My wife found this on her Facebook. It’s too good not to share. Needs no comment.
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Search code 20082025
Search keyword fun
stuff
Wednesday, August 20, 2025
Saturday, August 16, 2025
History Rhymes Pretty Close, Does It Not?
I found this on LinkedIn, and thought I would post it here, too. It’s rather self-explanatory. The parallel is quite eerie.
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Search code 16082025
Search keywords: bad
government, idiocy in politics
Wednesday, August 13, 2025
Dictatorship Is Upon You!
The main body of this article is almost exactly as I submitted it 7 August 2025 to the Waco Tribune-Herald newspaper (the “Trib”), as a board-of-contributors item. It is a final wake-up warning for anyone who bothers to look at it. Update 8-19-2025: It ran essentially unchanged in the Tuesday (8-19-2025) "Trib" on the opinion page.
The appended image below was not part of the submittal to
the “Trib”, it is something I found
on-line at Getty images. That photo was
taken in Spain, which is why the
leftmost figure is their former dictator,
General Franco. Left-to-right, they are the dictators Franco, Stalin,
Hitler, and Trump. (Missing:
Mussolini, Putin, Xi,
and many more.) It would appear
that most in Europe are very well aware of the evil that is happening to
America! They’ve seen this many times before!
I would only add that Trump subverting the Constitution he
swore to uphold, may not be treason per
the two (and only two) definitions in that Constitution, but it is something edging very close to
treason! Especially when throwing that
Constitution away to impose a dictatorship upon America. That imposition is now almost complete.
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Original article (highlighting added for posting here):
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Noah Feldman wrote an excellent column that appeared in the
“Trib” on Thursday 7 August 2025. While
he did not use the same words as me to name what is going on, he quite accurately described the ongoing
imposition of a Trump dictatorship. That
is exactly what consolidating all federal power into the executive branch
really means!
The Supreme Court majority has been giving Trump everything
he wants, no matter how
unconstitutional, by over-ruling those
lower courts’ rulings that go against him.
The Court’s minority dissent opinions clearly indicate this, and they do indeed highlight the danger to
our democracy, if you bother to read
them! My voice is not alone!
The majority of Congress has essentially abdicated all its
power to Trump, by giving him anything
he wants, even when he tries to
dismantle institutions Congress set up,
and refuses to spend funds Congress already allocated. Both of those outcomes are entirely
unconstitutional, by the way! Read it for yourself, including all the amendments. Congress’s last power, the power of the purse, is now no more!
Between
the Supreme Court and Congress, the
checks and balances have effectively already been destroyed! That was the real point of Feldman’s column!
Trump has begun muzzling the free press and academic
institutions, as well as large
corporations that might otherwise oppose what he does. You’ve all seen this taking place in the
news! Almost no entity has stood up to
him, excepting Harvard, and acting alone, they have no chance! Shame on those who failed to resist: you have helped destroy our democracy! Controlling all information is a hallmark of
every dictatorship this world has ever seen!
Trump has weaponized ICE to do his bidding instead of
following the law, and greatly expanded
it. This is going to be his secret
police to intimidate and oppress you all,
fulfilling the same role as Stalin’s KGB, and Hitler’s Gestapo and SS. Right now, it is deporting everyone it can find with
brown or dark skin, legal or not, and making them disappear to overseas
prisons, totally out of sight and beyond
help!
Hear my
warning: citizens of any color who
oppose him are next! The machinery to make
people disappear is already in place!
That is another hallmark of dictatorship.
Trump has weaponized multiple government departments and
agencies with minions as their heads who will do his bidding, not follow the law. This,
too, is a hallmark of every
dictatorship the world has ever seen.
One of the evils is misusing executive power to punish opponents or
people who say or do things Trump does not like, such as the head of the bureau of labor
statistics, among many, many others.
You are
about to lose your vote, your clean air
and water, your medical care, and your middle-class economy! Trump and his minions have proven that they
care not one whit about your life or anyone else’s, they only care about staying in power to have
control over all others! Putting an
incompetent vaccine denier in charge of your health care, and gutting all the science budgets and
environmental regulations, is proof
enough of this.
Don’t listen to the lies,
look instead at what they have actually done! Trump pardoned all the rioters that he
incited to attack the halls of Congress,
actually starting before he lost the 2020 election. You saw what they did, live on television, and you saw that Trump did not do anything to
stop the rioters, until it was clear
that his congressional opponents would not be killed. Why did he pardon the rioters? Because they were well-demonstrated by their
criminal actions to be supporters,
simple as that! Some of whom have
already gone on to commit more crimes after he pardoned them.
Why did Trump not want the Epstein files released? Two simple reasons: (1) he’s named in there multiple times, which should surprise no one, since he is an adjudged (and self-confessed) sex
abuser, in addition to being a convicted
criminal (which he is now trying to overturn),
and (2) he and his minions have been lying to you for years about how
the majority of their “deep state” opponents would be exposed there, when the truth really is that they are mostly
not listed. Trump and his minions are
actually the real “deep state”, and they
do not want you to know that, before
they can grab full dictatorial power over you!
The current between-census political gerrymandering talking
place here in Texas (and a few other places) is part of the larger effort to
rig the outcomes of all future elections.
This is exactly how the sham elections work in Putin’s Russia and in
Iran, among many others, that being a hallmark of many dictatorships. You’ve already seen this process start with
the 2016 election: the only elections
not falsely claimed to be rigged are the ones Trump or his minions win. The ones they lose, they try to overturn. Simple as that!
Your
last chance to stop this is the 2026 mid-term election. That is,
assuming their election-rigging efforts haven’t already rendered it a
sham by then, a very real risk!
Once your vote is no more,
your only remaining choice to stay free is revolution in the streets! And Trump knows that: he has been cashiering all the high-ranking
military officers who might choose to help you overthrow him. Surprise,
surprise!
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Appended image:
L to R: Spain’s
Franco, Russia’s Stalin, Germany’s Hitler, and America’s Trump. Photo is from Getty
images, freely available as a
downloadable jpg file. Taken at some
sort of protest in Spain: small figures
being thrown into the fire.
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Search code 13082025;
search keywords bad gov’t, idiocy in politics, treason
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Sunday, August 10, 2025
Rear of a Whale?
My wife found this on Facebook, and it is too funny not to share. Offered without further comment.
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Search code 10082025,
search keywords: fun stuff, bad gov’t, idiocy in politics
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Friday, August 1, 2025
Air Launch to Low Earth Orbit
There is a conundrum associated with launching to low Earth orbit from an airplane. The illustration tries to sum up the various parts of it. That is not to say that it cannot be done, because it already has. But, it may, or may not, be an attractive way to do the mission.
The first part of this conundrum is the low speed of the
launch aircraft (which for the Pegasus system is a wide-body subsonic
airliner). That forces the dropped
rocket vehicle to be at least two-stage,
despite the advantage of the low stratospheric launch altitude. As it says in the illustration, speed at drop is the biggest influence on the
rocket vehicle design, and altitude the
least, although both are
beneficial. Mach 0.85 at 45,000 feet is
but 822 feet/sec (0.25 km/s). The drag
loss of the rocket vehicle is (at least theoretically) less, because it starts in thinner air up high.
The second part of this conundrum is not so obvious: the level path angle of the carrier
airplane at the drop point. A
low-loss non-lifting ballistic trajectory begun at stratospheric altitude would
need a path angle at ignition on the order of 45 degrees, maybe even a little more. So,
either the carrier airplane, or
the rocket vehicle, has to pull up
rather sharply, to reach that path angle
from level flight. One or the other must
do this!
The usual airplane flying high in the stratosphere is at or
near its “service ceiling”, where there
is barely enough wing lift being produced at an efficient angle of attack, to hold up the weight, and essentially all the thrust the
airbreathing engines can make is just overcoming drag at the flight speed! The airplane can neither accelerate
path-wise, nor can it climb! That is the definition of “service ceiling”, and for most planes, it falls in the 45,000-55,000 foot altitude
range, at high subsonic speeds. There have been exceptions: the U-2 variants and the SR-71 variants could
fly higher, being very specialized
designs.
Left unaddressed in the airplane, the service ceiling problem puts the sharp pull-up
task squarely upon the rocket vehicle to be dropped. There are only two choices: put wings on the rocket vehicle, or fly it at very large angles of attack,
so that the cross-path vector component
of its thrust is effectively a large lift force.
Pegasus used large wings,
on the first stage of a two-stage rocket vehicle. Those add both weight and drag, especially drag-due-to-lift at the large
lift coefficient needed to pull up sharply.
That pretty-well eats up the advantage gained by launching the rocket at
elevated altitude in the thin air. The
wings are bigger than you would want,
precisely because of that thin air!
And that problem is why there have just not been that many Pegasus
launches.
Leaving the wings off of the rocket vehicle forces you to
pitch it up to very large angles of attack,
in the 45-75-degree range, to get
enough of a cross-path vector component of the rocket thrust, to serve as the necessary lift force for a
sharp pull-up maneuver. That reduces the
path-wise vector component of thrust,
while at the same time greatly increasing vehicle drag. So,
you accelerate slowly( if at all) in rocket thrust during the pull-up
maneuver, using up a great deal of
rocket propellant that adds nothing to your speed. That also eats up any advantage of launching
in the thin air, way up high!
The only other feasible alternative is to add another large
source of thrust to the launch airplane,
so that it can execute the pull-up maneuver into a zoom climb, without stalling and falling out of the
sky, out-of-control. Generally speaking, you would add a source of thrust immune to
the service ceiling effect, and that is
rocket thrust! Your launch
airplane would have to be modified for mixed (parallel-burn) rocket and gas
turbine propulsion, somewhat
similar to the NF-104 and some of the early high-speed X-planes.
So far, no
air-launch carrier plane has had this design approach, but it certainly would be possible! And it would take care of the high path angle
requirement that is second only to speed at launch in importance, while keeping the wings on the airplane
where they belong, and not on the
rocket vehicle!
That leaves speed at launch,
the most important variable affecting the rocket vehicle design. There are (or have been) very few supersonic
aircraft designs that are also large enough to serve as a drop aircraft for a
rocket vehicle of any significant size.
Those would include the B-58 Hustler (long-retired, and none are left), the SR-71 (also retired, but very expensive to operate indeed), and the B-1B bomber (currently in service as
a military strategic bomber).
The modifications to include rocket propulsion to the SR-71
likely would not fit within its very-critical shape. The M-21 variant that launched the D-21 drone
was limited in payload size, to the size
of that drone (not very large). A rocket
might be added in the tail cone of a B-1B,
but its payload would be limited to that which would fit in its bomb
bay. That B-1B option would reach a low
supersonic launch speed at the high path angle needed, with a rather-dangerous zoom climb and
recovery after drop.
That brings up the danger of supersonic store
separation. There is a very good
reason that most military aircraft, even
those capable of supersonic flight, are
limited to high-subsonic weapon release speeds.
That is because the inherent wobbles of a released store will include
pitch-up, thus developing lift. At high enough speeds, that lift generated by the wobbling store
will exceed its weight, and it can
easily fly up and collide with the drop aircraft, before the store’s drag can pull it behind.
It cost a destroyed airplane and the life of one of the two
crew, to learn this lesson with the M-21
trying to launch a D-21 drone (without a booster) at just about Mach 3. That is why the drone was re-fitted with a
big booster, and launched subsonically
from B-52’s instead. It’s not that
supersonic store separation cannot be done (because that booster separated at
Mach 3 from the D-21). But successful
supersonic store separation is very difficult to achieve, and the risks of doing it are inherently very
high.
So how fast a drop speed can be obtained? That depends upon the gas turbine engines
powering the launch aircraft. Those are
seriously limited by the high air temperatures associated with capturing
supersonic air. Most are limited to
about Mach 2.5. There are a very few
that went faster: those powering the
XB-70 at Mach 3, those powering the
SR-71 variants at Mach 3.2, and the 500
hour short-life, replace-don’t-overhaul engines
in the Mig-25 at Mach 3.5. So, to have a wide range of possible engines
available for new designs, it looks like
Mach 2.5 at drop is “about it” with gas turbine. Maybe Mach 3.
So, the answer would
seem to be a mixed-propulsion airplane with gas turbine propulsion, augmented by parallel-burn rocket
propulsion, added to enable the
zoom-climb by a sharp pull-up maneuver.
This would be at high altitude near 45,000 feet, for the drop of the rocket vehicle. To do this successfully, the very difficult supersonic store
separation problem must be very carefully addressed! Both aircraft and crews are at serious risk.
Mach 2.5 at that altitude would be 2419 feet/second (0.737
km/s), less than 10% of low circular
orbit speed, so one is still looking
at a two-stage rocket vehicle to reach orbit. Deliverable payload would be limited in size
by the size of the drop aircraft, since
that in turn limits the size of the rocket vehicle it can drop.
In a word, this has
already been done with subsonic carrier aircraft, although it has proven no more attractive
than vertical rocket launch, at
best. The supersonic release has yet to
be tried, and will prove both difficult
and dangerous, although the improvement
in attractiveness may be worth that effort and risk. No one yet knows.
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Search code 01082025;
search keywords: aerothermo, airplanes,
launch, space program
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Update 8-2-2025: Please do not misunderstand, air launch to LEO is possible and in fact has been done more than once! It's just not easy, because many of the problems associated with it are hard. They are hard enough that the attractiveness of this approach is still in question, relative to the tried-and-true vertical rocket launch.
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Update 8-4-2025: For an air launch-to-orbit
carrier aircraft, the gas turbine speed
limitation could be gotten around by instead using ramjet propulsion, which for a true high speed design might
reach speeds between Mach 3 and Mach 4 in the stratosphere, limited mainly by atmospheric drag of
something inherently not a “clean” missile shape.
One would still
need the rocket component of a mixed-propulsion parallel-burn scheme to achieve
the necessary climb angle at launch of the rocket payload, and one would still need to solve the
dangerous supersonic store separation problem.
But this would get the highest possible speed at launch, at the right launch angle, and at an altitude high enough to be
beneficial.
The downside
is that ramjet has no static thrust! You will need some
sort of booster to reach ramjet takeover speed,
and the necessary high-speed ramjet design is going to have a takeover
speed in the Mach 1.8 to 2.5 range. Given
that rocket is needed to reach the high climb angle at launch, that same rocket is likely the propulsion
needed to reach takeover speed.
Speeds will be
limited by the percentage of frontal blockage area occupied by each of the two
propulsion systems. The airbreather is
fundamentally lower in frontal thrust density than is the rocket, so it needs to occupy the larger fraction of
the total frontal blockage area.
Being a lower
percentage of vehicle frontal blockage area than the ~100% of a “clean” missile
design, the max possible speed
capability of a ramjet (near Mach 6) cannot be reached with this kind of a
vehicle. But the ramjet weighs far less
than any possible turbojet propulsion!
That makes a smallish rocket system feasible for getting off the ground
with wings, and reaching Mach 1.8 to 2.5
takeover speed at relatively low altitude.
From
there, you climb in ramjet to high
altitude at speeds near Mach 2.5, and
pull over level to accelerate to top speed in the thin air. Fire up the rocket to climb steeply for the
supersonic store separation, then shut
down the rocket and throttle-back the ramjet to execute a zoom climb and
descent back into air dense enough to support controlled flight. Cruise back in ramjet, then glide to a landing with the rocket in
reserve for go-around capability.
The real
trade-off here, yet to be
evaluated, is whether to integrate the
two propulsion systems into some sort of combined-cycle rocket-ramjet, or leave them as separate systems to be
operated entirely separately.
Combined-cycle usually seriously compromises the performance of both
components, while parallel-burn does
not, instead running into the
fraction-of-frontal area problem.
And there is
also the problem of there being “no such thing as cooling air” above about Mach
3 to 3.5 in the stratosphere. Vehicle
designs flying faster than that will need one-shot ablatives for their ramjet combustor
and nozzle heat protection. Which means
you must swap-out the entire combustor and nozzle unit after every flight! Given that eventuality, you could do a solid propellant integral
booster in the combustor and nozzle unit,
like a great big JATO motor, for
the initial takeoff. That reduces the volume (and cross-sectional area) of the on-board propellants for the liquid rockets.
None of these
issues have been resolved for an air launch-to-orbit application.
Monday, July 28, 2025
Education Department to be Shuttered by Trump?
I found this on LinkedIn. It’s too true not to share. It’s also rather funny, in a gallows humor sort of way.
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Search code 28072025
Search keywords: bad
government, idiocy in politics
Saturday, July 26, 2025
Tank Design for Easy Cryogenic Transfers in Weightlessness
I recently came up with a design for a cryogenic propellant
tank that makes transfers of propellant easy in weightlessness! I filed a provisional patent application on
it, with USPTO (the United States Patent
and Trademark Office). A couple of
preliminary searches on their site revealed nothing that duplicates it.
This design is depicted in cartoon form in the
illustration. Is there any outfit out
there, dealing in rocket launch vehicle
designs, that might be interested in
such a thing? If so, do please contact me! I would like to license this design to an
outfit that might actually use it to good effect! That would include propellant depot space
stations in Earth orbit, plus the tanker
launch vehicles that keep such stations supplied.
While one motor and a reversing gear is shown, two motors are also covered in the
provisional patent application, as well
as a variety of vane shapes.
Contact data:
Gary W. Johnson, PE(ret.), PhD
5886 New Windsor Parkway
McGregor, TX
76657 (USA)
Email gwj5886@gmail.com
Blog site http://exrocketman.blogspot.com
Update 8-1-2025: If anybody at NASA or one of the launch companies wants to use this invention, do please contact me.. I'd certainly be interested in licensing this notion. And, it's not the only skill I bring to the table for launch, or other kinds of space missions. While I'm an old retired guy, I can still consult.
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search code 26072025; search keywords: space program
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Friday, July 18, 2025
Why Trump Did Not Want To Release the Epstein Files
Trump has vehemently resisted releasing the Epstein
files, which his cult supporters
believed had a client list containing many names of their political opponents. He has insulted those cult supporters who
wanted those files, and he has lied
egregiously about this issue (something verified) multiple times.
There may, or may not
be, any sort of “client list” in those
legal files. If there is, it may or may not have been compiled by
Epstein or his people; it might well
have been compiled by the government lawyers.
There are photos documenting that Trump was once a close friend and frequent
visitor to Epstein’s haunts.
One such is shown here,
and it is not a fake or an AI construct,
but it is a real Getty image. It shows Trump with Melania before they were
married, with Epstein (deceased in jail
during Trump’s first term), and Ghislane
Maxwell (Epstein’s girl friend now serving a prison sentence for sex
trafficking).
Why was Trump so desperate not to reveal the Epstein
files? All I can say is what I
believe, without a public admission or
(so far) any proof. In a word, Trump is on that “client list”, however it was compiled and whoever compiled
it. He is on the “client list” of a
convicted sex trafficker, including the
trafficking of underage girls. He did
not want you to know that!
You Trump cult believers can add that character fault to all
the other verified character faults this man has.
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search code 18072025, search keywords bad government, idiocy in politics
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Update 7-29-2025: my wife found this on her Facebook. It is both too funny and too true, and fits right in with the original article here. It essentially summarizes succinctly and accurately all the bluster coming from Trump's mouth about this issue.
Tuesday, July 8, 2025
Oxygenation Issues for Habitats and Space Suits
search code 08072025; search keywords space program, spacesuit
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The following is an evaluation of oxygenation issues for
space habitations and oxygen suits, without
using any models for in-lung oxygen partial pressure. Only what is in the breathing gas to be
inhaled is considered here! That
way, the issue is not clouded with the
effects of breathing gas displacement by in-lung water vapor, or by in-lung carbon dioxide, or by in-lung dead-end volume effects. Not everyone agrees on the efficacy of those
models.
Shown in Figure 1 is a list of selected air pressures versus altitude from a US 1962 Standard Day atmosphere model, which is identical to the ICAO Standard Day model up to about 65,000 feet. The breathing gas to be inhaled is either Earthly air at 20.9 volume percent oxygen, or 100% oxygen in a vented face mask, with delivery at the altitude’s pressure. The corresponding oxygen partial pressures were computed and included, along with a description of the circumstances, and an indication of the duration of the exposure.
Figure 1 – Oxygenation Limits Short and Long Term
Partial pressure of oxygen is important, because it is related to the partial pressure
of oxygen in-lung. The difference
between in-lung partial pressure and that in the blood, is what drives the diffusion of oxygen across
the lung membranes into the blood.
The duration of the exposure is very important to
determining what levels of oxygen partial pressure are suitable. What I tried to identify as short-term
criteria relate to the military and civil altitude requirements for going
on oxygen in unpressurized airplane cockpits.
Use of such oxygen can be for many hours exposure, and it makes sure the pilots are fully
cognitive, up to the upper altitude
limits for such vented masks.
Those upper altitude limits for vented oxygen face masks are
“fuzzy”. Different people quote
different values, usually close to
40,000 or 45,000 feet. Below that upper
altitude “limit”, you are “good” for
hours. Above it, exposure time with high cognition is limited
to only minutes or even seconds. These
are typically very short zoom-climb experiences, peaking at 50-some thousand feet
altitude. One needs a pressure suit to
stay up there.
For long-term criteria, the experiences of populations living at high
elevations are very informative. There
are two things known that are relevant:
chronic hypoxia effects that manifest as “chronic mountain
sickness”, and an increase in pregnancy
and birthing difficulties above the low-elevation rates, presumably also due to chronic hypoxia. Both start above around 2500 m
elevation, and get worse as elevation
increases. Below 2500 m, there seem to be no detectable chronic
mountain sickness symptoms, and the rates
of difficulties with pregnancy and birthing seem indistinguishable from those
at sea level.
Maximum oxygen partial pressures are limited by enhanced
fire dangers above 21 volume percent near sea level, and seem to be “OK” up to about 0.83 atm
partial pressure for several hours flight time,
using the Navy criterion for going on oxygen at 5000 feet. The ultimate “fatal exposure” limit (1+ atm)
derives from experiences with oxygen in diving.
All of these things are shown in the figure, and highlighted in different colors. The overall conclusions I drew from this are
in a small table at the bottom of the figure.
I chose partial pressure limits for long-term exposure suitable for
habitations, and short-term exposure
limits suitable for hours-long work shifts in pure oxygen space suits. The space suit criteria further divide into
full cognition, versus mere survival
(with presumed cognitive impairment if longer than a few minutes).
Turning to the space suit issue, Figure 2 shows the suit pressures in a
variety of units of measure,
corresponding to the oxygen partial pressure criteria already identified
above, and also as corrected upward to
compensate for a 10% pressure leak-down during a long shift. These would obtain, if there were no other effects to
consider, but there are!
Experience also shows that breathing oxygen at low pressures
causes a loss of water from the tissues in the lungs and respiratory
tract. This drying-out of tissues can
cause bleeding, which is a very serious
problem indeed!
That same experience suggests that there is a minimum suit
pressure below which there is a tissue-drying problem, and above which there is no problem. This is a bit “fuzzy”, but the value most quoted is 3.00 psia
(corresponding to 0.2041 atm). This is
the value to which the 10% leak-down factor needs to be applied for a higher
design suit pressure, in order to avoid
tissue dry-out during a long work shift,
even with leakage.
The result is the final table at the bottom of the
figure, showing the “min suit design”
pressure, the 10% leak-down pressure for
long work shifts, and the short term
survival criteria with full cognition,
and with impaired cognition, after only minutes.
Figure 2 – Oxygenation Issues for Pure Oxygen Space Suits
Returning to the two-gas mixture habitat atmosphere issue, we have a good minimum partial pressure
criterion for very long-term exposures: near
0.15 atm, per the discussion above. However,
there are three other things to worry about when setting the habitat
breathing gas mixture, presumed to be
oxygen and nitrogen. These are: (1) a pressure leak-down over time, to be compensated when detected, (2) the enhanced fire danger of higher
percentage oxygen, but which is offset
by lower total pressures, and (3)
avoiding pre-breathe time, if
possible, when going from the two-gas
mix to the pure oxygen suit.
I picked the partial pressure of oxygen in the standard
atmosphere table at 8200 feet (2500 m) as the “exact” long-term criterion. That partial pressure of 0.1551 atm is
indicated in the first calculation with green highlighting, near the top of Figure 3. Just below it, I ran the compositions of air as it was known
in the 1960’s, air as it is today with
increased carbon dioxide, and a
synthetic air (2-gas mix) at the same oxygen content as today’s air. This includes evaluations of molecular
weight, gas constant, densities at 1 atm and 59 F (15 C) and also
at 1 atm and “room temperature” 77 F (25 C).
From those densities and the mass fraction of oxygen, I computed the oxygen concentrations in kg/m3, at 1 atm and 77 F (25 C) as “room temperature
air at sea level”. That value is 0.2738
kg/m3. That would be the max
oxygen concentration allowable in the habitat breathing gas, to keep the fire danger as no more hazardous
than that of “room temperature sea level air”.
It is based on an overall Arrhenius reaction rate model.
I also checked the oxygen concentration of 40% hospital
oxygen at sea level and room temperature,
known to be a severe fire hazard.
It is about twice the concentration of oxygen in ordinary air at sea
level and room temperature. That is near the bottom of the figure, result highlighted in blue. One would expect those fires to propagate
twice as fast.
The habitat atmosphere calculations start with design values
for gas composition and total pressure,
and include a leaked-down set of values.
These are on the right of the figure,
with much blue highlighting, and
user inputs highlighted yellow. Based
on prior work, I chose to
investigate what I call a “rule of 43” 2-gas mix atmosphere of oxygen and
nitrogen. The oxygen is 43 volume
percent of the mix (leaving 57% nitrogen),
and the total pressure is 43% of 1 standard atmosphere. The resulting oxygen partial pressure (0.1849
atm) exceeds the criterion 0.1551 atm,
which is a lower limit, and the
calculated oxygen concentration (0.2418 kg/m3) is less than the
criterion value, which is an upper
limit.
Just above that calculation is an estimate of the minimum
suit pressure, based on the nitrogen
partial pressure of 0.2451 atm, divided
by the “no pre-breathe” criterion of factor 1.2. That produces a 0.2043 atm min suit
pressure, which meets the “no tissue
dry-out” criterion of 3 psia, and also
far exceeds the cognition limits. That
would be the minimum suit pressure you can use with no pre-breathe interval to
blow off nitrogen: you can just don the
suit and go right out of the airlock.
Any higher suit pressure also qualifies.
Down in the lower right corner of the figure is the habitat
leak-down analysis, set by the min
partial pressure of oxygen. It says we
can leak down 19% in pressure at the same oxygen percentage, and still meet all criteria for safety. Even the fire danger is OK: the oxygen concentration reduces as pressure
reduces, depending as it does on
density.
Figure 4 below summarizes these results in one
place. The “rule of 43” habitat
atmosphere allows the use of rather low-pressure space suits without any
pre-breathe requirements, and provides
plenty of leak-down margin, while at the
same time keeping the fire spread danger similar to that in sea level room
temperature air. The recommended suit
pressure still meets the 3 psia tissue dry-out criterion as leaked-down 10%
after a long work shift.
Figure 3 – Oxygenation Issues for Space Habitats
Figure 4 – Results for Combined Habitats and Space Suits
Final Remarks
There are other habitat 2-gas mixtures and pressures that
would qualify. Not all of these produce
space suit designs with min pressures as low as the one found here.
My selection of the “rule of 43” habitat atmosphere is based
on previous work I did trying to meet all these criteria while getting as low a
suit pressure as possible. It is also an
easy specification to remember.
Further, that lowered suit
pressure is important for 2 very compelling reasons:
First, a
higher suit pressure not only is more difficult to design, it also stiffens like a sports ball at higher
pressures, greatly reducing the mobility
available to its wearer.
Second, higher
suit pressures pretty much rule out suit designs based on mechanical
counter-pressure (MCP), since the
materials and design practices for MCP are unavailable in any form that might
be donned and doffed with reasonable ease at higher pressures.
References:
All these listed references are prior studies posted at
http://exrocketman.blogspot.com. For
rapid access, there is an archive tool on
the left side of that page. All you need
is the posting date and the title. Click
on the year, then the month, then the title if need be (such as if other
articles were posted that same month).
1-2-22
Refining Proposed Suit and
Habitat Atmospheres best case and easiest-to-remember cases, plus an
independent estimate of the utter min suit pressures feasible
1-1-22
Habitat Atmospheres and
Long-Term Health adds a long term hypoxia
criterion for the habitat in addition to short term criteria for the min-P suit
3-16-18
Suit and Habitat Atmospheres 2018
11-23-17
A Better Version of the MCP Spacesuit?
2-15-16
Suits and Atmospheres for Space
1-15-16
Astronaut Facing Drowning Points Out Need for Better Space Suit
11-17-14
Space Suit and Habitat Atmospheres
2-11-14
On-Orbit Repair and Assembly Facility
12-13-13
Mars Mission Study 2013
1-21-11
Fundamental Design Criteria for Alternative Space Suit Approaches
Sunday, June 29, 2025
Where You Get Your “Facts” Matters!
This is another one I found on LinkedIn that I thought I would post here. As readers of this blog already know, I often say “you are entitled to your own opinions, but you are NOT entitled to your own facts”.
Most of the totally-unregulated right-wing social
media, many cable television news
outlets, and most infamously on
broadcast and cable television Fox News,
are all well-known purveyors of lies and conspiracy theories. About 30% of which was planted there by the
Russians to divide us, and
successfully, as near as I can
tell. My opinion of the veracity of Fox
News has been in the toilet for about 30+ years now. To me, they are “Faux News”.
So, if you who get
your “facts” from such sources want to be smarter than most dogs, please come out of your echo chambers and
look around elsewhere!
Wednesday, June 25, 2025
On the new Iran war
Update 7-1-2025: The Waco "Tribune-Herald" newspaper today published a version of the original article just below, as a board of contributors opinion piece (I am on that board). It was hardly edited at all. The recent update below was not included, not being in the original submittal as a column.
--------
Original article written 6-23-2025:
It would seem likely that we are starting down the path to
another long Mideast war, with no clear
end in sight, despite what government
officials claim. Netanyahu started
this, desperately wanting Trump to join
in, despite his campaign pledge not
to, and he did! Israel did not have the means to hit the
deeply buried facilities, and we
did, which is why this has taken place.
Iran’s regime is a set of terrorists, masquerading as religious clerics, using a private army (the Revolutionary
Guard) to stay in power as a dictatorship,
and abusing religion to justify to their captive people the evils they
have long done. They have been sending
out terrorist proxy armies to do their dirty work for about 4 decades now. I think most people would have to agree with
that entire assessment.
There never was any realistic hope of negotiating an end to
the Iranian nuclear weapon program,
because we are dealing with terrorists,
not any sort of people who value logic or the safety of their country
and its people. The previous nuclear
agreement only slowed their pace, until
Trump abrogated it in his first term.
It accelerated since then.
They now have a stockpile of reportedly-60% enriched uranium, which was evacuated from the sites before
Trump bombed them!
So all the pieces for an Iranian atomic bomb are still in
place, despite the bombing, including the terrorist government so
desperate to have those weapons!
Contrary to the claims in the news reports, you do not have to have 90% enrichment to
build an atomic bomb! Anything over 50%
will work!
Although, for the
same yield, much smaller devices can be
built at 90% than 50%. This is no
secret, it’s been in public libraries
since I first read it there as a young boy,
more than 65 years ago.
Regime change in Iran was the one and only realistic hope of
actually putting a stop to the Iranian atomic bomb! And now Netanyahu and Trump have made that
very much harder to accomplish, turning
the Iranian people against us by bombing their country, and killing civilians in the process. Plus,
the regime’s leaders have now gone into hiding, so that we cannot easily take them out
anymore.
The right way to have done this would have been to support
the Iranian people to rise up and do their own regime change from within, without making enemies of them by bombing
their country! They would just need help
overcoming the Revolutionary Guard.
Which without a war going on,
actually could have been done with targeted air strikes.
The Iranian people tried insurrection once before, during Obama’s administration, but failed,
because we failed to aid them.
Now, such a scenario is no longer
possible. The only regime change now
possible will have to be imposed from outside,
with boots on the ground, and
against a civil population rallying to defend their government from foreign
attackers.
You can “thank” Netanyahu and Trump for that really ugly
prospect! Although, “blame” is a better word.
Any child who has passed grade school social studies (taught
up to standard, not just “to the test”)
could have predicted some, or even
all, of this. But apparently neither Netanyahu nor Trump
understood the likely results of their actions,
and apparently they still don’t.
That conclusion is based on what they have done, not anything either of them said. Remember,
you can always tell when a politician is lying: his lips are moving.
I think both our countries have the wrong governments. The Iranians are not the only ones in need of
regime change.
Update 6-25-2025: The cease fire between Iran and Israel seems
to be holding, after some initial
violations. I am surprised but pleased
to see it. It means maybe we have
avoided getting into another endless war,
at least for a little while.
Meanwhile,
intelligence reports are still quite sparse, but some seem to indicate that what I said
above is true: the Iranians managed to
move out some of their enriched uranium and related equipment before the attack
took place. That is a thing that
President Trump really hates to hear,
because it directly conflicts with his chest-thumping.
Long term, do not
expect this cease fire to lead to any sort of permanent peace! You are not dealing with normal political
people as Iran’s government. You are
dealing with fanatical terrorists! They
will say anything and do anything, that
lets them continue their evil activities,
including building nuclear weapons.
Their history over the last 4 decades says so.
The only permanent solution here was, is,
and always will be, regime change
in Iran! Unfortunately, that will henceforth be hellishly
difficult, now that there has been a
direct war to alienate the civil population.
Plus, the ruling mullahs and the
Revolutionary Guard private army that keeps them in power, both survive intact.
Photo from Maxar showing immediately-visible damage:
Other photos taken a day or two before the strike show a lot
of unusual roadway truck activity.
Presumably, that was truck
traffic evacuating the materials and equipment,
anticipating a coming strike.
Update 6-29-2025: The continuing variance among intelligence reports within and without the government very strongly suggests that the US bombing did great damage to Iran's nuclear weapon efforts, but did not "obliterate it", as Trump insists. In fact, he gets quite angry with those who disagree with him over this, clear evidence of his fragile but enormous ego.
I think the truth lies somewhere in between the extremes of the various assessments, including ALL of them, even the first one Trump claimed to be "leaked". We set them back by somewhere between a few to several (or many) months. I also rather think that those Maxar photos showing heavy truck traffic at the Fordow site just before the strike, indicate that the Iranians got at least some of their enriched uranium out, and hid it elsewhere. And maybe some centrifuges, too.
Bear in mind, please, that further enrichment beyond their 60% is not necessary to build a workable nuclear weapon, it's just that the weapon will be very large and heavy, much like our first generation devices were. If too heavy for their rockets, they could always deliver it as a suicide truck bomb. Think about that!
Regime change in Iran is the only long term solution for this threat, exactly as I said above in the article! And Trump and Netanyahu have made that very difficult indeed, by starting this war, cease fire or not. The Iranian people will now tend to rally behind their government against foreign attackers, despite its brutal history of oppressing them. That's just human tribal nature.
Monday, June 23, 2025
Starship Explosion
Update 7-5-2025: search code 23062025.
-------
From AIAA’s “Daily Launch” email newsletter for Monday, 6-23-2025. This ship was intended for Flight Test 10. It blew up before they ever ignited the engines. Quote:
------
SpaceX
traces Starship test-stand explosion to failure of pressurized nitrogen tank
By Mike
Wall published 3 days ago (on Space.com)
"Initial analysis indicates the
potential failure of a pressurized tank known as a COPV."
SpaceX thinks it knows why its newest
Starship spacecraft went boom this week.
The 171-foot-tall (52-meter-tall)
vehicle exploded
on a test stand at SpaceX's Starbase site late
Wednesday night (June 18) as the company was preparing to ignite its six Raptor
engines in a "static fire" trial.
A day later, SpaceX narrowed
in on a likely cause.
"Initial analysis indicates the
potential failure of a pressurized tank known as a COPV, or composite
overwrapped pressure vessel, containing gaseous nitrogen in Starship's nosecone
area, but the full data review is ongoing," the company wrote in an update on Thursday (June
19).
"There is no commonality between
the COPVs used on Starship and SpaceX's Falcon rockets," the company
added. So, launches of the workhorse Falcon 9,
which has already flown 75 times in 2025, should not be affected.
The Starship explosion did not cause
any reported injuries; all SpaceX personnel at Starbase are safe, according to
the update. People living around the site, which is near the border city of
Brownsville, shouldn't be worried about contamination from the incident, SpaceX
said.
"Previous independent tests conducted
on materials inside Starship, including toxicity analyses, confirm they pose no
chemical, biological, or toxicological risks," the company wrote.
"SpaceX is coordinating with local, state, and federal agencies, as
appropriate, on matters concerning environmental and safety impacts."
That said, the explosion did damage
the area around the test stand, which is at Starbase's Massey site (not the
orbital launch mount area, from which Starship lifts off).
"The explosion ignited several
fires at the test site which remains clear of personnel and will be assessed
once it has been determined to be safe to approach," SpaceX wrote in the
update. "Individuals should not attempt to approach the area while safing
operations continue."
Wednesday night's explosion occurred
during preparations for Starship's 10th flight test, which SpaceX had hoped to
launch by the end of the month. (Static fires are common prelaunch tests,
performed to ensure that engines are ready to fly.) That timeline will now
shift to the right, though it's not clear at the moment by how much.
The incident was the latest in a
series of setbacks for Starship upper stages. SpaceX lost the vehicle — also
known as Ship — on the last three Starship flight tests, which launched in
January, March and May of this year.
Starship's first stage, called Super Heavy, has a better
track record of late. For example, on Flight
7 and Flight
8, the huge booster successfully
returned to Starbase, where it was caught by the launch tower's
"chopstick" arms as planned.
------
My take: if the
description “in the nosecone” for the location of the COPV is correct, then it is located very close to the oxygen
header tank (as the version 1 with 1200 metric tons propellant capacity was
laid out), which is also in the nose of
the vehicle, ahead of the “cargo bay”
area. Such a COPV explosion would easily
rupture that oxygen header tank.
Compressed gases drive great explosive violence (with shrapnel) when
such vessels burst. See Figure 1.
Figure 1 – Inboard Profile of Starship Version 1
There would seem to be an oxygen header tank transfer piping
line down the windward “belly” of the cargo bay section, based on descriptions I have read. In the explosion slow-motion video, the cargo bay splits open through its heat
shield, right where that transfer line
supposedly is, with gush of something
white (not fire) bursting through,
followed immediately by an explosion engulfing about the top half of the
vehicle, and a second or so later by a
second explosion seemingly centered lower down.
The main propellant tanks below the cargo bay would be the
main methane tank forward, with the
methane header tank located inside, at
the base of that tank, and finally the
main oxygen tank, just ahead of the
engine bay. The upgraded version 2 has a
bigger propellant capacity, but should
be laid out similarly.
I would hazard the guess that the COPV explosion and
bursting oxygen header tank somehow put a large force on the transfer
line, which split open the belly at the
cargo bay, allowing liquid (and vapor)
oxygen out through that split, as well
as releasing a few tons of liquid oxygen to fall down on top of the main
methane tank.
My guess is that spilled header oxygen and vented methane
vapors are much of the first explosion.
Bear in mind that the impact of a few tons of liquid oxygen on the top
of the main methane tank would rupture it as well, adding some fuel to that first explosion
pulse. That first explosion pulse would
massively rupture the main methane tank,
and also likely the main oxygen tank below it. That’s the second pulse of the
explosion, which was larger and
longer, reflecting the larger mass of
reactants.
All of that scenario is just an educated guess on my
part.
As for the nitrogen tank,
said to be a “COPV”, or
“composite overwrapped pressure vessel”,
maybe that is not the right choice this early in the flight test
program. Such a design is a metal shell
that is simply too thin to hold the pressure,
overwrapped by a yarn or fabric-reinforced composite material, to bring it up to strength at a lighter
weight.
Here’s the problem:
no composite material has a large plastic (post-yield) strain
capability. If the COPV over-pressures
for any reason whatsoever, failure will
be sudden, without any warning! Maybe a heavier all-metal nitrogen tank, one with much more plastic strain
capability, would be a better choice
until the other bugs all get worked out.
At least you could see it stretch before it explodes. You do not want to fly even
experimentally, with too many possible
failure modes! See Figure 2.
Figure 2 – Stress-Strain Curves for Low and High Plastic
Strain Capability
PS: note in Figure 1 the "typical" inert mass of the Starship Version 1 upper stage, as 120 metric tons. I do not have a figure for the Version 2 inert mass, but it simply cannot be very much different from Version 1! They are all built the same way. The hearsay bandied about on the internet, about 80 tons, or even less, is simply BS!
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