SCRUB: SpaceX Falcon 9/Dragon COTS Demo (C2+) LAUNCH ATTEMPT 1 UPDATES

[Chris Bergin]

Questions already.

Engine 5 was trending high from the start, but hit the abort limit at 0.5 seconds. Compared to static fire, was out of family. Static fire it was rock solid.

Does not look like a sensor failure. Never seen it before on the pad.

Need all nine engines for lift off. Two engines can fail later for nominal mission.

Not a software issue.

PC Pressure on Engine 5 (high pressure) was the abort on the first flight, but they had a window that time.

Ms Shotwell distancing herself from Elon's tweet. Need to look at the engine.

This is not a failure, this is aborted with purpose, it would have been a failure if we lifted off with this issue.

Engine change would be a couple of days. May swap engine 5 from the other F9 at Cape. If required.

Racing through this!

[psloss]

Ms Shotwell distancing herself from Elon's tweet. Need to look at the engine.

She said that was based on initial quick look.

[MP99]

High chamber pressure likely due to low fuel flow. Valve [edit:pre-valve] reported fully open, probably borescope engine to investigate.

cheers, Martin

[Chris Bergin]

Next T-0s:

03:44 - 22nd.
About 03:22 - 23rd.

Normal ignition for all nine engines. 5 started fine then started trending high.

Vehicle was held down at all times.

High pressure could be high temps/low fuel in combustion. Prevalve was fully open (nominal). Need to look at the data.

Visual inspection of the chamber, borescope the pump.

Flight 1 the engine wasn't trending like this one.

Traj of the ISS has allowed the possible May 24th opportunity.

Should be able to roll back to the hanger and back out by the 22nd if required.

And that's over.

[manboy]

[MP99]

Launch on 22nd would be 3:44.

23rd would be 3:22.

cheers, Martin

[MP99]

Could roll back and still be able to roll out again for 22nd window, but I don't think she committed re whether that could also include an engine change.

cheers, Martin

[Paul Howard]

Next T-0s:

03:44 - 22nd.
About 03:22 - 23rd.

Normal ignition for all nine engines. 5 started fine then started trending high.

Vehicle was held down at all times.

High pressure could be high temps/low fuel in combustion. Prevalve was fully open (nominal). Need to look at the data.

Visual inspection of the chamber, borescope the pump.

Flight 1 the engine wasn't trending like this one.

Traj of the ISS has allowed the possible May 24th opportunity.

Should be able to roll back to the hanger and back out by the 22nd if required.

And that's over.

Good notes, thanks for covering that and the launch attempt!

[Chris Bergin]

[sanman]

The worst case is that they swap an engine, right? I assume that's if they find something serious wrong, or if they can't quite find out exactly what went wrong?

Are these spare engines pre-tested to the same extent as the ones that were already onboard?

[MP99]

The worst case is that they swap an engine, right? I assume that's if they find something serious wrong, or if they can't quite find out exactly what went wrong?

Are these spare engines pre-tested to the same extent as the ones that were already onboard?

You'd have to assume they're fully tested, given that they were given the green light to be assembled onto F9 #004.

cheers, Martin

[John44]

   SpaceX/Falcon 9 Dragon Post-Scrub News Conference
http://www.space-multimedia.nl.eu.org/index.php?option=com_content&view=article&id=7585

[rickl]

I seem to remember reading that they had to change the Atlas sustainer engine on the pad for MA-6.

Should be a lot easier for SpaceX to do it in the hangar, if necessary.

[Thunderbird5]

Next T-0s:

03:44 - 22nd.
About 03:22 - 23rd.

Normal ignition for all nine engines. 5 started fine then started trending high.

Vehicle was held down at all times.

High pressure could be high temps/low fuel in combustion. Prevalve was fully open (nominal). Need to look at the data.

Visual inspection of the chamber, borescope the pump.

Flight 1 the engine wasn't trending like this one.

Traj of the ISS has allowed the possible May 24th opportunity.

Should be able to roll back to the hanger and back out by the 22nd if required.

And that's over.

Also noted that thresholds were lower for Flight 1.

Clearly they have been tweaking/relaxing thresholds in any case from previous data.

[sanman]

So a borescope is similar to an endoscope used by a doctor to check your insides?

http://en.wikipedia.org/wiki/Borescope

So this is a non-destructive means of examination, which will enable them to look at the feed channels for the chamber of Engine 5?

"trending" for "low fuel" could possibly point to a leak in the fuel feed line, perhaps?

[Chris Bergin]

Latest update of William Graham's article for the scrub info:
http://www.nasaspaceflight.com/2012/05/spacex-falcon-9-send-dragon-to-iss/

Going to have a break, so everyone please behave themselves

[Chris Bergin]

So a borescope is similar to an endoscope used by a doctor to check your insides?

Yep!

Here's a Shuttle article I wrote when the fleet had their inners checked!

http://www.nasaspaceflight.com/2009/11/sts-129-borescope-inspections-completed-aggressive-instrumentation-plan/

[kevin-rf]

I seem to remember reading that they had to change the Atlas sustainer engine on the pad for MA-6.

Should be a lot easier for SpaceX to do it in the hangar, if necessary.

Once integrated, has spaceX ever swapped a falcon 9 engine?

I wonder if such a swap would require a new hot fire. I would assume it is a component on the engine that needs to swapped, tweaked.

Fingers crossed they get off the pad before the Beta angle cause along delay.

[Mapperuo]

"trending" for "low fuel" could possibly point to a leak in the fuel feed line, perhaps?

With all the cameras they must have, Would a fuel leak not be visible and so be known at the time of the post briefing?

[ugordan]

Once integrated, has spaceX ever swapped a falcon 9 engine?

I once read a *rumor* on another site that they did do it once before. Take that with a grain of salt.