48E13 cu.ft of hydrocarbons. Cu.ft volume of hydrocarbons x 7.48 gal per cu.ft is 2.61E14 gal hydrocarbons; divide that by 42 gal/barrel. That's 6.2E12 (about 6 trillion) barrels of hydrocarbon volume down there in the pores of the dolomite layer, supposedly all hydro-fracturable, very light crude.
Assume we can recover 2% of it. That's about 1.24E11 barrels of light oil that could be recovered, or about 124 billion barrels in ordinary terms. That's quite significant. I could be off by a factor of 2-3 in rock volume assumptions, more likely toward the smaller than the larger, so these figures are rather optimistic.
At our 7-8 billion barrels / year consumption in the USA, then potentially, this could power us for about 16-17 years. That really is significant, even if it is optimistic by a factor of 2-3. If it is all light oil. If we really can recover 2% of it. If the rock pores are really full. Lots of "ifs".
Let's say this oil boom lasts 20-30 years (typical for a very large field). The average production rate from the mature field (which takes several years to achieve) might be as much as around 4-6 billion barrels a year, again possibly optimistic by factor of 2-3. That's still a lot, optimistic or otherwise.
Replacing Foreign Imports:
About 1/3 of our consumption is domestic production, about 1/3 comes from Mexico and Canada, and about 1/3 comes from OPEC (which includes Venezuela, along with that idiot running it; and our “friend” Iran, with that insane group of religious fanatics running it). That's about 2.5 billion barrels per year from each source. We might very well be able to replace much of the OPEC oil with domestic from the Bakken dolomite layer, even as the other sources decline. For a little while.
But, no matter how politically expedient, it is still clearly not at all wise to count on it “ending” our dependence on foreign oil. Although, you can bet more than one GOP/Tea Party candidate will run on "why not save ourselves from oil dependence with the Bakken, if the environmentalists and Democrats would just get out of the way?" They did exactly that in '08: remember “drill, baby, drill?”
Even with the new oil boom that I did not expect to see, it’s still a comic-opera puppet-theater issue intended to distract the public from the real truths that threaten us. It’s still just a fake electioneering issue for a bunch of comic-opera buffoon candidates. Beware! I warned you!
About the Tar Shale Layers:
I saw no thickness figures on the two shale units, in the new data that I found this year. I bet they're quite thick, though. You'd have to deep strip mine it, and what I saw said it averages 2 miles down. Figure shale at 0.5% or less porosity, for maybe another handful of trillions of barrels of potentially-recoverable hydrocarbon. This tar shale stuff would be very hard to extract and process, though, and so it would be a supremely expensive product.
And, we would get it for the environmental cost of a permanent crater some 500x500x2 miles in size, which is bigger by far than the volume of Lake Superior. That shale tar is what I was thinking about when I posted what I did about "the Bakken" last year (the 3-14-10 article). That’s still true, oil boom notwithstanding.
Conclusions:
Yep, we need to go get the hydro-fracturable light oil.
Yep, it’ll surely help with imports.
Nope, it will not “save” us.
There is no permanent answer among depletable (fossil) fuels, and never will be.
Update 6-5-2016: here is an updated curve of US oil production versus time obtained from the US EIA website. I have sketched upon it the Hubbert curve for conventional oil production. It is clear the fracking technology is a new effect. How tall this could go, and how wide this will be over time, are things that are completely unclear as of yet.
-------------------------------------------------------------
Update 1-3-15:
The recent explosion of US “fracking” technology (hydraulic
fracturing plus horizontal-turn drilling) has modified the picture of oil
prices versus recessions.
Unexpectedly, the US has become a
leading producer of crude oils for the world market. Plus,
there has been an associated massive production increase and price drop
in natural gas.
OPEC has chosen to take the income “hit” and not cut back
their production in response. Their
reasoning is twofold: (1) fear of loss
of market share, and (2) hope that low
oil prices will curtail US “fracking” recoveries. We will see how that plays-out.
Oil prices are now such (at around $55/barrel) that US
regular gasoline prices are nearing $2.00/gal for the first time in a very long
time. This is very close to the price
one would expect for a truly competitive commodity, based on 1958 gasoline prices in the US, and the inflation factor since then.
It is no coincidence that the exceedingly-weak US “Great Recession”
recovery has suddenly picked up steam.
The timing of the acceleration in our economic recovery versus the
precipitous drop in oil prices is quite damning. There can be no doubt that
higher-than-competitive-commodity oil prices damage economies. Oil prices are a superposition of the competitive
commodity price, overlain by an erratic
increase from speculation, and further overlain
quite often by punitive price levels when OPEC is politically unhappy with the
west. That’s been the history.
This economic improvement we are experiencing will persist
as long as oil, gas, and fuel prices remain low. (Government policies have almost nothing to
do with this, from either party.) How long that improvement continues depends
in part upon US “fracking” and in part upon OPEC. Continued US “fracking” in the short term may
depend upon adequate prices. In the long
term, we need some solutions to some
rather intractable problems to continue our big-time “fracking” activities.
The long-term problems with “fracking” have to do with (1)
contamination of groundwater with combustible natural gas, (2) induced earthquake activity, (3) lack of suitable freshwater supply to
support the demand for “fracking”, and
(4) safety problems with the transport of the volatile crude that “fracking”
inherently produces.
Groundwater
Contamination
Groundwater contamination is geology-dependent. In Texas,
the rock layers lie relatively flat,
and are relatively undistorted and unfractured. This is because the rocks are largely old sea
bottom that was never subjected to mountain-building. We Texans haven’t seen any significant
contamination of ground water by methane freed from shale. The exceptions trace to improperly-built
wells whose casings leak.
This isn’t true in the shales being tapped in the
Appalachians, or in the shales being
tapped in the eastern Rockies. There the
freed gas has multiple paths to reach the surface besides the well, no matter how well-built it might have
been. Those paths are the vast
multitudes of fractures in the highly-contorted rocks that subject to mountain-building
in eons past. That mountain-building may
have ceased long ago, but those cracks
last forever.
This is why there are persistent reports of kitchen water
taps bursting into flames or exploding,
from those very same regions of the country. It’s very unwise to “frack” for gas in that
kind of geology.
Induced Earthquake
Activity
This does not seem to trace to the original “fracking”
activity. Instead it traces rather
reliably to massive injections of “fracking” wastewater down disposal
wells. Wherever the injection quantities
are large in a given well, the frequent
earthquakes cluster in that same region.
Most are pretty weak, under
Richter magnitude 3, some have
approached magnitude 4.
There is nothing in our experience to suggest that magnitude
4 is the maximum we will see. No
one can rule out large quakes. The risk is with us as long as there are
massive amounts of “fracking” wastewater to dispose of, in these wells. As long as we never re-use “frack”
water, we will have this massive
disposal problem, and it will induce
earthquakes.
Lack of Freshwater
Supply to Support “Fracking”
It takes immense amounts of fresh water to “frack” a single
well. None of this is ever re-used, nor it is technologically-possible to
decontaminate water used in that way. The
additives vary from company to company,
but all use either sand or glass beads,
and usually a little diesel fuel.
Used “frack” water comes back at near 10 times the salinity of sea
water, and is contaminated by heavy
metals, and by radioactive minerals, in addition to the additives. Only the sand or glass beads get left
behind: they hold the newly-fractured
cracks in the rocks open, so that
natural gas and volatile crudes can percolate out.
The problem is lack of enough freshwater supplies. In most areas of interest, there is not enough fresh water available to
support both people and “fracking”, especially
with the drought in recent years. This assessment
completely excludes the demand increases due to population growth. That’s even worse.
This problem will persist as long as fresh water is used for
“fracking”, and will be much, much worse as long as “frack” water is not
reused. The solution is to start with
sea water, not fresh water, and then to re-use it. This will require some R&D to develop a
new additive package that works in salty water to carry sand or glass
beads, even in brines 10 times more
salty than sea water.
Nobody wants to pay for that R&D.
Transport Safety with
Volatile “Frack” Crudes
What “fracking” frees best from shales is natural gas, which is inherently very mobile. Some shales (by no means all of them) contain
condensed-phase hydrocarbons volatile enough to percolate out after hydraulic
fracturing, albeit more slowly than
natural gas. Typically, these resemble a light, runny winter diesel fuel, or even a kerosene, in physical properties. More commonly, shale contains very immobile condensed
hydrocarbons resembling tar. These cannot
be recovered by “fracking” at all.
The shales in south Texas,
and some of the shales and adjacent dolomites in the Wyoming region
actually do yield light, volatile
crudes. The problem is what to transport
them in. There are not enough
pipelines to do that job. Pipelines are safer
than rail transport, all the spills and
fires notwithstanding.
The problem is that we are transporting these
relatively-volatile materials in rail tank cars intended for normal (heavy)
crude oils, specifically DOT 111 tank cars. Normal crudes are relatively-nonvolatile and
rather hard to ignite in accidents. DOT
111 cars puncture or leak frequently in derail accidents, but this isn’t that serious a problem as long
as the contents are non-volatile. These
shale-“frack” light crude materials resemble nothing so much as No. 1 winter
diesel, which is illegal to ship in DOT
111 cars, precisely since it is too
volatile.
The problem is that no one wants to pay for expanding the
fleet of tougher-rated tank cars. So, many outfits routinely mis-classify “frack” light
crudes as non-volatile crudes, in order
to “legally” use the abundant but inadequate DOT-111 cars. We’ve already seen the result of this kind of
bottom line-only thinking, in a series
of rather serious rail fire-and-explosion disasters, the most deadly (so far) in Lac
Megantic, Quebec.
Volatile shale-“fracked” crudes simply should not be shipped
in vulnerable DOT 111 cars, period. It is demonstrably too dangerous.
Conclusions
“Fracking” shales for natural gas and light crudes has had a
very beneficial effect on the US economy and its export-import picture. We should continue this activity as a
reliable bridge to things in the near future that are even better.
But, we must address
the four problem areas I just outlined.
And I also just told you what the solutions are. The problem is, as always,
who pays. What is the value of a
human life? What is the value of a
livable environment? It’s not an either-or
decision, it’s striking the appropriate balance!
Friday, September 2, 2011
Balanced News
TRY CHECKING YOUR PERSONAL IDEOLOGICAL BELIEFS AGAINST THE DATA
Left-wing, right-wing, doesn’t matter. Here are the actual data:
Spending
So who increased spending the most?
(No doubt it’s too much.)
(War spending does not explain all of this.)
Deficits
So which is the better trend?
(And this is before any of the recently-negotiated cuts “kick in”.)
The Stimulus and Jobs
So did the stimulus help job growth or not? (And remember, each man spent about half of the total stimulus)
Did we stop too soon?
Could we have better-targeted the money to steepen the job growth trend?
A Very Good Question:
If your beliefs about what has been happening do not square with the actual data, then what are you going to do?
Change your thinking and use the data? Or keep your beliefs?
Left-wing, right-wing, doesn’t matter. Here are the actual data:
Spending
So who increased spending the most?
(No doubt it’s too much.)
(War spending does not explain all of this.)
Deficits
So which is the better trend?
(And this is before any of the recently-negotiated cuts “kick in”.)
The Stimulus and Jobs
So did the stimulus help job growth or not? (And remember, each man spent about half of the total stimulus)
Did we stop too soon?
Could we have better-targeted the money to steepen the job growth trend?
A Very Good Question:
If your beliefs about what has been happening do not square with the actual data, then what are you going to do?
Change your thinking and use the data? Or keep your beliefs?
Tuesday, August 9, 2011
Post-Meeting Results (Mars Mission)
The Mars Society convention was a lot of fun and very informative. My paper was presented in the advanced technology track on Saturday afternoon. It was well received: I had several people come up to me afterwards and tell me so.
Most of the other mission designs included some sort of Mars base assets with the first manned mission. This is quite different from what I assumed regarding the nature of exploration versus subsequent activities. So, I pitched my paper as less of a “real” mission plan, and more of a “mine” for different and potentially useful ideas. In part, that’s why it was so well received.
Changes to My Paper (see the 7-25-11 posting not far below)
I did learn some very interesting things, two in particular. One has to do with my alternate for the manned ship’s “hot rod propulsion”. It seems VASIMR is not really an improvement on electric propulsion, just another way of doing it. Its weakness is indeed what I thought: the mass of the nuclear electric power plant required. Its thrust per unit power supplied is just a lot worse than I thought it was when I did the calculations. It’s just not suitable for really fast missions.
The other interesting thing is the notion of a light gas gun for launching hardened payloads into orbit very inexpensively. It should be possible to launch large quantities of propellants and tough hardware for something on the order of $300/pound, if they can be hardened to withstand 3200 gees. This is based on a smaller gun already launching small experimental scramjet payloads for the Air Force at Mach 9. Refueling of my reusable manned ship looks really good in such a situation. Once there is a water mine and propellant station on Mars, the same thing is true for refueling the lander assets left in Mars orbit.
In any event, about the only change I might make in my paper is to replace the VASIMR alternate with a solid core nuclear thermal version, and include artificial gravity and frozen food in the habitat configuration. Its one-way trip time would be 6 to 8 months, and the stay at Mars a little longer than the baseline 16 weeks. The technology development, to be run in parallel with the baseline gas core nuclear thermal rocket effort, would be the artificial gravity habitat. I think a pair of rigid arms out to inflatable living spaces, and spinning the entire T-shaped ship, might work well enough.
Another Interesting Idea
A third very interesting idea is to store and ship hydrogen as frozen water. In this form, it is very strong and so is proof against accidents or mishap. You thaw and electrolyze what you need as you go, which does require power, although solar thermal thawing offers a big help. The oxygen liberated by electrolysis can be used for a lot of things. It takes very little pressure to prevent sublimation of the ice, and a simple sunshade keeps it very cold.
This would apply to chemical as well as nuclear propulsion. Nuclear uses only hydrogen. Chemical uses both hydrogen and oxygen at a mass ratio of 1:6. The ratio in the water is 1:8, so that leaves excess oxygen left over for other uses, even with chemical systems. There is just more available in a nuclear scenario.
A Very Serious Near-Term Problem
Consider: 100% of the humans who ever walked on the moon were Americans, sent there by NASA in its human spaceflight program. 100% of the so-far successful landers on Mars were (and are) American, sent there by NASA in its robotic exploration program. Almost 100% of the probes sent to other celestial bodies are American, sent there by NASA in its robotic exploration program.
The human and robotic programs began together in the late 1950’s; they are synergistic. You cannot successfully do one without the other. Regardless of your opinion of NASA and its effectiveness today, it is the premier entity for the exploration of space, and therefore it is irreplaceable.
Here is the problem: there has been no human exploration target since Apollo ended in 1973. Manned operations in Earth orbit, while essential and even inspiring, are not exploration. We have had men and machines in Earth orbit, beginning with Sputnik in 1957. Going back to the moon is not exploration in the public’s eyes, because “we’ve already been there”. This perception is quite real, even though we didn’t really explore the moon (in the sense of my paper) during Apollo.
The public supports exploration: that is why the probes, the Mars landers, and the Hubble pictures are so popular. Of all the probes and landers, it is the Mars probes that hold the public’s fascination best. This is because Mars has fascinated people for centuries. It is not just the best target for human exploration, it is the only one. Those other near-Earth targets are at best but steps along the way to Mars. (The next destination after Mars is the stars, with the outer solar system destinations but steps along the way.) Reality has nothing to do with perception, and experience says you cannot fight perception.
We have a budgetary and political tsunami about to sweep America, with a great likelihood of doing massive damage to all aspects of all of our lives. One’s politics and outlook on this do not matter, discretionary spending is about to be drastically cut or eliminated, no matter how useful or necessary, for the sake of election politics. That means NASA, among many other things. And NASA has had no viable target or plan for manned exploration since Apollo. A vague “give us X-billion dollars for the next 20-40 years and we might reach Mars” is not a manned exploration program. If the manned spaceflight program is cancelled, the robotic program will eventually fall, as well.
Folks, this cannot be allowed to happen.
It is feasible to send men to Mars right now, with the technologies and hardware we have right now or within the next very few years. We don’t even have to have giant launch rockets. We can do this for under $50 billion, not the trillions everybody out there seems to think it will take. But we cannot do this with the “business as usual” techniques of the last 4 decades, and that includes the way NASA works. Massive management change is required, and that is the hardest part, not the actual flying to Mars.
If you are a space exploration enthusiast, then help get the word out. Technologically we are ready to send men to Mars. And we can do it for a few billions, not multiple trillions, of dollars. The real change required is managerial (and political, not surprisingly).
Most of the other mission designs included some sort of Mars base assets with the first manned mission. This is quite different from what I assumed regarding the nature of exploration versus subsequent activities. So, I pitched my paper as less of a “real” mission plan, and more of a “mine” for different and potentially useful ideas. In part, that’s why it was so well received.
Changes to My Paper (see the 7-25-11 posting not far below)
I did learn some very interesting things, two in particular. One has to do with my alternate for the manned ship’s “hot rod propulsion”. It seems VASIMR is not really an improvement on electric propulsion, just another way of doing it. Its weakness is indeed what I thought: the mass of the nuclear electric power plant required. Its thrust per unit power supplied is just a lot worse than I thought it was when I did the calculations. It’s just not suitable for really fast missions.
The other interesting thing is the notion of a light gas gun for launching hardened payloads into orbit very inexpensively. It should be possible to launch large quantities of propellants and tough hardware for something on the order of $300/pound, if they can be hardened to withstand 3200 gees. This is based on a smaller gun already launching small experimental scramjet payloads for the Air Force at Mach 9. Refueling of my reusable manned ship looks really good in such a situation. Once there is a water mine and propellant station on Mars, the same thing is true for refueling the lander assets left in Mars orbit.
In any event, about the only change I might make in my paper is to replace the VASIMR alternate with a solid core nuclear thermal version, and include artificial gravity and frozen food in the habitat configuration. Its one-way trip time would be 6 to 8 months, and the stay at Mars a little longer than the baseline 16 weeks. The technology development, to be run in parallel with the baseline gas core nuclear thermal rocket effort, would be the artificial gravity habitat. I think a pair of rigid arms out to inflatable living spaces, and spinning the entire T-shaped ship, might work well enough.
Another Interesting Idea
A third very interesting idea is to store and ship hydrogen as frozen water. In this form, it is very strong and so is proof against accidents or mishap. You thaw and electrolyze what you need as you go, which does require power, although solar thermal thawing offers a big help. The oxygen liberated by electrolysis can be used for a lot of things. It takes very little pressure to prevent sublimation of the ice, and a simple sunshade keeps it very cold.
This would apply to chemical as well as nuclear propulsion. Nuclear uses only hydrogen. Chemical uses both hydrogen and oxygen at a mass ratio of 1:6. The ratio in the water is 1:8, so that leaves excess oxygen left over for other uses, even with chemical systems. There is just more available in a nuclear scenario.
A Very Serious Near-Term Problem
Consider: 100% of the humans who ever walked on the moon were Americans, sent there by NASA in its human spaceflight program. 100% of the so-far successful landers on Mars were (and are) American, sent there by NASA in its robotic exploration program. Almost 100% of the probes sent to other celestial bodies are American, sent there by NASA in its robotic exploration program.
The human and robotic programs began together in the late 1950’s; they are synergistic. You cannot successfully do one without the other. Regardless of your opinion of NASA and its effectiveness today, it is the premier entity for the exploration of space, and therefore it is irreplaceable.
Here is the problem: there has been no human exploration target since Apollo ended in 1973. Manned operations in Earth orbit, while essential and even inspiring, are not exploration. We have had men and machines in Earth orbit, beginning with Sputnik in 1957. Going back to the moon is not exploration in the public’s eyes, because “we’ve already been there”. This perception is quite real, even though we didn’t really explore the moon (in the sense of my paper) during Apollo.
The public supports exploration: that is why the probes, the Mars landers, and the Hubble pictures are so popular. Of all the probes and landers, it is the Mars probes that hold the public’s fascination best. This is because Mars has fascinated people for centuries. It is not just the best target for human exploration, it is the only one. Those other near-Earth targets are at best but steps along the way to Mars. (The next destination after Mars is the stars, with the outer solar system destinations but steps along the way.) Reality has nothing to do with perception, and experience says you cannot fight perception.
We have a budgetary and political tsunami about to sweep America, with a great likelihood of doing massive damage to all aspects of all of our lives. One’s politics and outlook on this do not matter, discretionary spending is about to be drastically cut or eliminated, no matter how useful or necessary, for the sake of election politics. That means NASA, among many other things. And NASA has had no viable target or plan for manned exploration since Apollo. A vague “give us X-billion dollars for the next 20-40 years and we might reach Mars” is not a manned exploration program. If the manned spaceflight program is cancelled, the robotic program will eventually fall, as well.
Folks, this cannot be allowed to happen.
It is feasible to send men to Mars right now, with the technologies and hardware we have right now or within the next very few years. We don’t even have to have giant launch rockets. We can do this for under $50 billion, not the trillions everybody out there seems to think it will take. But we cannot do this with the “business as usual” techniques of the last 4 decades, and that includes the way NASA works. Massive management change is required, and that is the hardest part, not the actual flying to Mars.
If you are a space exploration enthusiast, then help get the word out. Technologically we are ready to send men to Mars. And we can do it for a few billions, not multiple trillions, of dollars. The real change required is managerial (and political, not surprisingly).
Tuesday, August 2, 2011
What Should the Government’s Manned Space Exploration Strategy Be?
Going beyond the moon requires fundamental changes in the way we approach spacecraft and mission design. Mars makes an excellent target for starting this new process.
Inner Solar System
The key is going back to fundamentals to figure what we really want out of exploration, then looking at required technologies, given that crew survival, safety, and self rescue are THE paramount design requirement for every single phase. You do that for the most challenging mission (Mars) FIRST, and force every single piece of hardware to be totally reusable.
Exploration and the Greater Scheme of Things
This produces one set of "tinkertoys" that takes you anywhere within range: Mars, Venus, NEO's, and Mercury (the entire inner solar system). Plus, you don't have to keep launching components, just propellants and supplies.
This is my Mars mission paper to be presented to the Mars Society convention in Dallas, August 4-7. A shorter version is posted at http://exrocketman.blogspot.com, dated 25 July, 2011.
Inner Solar System Hardware Designed Around a Mars Mission
Main Asteroid Belt
To go further soonest, we simply upgrade the inner solar system “tinkertoys” with knowledge obtained between now and then. Add a provision for artificial gravity, and either solve the food preservation problem, or add frozen food (which is bigger and heavier). That should make two-or three year trips feasible, most likely limited by the accumulation of cosmic ray exposure. It puts the main belt asteroids and some comets within reach.
The Artificial Gravity Problem As We Know It Now
Giant Planets and Outer Solar System
If a better way to shield against radiation can be devised, and even faster “hot rod propulsion” developed, the giant planets and outer solar system become reachable. It would help greatly to know how to build closed-ecology life support by this time.
At this point, we have to repeat the design process from scratch, because upgrades to the inner solar system “tinkertoys” are no longer feasible. We will know more about what to do when that time comes. The target for design should be the Kuiper Belt, where Pluto is.
I suggest some version of the old Project Orion nuclear pulse propulsion. One must build much larger ships for this: it has the odd characteristic of working more efficiently, the larger the mass to be moved.
Nuclear Pulse Propulsion from 1959-1965 USAF "Project Orion"
A Place To Do the Supporting Work
The kinds of “hot rod propulsion” that we will need to explore these places are very dangerous to develop and test on Earth, because the energy sources for the drives are all nuclear. We need a safe place to test, but it has to be dynamically stable (you cannot test a rocket engine in zero gravity where every test is a flight test).
I suggest the airless, waterless, uninhabited moon. Pick a smaller crater with high ring walls, plant a base adjacent to it, and put the test stands down inside the crater. It’s reachable from Earth without any exotic propulsion at all, and the mildest of the “hot rod propulsion” techniques just makes it less expensive. Perfect!
Inner Solar System
The key is going back to fundamentals to figure what we really want out of exploration, then looking at required technologies, given that crew survival, safety, and self rescue are THE paramount design requirement for every single phase. You do that for the most challenging mission (Mars) FIRST, and force every single piece of hardware to be totally reusable.
Exploration and the Greater Scheme of Things
This produces one set of "tinkertoys" that takes you anywhere within range: Mars, Venus, NEO's, and Mercury (the entire inner solar system). Plus, you don't have to keep launching components, just propellants and supplies.
This is my Mars mission paper to be presented to the Mars Society convention in Dallas, August 4-7. A shorter version is posted at http://exrocketman.blogspot.com, dated 25 July, 2011.
Inner Solar System Hardware Designed Around a Mars Mission
Main Asteroid Belt
To go further soonest, we simply upgrade the inner solar system “tinkertoys” with knowledge obtained between now and then. Add a provision for artificial gravity, and either solve the food preservation problem, or add frozen food (which is bigger and heavier). That should make two-or three year trips feasible, most likely limited by the accumulation of cosmic ray exposure. It puts the main belt asteroids and some comets within reach.
The Artificial Gravity Problem As We Know It Now
Giant Planets and Outer Solar System
If a better way to shield against radiation can be devised, and even faster “hot rod propulsion” developed, the giant planets and outer solar system become reachable. It would help greatly to know how to build closed-ecology life support by this time.
At this point, we have to repeat the design process from scratch, because upgrades to the inner solar system “tinkertoys” are no longer feasible. We will know more about what to do when that time comes. The target for design should be the Kuiper Belt, where Pluto is.
I suggest some version of the old Project Orion nuclear pulse propulsion. One must build much larger ships for this: it has the odd characteristic of working more efficiently, the larger the mass to be moved.
Nuclear Pulse Propulsion from 1959-1965 USAF "Project Orion"
A Place To Do the Supporting Work
The kinds of “hot rod propulsion” that we will need to explore these places are very dangerous to develop and test on Earth, because the energy sources for the drives are all nuclear. We need a safe place to test, but it has to be dynamically stable (you cannot test a rocket engine in zero gravity where every test is a flight test).
I suggest the airless, waterless, uninhabited moon. Pick a smaller crater with high ring walls, plant a base adjacent to it, and put the test stands down inside the crater. It’s reachable from Earth without any exotic propulsion at all, and the mildest of the “hot rod propulsion” techniques just makes it less expensive. Perfect!
End of an Era Need Not Be End of a Capability
Update 7-6-21 added below
----------------------------------------
This one appeared as a guest column in the Waco Tribune-Herald newspaper of Waco, Texas. It is not about exploration, but about useful and necessary infrastructure in Earth orbit. The last shuttle flight is complete, the orbiters are headed for museums, and thousands are being laid off at Cape Canaveral and Mission Control. There is going to be a hiatus in America’s ability to launch its own astronauts that may continue for a few years.
Actually, I do believe the private companies like SpaceX will fill that void sooner rather than later. I also believe there will be a second, privately-owned, space station up there, very soon.
But, these private ventures, which build upon 50 years’ expertise, will require smaller teams on the ground at the Cape and in Mission Control. Except for local employment prospects, that’s a good thing, because it means spaceflight will become less expensive.
I predict that more than one commercial spacecraft will be flying soon, and that some of our familiar launch rockets will be updated and man-rated to launch them. That’s what NASA’s commercial spaceflight initiative was supposed to achieve, and it looks to me as if it is succeeding.
Here is what we will have: space capsules as taxis to orbit, space stations conducting research and business, and NASA looking outward beyond orbit with men for the first time in 40 years. But, something is missing from that picture!
Oh, yes, the “space repair truck” function of the space shuttle will be missing. Remember it?
It was the self-maneuvering shuttle with the adaptable human crew, that enormous cargo bay as a work area, and that manipulator arm, which repaired so many important satellites, most notably the Hubble Space Telescope.
In hindsight, having to launch that capability in every mission makes less sense than having two or three vehicles like that up there all the time. When you need one, send the crew and some thruster fuel up with one of the new space capsules: same results, far less expense.
All we need is a crew cabin, a space frame about the size of the shuttle cargo bay, that manipulator arm, some thrusters, and thruster fuel tanks.
These could be assembled in place by docking-together modules small enough to be launched by the rockets we already have. This is not a gigantic project, there is no new technology here, just a planned series of launches to regain a capability that we lost with Atlantis’s final landing.
It makes sense to have one in the highly-inclined orbit near or docked to the ISS, one in the more standard orbit eastward from the cape (the kind of orbit Hubble is in), and one in polar orbit to service those satellites. This may not be exploration, but it would certainly be helpful to what we are already doing in space.
There will always be satellites needing repair, and we already have one space station to repair, maintain, and upgrade. We might even use this capability to help build the new exploration vehicles.
I recommend this idea to NASA as something worthwhile and necessary. Maybe some of those laid-off workers could be re-hired to carry it out.
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Update 7-6-2021:
An update to this idea takes advantage of vehicles that have since become available, and also some suit and breathing gas technology that has been forgotten-to-death, about which I have written some articles.
Vehicles already available or available soon:
These include the Russian Soyuz crew and cargo vehicles, the Spacex crew Dragon / Falcon-9 combination, and fairly soon the Boeing Starliner / Atlas-5 combination. There is also Falcon-Heavy and Ariane-5 for delivery of large cargoes to orbit. The Sierra Nevada Dreamchaser spaceplane may also become available fairly soon, as will the NASA Orion.
Suit and breathing gas technology:
The trend to ever-higher suit pressures has produced bulky and constraining space suits. They need not be operated at that high a pressure. There is no reason they could not be operated quite safely at significantly-lower pressures, as detailed in Ref. 1. We did it that way decades ago. Why not do it again?
Given that truth, the spacecraft transferring crew to the repair vehicle could transition from full-pressure synthetic air to a lower-pressure enhanced-oxygen mix, while on the way to the repair vehicle. As discussed in the reference, this could be done with about the same fire risks as sea level Earthly air, based on the chemical concentration of oxygen available to support combustion. Yet, the transition from this mix to a low-pressure pure-oxygen suit would require no pre-breathe time.
Since these repair missions are at most a few days, there is little risk in human exposure to low-pressure enhanced-oxygen mixes. Exposure to pure oxygen is limited to a few hours at a time, that being about the longest duration we can expect of a real repair-work EVA.
Longer term, this is also quite the convenient scenario in which to experiment with MCP suit designs, especially those done as vacuum-protective underwear, with appropriate unpressurized mix-and-match outerwear for thermal, mechanical, and UV light protection. See Refs. 2 and 3 and 4.
Updated figure:
The updated figure shows essentially the same features as are in the original. The changes explicitly show the visiting crew transfer spacecraft, the EVA airlock, and some redundancy to the propellant tankage and maneuvering engines. Depending upon the visiting spacecraft, both parts, equipment, and supplies, plus the refill propellants, might be brought up, if cargo capacity permits. If not, the refill operation might be a separate launch.
I have shown a rough guess as to size, based on the old space shuttle cargo bay, and a rough guess for the maximum maneuver delta-vee. The propellants should be storables, to take advantage of refilling techniques already being used at the ISS. They could be the new "green" propellant, if an appropriate oxidizer is available. Monopropellant performance would be too low.
Unchanged are the suggestions for how many such vehicles, and where pre-positioned. One should be at the ISS in its high-inclination orbit. Another should be parked in a low-inclination eastward orbit, to take care of a great many items, including Hubble. A third should be parked in a polar or near-polar orbit, to take care of a great many items in orbits like that.
The fundamental design features are still: (1) a shirtsleeve crew cabin in which to work, (2) and EVA airlock, (3) a manipulator arm (two may even be better), (4) maneuver propulsion sufficient to reach the job site, (5) easy refill of propellants and supplies, and (6) docking capability to support many crew arrival vehicles. The manipulator arm is required to achieve "docked" position control with the object to be repaired, regardless of the forces from moving people and supplies. It also is required to hold the astronauts in position as the apply forces doing their work.
Timing:
With Hubble having serious failures right now, it is clear that we have lost this wonderful asset, or will lose it soon, if it cannot be "fixed" from the ground. Once it fails, there are but two responsible alternatives: (1) de-orbit the thing to destruction over the ocean, or (2) mount a repair mission and replace the failing over-age avionics. It will be a few years, not months, before the Spacex cargo "Starship" design might be ready to undertake such a mission.
We currently have no vehicle that could capture it and bring it home for repair, or could dock with it and make repairs. There is just not time (or budget) to pursue a massive program to repair it. Yet Hubble really is worthy of repair: the mirrors and corrective lenses are the kind of asset that could be useful for over a century, as have been many ground-based telescopes. It is the avionics and the camera equivalents that need replacing from time-to-time.
Programmatics:
There is no need to pursue a long, drawn-out program to come up with a vehicle that actually could make the necessary repairs, nor is there available budget to support a big massive "typical" government program. This has to be done fast, and it has to be done relatively inexpensively. It makes sense to use existing assets to the maximum extent possible.
I suggest these approaches: (1) use an existing craft (such as a Cygnus cargo vessel) to be the basic hull of the crew cabin of the depicted vehicle, (2) use the same manipulator arm that was used on the shuttle and is being used at ISS, (3) use the same tankage, propellants, and engines that were the space shuttle's orbital maneuvering system, and (4) use the same atmosphere hardware that is used on the ISS, but with a reduced-pressure, enhanced-oxygen mix (about 6.2 psia of 45% oxygen diluted with nitrogen). (5) The airlock can be the same as one of the ISS airlock modules. (6) Use the refilling connections currently used at ISS with Soyuz tankers. (7) Pure oxygen space suits can be operated at or slightly under 3 psia (2.8 to 2.9 psia nominal, with a safe-enough leakdown to 2.5 psia).
Only the truss connecting them need be custom-built, and trusses are not complicated! Speed and rapid results are essential, and budgets must be modest. This is not (repeat NOT) the usual NASA program! This cannot be (repeat CANNOT BE) the usual corporate welfare program for "old space". One or more of the "new space" contractors should do this!
References:
1. 16 March 2018, "Suit and Habitat Atmospheres 2018" [analysis of in-lung wet oxygen partial pressures and oxygen chemical concentrations to address supple space suits, adequate oxygenation, elimination of pre-breathe times, and fire dangers no worse than in Earthly sea level air]
3. 15 February 2016, "Suits and Atmospheres for Space" [definition of adequate wet in-lung oxygen partial pressure for any space suit, at reduced suit pressures, plus illustrations of suits over time, including MCP designs]
4. 11 February 2014, "On Orbit Repair and Assembly Facility" [an earlier article on a potential application of low-pressure oxygen breathing, MCP space suits, into an on-orbit facility for working in a vacuum environment protected from bright sunshine; this facility is more of a repair base than a mobile repair truck]
Updated Figure
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