Launch News SpaceX Falcon 9 v1.2 with SES-9 March 4 2016

[Thunder Chicken]

Instead of trying to land their stage on the barge next attempt, they should track down that boat and attempt to land on that.

I like that. I like that a lot. Burn it. Burn it with fire.

 

[Unstung]

Looks like I missed nothing Wednesday, Thursday, and Sunday.

 

[boogabooga]

The fouled range KEEPS HAPPENING! This is a recurring problem at Cape Canaveral.

They should start using the sound weapons that are used to deter pirate attack.

 

[Andy44]

The fouled range KEEPS HAPPENING! This is a recurring problem at Cape Canaveral.

They should start using the sound weapons that are used to deter pirate attack.

Guns make sounds...

 

[Thunder Chicken]

Guns make sounds...if you're the target.

 

[boogabooga]

It is right there in the Notices to Mariners on page 3:
http://www.navcen.uscg.gov/pdf/lnms/lnm07082016.pdf

 

[Col_Klonk]

Guns make sounds...if you're the target.

Only if they miss.. otherwise guns make no sounds

 

[Urwumpe]

The fouled range KEEPS HAPPENING! This is a recurring problem at Cape Canaveral.

They should start using the sound weapons that are used to deter pirate attack.

Considering that the real problem is the fact, that KSC is simply next to one of the busiest shipping lanes in the world, maybe it would be better to use maritime patrol planes to patrol the protected area before launch.

 

[RGClark]

SpaceX needs to supply extra insulation to the chilled LOX tank or supply chilling equip to it. There is no way a 10 minute hold should make the vehicle unflyable.

 

[Urwumpe]

SpaceX needs to supply extra insulation to the chilled LOX tank or supply chilling equip to it. There is no way a 10 minute hold should make the vehicle unflyable.

10 Minutes are no problem. 50 minutes are the limit right now. You could of course clad the rocket with insulation bricks that should fall off during launch (like it was done on the Ariane 4, which launched in much hotter climate).

But it is technically simpler and cheaper, to just replace boil-off losses with cold LOX from storage until engine start (like it is also done by the Ariane 5 ECA). And that simply works only as long as you have LOX on the launch site.

 

[ADSWNJ]

But it is technically simpler and cheaper, to just replace boil-off losses with cold LOX from storage until engine start (like it is also done by the Ariane 5 ECA). And that simply works only as long as you have LOX on the launch site.

They do that already. The issue is not the boil-off, but rather the base temp of the whole tank. They need the ability to continuously cycle the fuel and have either enough cryo-reserves for a long period (e.g. 2 hours), or the ability to re-chill once taken out. The full cycle drain & replenishment time needs to be less than the max allowable temp gain.

 

[APDAF]

Are you totally sure it's not the Janitor's fault? /really bag joke

 

[RGClark]

10 Minutes are no problem. 50 minutes are the limit right now. You could of course clad the rocket with insulation bricks that should fall off during launch (like it was done on the Ariane 4, which launched in much hotter climate).
...
But it is technically simpler and cheaper, to just replace boil-off losses with cold LOX from storage until engine start (like it is also done by the Ariane 5 ECA). And that simply works only as long as you have LOX on the launch site.

Didn't see the launch. I thought it was only a 10 minute hold in this case?

Bob Clark

 

[Urwumpe]

Didn't see the launch. I thought it was only a 10 minute hold in this case?

Bob Clark

No, this time it was a short hold because of a range safety violation (Boat in the first stage landing zone), followed by a T-0 launch abort after engine start.

After the launch abort, the launch attempt was scrubbed for cycling back and investigating the cause of the automatic launch abort.

 

[RGClark]

No, this time it was a short hold because of a range safety violation (Boat in the first stage landing zone), followed by a T-0 launch abort after engine start.
After the launch abort, the launch attempt was scrubbed for cycling back and investigating the cause of the automatic launch abort.

The implication of the Elon tweet seemed to be the short hold was the cause of the abort, implied also to be from over-pressurization of the LOX tank.

Bob Clark

 

[Urwumpe]

The implication of the Elon tweet seemed to be the short hold was the cause of the abort, implied also to be over-pressurization of the LOX tank.

Bob Clark

No tweets here. See also: "Things that Elon said"

EDIT: From what I can tell about his wild tweeting, the possible helium ingestion into the engine is the far worse problem because it should absolutely not happen at standard gravity.

 

[RGClark]

No tweets here. See also: "Things that Elon said"
EDIT: From what I can tell about his wild tweeting, the possible helium ingestion into the engine is the far worse problem because it should absolutely not happen at standard gravity.

If the short hold due to a range violation had no impact on the launch abort then it really would not present a serious problem. You just hold for the short time, then launch after the short hold.

I get the impression that even short holds present a problem for the superchilled LOX.

Bob Clark

 

[Urwumpe]

If the short hold due to a range violation had no impact on the launch abort then it really would not present a serious problem. You just hold for the short time, then launch after the short hold.

I get the impression that even short holds present a problem for the superchilled LOX.

Bob Clark

Seriously - every kind of delay means effort to keep the LOX super-chilled inside the rocket, which is practically nothing else but a mediocre effective heat exchanger. It is worth the effort if you can launch quickly, but it means more effort, if you plan to stay super-chilled for a longer period of time.

Especially since you have to include: You can't install large heat exchangers directly at the pad for cooling the LOX, you need more or less long pipes between rocket and the pumps and heat exchangers for keeping the LOX even below that the target temperature.

But it is not the primary problem - the helium is it. Something made it possible to create helium bubbles between tank and engine. Possibly a leak.

 

[Frilock]

Launch set for Tuesday at 6:46.

 

[Lmoy]

Launch set for Tuesday at 6:46.

Excellent, we'll get to learn about another new and exciting cause for abort tomorrow.