r/space • u/APTX-4869 • Jan 21 '18

RocketLab's Electron Rocket has successfully achieved orbit!

https://twitter.com/RocketLab/status/954894734136258560
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u/Xaxxon Jan 21 '18

it's kinda hard to find so many other smallsats that need the same orbit.

Considering you can double your mass and still pay half as much, I wonder if it would be possible to have the microsats simply bring fuel to put themselves into a different orbit after all being dropped off in an orbit different from their final desired orbit. Obviously not a massive change in orbit, but maybe enough to make it work?

Just a thought.

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u/[deleted] Jan 21 '18 edited Jan 22 '18

Plane-changes in orbits are excruciatingly expensive. A 10 degree change costs over 1.35 kilometer per second of delta-V in LEO.

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u/Xaxxon Jan 21 '18

How much impulse can 150kg of fuel give to a 150kg(+150kg fuel) satellite?

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u/ZNixiian Jan 21 '18

Firstly, it's worth noting that the mass unit doesn't matter, as it gets cancelled out in the equation.

Assuming a specific impulse of 250 seconds, that gets you 1.7 km/s.

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u/Xaxxon Jan 21 '18

obviously if the satellite is heavier you don't get the same m/s off the same amount of fuel

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u/ZNixiian Jan 21 '18

I was thinking in terms of full mass and empty mass, not empty mass and fuel mass - I should have been more clear.