Author Topic: SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION (Read 1360715 times)

Kabloona · « **Reply #1040 on:** 12/18/2015 05:54 pm »

Quote from: Prober on 12/18/2015 05:49 pm

any news we should be close

Chris B is AWOL, so it should be happening shortly.

http://forum.nasaspaceflight.com/index.php?topic=38678.msg1459612#msg1459612

cro-magnon gramps · « **Reply #1041 on:** 12/18/2015 06:12 pm »

Come on folks, just cause CB is away, we don't want to do a Denial of Moderator Service (aka drive the mods up the wall) lets keep it on topic...
meanwhile at the pad, haven't heard from Padrat for a long time... any news from our eyes and ears on the pad??

Chris Bergin · « **Reply #1042 on:** 12/18/2015 06:13 pm »

Chris is back. They've gotten close, apparently, but not static fired yet.

laika_fr · « **Reply #1043 on:** 12/18/2015 06:13 pm »

my bad wasn't using historical data for TX, so if Elon was referring to the 9/21 test

Waco-TX 9/21/2015
Avg humidity : 56% (max 80%)
min temp : 20°C

Patrick AFB yesterday
Humidity : 90-96%
temp 23-24 °C

Chris Bergin · « **Reply #1044 on:** 12/18/2015 06:26 pm »

So it looks like it'll play out one of two ways.

1) People in the area spot engine ignition (the exhaust) coming from the pad complex. If it was a good firing (remember, needs to be all nine engines and within parameters), ORBCOMM or SpaceX will likely tweet something due to the interest. Remember, engine ignition is one thing, good firing is another.

2) If not - and they can't get it done over the next few hours - I would assume Elon will take to Twitter.

Toastmastern · « **Reply #1045 on:** 12/18/2015 06:33 pm »

Quote from: Chris Bergin on 12/18/2015 06:26 pm

So it looks like it'll play out one of two ways.

1) People in the area spot engine ignition (the exhaust) coming from the pad complex. If it was a good firing (remember, needs to be all nine engines and within parameters), ORBCOMM or SpaceX will likely tweet something due to the interest. Remember, engine ignition is one thing, good firing is another.

2) If not - and they can't get it done over the next few hours - I would assume Elon will take to Twitter.

Don't get it has people been observing the *puff*?

brettreds2k · « **Reply #1046 on:** 12/18/2015 06:58 pm »

Why are they having so many issues with a static fire test? What was the reason to adjust LOX temps which seems to be what is delaying everything the past few days? I would think Elon just wants to get this one off without any issues so why mess with things for this flight?

docmordrid · « **Reply #1047 on:** 12/18/2015 07:01 pm »

Musk tweeted 5 minutes to static test

The Amazing Catstronaut · « **Reply #1048 on:** 12/18/2015 07:05 pm »

C'mon, let's do this!

abaddon · « **Reply #1049 on:** 12/18/2015 07:05 pm »

Quote from: brettreds2k on 12/18/2015 06:58 pm

Why are they having so many issues with a static fire test? What was the reason to adjust LOX temps which seems to be what is delaying everything the past few days? I would think Elon just wants to get this one off without any issues so why mess with things for this flight?

The Falcon 9 1.1 FT is designed to work with subcooled LOX, so not using it is not an option.

Kabloona · « **Reply #1050 on:** 12/18/2015 07:07 pm »

Quote from: abaddon on 12/18/2015 07:05 pm

Quote from: brettreds2k on 12/18/2015 06:58 pm
Why are they having so many issues with a static fire test? What was the reason to adjust LOX temps which seems to be what is delaying everything the past few days? I would think Elon just wants to get this one off without any issues so why mess with things for this flight?
The Falcon 9 1.1 FT is designed to work with subcooled LOX, so not using it is not an option.

The reason for reducing the LOX and RP-1 temps is to increase their density so the rocket can carry more propellant for more performance.

More on that topic here:
http://forum.nasaspaceflight.com/index.php?topic=39072.0

mtakala24 · « **Reply #1051 on:** 12/18/2015 07:12 pm »

Quote from: brettreds2k on 12/18/2015 06:58 pm

Why are they having so many issues with a static fire test? What was the reason to adjust LOX temps which seems to be what is delaying everything the past few days? I would think Elon just wants to get this one off without any issues so why mess with things for this flight?

Also, it was always the plan to get this new version (1.1 FT) flying from this mission onwards. The CRS-7 accident just happened to happen on the second to last flight of the previous version of the rocket. Only the Jason 3 -rocket is left, and it is launching from the west coast.

abaddon · « **Reply #1052 on:** 12/18/2015 07:12 pm »

Well, it is well after five minutes. We need* a short-lived poll as to what happened.

* No, we don't

Lee Jay · « **Reply #1053 on:** 12/18/2015 07:15 pm »

"Abort triggered by flight computer on upper stage throttle valve. Adjusting thresholds and restarting count at T-10 mins." Elon - Twitter

https://twitter.com/elonmusk/status/677945101184708609

abaddon · « **Reply #1054 on:** 12/18/2015 07:18 pm »

I really don't get people who complain about SpaceX and transparency. Musk is often way more transparent than I would be in his position.

Semmel · « **Reply #1055 on:** 12/18/2015 07:19 pm »

What are the thresholds good for if they can be just adjusted like that?

Also, how can they test the throttle valve when the engine is not running?

@edit: Love it that Elon is tweeting things like that. Very much appreciated!

abaddon · « **Reply #1056 on:** 12/18/2015 07:23 pm »

Quote from: Semmel on 12/18/2015 07:19 pm

What are the thresholds good for if they can be just adjusted like that?

They set conservative thresholds to be safe and then dial them back. I am not sure I understand it either, to be honest, but I remember the same things happening with F9 first flight (I think?) and definitely F9 1.1 first flight.

Jeff Lerner · « **Reply #1057 on:** 12/18/2015 07:24 pm »

Not meant as criticism but aren't thresholds tested prior to shipping to launch site ??

guckyfan · « **Reply #1058 on:** 12/18/2015 07:28 pm »

They did it before. First try with very narrow values, then adjust. They did the same with early 1.0 and I believe with early 1.1 too. Why exactly they chose that approach I don't know.

nadreck · « **Reply #1059 on:** 12/18/2015 07:28 pm »

Quote from: abaddon on 12/18/2015 07:18 pm

I really don't get people who complain about SpaceX and transparency. Musk is often way more transparent than I would be in his position.

I don't get it, but I see it and related cognitive distortions all over the place. There is something about having to have an overriding opinion on people/companies/groups that are in the public eye that uses the notoriety of the target to leverage their own self-worth by proclaiming how the person/company/group should behave.