Questions tagged [thermal]
How heat affects spacecraft and space missions, or materials and methods to deal with heat.
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How have space suits dissipated the heat removed from astronauts?
I never thought about this until reading the comments below this answer. To radiate something like 150W (a very conservative lower limit of human + suit systems heat production - see @Uwe 's comment ...
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Would it be possible to build a probe that could operate at about 480 °C (900F degrees) without insulation?
I read a question about cooling a Venus lander, and got to thinking that the problem was in building a probe that has no problem with Earthlike temperatures and pressures, then trying to insulate it ...
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Why are RTGs different colors?
This is an image of the radioisotope thermoelectric generator (RTG) for Cassini:
This one was for one left on the Moon:
And this one is for the Multi-Mission RTG, used by Curiosity on Mars:
One is ...
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Is it normal for thrusters to "ice up"?
Towards the end of the JSSAT-14 webcast (around T+32:58), we see a thruster firing. Over the space of around 20 seconds, you can see it "icing up":
What is this that's forming? Is this a normal ...
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Is it bad if hydrazine freezes on a spacecraft? Is it always kept as liquid, or can it be safely allowed to freeze and then thawed when needed?
After having read this answer I wondered what happens if hydrazine freezes.
It looks like it is "normal" and not like water, in the sense that it contracts when freezing, unlike water which expands ...
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How cold is the Martian sky at night? Or the day for that matter?
If you take a simple infrared "thermometer" which is actually a lot like a bolometer and point it at a clear sky, it says "cold!" because in the wavelength range that it's using (...
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How will Robotic Refueling Mission-3's liquid methane tank remain full for six months without any boil off?
Space.com's Lasers, Crystals and 36,000 Worms Will Ride a SpaceX Dragon to Space Station says:
To fly on those journeys, astronauts might have to someday harvest fuel from the surface of the moon ...
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How much wax is on the Moon? (Lunar Roving Vehicles)
I found the Cody's Lab videos from Scott Manley's video as described in this answer. Browsing through I learned from the first 30 seconds of Hot Wax Bottle? that the phase change of wax was used on ...
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Why were early satellites produced with polished "mirror-like" surfaces?
Many/most early artificial satellites were spheres with mirror-like polished outer surfaces.
I am guessing that for lower orbits the spherical shape minimized drag as well as simplified the analysis ...
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Are fans ever used in un-crewed spacecraft?
The question For a Venus bound space probe could could a fan be used to prevent overheating? got me thinking.
Most if not all crewed spacecraft have had fans to move air for one reason or another.
...
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Is it feasible to paint SpaceX Starlink satellites black so as not to frequently saturate the CCDs of the Large Synoptic Survey Telescope?
update: From Nature.com News article: SpaceX launch highlights threat to astronomy from ‘megaconstellations’:
But an upcoming, cutting-edge telescope could be in bigger trouble. The US Large Synoptic ...
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Are black and white stripes any better than uniform gray for thermal control?
Q: What color is a spaceship?
Several answers and comments on Why were Europe's first few satellites so stylish? Why the pronounced alternating white and black stripes? contain phrases like "...
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Has any technology been demonstrated that allows a useful payload to survive at least one month on Venus' surface?
According to the Wikipedia article on Venera-D,
A lander, based on the Venera design, is also planned, capable of surviving for a long duration on the planet's surface.
The surface of Venus has ...
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Why exactly does Curiosity's RTG make more electricity on cold days?
There is a fascinating factoid in this answer to MMRTG- thermal and electrical output:
The electric power of the thermocouples depends on cooling influenced by the environment. On a cold day on Mars ...
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How long is it feasible to store cryogenic fuels?
Working with liquid nitrogen all day, I am constantly bothered by their boiling away, forcing me to go get more from the storage dewar. Likewise should be the case with any cryogen, e.g. LH2 and LOX ...
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What material properties would be necessary to shield a lander from the environment of the Venusian surface?
On March 1, 1982, the Venera 13 lander survived for 127 minutes in an environment with a temperature of 457 °C (855 °F) and a pressure of 89 Earth atmospheres (9.0 MPa). This says nothing of the ...
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Why the thermal imaging of Mercury's surface requires a telescope on a jet flying through an eclipse?
The NASA News Feature Chasing the Total Solar Eclipse from NASA’s WB-57F Jets describes two telescope-equipped NASA jets that will fly fast enough to spend about 7 minutes in the Umbra (totality) of ...
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What were the uses of the RTGs in the Apollo spacecrafts?
I was listening to the Plutonium episode of "the Elements" on the BBC, and between 07:00 and 08:30 they talked about uses of plutonium such as spacecraft power and heat. While the returning astronauts ...
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How many different kinds of insulation film are wrapped around the Apollo Lunar Module?
In the image shown in the question Why is the Apollo LM landing gear covered with so much thermal isolation? (also shown below) it appears that the color of the film around the bottoms of the lander's ...
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Now that Perseverance is "hot" (RTG in place) and before it gets to deep space, how will it stay cool?
As soon as they are assembled MMRTGs continuously produce about 2,000 watts of heat energy. That dips only slightly when they are connected to a load and producing electrical power (about 125 watts ...
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What is the cause of discoloration along the edges of the Quest Joint Airlock thermal cover?
I've noticed this discoloration / stains / burn marks along the edges of the Quest Joint Airlock thermal cover on the hatch before, but they seem even more pronounced and contrasting with the cover's ...
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How will Bennu's volatile compounds stay cool and unmodified by the heat of re-entry (OSIRIS-REx)?
Watching the video in this NYTimes article NASA Aims at an Asteroid Holding Clues to the Solar System’s Roots I realized for the first time how the samples actually make it back to Earth.
The ...
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When did deep-space probes start getting wrapped in germanium-coated film?
The NASA video Juno Engineering: Precision Matters shows the Juno spacecraft on what look like it might be a spin balance table after about 02:50 and there one can ...
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Is Perseverance's heat shield's thickness radially symmetric?
I came across this video1 about the Mars 2020 Perseverance rover mission, especially the atmospheric entry phase.
It says between about 03:50 and ...
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Is there a rule of thumb for the mass of thermal protection systems?
A lot of discussions of SSTOs and the potential for making upper stages re-usable hinge on the fact that thermal protection systems for reentry from full orbital velocity are pretty heavy (and ...
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Simulating the thermal heating of a nose cone exiting an atmosphere
I have a simulation that describes a vehicle traveling at very high speeds (near or even above orbital) up out of the atmosphere and into space. I'd like to chart the rate of heating ($\dot{q}_{conv}$ ...
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How are coatings like Vantablack and Aeroglaze Z306 used on spacecraft components? Exactly what functionalities do they provide?
Business Insider's SpaceX is launching 'dark satellites' to stop its Starlink project from wreaking havoc with astronomical research. Astronomers are skeptical. includes the following passage:
"...
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Why does JWST need "a carefully designed series of oscillations" to avoid overheating during the 2nd stage burn? Why not rotate "rotisserie style"?
The Northrop Grumman video James Webb Space Telescope Launch and Deployment describes the trajectory from launch to orbital insertion and illustrates several key maneuvers and incremental steps in the ...
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What do the insulation and meteorite protection layers being opened on the Soyuz MS-09 spacecraft look like?
This current news item in TASS Russian cosmonaut Kononenko approaches Soyuz MS-09 spacecraft for inspection says:
Earlier in the day, the two Russian cosmonauts began their six-hour spacewalk, ...
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Are there fluid disconnects that sever just before the Curiosity or Perseverance rovers separate from their cruise stages or landers?
In this comment under an answer to Heating Perseverance components prior to deployment I wrote:
I think (but can not find a source yet) that there is even a loop of "hot water plumbing" ...
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What was NASA's “LUROVA” Operational Thermal Computer Model analog or digital? How were capacitors used?
@GremlinWrangler's answer links to
Apollo Rover Lessons Learned
Applying Experiences on the Apollo Lunar Rover Project to Rovers for Future Space Exploration
by Ronald A. Creel, Space and Thermal ...
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Why would it be "less bad" for hydroxylammonium nitrate monopropellant to freeze than for hydrazine?
Answers to Is it bad if hydrazine freezes on a spacecraft? Is it always kept as liquid, or can it be safely allowed to freeze and then thawed when needed? explain that while the freezing of hydrazine ...
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How do phonesats stay cool?
To the question Can a smart phone function in space? this answer says
Multiple android based phone satellites have been launched into space. (At least six according to Wikipedia). I haven't looked ...
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How cold do Curiosity's & Perseverance's appendages get at night with all those sensitive cameras and lasers?
cropped from PIA19920: Curiosity Self-Portrait at 'Big Sky' Drilling Site
MastCam-Z, ChemCam/SuperCam and MAHLI are optical systems and ChemCam includes a telescope and a pulsed laser, but the ...
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Do aeroshells really get hotter than the surface of the sun?
This answer to How to design heatshield bluntness? says:
Curiosity reentry dumped about 98% of its entry energy into the atmosphere, the aeroshell can still get to be temps greater than the surface ...
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Why aren't the radiators on the ISS straight?
The radiators look like a highly stretched paper accordion. Is it just because of how they decomposed, or is there a deeper reason?
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Are there any promising next-generation space station cooling technologies?
The ISS had problems related to ammonia more than once.
These problems happened in different calender years, and it seems like almost every "near miss" that makes the news about the ISS is connected ...
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How much does the ISS "banana" or flex under the constantly changing conditions of solar heating?
This answer to Do antennae on the ISS have to constantly move to maintain data links? discusses some of the challenges precisely pointing an antenna mounted to the ISS exterior. While the ISSs orbit ...
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Ablative heat shield and conservation of energy, how much does ablated matter in fact "carry away" versus re-radiate the absorbed heat?
I saw
Most heat shields ablate, that is they sacrifice material to carry heat away...
in a comment under this answer and started writing:
I think that shields ablate to produce a layer of complex ...
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How brightly does Venus's hot surface glow at night? Could you see it? Could you see well enough to walk around?
NASA's Parker Solar Probe Captures its First Images of Venus' Surface in Visible Light, Confirmed links to the new Geophysical Research Letter Parker Solar Probe Imaging of the Night Side of Venus.
...
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Insulation on rockets--why take it to space?
I'm especially thinking of the loss of the Columbia due to damage from chunks of insulation that came off. I got to wondering, why is it there in the first place?
Of course it's needed while you are ...
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In space can the difference in temperature between the inside and outside, provide useful energy?
The Thermoelectric effect allows for electrical energy to be created, based on a difference of temperature. In fact the Radioisotope thermoelectric generator is based on this principal and does/has ...
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Lunar launch pad cooling
I read recently about the huge volumes of water that is sprayed on a launch pad during lift off. I remember it to be about four times as much water as fuel burned. This is done to reduce noise (energy ...
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Why is the Heat Shield of ESA's Solar Orbiter Black in colour?
Solar Orbiter (SolO) is a planned Sun-observing satellite, under development by the European Space Agency (ESA). Due to its proximity to the Sun, it receives about 13 times more solar energy than we ...
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Why is Adiabatic wall temperature taken as the driving temperature in rocket engines?
Going by the definition of convective heat transfer coefficient from Wikipedia (which I have started to doubt; reason follows):
$h=\frac{q}{\Delta T}$, where the $\Delta T$ is taken as the difference ...
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Could a fan be used to prevent overheating on a Venus bound space probe?
I saw something saying that the circuits on a Venus bound space craft would overheat and basically ruin the the spacecraft.
Is that true?
If so, could they install fans to keep the circuits cool?
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What kind of insulation is used in the Ingenuity helicopter?
A press release from NASA today states
“This is the first time that Ingenuity has been on its own on the
surface of Mars,” said MiMi Aung, Ingenuity project manager at NASA’s
Jet Propulsion ...
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What is the maximum velocity at which Soyuz TMA-M may transit through Earth' atmosphere at reentry without a heat-shield?
A quick follow-up to Re-entry Heat Shield Alternative
Instead of looking for an alternative to heat-shield, I'd like to draw from analogous naval tactics I heard about; Back in the 1950's to 1960's, ...
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Why would the Falcon 9 Block 5 carbon fiber thermal protection material need to be hydrophobic?
This answer to Nature of “the silky black 'highly flame-resistant felt'” on Block 5 Falcon 9's, and its intended functions? contains the following:
This came into Falcon 9 design with Block 5 ...
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Why put chromium on the back side of this JPL-designed solar sail?
This 2013 JPL presentation Solar System Escape Architecture for Revolutionary Science March 2013 Conference NIAC Phase 1: 2012-2013 by PI: Jeff Nosanov Co-Is: Dr. Daniel Grebow, Dr. Brian Trease, John ...
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