Questions tagged [pressure-fed-engine]

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3 answers
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How to read this Cassini Main Engine Operating Box (oxidizer vs fuel tank pressures)?

The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen. At about 34:32 it covers the period just before SOI (Saturn ...
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6 votes
0 answers
58 views

Has biological pressurization ever been used in spacecraft or in experimental applications?

I love kimchi and I love space exploration, so I was doing some research about whether and how fermented foods such as kimchi might have been consumed in space. For those who haven't tried it, kimchi ...
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4 votes
4 answers
233 views

How do pressure-fed engines stay cool?

Does anyone know how pressure-fed/hypergolic rocket engines cool themselves down? Do they regenerativly cool themselves? Thanks!
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1 vote
0 answers
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what is the ISP loss associated with pressure fed engines

Numerically, what is the approximate loss of overall system specific impulse associated with pressure-fed rocket engines, not only as a result of the low chamber pressure but also of the additional ...
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6 votes
1 answer
332 views

Do lower pressure pressure-fed rockets get more Delta-V?

I was playing around with the math for getting a pressure-fed rocket to orbit and came across something that I haven't seen addressed anywhere. In a pressure-fed rocket, the chamber pressure of the ...
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6 votes
0 answers
106 views

How much cheaper are pressure fed engines compared to other cycles (e.g. staged combustion, gas generator, electric pump-fed)?

It's well known that pressure fed engines are mechanically simpler, and therefore cheaper than pump-fed cycles (although pressure fed has worse performance). However, I haven't found any sources that ...
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1 vote
1 answer
234 views

Can pressure fed engines augment Starship's landing on the Moon?

Can a pressure fed engine be powerful enough to augment the landing of Starship on the Moon? How much thrust is needed to land SS if it’s brought to zero velocity at an altitude of 10 meters? A ...
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6 votes
2 answers
2k views

How (the heck) will SpaceX's Starship's future pressure-fed thrusters work at "any gee’s, any attitude"?

In the SpaceX video Starship Update at about 57 minutes Tim Dodd the Everyday Astronaut asks about how the Starship rotates from reentry orientation to landing (vertical) and Musk explains that in the ...
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2 votes
1 answer
301 views

Chamber pressure of a gas pressure fed liquid rocket motor

I am studying rocketry and am currently learning about pump fed vs gas pressure fed propulsion systems. Upon reading about gas pressure systems, I googled the formula to find the chamber pressure for ...
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5 votes
1 answer
344 views

How do pressure fed and pump fed systems compare at different scale of rockets

Rocket Design is all about optimising mass, within cost constraints while accepting a certain amount of risk. Both pressure fed and pump fed systems have their pros and cons, but how do they compare ...
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1 vote
1 answer
121 views

What differences exist between the pressurants and their associated systems between a pressure fed and pump fed liquid rocket engine

There is an apparent need to have pressurants in both pressure fed and pump fed systems. However, since pump fed systems can create the necessary pressure, they can work with less pressurants and ...
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10 votes
3 answers
903 views

How reliable are pressure fed hypergolic engines?

A fair amount of "what-if" discussion surrounds rocket engine failure at critical points in various crewed missions -- lunar ascent and trans-Earth injection on lunar landing missions, ...
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3 votes
2 answers
874 views

Some examples of pressure fed engines used on launch vehicles

Are there any examples of pressure fed engines used on launch vehicles? I already know of the ones on the wikipedia page which include Firefly Space Systems OTRAG (rocket) Quad (rocket) of Armadillo ...
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12 votes
4 answers
9k views

Why do pressure-fed systems have to be pressurized with helium or nitrogen?

This is something I just don't understand. The way I see it, propellant can be pressurized all on its own in the tank. Just pump a lot of the stuff in there and make sure the tank is strong enough. ...
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15 votes
4 answers
4k views

Why do pump and pressure fed liquid engines need to operate at high pressures?

There is apparently some confusion as to why pump or pressure fed liquid rocket engines need to operate at high pressure to product significant thrust, based on the comments to this question about ...
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25 votes
2 answers
4k views

Why do pressure fed engines have combustion instabilities?

Reading about the Sea Dragon idea, I came upon this argument against it, which sounds compelling, but relies on more detailed knowledge than I have: Those are to be pressure-fed to avoid "...
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