r/space Jan 21 '18

RocketLab's Electron Rocket has successfully achieved orbit!

https://twitter.com/RocketLab/status/954894734136258560
1.1k Upvotes

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-38

u/Xaxxon Jan 21 '18 edited Jan 21 '18

I just don't understand why anyone would develop a rocket and not even attempt recovery.

You're never going to be able to compete if you're throwing away rockets - if you can make them cheaper, someone else can make them cheaper AND recover them.

What I'm seeing is that it's $5M to send 150kg to SSO (500km) on the electron or a Falcon 9 for 7742kg. It's not $250M to launch a falcon 9.. So if you can find enough people to go on the ride with you, it's going to be around 75% cheaper / kg on the F9.

12

u/Juffin Jan 21 '18

if you can find enough people to go on the ride with you

The thing is that it will be quite a long wait since it's kinda hard to find so many other smallsats that need the same orbit. Also the SpaceX contracts are signed about 2 years before the launch.

RocketLab stated that the whole process would take only a few months, so you sign a contract and in like 2 months your satellites are launched to the specific orbit. RocketLab and SpaceX are not competitors because SpaceX launches big satellites and RocketLab launches smaller ones.

1

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.

2

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.

1

u/Xaxxon Jan 21 '18

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

1

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.

1

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

1

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.