Author Topic: SpaceX: Falcon 9 Hotfire Updates (Read 92667 times)

mr. mark · « **Reply #180 on:** 03/10/2010 01:32 am »

It's great to see that they are doing this in a careful manner and that the abort systems as well as the vehicle system were working. Hope to see them fix the problem and get a second crack at this in a few days.

stockman · « **Reply #181 on:** 03/10/2010 01:41 am »

well I have to say that was a reasonably timely update from SpaceX... thank you in case anyone is reading this...

Now one question if I may -

"We counted down to T-2 seconds and aborted on Spin Start"

this may be obvious to others but I am not an in depth techie type- what is the Spin Start they refer to exactly? Just trying to understand what part of the system caused the abort...

Thank you in advance for any descriptive input....

00rs250 · « **Reply #182 on:** 03/10/2010 01:42 am »

Seems this was a logical step in proving that the vehicle can safely shut itself down if there was an issue. Is there anyway that the Air Force would have asked them to do this by chance as part of their pending safety approval? Even if we find out that it was caused by a mechanical issue or human intervention?

robertross · « **Reply #183 on:** 03/10/2010 01:48 am »

Quote from: stockman on 03/10/2010 01:41 am

well I have to say that was a reasonably timely update from SpaceX... thank you in case anyone is reading this...

Now one question if I may -

"We counted down to T-2 seconds and aborted on Spin Start"

this may be obvious to others but I am not an in depth techie type- what is the Spin Start they refer to exactly? Just trying to understand what part of the system caused the abort...

http://forum.nasaspaceflight.com/index.php?topic=19228.msg557620#msg557620

docmordrid · « **Reply #184 on:** 03/10/2010 01:56 am »

So, a problem with the helium pressure/flow to the turbopumps? Doesn't sound too drastic.

WHAP · « **Reply #185 on:** 03/10/2010 01:59 am »

Quote from: Antares on 03/09/2010 07:17 pm

TEA-TEB does make a nice bang.
RS-27 spins up in a couple of seconds. Small engines don't take much time to spin up.

Quote from: Ben the Space Brit on 03/09/2010 05:59 pm
They don't want GOX pooling in the tanks and staying there after de-tanking.

The tanks are essentially full of GOX moments after exposure to LOX as they are quenched. After detanking, when the fill and drain valve is closed, the tanks are purged with N2. This is how all LVs work, though H2 tanks may be purged with helium instead of N2 depending on how close the next attempt is.

The statement about LOX tanks being purged with N2 after detanking is not true for at least one of the EELV's. Nor does that same LV ever use N2 to purge LH2 tank(s) at the launch site, regardless of the length of time between attempts.

kkattula · « **Reply #186 on:** 03/10/2010 02:00 am »

Quote

We encountered a problem with the spin start system and aborted nominally.

At a guess, one or more turbo pumps didn't reach sufficent RPM when spun up by pressurised helium. Could be the helium didn't flow properly in the pad layout, (I think it's from GSE not on-board). Or there was a stuck valve, etc.

I expect SpaceX will let us know when they do. Contrary to some opinions, I think they've been pretty good at explaining issues like these.

stockman · « **Reply #187 on:** 03/10/2010 02:28 am »

""We'll look to do the next static fire attempt in three or four days."

This is the most encouraging piece of the small release tonight by SpaceX... Lets hope the data review doesn't reveal anything more serious... 3 or 4 days is not too long to wait for another attempt...

btw - Thanks Robertross for the pointer on the Spin Start Question I had... I get it now..

Robotbeat · « **Reply #188 on:** 03/10/2010 02:45 am »

That's a much larger, more detailed press release than I expected. Thanks, SpaceX!

corrodedNut · « **Reply #189 on:** 03/10/2010 02:52 am »

SFN has a larger article up now, with new photos:

http://www.spaceflightnow.com/falcon9/001/100309hotfire/

Carl: It's a press release, see full release and full res images here:
http://forum.nasaspaceflight.com/index.php?topic=20799.0)

Jim · « **Reply #190 on:** 03/10/2010 03:28 am »

Quote from: 00rs250 on 03/10/2010 01:42 am

Is there anyway that the Air Force would have asked them to do this by chance as part of their pending safety approval?

No way. There is no requirement to demonstrate this

just-nick · « **Reply #191 on:** 03/10/2010 04:17 am »

Quote from: corrodedNut on 03/10/2010 02:52 am

SFN has a larger article up now, with new photos:

http://www.spaceflightnow.com/falcon9/001/100309hotfire/

Thanks...

Notice the little spurt of green flame coming from one of the nozzles in the 2nd photo? As I recall from some books on the SR-71 (which used TEB as an ignition source), the ignition flame was a characteristic green.

Pretty.

--Nick

Comga · « **Reply #192 on:** 03/10/2010 04:46 am »

Quote from: just-nick on 03/10/2010 04:17 am

Quote from: corrodedNut on 03/10/2010 02:52 am
SFN has a larger article up now, with new photos:

http://www.spaceflightnow.com/falcon9/001/100309hotfire/
Thanks...

Notice the little spurt of green flame coming from one of the nozzles in the 2nd photo? As I recall from some books on the SR-71 (which used TEB as an ignition source), the ignition flame was a characteristic green.

Pretty.

--Nick

The caption says: "SpaceX released this view of the base of the Falcon 9 rocket moments before the planned ignition. The green color under the rocket is from the TEA-TEB ignition source. Credit: SpaceX". Your memory seems to be correct.