B The Falcon Landing: How Did They Do It?

[wolram]

How did they do it, it must have been incredibly difficult.

 

[Jonathan Scott]

It obviously takes a lot of practice - fifth time lucky!

But they were close on each of the previous attempts (especially the third one, which landed successfully but the leg didn't latch so it fell over).

It's pretty amazing anyway. This one appeared to bounce slightly and shift towards the edge as it settled, which was a bit scary.

 

[wolram]

How high were they when they turned around for landing? and how did they stop the exhausts from burning, out there must have been an incredible amount of heat reflected back at them.

 

[Jonathan Scott]

If you play the full launch video, you can see the figures on speed and height in the corner of the screen. The first stage booster is well short of orbital speed when it separates from the second stage. It is effectively in space when it turns round (using thrusters) then slows down a lot before reentry using a subset of its main engines. There are some diagrams easily found by Googling for images with keywords such as: SpaceX booster return profile

 

[Jonathan Scott]

I just had another look at the launch video:

Main Engine Cut-Off was at +2:34 into the flight (about 29:43 in the video), at a speed of about 6654 km/h and altitude of about 67.0 km.

 

[nikkkom]

These are two different landings, btw.

 

[Jonathan Scott]

These are two different landings, btw.

Yes, the video link in the first post is to the earlier successful landing on land, but I assume the intention was to discuss last night's first successful landing on the droneship.

 

[1oldman2]

http://www.space.com/32518-spacex-nails-ocean-barge-landing-on-5th-try-video.html

 

[1oldman2]

How did they do it, it must have been incredibly difficult.

Gimbal thrust and steering fins and a lot telemetry channels.

Here is your user guide if you would like your own.
http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_2.0.pdf

 

[mfb]

We have another thread about the same topic already, please continue discussion there.