SpaceX Tuesday...

[MartG]

Eric Mc said:

I always knew landing Thunderbird 3 back into its underground launch facility was harder than it looked.

Yes - paying the string out smoothly while balancing on the puppeteers gantry must have been quite difficult

[anonymous-user]

Eric Mc said:

If I was a certification officer I would not allow any attempts to land back at Cape Canaveral until they had landed successfully on the barge at least ten times - demonstrating that at all stages in the descent they were fully in control of the proceedings.

But just 10 times isn't statistically nearly enough. I mean, if you'd flown the shuttle 24 times and called a halt you'd have been fine...........

The only way you'd ever be allowed to return this stage to a dry landing is to demonstrate that even in the case of gross failure you have a "safe" ballistic trajectory surely?

[MartG]

So you ensure that when carrying out the 'return to base' retrofire, the trajectory lands short ( in the sea ) and requires the final landing burn to reach the pad on land

[RobDickinson]

@elonmusk
Cause of hard rocket landing confirmed as due to slower than expected throttle valve response. Next attempt in 2 months.

[Eric Mc]

They'll have to work out why the throttle didn't respond quickly enough and whether it is capable of reacting more quickly.

The video seemed to show that the gimballing system wasn't acting fast enough either.

[CrutyRammers]

If it thought it was reacting faster than it was, then that could cause it to get into an overcompensation / oscillation. Depends on how the feedback system works I guess.

[MartG]

More on the valve

http://spaceflightnow.com/2015/04/21/throttle-valv...

Next landing attempt June 19 . They also have the Falcon Heavy test later this year as well as several other scheduled launches - busy times at SpaceX

[Mojocvh]

So close, so close.

I do have to wonder if they have reached that systems peak performance though, if that is the case then it may be a bigger problem that we think just now.

Hope not, this IS inspirational stuff indeed.

[Eric Mc]

I did suggest right at the start that using a parachute would be a better bet. Maybe if they added a chute but retained the rocket assisted landing, they could get a much lower rate of descent and it would give the stabilisation system time to do what it has to do.

[MartG]

Latest reports from SpaceX indicate that after it started to topple one of the legs gave way which accelerated the process - seems they aren't strong enough to support it past a certain angle

[MartG]

Dragon 2 pad abort test set for early next month

http://spaceflightnow.com/2015/04/21/dragon-pad-ab...

[annodomini2]

MartG said:

Latest reports from SpaceX indicate that after it started to topple one of the legs gave way which accelerated the process - seems they aren't strong enough to support it past a certain angle

I'd put money one leg isn't capable of withstanding the weight of the rocket + kinetic energy of it hitting the deck.

[Eric Mc]

I don't normally quote myself but this is what I posted just after the incident.

Eric Mc said:

With a touchdown speed of around 90 mph and not being completely vertical, I recon one of the legs gave way

[MartG]

Commercial launch tonight

[MartG]

Hold due to weather. Count recycled to T-20 mins hoping weather improves in next 90 mins

[ninja-lewis]

T-3 mins

http://livestream.com/spacex/events/3995038

[RobDickinson]

making it look easy.

[MartG]

[Mojocvh]

Brilliant! the second stage nozzle downlink video was kind of mesmerising!!

[RobDickinson]

June's ISS resupply mission is going to be critical now.

AFIK Dragon cant resupply fuel though, not sure when they will need that for though, or how long the russians will be out of service.