Author Topic: SpaceX: Falcon 9 Hotfire Attempt 2 Updates  (Read 87981 times)

Offline Carl G

  • Moderator
  • Global Moderator
  • Full Member
  • *****
  • Posts: 1126
  • Liked: 211
  • Likes Given: 113
SpaceX: Falcon 9 Hotfire Attempt 2 Updates
« on: 03/10/2010 05:10 AM »
SpaceX:

Today SpaceX performed our first Static Fire for the Falcon 9 launch vehicle.  We counted down to an T-2 seconds and aborted on Spin Start.  Given that this was our first abort event on this pad, we decided to scrub for the day to get a good look at the rocket before trying again.  Everything looks great at first glance.

 

We completed pad preps on time and with good execution.  The integrated countdown with the range included holdfire checks, S- band telemetry, C-band, and FTS simulated checks.  We completed helium, liquid oxygen (LOX), and fuel loads to within tenths of a percent of T-zero conditions.  Tanks pressed nominally and we passed all Terminal count, flight software, and ground software abort checks right down to T-2 seconds.  We encountered a problem with the spin start system and aborted nominally. 

 

As part of the abort, we close the pre-valves to isolate the engines from the propellant tank and purge the residual propellants.  The brief flames seen on the video are burn off of LOX and kerosene on the pad.  The engines did not ignite and there was no engine fire.

 

We detanked and safed the vehicle and launch pad. Preliminary review shows all other systems required to reach full ignition were within specification.  All other pad systems worked nominally.   Inspections will be complete tonight.  Tomorrow will consist of data review and procedure updates.  Commodities will be replenished tomorrow including TEA TEB load, LOX and helium deliveries. 

 

We’ll look to do the next static fire attempt in three or four days: I will keep you posted of any additional updates—thanks!  Emily
« Last Edit: 03/11/2010 07:14 PM by Chris Bergin »

Offline Damon Hill

  • Veteran
  • Full Member
  • ****
  • Posts: 548
  • Auburn, WA
  • Liked: 72
  • Likes Given: 124
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #1 on: 03/10/2010 05:21 AM »
Looks to me like TEA/TEB flow in the bottom image with the green flames.  I'm guessing things went right up to the point of main propellant flow valves (not?) opening.

First time I recall seeing a close-up of the Falcon 9 on the launch pad showing how the rocket is supported.  I had a very different mental image.

Offline MKremer

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 3903
  • Liked: 11
  • Likes Given: 472
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #2 on: 03/10/2010 07:27 AM »
First time I recall seeing a close-up of the Falcon 9 on the launch pad showing how the rocket is supported.  I had a very different mental image.

They've designed an interesting holddown/release system, and it appears to be overengineered by a large factor. Too much, as opposed to just enough, is better in this case, IMO.

Also, it looks like the outer (corner) engines are angled away for ignition.

« Last Edit: 03/10/2010 07:30 AM by MKremer »

Online ugordan

  • Senior Member
  • *****
  • Posts: 7417
    • My mainly Cassini image gallery
  • Liked: 1567
  • Likes Given: 339
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #3 on: 03/10/2010 08:20 AM »
They've designed an interesting holddown/release system, and it appears to be overengineered by a large factor.

Not necessarily overengineered if you take into account F9 is supposed to have a fairly high T/W ratio, higher than either EELV w/no SRBs.

Quote
Also, it looks like the outer (corner) engines are angled away for ignition.

Yep, looks that way to me, too. Guess that'll be another thing in which F9 is similar to a Zenit. Cosine losses, but better control if unexpected engine shutdowns happen. Or expected ones at MECO-17 s.
« Last Edit: 03/10/2010 09:03 AM by ugordan »

Offline JohnWT

  • Member
  • Posts: 31
  • Donington le Heath, Leicestershire, UK
  • Liked: 9
  • Likes Given: 7
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #4 on: 03/10/2010 08:24 AM »

First time I recall seeing a close-up of the Falcon 9 on the launch pad showing how the rocket is supported.  I had a very different mental image.

Shown in action here: http://spacex.com/assets/video/20100104_11f9release.wmv

Offline pippin

  • Regular
  • Senior Member
  • *****
  • Posts: 2546
  • Liked: 285
  • Likes Given: 39
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #5 on: 03/10/2010 09:11 AM »
They've designed an interesting holddown/release system, and it appears to be overengineered by a large factor.

Not necessarily overengineered if you take into account F9 is supposed to have a fairly high T/W ratio, higher than either EELV w/no SRBs.

Actually it looks like a passive system activated by the thrust building up, similar to what Soyuz uses, to me.
A few springs and cylinders are not really "over engineered". Recently had a look at the suspension of your car?

Online ugordan

  • Senior Member
  • *****
  • Posts: 7417
    • My mainly Cassini image gallery
  • Liked: 1567
  • Likes Given: 339
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #6 on: 03/10/2010 11:07 AM »
Video of abort recorded from SFN live stream:


Offline kevin-rf

  • Elite Veteran
  • Senior Member
  • *****
  • Posts: 8570
  • Overlooking the path Mary's little Lamb took..
  • Liked: 1063
  • Likes Given: 238
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #7 on: 03/10/2010 12:31 PM »
Also, it looks like the outer (corner) engines are angled away for ignition.

Yep, looks that way to me, too. Guess that'll be another thing in which F9 is similar to a Zenit. Cosine losses, but better control if unexpected engine shutdowns happen. Or expected ones at MECO-17 s.

Does not mean it will be this way through out powered flight. Once they are clear of the pad and have more room to move, they "could" undo the angle and reduce Cosine losses.
« Last Edit: 03/10/2010 12:32 PM by kevin-rf »
If you're happy and you know it,
It's your med's!

Online ugordan

  • Senior Member
  • *****
  • Posts: 7417
    • My mainly Cassini image gallery
  • Liked: 1567
  • Likes Given: 339
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #8 on: 03/10/2010 01:15 PM »
Does not mean it will be this way through out powered flight. Once they are clear of the pad and have more room to move, they "could" undo the angle and reduce Cosine losses.

That would be atypical for launchers. Normally, they toe out after clearing the pad to reduce flame damage on the pad and maybe get out of there a bit quicker. Zenit does it from what I can see. Delta IV SRMs also. I'm not sure what would be gained the other way around.

Offline FinalFrontier

  • Senior Member
  • *****
  • Posts: 3845
  • Space Watcher
  • Liked: 262
  • Likes Given: 132
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #9 on: 03/10/2010 04:39 PM »
Video of abort recorded from SFN live stream:


IMHO: Looks like: Propellant valves opened, Chamber ignited at the "low pressure" point, but that when the turbo pumps were supposed to spin up they did not, or did not get going fast enough, so they aborted. Perhaps the lack of rpms was due to insufficient pressure in the spin start system? Could this be caused by a valve that wasn't open all the way? (like a stuck helium or n2 valve or just one that did not open all the way)
3-30-2017: The start of a great future
"Live Long and Prosper"

Offline TOG

  • Full Member
  • **
  • Posts: 204
  • Near Chicago, Illinois
  • Liked: 46
  • Likes Given: 41
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #10 on: 03/10/2010 05:30 PM »
Does not mean it will be this way through out powered flight. Once they are clear of the pad and have more room to move, they "could" undo the angle and reduce Cosine losses.

That would be atypical for launchers. Normally, they toe out after clearing the pad to reduce flame damage on the pad and maybe get out of there a bit quicker. Zenit does it from what I can see. Delta IV SRMs also. I'm not sure what would be gained the other way around.

This is an excellent topic of discussion, but IMHO is better suited for the "SpaceX: General Falcon and Dragon discussion" perhaps here:
               http://forum.nasaspaceflight.com/index.php?topic=19228.1466

M's Laws of Aerodynamics:                                    On Physics Exam:
1) if you push anything hard enough it will fly          Q)The allegory of Schrödinger's cat shows what?
2) if you stop pushing it stops flying                        A)That Shrödinger was a sadistic cat hater

Offline stockman

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 6916
  • Southern Ontario - Canada
  • Liked: 3
  • Likes Given: 0
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #11 on: 03/10/2010 06:03 PM »
hmmm.. just noticed this.. it appears either it rained and cleaned the vehicle or someone was out with the spic-N-Span cleaning it... I notice the black char area from yesterday is not there this morning.. (see yesterday and today photos below)
One Percent for Space!!!

Offline astrobrian

  • NSF Photographer
  • Senior Member
  • *****
  • Posts: 2934
  • Austin Texas
  • Liked: 19
  • Likes Given: 43
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #12 on: 03/10/2010 07:10 PM »
Probably so they get more accurate charring after a good test fire

Offline Lars_J

  • Senior Member
  • *****
  • Posts: 6161
  • California
  • Liked: 664
  • Likes Given: 195
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #13 on: 03/10/2010 07:31 PM »
I guess that proves it was just 'soot', not actual burn damage.

Offline Damon Hill

  • Veteran
  • Full Member
  • ****
  • Posts: 548
  • Auburn, WA
  • Liked: 72
  • Likes Given: 124
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #14 on: 03/10/2010 08:22 PM »

First time I recall seeing a close-up of the Falcon 9 on the launch pad showing how the rocket is supported.  I had a very different mental image.

Shown in action here: http://spacex.com/assets/video/20100104_11f9release.wmv

Ah, that makes much more sense (once I actually got the video to play; Firefox just sat and sucked its thumb).  That and the rollout video which shows the pivot points and a tractor to pull into position.  Nice system, not too complex.  I could see a company party with everyone pitching in to manually push it to the pad...(in railroad parlance, the Armstrong method)

Online docmordrid

  • Senior Member
  • *****
  • Posts: 4381
  • Michigan
  • Liked: 1502
  • Likes Given: 1
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #15 on: 03/10/2010 08:46 PM »
I could see a company party with everyone pitching in to manually push it to the pad...(in railroad parlance, the Armstrong method)

LOL!!  My dad was a railroad mechanic and hearing that again brought back some fond memories of hanging out at the roundhouse :)
DM

Online ugordan

  • Senior Member
  • *****
  • Posts: 7417
    • My mainly Cassini image gallery
  • Liked: 1567
  • Likes Given: 339
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #16 on: 03/10/2010 08:58 PM »
FWIW, @jeff_foust cites Larry Williams as saying "spin start" abort during F9 test firing happens frequently in tests in Texas; "not a big issue".

Not a thing you'd want happening regularly on an operational vehicle, though.

Online Chandonn

  • Extreme Veteran
  • Full Member
  • ****
  • Posts: 1227
  • "Pudding!!! UNLIMITED Rice Pudding!!!"
  • Lexington, Ky
  • Liked: 5
  • Likes Given: 9
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #17 on: 03/10/2010 09:11 PM »
FWIW, @jeff_foust cites Larry Williams as saying "spin start" abort during F9 test firing happens frequently in tests in Texas; "not a big issue".

Not a thing you'd want happening regularly on an operational vehicle, though.

If it's a known issue, and you can quickly recycle for another launch attempt, it shouldn't be a problem, I would think.

Online ugordan

  • Senior Member
  • *****
  • Posts: 7417
    • My mainly Cassini image gallery
  • Liked: 1567
  • Likes Given: 339
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #18 on: 03/10/2010 09:18 PM »
That is definitely something that should not become SOP. Aborting after ignition and safing a vehicle should be a safety net, not an accepted thing. Like a LAS for crewed launches.

Just my 2c.

Offline corrodedNut

  • Full Member
  • ****
  • Posts: 1541
  • Liked: 207
  • Likes Given: 130
Re: SpaceX: Falcon 9 Hotfire Attemp 2 Updates
« Reply #19 on: 03/10/2010 09:29 PM »
From the SFN updates:

""Computers monitor parameters in various systems on the rocket and the launch pad during the final seconds of the countdown. Small deviations from expected values can trigger an abort.

"We want to set our aborts tighter initially, and we don't want one tight abort to scrub a whole launch day," said Tim Buzza, the Falcon 9 launch director.

"The key thing is it's not cavalier, it's thought out. We have rules when we see that abort how we go into an anomaly team and get the engineers to say, OK, it was tight. I'm going to open it up 1 psi""


I wouldn't be surprised if that's exactly what happened, if the spin start anomaly is already known, then its just a matter of deciding if and how much to "loosen" the parameters.

Tags: