Author Topic: FAILURE: SpaceX Falcon I Launch III - August 2 (Read 345715 times)

jimvela · « **Reply #220 on:** 08/03/2008 12:58 am »

LC- countdown 1: on the loop:

Refuel no estimate on refuel, still de-tanking.

jimvela · « **Reply #221 on:** 08/03/2008 12:59 am »

RTS asking RCO to call on land line.

StuffOfInterest · « **Reply #222 on:** 08/03/2008 01:00 am »

According to SpaceflightNow, the delay is due to the helium system. The launch window goes until midnight, EDT.

jimvela · « **Reply #223 on:** 08/03/2008 01:01 am »

FTS powered down, carrier off.

hektor · « **Reply #224 on:** 08/03/2008 01:01 am »

Any clue about at which mark they would restart the countdown ?

pbreed · « **Reply #225 on:** 08/03/2008 01:01 am »

It could also be too hot, from sitting in an uninsulated tank in the hot wind.

The fuel density goes down as it gets warmer.
If I remember the last flight they fired up realized the Chamber pressure was low and off loaded and reloaded the fuel to lower the temp if
I remember correctly.

(I'm 99% sure the fuel offload reload was for temp, I'm only 75% asure it was to cool the fuel.

shuttle_buff · « **Reply #226 on:** 08/03/2008 01:03 am »

Looks like Elon made good on his promise to automate the launch countdown. (Aviation Week article interview).

He can hold this puppy anywhere!

jimvela · « **Reply #227 on:** 08/03/2008 01:05 am »

Max just now acknowledging the hold. Taking a break. Asking us to join back in 30:00

Jim · « **Reply #228 on:** 08/03/2008 01:07 am »

Quote from: jimvela on 08/03/2008 12:56 am

Very possibly, it's a trick of the trade. The more energy you get in the propellant before you burn it, the more chamber pressure you get when you fly... Within limits, of course.

It goes both ways. Cold for higher density, hot for more energy

jimvela · « **Reply #229 on:** 08/03/2008 01:08 am »

jongoff · « **Reply #230 on:** 08/03/2008 01:08 am »

Quote from: pbreed on 08/03/2008 01:01 am

(I'm 99% sure the fuel offload reload was for temp, I'm only 75% asure it was to cool the fuel.

Paul, I'm pretty sure you have that backwards. The kerosene shares a common bulkhead with the LOX. If it gets too cold, it can throw off the chamber pressure on the low side. Remember one of the second or third order benefits of going with a regen cooled engine is that the heat from the chamber gets hauled back into the chamber, increasing the Isp by a tiny bit. Also, I can't help but think that if the kero gets too cold (it's freezing point is a lot higher than alcohol), it can't be good for the pumps, and probably doesn't help injection efficiency either.

~Jon

Jim · « **Reply #231 on:** 08/03/2008 01:10 am »

Quote from: shuttle_buff on 08/03/2008 01:03 am

Looks like Elon made good on his promise to automate the launch countdown. (Aviation Week article interview).

He can hold this puppy anywhere!

That is not a function of automation and also not not unique to spacex. Hold points are for convenience not hardware or software driven

collectSPACE · « **Reply #232 on:** 08/03/2008 01:12 am »

Defueling is to ensure that the helium does not cool the fuel.

For those that heard 'Depowering the FTS'. That means Flight Termination System. Just powering down to ensure that we don't overheat.

http://kwajrockets.blogspot.com/

Ford Mustang · « **Reply #233 on:** 08/03/2008 01:13 am »

Launch Control is working a minor issue. We are still very confident we will launch during today's window. Please stay tuned on this page, we will be back in approximately 30 minutes. (6:30 PDT / 9:30 EDT / 01:30 UTC)

The above is from SpaceX's site.

Fuel offload shutdown complete.

StuffOfInterest · « **Reply #234 on:** 08/03/2008 01:13 am »

Starting fuel load sequence.

collectSPACE · « **Reply #235 on:** 08/03/2008 01:14 am »

Not official yet, but based on reports from Kwaj, expected T-Zero is around 7pm PDT.

http://kwajrockets.blogspot.com/

simonbp · « **Reply #236 on:** 08/03/2008 01:17 am »

When does the window close?

Simon

William Graham · « **Reply #237 on:** 08/03/2008 01:19 am »

Quote from: simonbp on 08/03/2008 01:17 am

When does the window close?

Simon

04:00 GMT

jongoff · « **Reply #238 on:** 08/03/2008 01:19 am »

Quote from: simonbp on 08/03/2008 01:17 am

When does the window close?

I think someone said 12pm EDT, which gives them another 2hrs, 40min to get the launch off today. They have plenty of time. Of course, I'd rather have them scrub this than have it end up in the drink.

~Jon

shuttle_buff · « **Reply #239 on:** 08/03/2008 01:20 am »

Ok, fine Jim.

It still appears Elon has automated the launch sequence so it's all handled by computers. This was not the case in launch attempt #1 or #2.