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Questions tagged [thermal-control]

Questions about heat management in spacecraft

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In Zero G, can excess heat be used propel a spaceship forward?

In Zero G, can excess heat be used propel a spaceship forward? I was looking for a similar answers online, and have bounced around a few places, I found this question, and it's responses thread useful ...
TheDayitwasWritten's user avatar
2 votes
0 answers
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Why are tiles used instead of other novel solutions, for non-ablative heatshields?

Are tiles that much more cost effective as a thermal protection system? What other novel methods have been tried? The obvious issues seem to be different thermal properties and rigidity and how to ...
Dagelf's user avatar
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3 votes
2 answers
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Typical external temperature profile for a LEO satellite

I bumped into a question regarding LEO orbit. Is an external temperature profile available in literature as a first approximation for thermal analysis? I bumped into articles mentioning that the ...
Enrico's user avatar
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23 votes
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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?
Saturn V's user avatar
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What is the relationship between the power supply system and the thermal control system?

According to Wikipedia, the solar panels of the ISS produce an average of about 120 kW of electrical energy, which is then used by the station's systems. Can it be converted into something other than ...
Saturn V's user avatar
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Why is insulation used in spacecraft thermal control?

The temperature of spaceships can range from -126° C to 149° C. Wouldn't it be better for the spaceship envelope to have as high a thermal conductivity as possible to even out the temperatures (the ...
Saturn V's user avatar
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How to get the reduction in Heat Flux due to Barbecue Roll on Spacecraft?

As we know, to keep the surface of the spacecraft relatively cool, we spin the spacecraft so that not just one side of the spacecraft is heated. Due to this what is the effective Heat Flux encountered ...
Taha Merchant's user avatar
10 votes
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How close can a spacecraft get to the Sun if it is limited solely by passive cooling?

The Parker Solar Probe’s trajectory will take it within 8.5 solar radii of the sun’s photosphere. Its instruments, hiding in the shadow of the alumina-coated composite sun shield, will bask in 29 °C ...
Woody's user avatar
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Were the Apollo astronauts constrained in how they could set their PLSS cooling?

During EVA 2 of Apollo 17, Gene Cernan pointed out that having his PLSS on the "min cooling" setting was a little warm for him. That's probably because driving the lunar rover made his ...
olamarre's user avatar
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2 votes
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How can you calculate the pressure that a liquid develops when freezing in a pipe?

My current understanding is that in addition to the reasons pointed out in the answer to this question here, another reason for choosing ammonia in the space station external coolant loops is that the ...
Joe's user avatar
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Why is the sunny side of JWST's sunshield purple and covered with silicon?

After about 08:52 in Destin's Smarter Every Day's Why Are there Holes in the James Webb Sunshield? (Explained by My Dad) - Smarter Every Day 270 (linked below) ...
uhoh's user avatar
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First use of spacecraft thermal control louvers, doors, pinwheels, or other things that physically actuate either passively or actively?

Below are some examples of Question: What was the first use of spacecraft thermal control louvers, doors, pinwheels, or other things that physically actuate either passively or actively? From this ...
uhoh's user avatar
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The temperature displayed online for Webb has not changed even one degree in days, even though the sunshield deployed in that time. Why? [closed]

First exposed, then shaded by sunshield, no change in displayed temperature, how can this be correct? As soon as I posted, they updated the temps. I have watched this for days before this and no ...
Dave McKinley's user avatar
4 votes
2 answers
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How long can astronauts wearing Dragon capsule suits walk around unconnected to water coolers?

At various moments in the NASA video NASA’s SpaceX Crew-3 Astronauts Launch to the Space Station astronauts are shown standing or walking or otherwise posing for the camera in their Dragon capsule ...
uhoh's user avatar
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JWST -- thermal control predictions

JWST app "where is webb" just started displaying vehicle temperatures. It is said in the background info that these temperatures were predicted from thermal modeling. I would like to know ...
tckosvic's user avatar
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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 ...
uhoh's user avatar
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Thermal batteries rather than battery-powered heaters for small craft on Mars; how much mass would it add, how much would it replace?

As an example, the Ingenuity helicopter on Mars charges its batteries each sunny day (which is every day except when it isn't) and discharges them substantially each cold night (which is all of them) ...
uhoh's user avatar
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Just how preferable are afternoons for flying Ingenuity? Why?

JPL tweet links to mars.nasa.gov's Flying on Mars Is Getting Harder and Harder which explains that seasonal changes are lowering the density of the local atmosphere, presumably due to warmer seasonal ...
uhoh's user avatar
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Where exactly are the Apollo space suit sublimators venting steam into space? is there a photo of an astronaut in space that shows the opening?

This excellent answer to How have space suits dissipated the heat removed from astronauts? shows a diagram including the sublimator unit in the red square where the phase transition of water from ...
uhoh's user avatar
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Why aluminum is added in Multi Layer Insulation?

Aluminum is a highly conductive material. Instead of insulating the system from heat, it conducts. Multi-Layer Insulation aims to protect spacecraft from extreme heat by acting as a thermal barrier. ...
Auberron's user avatar
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How does a radiator work fast enough on a space craft?

Basically, after some heat exchanger, a fluid is pumped to a radiator and then releases its heat to the void of space. But I'm having a hard time seeing how that is done fast enough. The fluid should ...
DrZ214's user avatar
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2 votes
2 answers
238 views

How much electrical energy is required to dissipate heat?

I'm modeling the electrical energy consumption of a chemical reactor for the Moon base. The reaction taking place in this reactor is highly exothermic, and the device must be cooled. My question is ...
dlight's user avatar
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Why does ISS uses liquid ammonia in the Active Thermal Control System?

I saw this today and it made me very curious. See page 8 here: https://www.nasa.gov/pdf/167129main_Systems.pdf Ammonia has a boiling point of -30 C. The ammonia is liquid in these loops, so if ever ...
dlight's user avatar
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14 votes
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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 ...
uhoh's user avatar
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7 votes
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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 ...
loopbackbee's user avatar
7 votes
1 answer
2k views

How are the electronic circuits in interplanetary missions protected from extremely low temperatures?

In an interplanetary mission, a spaceship travels through deep space, where the temperature is almost zero degrees Kelvin, and it is likely that its electronic circuits get permanently damaged. How ...
Ganesh Kulkarni's user avatar
1 vote
1 answer
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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 ...
uhoh's user avatar
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4 votes
2 answers
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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" ...
uhoh's user avatar
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Likely explanation for the bottom of the SLS rocket being covered with reflective silver "muffler" tape?

NASA.gov's First Artemis Rocket Stage Moved onto NASA Barge Ahead of Green Run contains a high resolution image of the rocket. The bottom end of the rocket's cylindrical shape is closed flat and ...
uhoh's user avatar
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1 vote
1 answer
255 views

Why are some rockets painted black? [duplicate]

Why are Rocket Lab's and other rockets painted Black? Shouldn't they be painted white to reflect most light and therefore absorb less heat from sunlight?
kiraman's user avatar
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2 answers
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How did the Space telescopes lose their coolant helium?

How did the Planck satellite lose its helium? Spitzer, Herschel had the same problem. How was it consumed? How come other satellites, like Hubble, don't have this problem? And basic logic says that ...
Joe Jobs's user avatar
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10 votes
2 answers
329 views

Vacuum tube microchips for Venus probe; feasibility and challenges?

Venus surface temperature is around 460 °C which makes conventional semiconductors useless. So nasa proposed a clockwork rover, drawing power from wind and using springs and gears to navigate the ...
Andrew Butenko's user avatar
2 votes
1 answer
238 views

In what conditions are the electronics of New Horizons housed?

In one of answers to the question What are the long term effects of Space Weathering on man-made materials? there is a link to Wikipedia article about Kapton. In this article mentioned that NASA's ...
Peter Nazarenko's user avatar
4 votes
0 answers
301 views

Could Ingenuity stay warmer at night by landing on (or near) Perseverance's RTG?

One concern in How long could the Mars helicopter Ingenuity keep up with the Perseverance rover if it wanted to? is that the helicopter must cycle its battery every night to stay warm, and that could ...
uhoh's user avatar
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14 votes
1 answer
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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 ...
uhoh's user avatar
  • 149k
6 votes
1 answer
516 views

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 ...
uhoh's user avatar
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3 votes
1 answer
215 views

Are there any uncrewed spacecraft that maintain(ed) an atmosphere?

In How do phonesats stay cool? I wonder if phonesats might have had "cabin pressure" to keep the phones from overheating since they are not designed for space. But now I'm just wondering if ...
uhoh's user avatar
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2 votes
1 answer
178 views

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 ...
uhoh's user avatar
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1 vote
1 answer
82 views

Thermal management of manned craft at Ceres

I would like help in designing a manned craft for exploration and mining activities on Ceres. The sunlight reaching Ceres is approx 10% of that in LEO. Does this mean the spacecraft would have ...
Innovine's user avatar
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14 votes
3 answers
3k views

Why do many RTGs have finned heatsinks, when this is considered bad for radiation heat transfer?

Related: Finned heatsinks in space Multi-fin heatsinks are not normally considered good for heat dissipation in space because adjacent fins radiate into each other, and you would be better off with ...
ikrase's user avatar
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1 vote
0 answers
171 views

Is heat transfer in space through radiation 100% efficient? [closed]

Flat 1x1 meter plate. Heat source indicated by red arrow. The rest is in space. No sun exposure at all. Some of the photons will exit through the gaps between plates. No problem. My question is ...
martin's's user avatar
  • 549
5 votes
1 answer
319 views

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 ...
uhoh's user avatar
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47 votes
11 answers
8k views

Finned heatsinks in space

Most heat radiators in space are flat surfaces. In a sense they are single fin radiators. Has anyone studied the used of multi-finned radiators in space (the vacuum of space, not inside a spacecraft)?...
martin's's user avatar
  • 549
8 votes
0 answers
554 views

Is thermal soakback from the engine a problem for rocket stages? Especially ones that complete several burns over several hours (e.g. S-IVB, Centaur)?

Thermal soakback is a phenomenon whereby a hot, operating engine transfers heat into the spacecraft, usually conduction through the engine mounts. I've only ever seen this problem discussed with RCS ...
dasvitek's user avatar
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24 votes
1 answer
4k views

Did Apollo 13 "barbecue roll" under the propulsion of the lunar module?

Apollo spacecraft were often put in a "barbecue roll" (officially called passive thermal control mode), which slowly rotated the spacecraft along its main axis. Without this maneuver, one side of the ...
DrSheldon's user avatar
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7 votes
1 answer
356 views

How to calculate the lowest possible altitude a satellite can orbit at due to aerodynamic heating if provided with a sufficient propulsion system?

If a satellite is equipped with a propulsion system which is enough for compensating the local drag and maintaining the orbit, then aerodynamic heating would be the limiting factor for attaining the ...
Curious's user avatar
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8 votes
1 answer
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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 "...
uhoh's user avatar
  • 149k
18 votes
2 answers
5k views

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. ...
uhoh's user avatar
  • 149k
7 votes
5 answers
6k views

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?
Elle's user avatar
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8 votes
2 answers
952 views

Why does the Alpha Magnetic Spectrometer (AMS) on the ISS use carbon dioxide for coolant?

Spaceflight Now's Astronauts finish repairs to space station cosmic ray detector says: Originally designed to operate for just three years, the AMS chalked up eight years of operation before being ...
uhoh's user avatar
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