Sunday, October 2, 2016

Elon Musk Reveals His Plans for Mars

Every year,  the International Astronautical Federation (IAF),  the International Academy of Astronautics (IAA),  and the International Institute of Space Law (IISL) hold a meeting somewhere in the world called the International Astronautical Congress (IAC).  The latest one was September 26-30 in Guadalajara,  Mexico.  The next ones are:

·         2019 - Washington DC, USA; 70th IAC
·         2018 – Bremen, Germany; 69th IAC
·         2017 – Adelaide, Australia; 68th IAC (September 25–29, 2017)[1]

Elon Musk of Spacex gave a very astonishing presentation at that recent meeting,  revealing how he plans to enable a settlement on Mars at an affordable price, sooner than anyone ever thought.  I saw the on-line video of his presentation,  and downloaded the slides he used. 

After taking some time to digest both content,  and the comment and criticism this presentation has generated,  here is my best shot at the most-factual summary.  This is not a full-blown colony that Mr. Musk proposes to establish all by himself,  despite what the news story headlines say. 

He is creating the essential practical transportation system that is necessary to enable many entities to participate in establishing a permanent colony.  No one entity can do this.  The timeline for creating such a colony is around a century long.

Some of the comments I have seen claim Musk is living in “fantasyland”,  because his proposals are so vastly different than anything we have ever seen out of NASA.  They look almost like the 1940’s-1950’s dreams of big spaceships that don’t seem limited in their range. 

But I disagree with the critics;  Musk can now take advantage of enabling technologies and materials today,  that were simply unavailable to NASA or anyone else in prior decades.  If he does embark on this plan,  and he can successfully pull off developing these vehicles and flying them,  it will fundamentally and forever change the world of human space travel. 

Can he do this?  His history says that he does what he says he will do,  but just not quite as fast as he wanted to do it,  because space flight is hard,  with many setbacks.  As proof,  I cite the development of Falcon family of launch vehicles that has so very dramatically helped to reduce the cost of expendable launch to Earth orbit.  Musk has already begun to recover those boosters,  and will soon attempt re-flying them (a key feature of the Mars ship he proposes). 

This isn’t something Musk and Spacex can do all alone.  They have to make money by selling rides in this giant vehicle.  This thing offers something like 300 ton capacity to low Earth orbit,  and at a price per delivered ton far below today’s prices.  This completely opens up the field for entrepreneurs wanting to build space stations in Earth orbit for all sorts of purposes. 

Musk’s “big rocket” is really two things,  a giant launch booster based on scaled-up Falcon technology,  and a spacecraft that is also its second stage getting to orbit.  The booster flies back to launch site for reuse,  and the second stage/spaceship is refueled in orbit to enable it to fly to any desired low-gravity destination,  without further staging. 

Musk's 2-Stage Vehicle with 2nd Stage the Interplanetary Spaceship

Data on the Reusable 1st Stage Booster

 Data on the Reusable 2nd Stage Spaceship (there is a tanker version)

Depiction of Booster Fly-Back Similar to Falcon Boosters

There are actually two versions of that second stage/spaceship:  one is the spaceship that must be refueled in orbit to go anywhere else.  The other version is a tanker that does the refueling in orbit,  and then flies home for reuse.  But,  for the spaceship to come home from its trip,  its crew must make more propellant at that destination.

This thing dwarfs the old Saturn 5 moon rocket.  At launch it’s about 400 feet tall,  3.5 times the weight,  and 3.6 times the thrust,  of the Saturn-5.  It also dwarfs NASA’s three-stage Space Launch System (SLS) rocket,  currently in development,  and which is not reusable at all. 

Comparison of Mars Vehicle and Booster with Saturn-5

There are lots of low-gravity places that a vehicle like this can go.  These include Mars,  our moon,  any moon of Jupiter or Saturn,  and the asteroids and comets.  Maybe Mercury.  Maybe the outer planet moons.  But not high-gravity places like Earth without a booster and tankers.  (Venus isn’t a feasible destination for several reasons besides its gravity.) 

Musk’s schedule calls for development and testing of actual hardware beginning 2018,  aimed at a first Mars flight late in 2022.  Personally,  I think it’ll take a little longer than that,  precisely because space travel is hard and there will be setbacks.  There already have been,  with his Falcon rockets.  But I would guess his Mars ship,  tankers,  and giant booster will be flying no later than about 2030,  maybe a little sooner. 

His presentation showed launches out of Cape Canaveral.  But I think he really wants to launch this thing out of his private space launch facility in deep south Texas.

Location of South Texas Private Launch Site

This thing has enough performance to fly a little faster to Mars than an absolute minimum-energy trajectory.  That shortens trip times considerably,  from 8 months to 3-4 months,  one-way. 

Shorter flight times mean we are “OK” with no artificial gravity and no high-efficiency life support systems,  and that the accumulated space radiation dose is much lower.  There’s plenty of room inside the ship for maybe a hundred people to live,  for journeys of that shorter duration.  Only for further destinations would these issues need to be addressed. 

Once at Mars,  the ship makes a direct entry from its interplanetary trajectory and a retropropulsive landing without parachutes.  Direct entry is something NASA has done for decades with its probes.  Doing propulsive landings without parachutes is something NASA has never done,  except on the moon with Apollo,  and never since.  Problem is,  chutes are ineffective on Mars for masses over about a ton.   

This Mars mission architecture depends upon making propellant on Mars,  because the vehicle uses up all its propellants getting there.  In that sense,  Musk is betting the lives of the ship’s occupants that they can make enough propellants on Mars fast enough to refuel it for the journey home.  It needs no booster to do that:  Mars gravity is only 38% that of Earth.  The ship holds over 1900 tons of propellants,  as currently envisioned.  That’s a lot to make in only a few months!

The choice of which propellants to make is crucial for success.  Musk and Spacex have chosen liquid methane and liquid oxygen,  made with the local Martian “air” (which is 98% carbon dioxide),  and local water-as-ice.  There is a chemical process called “Sabatier” that uses carbon dioxide,  water,  and electricity,  to make methane and oxygen.  Then you liquefy them,  which also requires electricity. 

The key to this is finding local sources of ice to melt for the water.  It means the astronauts are going to have to be ice miners when they get to Mars.  The nature of the buried ice deposits will determine the complexity and weight of the tools,  equipment,  and facilities that the vehicle must transport there. 

If there is a massive buried glacier at the landing site,  then one can simply slant-well drill into it,  use hot steam from a steam generator to melt the subsurface ice,  and bring gobs of water right back up the well.  If the ice veins are thin layers,  or separated pockets,  strip mining will instead be required,  with enormous dirt-moving equipment,  and a gigantic facility processing enormous volumes of surface material,  for each precious ton of water. 

Obviously,  selecting the right landing site is critical. 

Musk’s plans begin with what he already has in-hand today.  There is a new version of the Falcon called Falcon-Heavy,  which should start flying in 2017.  This rocket is powerful enough to send a version of his Dragon capsule unmanned to Mars,  for a direct retropropulsive landing,  with 2+ tons of “stuff” on board. 

That version is called “Red Dragon”,  and will carry as-yet unidentified robotic payloads to investigate multiple potential landing sites.  Musk expects to start these flights in 2018.  NASA is finally participating,  hoping to learn about retropropulsive landings on Mars,  but is too late for them to add any payload items to that first flight.

Depiction of Unmanned Red Dragon Landing on Mars

So,  what would constitute the right landing site?

First,  Musk’s Mars ship is 3-4 times as tall as its landing legs are wide.  That makes it very intolerant of rough ground,  or obstructions like boulders and dunes.   The site must be very flat and clean of hazards. 

Second,  there needs to be massive buried ice deposits directly underneath the landing site.   That’s something remote sensing is just not capable of determining.  Ground truth has always been at variance with remote-sensing claims,  often enormously so. 

It will take real drilling to determine this,  just like it does here exploring for water or for oil/gas/coal.  Whatever payloads Red Dragon carries,  a robot drill rig capable of drilling at least a football-field down is required.          

A Canadian outfit called NORCAT built a robot drill rig that it called “CanaDrill” a few years ago.  They offered it to NASA without success,  my sources tell me.  But,  to me,  it looks like some version of this thing is exactly what Musk needs to ride his Red Dragons to Mars,  looking for that “right” landing site. 

So how will this “play out”? 

Falcon-Heavy/Red Dragon shots identify the right landing site between 2018 and the time the big Mars ship is ready to make its first Mars flight. 

The first big Mars ship flight brings mostly cargo and a small crew.  This crew sets up that first “outpost” as a modest habitat in which to live,  and a minimally-adequate propellant-making plant for the return trip.  They do human exploration of Mars while there,  of course.  As the flights continue every two years when the orbits are favorable,  the propellant plant grows in capacity,  and the habitat also starts enlarging to accommodate larger populations later. 

Based on our history attempting such things so far,  I have very serious doubts that a closed-cycle ecology,  a self-sustaining life support and food production scheme,  is going to be successful in the early years of this outpost.  That means it will initially be dependent upon regular resupply,  as part of the cargoes of these big ships. 

Later on,  this issue will get resolved,  and the outpost becomes essentially self-supporting from a life support/food production standpoint.  That’s the point at which it can first evolve into a real “city on Mars”,  with some serious local production of supplies and infrastructure items (yet to be identified).  By that time,  the ships will be bringing more people than equipment and supplies. 

Eventually,  somewhere in this process,  some sort of Martian exports yet-to-be-identified will be making the return voyages to Earth.  Some sort of interplanetary economy will evolve from that.  That is the point at which you can really call this a proper “colony on Mars”.  I think (as does Musk and Spacex) that’s about a century down the road. 

Comparison to NASA/”Big Space” business-as-usual:

Musk wants people on the surface of Mars by about 2025.  RealisticallyI think he will do this closer to 2030.  Compare that to NASA/”Big Space’s” plans to fly around Mars without landing in the late 2030’s,  with the actual first landing sometime in the 2040’s.  Musk beats them by at least a decade

Musk has already begun to develop his fully-reusable spaceships of enormous cargo capacity.  He has already started landing boosters,  he will soon re-fly used boosters,  he already has a good heat shield for entry at Mars or returning to Earth,  he is already starting to test his methane-oxygen rocket engine (see photo),   and he is already constructing his first giant propellant tank test articles needed for the big booster and ship.  Compare that to the cramped capsules and throw-away stages seen proposed by NASA/”Big Space”,  or by any another entity on the planet. 

Raptor Engine Test (Big Methane-Oxygen Engine)

According to Musk’s presentation,  they are projecting around $200 million per launch of their reusable boosters and ships.  They project a price under $200,000 for each ton delivered to Mars,  which is also roughly the same as the ticket price per person.  Compare that to around $1 billion per launch of NASA’s SLS,  and a per-astronaut cost to Mars in the 10’s of billions of dollars. 

What makes this affordable transportation possible at all,  and what makes this plan look like something out of the dreams from the 1940’s and 1950’s,  is this specific list of enabling technologies,  taken right from Musk’s own slides:  
Reusable vehicles (NASA doesn’t do this,  Virgin Galactic,  Blue Origin,  and XCOR Aerospace do)

Refueling in orbit (NASA doesn’t do this;  the Russians do,  but not with cryogenic propellants)

Select the right propellant that can be manufactured at destination (NASA doesn’t do this,  yet)

Manufacture of said propellant at destination (NASA doesn’t do this,  yet)

This is a total “leap-frog jump” into the futurethat leaves everyone else behind.  I think it is really possible to do this,  although I also think it will be harder to accomplish than it looks to Musk and Spacex right now.  Being a life-long fan of human space travel,  I can only wish them success. 

Update 10-8-16:  There should probably be a 5th item in Mr. Musk's list of 4 enabling items just above:  gigantic size.  He and Spacex have thrown the artificial,  self-imposed "minimum thrown weight" constraint right out the window.  This is unlike anything proposed since the giant spaceship concepts of the mid-1950's.

The New World was not settled from Europe with small boats.  They used the full-size ships of that time.  The airline industry in the US was not started successfully with small airplanes that had only a few passenger seats.  It took Ford leaping in with the Tri-Motor,  and Douglas leaping in with the DC-3,  to point the right way: that large aircraft were what really worked.  The same is true here:  one of the cost savers with Musk's giant rocket is simple economy-of-scale.  

Update 10-28-16:  Do not be confused by the talk of 100 people to Mars per ship,  or colonies with a million people.  That's "far future" stuff,  some decades after the initial landings,  if not longer time spans.  Musk is concentrating on the transportation system,  not the actual establishment of a colony.  He cannot do all of this by himself.  He will be very lucky just to get the transportation system done. 

There is a timeline disparity in what he presented at Guadalajara:  first giant ship to Mars late 2022,  versus first men to Mars late 2024.  This is preceded by Falcon-Heavy/Red Dragon "pathfinder" unmanned shots in 2018,  2020,  and presumably into 2022.  

To me,  this sort-of looks like the first large-ship shot or two is unmanned.  Presumably,  that would have something to do with the return propellant processing factory,  and perhaps other infrastructure,  for a putative manned base to start around 2022.  

And,  as always,  calibrate this with the history so far.  Musk typically does what he says he will do;  it just takes him about 50+% longer than he wanted,  to actually get it done.  


If you go to "Mars Mission Outline 2016" on this site,  dated 5-28-2016,  you can see what I had been working on.  Musk and I share the concepts of big ships,  and of re-usability to the maximum extent possible.  Where we differed was (1) I used separate landers rather than a direct landing,  and (2) I did not presume local propellant manufacturing capability from the very first manned landing.

That is why the two transportation systems look so very different.  Assumptions make a gigantic difference.