Propelling deep space flight with new fuel source, Momentus prepares for liftoff

Re:Propelling deep space flight with new fuel source, Moment... by syntaxing on Monday July 23, 2018 @03:26PM (#17595206)

Yup, people do not understand how stable water is (hence the low energy density). Phase change on the other hand, is a extremely effective method to harness work from heat.

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Re:Propelling deep space flight with new fuel source, Moment... by Animats on Monday July 23, 2018 @06:52PM (#17596688)

They're going all the way to plasma. The idea is to pump as much energy as possible into small amounts of reaction mass, to maximize momentum while minimizing reaction mass consumption. They can get more energy from solar panels over time, but not more reaction mass.

Remember, not only do rockets need something to push against, you have to bring that something with you.

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Re:Propelling deep space flight with new fuel source, Moment... by GW150914 on Monday July 23, 2018 @06:55PM (#17596702)

Remember, not only do rockets need something to push against, you have to bring that something with you.

Rockets do not need to push against anything... they expel reaction mass out one end ensuring an equal and opposite reaction. Hence the term “reaction mass” in the first place. Rockets would work just as well in a vacuum as in atmosphere, but it is true that you have to carry your fuel with you.

Downvote if you must, but Newton’s third law still exists. ;)

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Re:Propelling deep space flight with new fuel source, Moment... by lgats on Monday July 23, 2018 @10:35PM (#17597701)

I suppose the rocket is "pushing against" the particles as they are exhausted

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Re:Propelling deep space flight with new fuel source, Moment... by outworlder on Monday July 23, 2018 @03:47PM (#17595384)

Yeah, I call water hydrogen ash.

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