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SpaceX lands rocket at sea second time after satellite launch

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Re: SpaceX lands rocket at sea second time after satellite launch

#3
post #2

Looks like the landing was perfectly centered on the barge this time as well. Does anyone know when they plan on reusing one of these recovered first stages?

They said at the beginning of the live stream that they plan to do a test fire on the first recovered first stage "sometime soon".

Re: SpaceX lands rocket at sea second time after satellite launch

#4
post #3
post #2

Looks like the landing was perfectly centered on the barge this time as well. Does anyone know when they plan on reusing one of these recovered first stages?

They said at the beginning of the live stream that they plan to do a test fire on the first recovered first stage "sometime soon".

Did they say anything more specific than that? They have already done a static fire of the first one they recovered.

Re: SpaceX lands rocket at sea second time after satellite launch

#5
post #2

Looks like the landing was perfectly centered on the barge this time as well. Does anyone know when they plan on reusing one of these recovered first stages?

Good question - Elon tweeted this https://twitter.com/elonmusk/status/728459808270000128 - sounds like they could end up with a backlog ;)

Re: SpaceX lands rocket at sea second time after satellite launch

#7
For those wondering, this isn't a simple repeat of CRS8 which landed on a drone ship about a month ago. CRS8 was a mission to low earth orbit which left the first stage with plenty of fuel to effect a landing. The landing was made as slow as possible and limited only by how low a single engine could be throttled. The re-entry burn which slows the rocket down before the landing burn was also more agressive.

This mission was to launch JCSAT-14 to geosynchronous orbit which requires the falcon 9 to move the already heavy satellite into a geosynchronous transfer orbit. That meant the first stage had to do a lot more work and was left with a lot less fuel as a result. Therefore, the re-entry burn was less aggressive, the first stage came in with twice the speed, and SpaceX needed to do a far harder landing with three engines lit in the quicker and riskier suicide burn. Somehow, despite playing down expectations, they managed an even more precise landing than last time.

Re: SpaceX lands rocket at sea second time after satellite launch

#8
post #2

Looks like the landing was perfectly centered on the barge this time as well. Does anyone know when they plan on reusing one of these recovered first stages?

A few months ago Elon said they were at least initially looking at June or July for a re-fly.

Re: SpaceX lands rocket at sea second time after satellite launch

#10
post #7

For those wondering, this isn't a simple repeat of CRS8 which landed on a drone ship about a month ago. CRS8 was a mission to low earth orbit which left the first stage with plenty of fuel to effect a landing. The landing was made as slow as possible and limited only by how low a single engine could be throttled. The re-entry burn which slows the rocket down before the landing burn was also more agressive. This missi…

To expand on this slightly the CRS8 (and OG2, the land landing) landing was done using only 1 engine, which even then was presumably throttled. This landing burn was done using 3 engines so they spend less time below terminal velocity, and thus use less fuel. The total deceleration should be ~40 m/s during the burn.
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