Comments on: SpaceX Identifies Falcon 9 Problem, Hopes for Tuesday Launch

By: Marcus Zottl

Marcus Zottl — Mon, 21 May 2012 19:49:22 +0000

I never said they do anything special, but does ULA test fire their stages before shipping them to the launch sites? Do they do static fires of the integrated vehicles?

I have never heard about either, but until SpaceX showed up, nobody would have cared anyway so there probably was no incentive for them to announce such things.

By: AB

AB — Mon, 21 May 2012 17:17:18 +0000

Both Atlas V and Delta IV use hold-before-launch with health checks. For configurations with SRBs, the health checks on the liquid engines are completed before the SRBs are lit. It seems likely this was a requirement for them to carry one-of-a-kind national security payloads.

To say SpaceX is doing anything special there is kind of silly.

By: Marcus Zottl

Marcus Zottl — Mon, 21 May 2012 08:37:43 +0000

@ jerry
Imho your dripping sarcasm invalidates any good argument you may have had.

Seriously, what exactly is your point? Those “amateurs” have done two static fires of the first stage engines (one at the cape, the other long before in Texas), both tests went fine and still they have been able to detect a possibly catastrophic fault before lift off and safely aborted the launch.

If anything, this shows that they are way ahead of their competition regarding operations and processes, despite their hardware being less mature than what is flown on other vehicles (hint: most is decades old).

By: Jason

Jason — Mon, 21 May 2012 04:14:03 +0000

SpaceX has not mentioned doing a static fire, and it is probably not necessary because the check valve was accepted beforehand. The last three seconds of the next count will serve as a static fire.

By: warshawski

warshawski — Mon, 21 May 2012 00:52:16 +0000

Jason, I stand corrected I posted above before viewing the post scrub press conference.
http://www.parabolicarc.com/2012/05/19/video-post-scrub-launch-press-conference/
Gwynne was asked how long into the flight they could lose one or 2 engines and she did not have the answers but would get back. It would be interesting to know but it may well depend on the mission profile.
I wonder if they will do another static fire to prove the engine repair? Anyone know the time required to do a static fire then prep for launch?

By: Andy

Andy — Sun, 20 May 2012 15:54:31 +0000

@JohnHunt Gwynne Shotwell mentions it in the post-scrub press conference.

By: JohnHunt

JohnHunt — Sun, 20 May 2012 15:48:23 +0000

Jason, Do you have a hyperlink about that?

By: Jason

Jason — Sun, 20 May 2012 12:18:20 +0000

Falcon 9 can’t lose an engine right at launch, but it can lose two later in flight.

By: Warshawski

Warshawski — Sun, 20 May 2012 11:03:57 +0000

Although the abort is disapointing in that I like to see rockets fly, it does demonstrate the fundamentally safe practice of SpaceX with good sensors, real time computer analysis and Hold before launch. No one was hurt, the rocket is able to be fixed and in a very short time the data had an initial probable fault, verified by visual inspection and repair underway.
With the engine out capability of Falcon 9 it would have been interesting to let it fly without engine 5 but with this test flight being so complex and ambitious I suppose everything has to be perfect prior to launch.

By: jerry

jerry — Sun, 20 May 2012 09:40:24 +0000

Too bad the “rigorous inspection” didn’t take place before the launch attempt. That shows a serious process failure.
What if the problem had been detected seconds later, after take off ? mission would have completely failed.
They have been lucky this time, but it doesn’t seem they have learned the lesson. Otherwise, they would first get to the bottom of it, finding the faulty valve is one thing, finding why it’s faulty and why they missed it, is another one.
Seeing them rush to another attempt only a couple days later, only show those guys are amateurs in this business

By: Brian

Brian — Sun, 20 May 2012 02:45:11 +0000

LOL. You should probably wait until SpaceX gets this thing off the ground in one piece before patting them on the back.

By: Andy

Andy — Sun, 20 May 2012 01:28:58 +0000

I’ve spent a lot longer than a few a hours trying to troubleshoot far less complicated problems than spaceship. The time it took them to figure out their anomaly is really really really impressive. Way to go, SpaceX engineers!

By: Ron Davis

Ron Davis — Sat, 19 May 2012 23:08:09 +0000

I love good trouble shooting. I especially like to see good access through sensors that provide complete analysis during operation. Finally good physical access means proper engineering. These guys must be doing it right to be this quick. Love It.