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.
67
questions
5
votes
2
answers
152
views
What propellant (coolant) mass is required for an actively cooled heat shield?
Stoke Space are using a regeneratively cooled heat shield to allow their second stage to survive re-entry. The basis of the design flows LH2 through the aeroplug, then using the heat captured to power ...
- 4,223
6
votes
2
answers
1k
views
What's the difference between cryogenic and Liquid propellant?
According to my understanding (which may be incorrect), the cryogenic form and liquid form of propellant both use a fluid as an oxidizer and fuel. Research tells me crygenic propellant is more ...
- 527
3
votes
0
answers
199
views
Does Starship run on Slushies?
Cryogenic slush (a mixture of liquid and solid) can potentially store propellants at higher density than cryogenic liquid. For instance, hydrogen slush is 16-20% denser than liquid hydrogen. https://...
- 22.8k
2
votes
2
answers
194
views
Can surrounding methalox by hydrolox save it from boil off
In case of a (single) Starship (as a) fuel depot orbiting the Earth, how can we prevent boil off, may be so? Some fuels have lower temperatures such as hydrolox is colder than methalox. Could we may ...
- 401
3
votes
1
answer
198
views
Prevent boil off in StarShip fuel depot by a JWST-like sunshield?
Can we use Webb’s telescope shield to prevent or significantly reduce boil off of propellant from StarsShip fuel depot, made from a single StarShip in Earth orbit?
For JWST, its sunshield covers its ...
- 401
0
votes
1
answer
97
views
Semi-Cryogenic HTP/LH2 engine?
Also see HTP as oxidizer for main propulsion
(for more info on history of H2O2/HTP in rocketry)
Note: HTP and H2O2 will be used interchangeably
I know the Black Arrow LV (The first orbital lipstick) ...
- 1,169
9
votes
2
answers
2k
views
Why is the hot part of Webb's MIRI cryocooler in the 300K area?
Longer wavelengths require cooler temperatures to detect efficiently. The MIRI detects all the way out to 25 μm and so needs to be cooled to 7 K.
Webb can passively cool down to 40 K with its sun-...
- 771
5
votes
1
answer
351
views
Does a cryogenic liquid propellant engine exist capable of using multiple fuels?
For example, a rocket engine which can use both liquid methane and liquid hydrogen.
- 3,298
12
votes
1
answer
3k
views
Why is an inflatable balloon inside a fuel tank not used to prevent fuel from "sloshing around"?
After seeing all the Starship failures, having something with a membrane keep things in place seems like an obvious solution. Has it been considered or tested - or do we simply lack a material that is ...
- 517
4
votes
1
answer
602
views
Why are propellant tanks filled from the bottom?
It seems that the norm is to (fast-) fill fuel and oxidiser tanks from the bottom. For example, on this drawing of the Saturn S-IC stage you can see the LOX and RP-1 fill valves at the bottom of the ...
- 14.4k
3
votes
2
answers
416
views
Cryogenic storage in Starship header tanks
Since Starship uses cold liquid oxygen and methane fuel in its header tanks, how will these cryogenic tanks been kept full and cold on long missions in space?
- 51
4
votes
2
answers
349
views
How does the open expander cycle separate the fuel for the pump and combustion chamber? [closed]
I'm designing a single open cycle expander rocket engine using propane. However, I've been unable to find out whether or not the fuel is split into the turbine and combustion chamber before or after ...
- 822
9
votes
1
answer
529
views
ULA's ACES upper stage with IVF - Why are they using internal combustion engines?
I recently read out about ULA's ACES (Advanced Cryogenic Evolved Stage) upper stage with IVF (Integrated Vehicle Fluids), which crazy as it sounds, has two six-cylinder engines developed by Roush that ...
- 225
11
votes
1
answer
1k
views
Falcon-9's subcooled LOX is continuously refrigerated in-situ, what about its subcooled RP-1?
@Uwe's answer to Why would sub-cooled LOX tanks need to “topped-off” until the last minute or so? explains how subcooled LOX is kept cold and dense by "in situ refrigeration"; helium is bubbled ...
- 148k
2
votes
1
answer
411
views
How is Cryogenic fuel kept... Cryogenic in rockets [duplicate]
How is cryogenic fuel & oxidizer kept at cryogenic temperatures in rockets? I am mostly interested in the first stage of launch vehicles rather than something like a Centaur that keeps hydrolox ...
- 703