
Sprite: An in-space propulsion system running on water - drummerboy2543
https://medium.com/plasma-matters/sprite-engine-d794d71afd69
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DannyK23
Wow, that was a seriously interesting post! Those are some significant
improvements in cost and efficiency. One question I had is what tradeoffs you
made by using water instead of traditional xenon based propellants?

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drummerboy2543
Hey DannyK23, xenon and other noble gases are expensive and a depleting
resource, obviously water is abundant and can be acquired cheaply. For example
xenon cost around ~ 15 - 20 dollars per liter. While water cost around ~ .17 -
.50 cents.

Another reason why water has been cheaper is the logistics side of it. Water
can be stored as a liquid, so there is no need to have pressure vessels. This
lets launchpad logistics get simplified and get cheaper. One of the main pro
for xenon is its performance. That is why typically people have gravitated
towards that gas. The reason for that is xenon is the heaviest non-radioactive
noble gas. Generally speaking, the heavier the mass the better performance.
Another good trait for xenon is that it stores at higher density than other
noble gases, allowing more punch in a packed spacecraft volume.

For us, the biggest factor is cost and not performance. We see that the
industry is going for cheaper simpler solutions so space hardware can be more
easily innovated upon, and launched into space. Old school aerospace focused
on performance, due to the fact once the satellite was in space, it needed to
work and perform due to how expensive it is to launch it in space.

However, due to the lowering of cost in space, our goal is to optimize mass
manufacturing and cost. This is why we feel that water might be a great
propellent solution to our problem.

So as you can tell one solution for one company does not make sense for
another company. It depends on the goals.

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drummerboy2543
Hey, guys, I am a software engineer at phase four. Our company just sent this
update and I thought the hacker community would like to see it.

Let me know if you have any questions and I will be free to answer them! Happy
Hacking!

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rgmann
This is huge! Sustainable, scalable, and inexpensive. The lethal trifecta.
Nice work Phase Four!

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poppindillz
Pretty cool, but can it withstand a steel ball?

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boznz
Nice. Any takers from the big guys yet?

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basicjuice
watch this space! (announcements forthcoming in '20)

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Robertyeg07
cool stuff Drummer boy!

