Questions tagged [cryogenics]

Questions regarding use, design, storage, consumption, or other considerations of materials, propellants, systems, or biological samples stored and/or used under very low temperatures, often under larger than ambient pressure.

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1answer
126 views

In a rocket engine, do the propellants come out as liquid or gas if they’re cryogenic?

My cousin and I were talking about this and we could not come to a conclusion. Obviously it is very hard to keep cryogenic propellants at a liquid with the temperatures involved, but if they ...
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1answer
108 views

Cryogenic systems in kwajalein Island- Spacex- falcon 1

Is the LOX (liquid oxygen) required for the falcon-1 launch transported or produced? If transported, how? If produced, did they set up a cryogenic oxygen plant in Kwajalein?
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1answer
602 views

How cryogenic oxygen was heated up for CM cabin repressurization?

In related question How was temperature and humidity maintained inside the Apollo mission capsules? the basic concept of conditioning Apollo mission capsules environment is described. After ...
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1answer
64 views

How do Expander Cycle Engines Inject Liquid Fuel During Startup?

My understanding is that the H2 in an expander-cycle engine is vaporized by the heat from the combustion chamber and nozzle wall. This is used to power a turbine and then get injected, in gas phase, ...
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Can anyone suggest me some resources for studying about the different types of cryogenic valves and their design aspects [closed]

Book titles, videos, articles or any other resource that I could refer
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1answer
98 views

Could in situ (in-rocket) evaporative cooling/refrigeration be used for methane or hydrogen cryogenic propellants?

@Uwe's excellent answer to the question Why would sub-cooled LOX tanks need to “topped-off” until the last minute or so? explains that the LOX is sub-cooled in situ within the rocket's tank using ...
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1answer
277 views

Why can’t cryogenic propellants be storable, at least on the ground, via refrigeration?

Cryogenic fuels (liquid hydrogen, liquid methane)1 and oxidisers (liquid oxygen)2 are the rocket propellants of choice where raw performance is the overriding concern, due to the very high performance ...
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187 views

How would a body be stored in a dark hole in the moon?

How well would the human body stay preserved if it was frozen while pressurized and vacuum sealed before being placed in a crater on the Moon? Would the temperature be more reliably stable on the moon ...
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62 views

LOX as annular heat sink

I'm thinking of my time spent working with cryostats. Liquid helium pot on the inside, and surrounded by a liquid nitrogen jacket. And the whole thing insulated with vacuum and superinsulation. (...
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177 views

What methods are proposed for storing cryogenic fuels (esp. hydrogen) in space for months or years?

Current Launch vehicles and upper stages must only keep their fuels for minutes or hours, so they are only insulated to keep boiloff to a few % per day - I've seen 21% per day quoted for Centaur on ...
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Cryogenic liquid pressurization resulting in overpressurized tank

I want to pressurize a cryogenic liquid (LN2 in this test. Eventually LOX). I have a setup similar to this and follow a similar procedure to what is described, but I don’t see the same tank pressure ...
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1answer
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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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Why are LOx plumbing not insulated?(ref: Huzel and Huang)

In the book Modern Engineering for Design of Liquid Propellant Rocket Engines, the following excerpt appear in chapter 9 - Interconnecting Components and Mounts: The liquid-oxygen lines were not ...
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Air-launching an Electron-like LOX-based rocket from a plane; technical challenges?

@GremlinWranger's answer and comments to the question Is it coincidence that the Electron has very similar dimensions to the Pegasus? motivates my asking for the technical challenges to air-launching ...
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1answer
240 views

Insulation used in the plumbing line of the actual rockets

While using the pipes for plumbing of the liquid propellants at pretty low temperature because of which ice form on the line if not insulated or poorly insulated, which can lead to liquid to gas ...
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2answers
576 views

How does SpaceX plan to deal with boiloff on the trip to Mars?

Both BFR booster and BFS are to run on Raptor engines, fueled with liquid methane and liquid oxygen - cryofuels. The trip to Mars will take at least a couple months, and BFS requires fuel for powered ...
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1answer
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What is the advantage of using Helium over Nitrogen when used for pressurising LOx?

In this Twitter post of the plumbing line diagram(left half) by LauncherSpace, one can notice that Helium is used for pressurising LOx while Nitrogen is used for pressurising Kerosene. Why the ...
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Why do Ariane rockets not have ice break off on liftoff?

In a recent question asked here, it was asked what debris falling from a Rocket Lab Electron Rocket was during launch. e.g.: The answer, was that it was ice that had formed after cryogenic fuel/...
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1answer
183 views

Filling the propellants in the rocket tanks

After putting the rocket on the launch pad the propellants are filled. But before that how to maintain the lower temperatures of the tanks so that when filling the propellants don't boil off?
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55 views

Cryogenic engines till date

How many cryogenic engines are there till date. Names are mostly necessary.
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3answers
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How was the Centaur stage fueled in the Space Shuttle?

The Space Shuttle had the ability to launch Centaur booster stages stored inside of the Shuttle during launch. How was this stage fueled, being fueled with cryogenic fuels?
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1answer
300 views

Falcon-centaur or Falcon-ACES?

For very high delta-V missions (eg outer solar system) the Falcon family really starts to suffer from that fact that its second stage is still using RP-1/LO2 rather than LH2/LO2 with a consequently ...
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1answer
453 views

ULA's plan for LH2/LOX 2nd stage that can maintain propellant for an extended period of time?

Business Insider's (long) article SpaceX's biggest rival has a 'genius' plan to cut its rocket launch costs more than 70% contains the statements sourced from ULA's CEO Tory Bruno: Vulcan should ...
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2answers
770 views

Propellant boil-off in zero G

The Falcon Heavy test flight included a demonstration of capability to coast for several hours and then re-light the second stage for a final burn. During the coast, the cryo propellants are absorbing ...
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0answers
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Is ISRO Making a Methane Engine?

I'd read some stray comment on the internet claiming that ISRO is working on a methane-LOX engine, just as a technology demonstrator. Is this true?
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The principle behind regenerative cooling?

In regenerative cooling the fuel is passed around the nozzle before being pumped into the combustion chamber right? I don't really see how this affects cooling itself, since the heat captured around ...
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1answer
355 views

Liquid Helium (4.2K) sealed, then raised to sub-LOX temperature (~70K) - what is the new pressure?

In this question there is discussion of the large differences in temperature between liquid helium-4, subcooled liquid oxygen (sub-LOX) and cold kerosene (RP-1). Approximate temperatures are 4.2K, ~...
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1answer
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Has solidifying liquid propellant been considered for space exploration?

Liquid hydrogen is $0.071 g/cm^3$ Solid hydrogen is $0.086 g/cm^3$ Since denser fuel is desirable, has solid hydrogen been considered for use in space exploration? I suspect the very low ...
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3answers
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Autogenous pressurization with sub-cooled propellant

In his IAC 2016 talk, Elon Musk said (at 28m 4s in the video) that the ITS booster tanks would use autogenous pressurization. This means there is gaseous oxygen resp. methane in the tank. To stay ...
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1answer
599 views

Is the “cryogenic helium” system in recent discussions actually LHe for cryopumping?

I am wondering if the "cryogenic helium" system discussed in articles about the 1-Sept-2016 SpaceX Falcon 9 anomaly (see this answer for a good summary to date) is not actually related to the high ...
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1answer
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How did the Space Shuttle keep its cryogenic fuel cold?

As I understand it, the Space Shuttle used cryogenic fuel in its main engines and it kept a supply onboard for the duration of its mission for a deorbit burn. Since Space Shuttle missions often lasted ...
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4answers
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Does the NK-33 engine require subcooled kerosene so cold that it turns to wax?

It was mentioned in this answer and in several other places on the internet that the kerosene fuel used by NK-33 engines needed to be subcooled enough so that it reached the same density as the LOX, ...
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1answer
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Could IR space telescopes and other very cold devices use Zeeman slowers effectively in the near term?

Infrared telescopes need to be very cold (often below 10 K) to be effective. So do a few other miscellaneous things, including superconductors, if we ever use them in space for e.g. mass drivers or ...
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2answers
297 views

Are cryo tanks heavier than normal tanks (on a per surface area basis)?

From my related question, it turns out cryo tanks are not double-walled for insulation purposes. So now I will continue along a similar line and ask, aren't cryo tanks heavier than normal tanks on a ...
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2answers
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How big a weight problem is ice sticking to a rocket?

Cryo tanks are so cold, they tend to condense moisture out of the air, creating ice covering a lot of the rocket. I've seen many videos where this ice starts shedding at launch, but I still have to ...
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2answers
907 views

A cryo tank within another cryo tank…is it a sound engineering concept?

Here's the idea: A large spherical LH2 tank is placed inside a spherical LOX tank. The reason I thought of this is so the inner tank doesn't need to be insulated. It doesn't need to be a double-...
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1answer
227 views

What cryogenic selective surface materials have high Technology Readiness Level?

NIAC ("NASA Innovative Advanced Concepts") has approved the following research application for 2015 funding: https://www.nasa.gov/feature/cryogenic-selective-surfaces Cryogenic Selective Surfaces ...
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3answers
1k views

How are cryogenic rocket propellants delivered to the launch pad?

I work at a university that gets LN2/LHe (liquid nitrogen and helium) delivered a couple times a week by a large tanker truck outside my office. It seems to work well enough to deliver a couple tons ...
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1answer
1k views

If a rocket launch is delayed, what happens to the cryogenics?

On February 8, SpaceX had to scrub a launch due to an Air Force technical problem. What happens to the cryogenic fuels when such a launch is delayed? Are the tanks (LOx for the Falcon 9) drained? Are ...
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1answer
200 views

How would cryogenics work to keep a pilot alive during long term travel?

How would a cryofreeze work in order to keep the pilot alive long enough to survive an automated travel to some destination?
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1answer
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What are the droplets/particles falling off rockets at launch?

In this picture from the AsiaSat 6 launch by Falcon 9 on 8th September 2014, the part of the rocket between the fairing and the engine appears to be surrounded by dust, water droplets or debris: And ...
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1answer
149 views

What temperature difference do the injectors in a cryo engine experience?

A quick follow-up to Does ISRO's Cryogenic Upper Stage have restart capability? What temperature difference do the injectors in a cryo engine experience between the propellant tank, and the ...
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609 views

Does ISRO's Cryogenic Upper Stage have restart capability?

Does the CUS of ISRO have restart capability? If so why was it not tested in the recent GSLV-D5 flight? Maybe by restarting the stage after S/C release? What enhancements are required to make a ...
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Why was the Shuttle's LOX tank on top of the LH2 tank, since that makes it more top-heavy?

The external tank for the shuttle contained tanks of liquid Oxygen and Hydrogen for the main engines to use. These two have similar (though not equal) volumes, but the Oxygen is heavier in an obvious ...
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Can I drink the water from the plumes of SSME?

Shuttle's SSME uses cryogenic Hydrogen(LHX) and Oxygen(LOX) as their propellent to give hot water vapour. If I somehow manage to get the exhaust plume and condense it to liquid, Can I drink it ...
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How are fuel tanks filled with cryogenic hydrogen?

Cryogenic hydrogen can react with the atmospheric Oxygen to produce an explosion: as well as being cold enough to liquefy (and possibly solidify) atmospheric oxygen, which can be an explosion ...
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1answer
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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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Changes made to ISRO GSLV-D5's CUS and FBTP since GSLV-D3's LH2/LOX CUS failure to sustain ignition?

The launch of the ISRO GSLV-D5 launching India's GSAT 14 advanced communications satellite (weighing 1,980 kg) is slated for 19th of August, 2013, flying in the GSLV Mk.2 configuration with an Indian-...
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In a cryogenic fuel rocket, at what pressure is the fuel injected into the engine?

The pressure in the Space Shuttle's main engines must be very high to get the vehicle off the ground (with the SRB assist, of course). With such high pressures inside the engine, how do you inject ...