SpaceX Falcon 9 v1.1 - Thaicom 6 - DISCUSSION THREAD

[Comga]

Orbital is announcing a delay in the Orb-1 launch due to forecasted weather on the 7th and 8th.  Do things still look good for the 6th?

[Lee Jay]

It's the 6th in Florida versus the 7th in Virginia.  Big difference.

[DigitalMan]

Weather here has been lousy

[Comga]

It's the 6th in Florida versus the 7th in Virginia.  Big difference.

You are correct, or course, and it is coming in from the north.

[Avron]

Why can't the Bermuda station support both launches on the 7th? Does it take too long to reconfigure?

I was asking myself the same question  - sounds like Bermuda is  provided and operated by Wallops under NASA's Research Range Services Program.. anyone know anything on 'Research Range Services Program".. I would hope that part of that "Research" would be to support concurrent launches on the same day?

[Comga]

Actually, I meant to ask the opposite question.   
With Orbital delaying from the 7th to the 8th or 9th does SpaceX get the 7th as a backup opportunity?

[macpacheco]

THE FOLLOWING AIRSPACE IN USE FOR A MISSILE LAUNCH/SPLASH DOWN....

Hopefully no spin-up and a soft slash down. Anyone know if they'll attempt a recovery & tow it in? Lots of data there....

I'm assuming this mission is almost the same as the SES-8 (payload weight is just about the same and target orbit should be too).
Musk stated they gave 100% of the rocket performance on the SES-8 and Thaicom-6 missions to the customers.
So at first sight, there would be zero fuel margins for any re usability related burns.
But after the SES-8 launch Musk stated the F9R performance was better than expected (more fuel left on the 2nd stage than expected).
Since it would be unwise that SpaceX would put on the contract 100% of the rocket performance, instead they should have put a minimum target orbit (that would make sense), so by changing the staging altitude a little shorter, they could burn all usable fuel on the 2nd stage, leaving some fuel in the 1st stage, the burning question (pun intended) is how much fuel was left in the 2nd stage on SES-8 mission, apparently only SpaceX knows.
So since the one burn that's considered the "secret sauce" is the re-entry burn, I'm expecting that to be the real test. That is finding how little delta-V they need to keep the 1st stage in one piece through re-entry.
The Cassiope flight did a long re-entry burn that did it's job.
The SES-8 flight did no re-entry burn, but just by orienting the stage tail first during re-entry, the information was it faired much better than expected, breaking up right at the critical point (MaxQ), so I speculate they will try a much smaller burn, I'm hoping a 1/3 delta V burn versus Cassiope would do the job.
This is actually the most critical data to be obtained, since reducing the re-entry burn directly changes the quoted 15% performance penalty for downstream recovery and 30% performance penalty for boost back. Imagine if they end up with 10% performance penalty for downstream recovery and 20-25% for boost back, it would much increase the flexibility of F9R missions with re use.

[Avron]

Actually, I meant to ask the opposite question.   
With Orbital delaying from the 7th to the 8th or 9th does SpaceX get the 7th as a backup opportunity?

That's easy, yes they then get the 7th

45th Space Wing
The Eastern Range has approved a launch date of 6 Jan 14 with a window of 5:06 - 7:08 p.m. EST with a backup date of 7 Jan 14 window of 5:07 - 7:08 p.m. EST.

however I note that Chris has it down for "Launch window is: 1706L -1918L." in the update thread

[rpapo]

I suppose it has occurred to others here that "Splash Down" could simply mean emergency abort debris splashdown, like any normal launch.  Unless, of course, they don't normally put those words in these advisories.

[Jcc]

I guess we would look for boat/barge activity in the area, and if SpaceX or a contractor is chartering one.

[MP99]

I'm assuming this mission is almost the same as the SES-8 (payload weight is just about the same and target orbit should be too).
Musk stated they gave 100% of the rocket performance on the SES-8 and Thaicom-6 missions to the customers.
So at first sight, there would be zero fuel margins for any re usability related burns.
But after the SES-8 launch Musk stated the F9R performance was better than expected (more fuel left on the 2nd stage than expected).
Since it would be unwise that SpaceX would put on the contract 100% of the rocket performance, instead they should have put a minimum target orbit (that would make sense), so by changing the staging altitude a little shorter, they could burn all usable fuel on the 2nd stage, leaving some fuel in the 1st stage, the burning question (pun intended) is how much fuel was left in the 2nd stage on SES-8 mission, apparently only SpaceX knows.

ISTR that part of the experience gained from the first few launches of a new rocket is to determine any variability in performance.

I suspect this launch will operate with the same margins as SES-8, IE nothing much more than an engine restart attempt.

Cheers, Martin

[cro-magnon gramps]

I'm following a developing storm and post storm freeze up here in the NE of North America, but I am curious as to why there has been no weather updates here from our MET friends, for the SE... anyone out there with their ears to the ground want to give us a heads up for tomorrows launch time...

Gramps

[fatjohn1408]

Any word on a mission kit and a target orbit?

[macpacheco]

ISTR that part of the experience gained from the first few launches of a new rocket is to determine any variability in performance.

I suspect this launch will operate with the same margins as SES-8, IE nothing much more than an engine restart attempt.

Cheers, Martin

You'd be correct if there were zero / very little reserves for an engine failure. The only argument in your favor is the contract might stipulate a guaranteed minimum orbit (in case of a single engine failure) and a nominal target orbit (no engine failures), so the nominal scenario might use all the fuel except for residuals.

I don't know (and I think you don't either) how much fuel reserves the 2nd stage was planned to have on top of the extra performance (fuel left after SECO2) found.

I'll grant you we're just tracing the most optimistic and most pessimistic scenarios possible.

Finally, we don't know if anything was negotiated with Thaicom to release just a little bit of performance in order to allow some room for testing.

F9 v1.1 specs call for 4850Kg to GTO, this is a 3300Kg payload, so lots of room, except that's payload to GTO, not to GSO.

In the end, we're all cheering for success, and that's what really matters !


Edit... I stand corrected, 3016 Kg satellite, transfer orbit 90000 Km x 295 Km, now it's clear where the extra performance goes.

[aga]

F9 v1.1 specs call for 4850Kg to GTO, this is a 3300Kg payload, so lots of room

iirc, the 4850 is to 27 deg. gto... they need the "room" to get the payload to a "more standard" gto (or what should i call it) - similar to the ses-8 launch

[MP99]

ISTR that part of the experience gained from the first few launches of a new rocket is to determine any variability in performance.

I suspect this launch will operate with the same margins as SES-8, IE nothing much more than an engine restart attempt.

Cheers, Martin

You'd be correct if there were zero / very little reserves for an engine failure. The only argument in your favor is the contract might stipulate a guaranteed minimum orbit (in case of a single engine failure) and a nominal target orbit (no engine failures), so the nominal scenario might use all the fuel except for residuals.

I don't know (and I think you don't either) how much fuel reserves the 2nd stage was planned to have on top of the extra performance (fuel left after SECO2) found.

Reserves are in the upper stage, and has lowest risk assuming full duration burn from the first stage. While first stage has engine out, any extra duration on the upper stage has some small increase in risk of engine failure or under performance.

I'll grant you we're just tracing the most optimistic and most pessimistic scenarios possible.

Finally, we don't know if anything was negotiated with Thaicom to release just a little bit of performance in order to allow some room for testing.

F9 v1.1 specs call for 4850Kg to GTO, this is a 3300Kg payload, so lots of room, except that's payload to GTO, not to GSO.

In the end, we're all cheering for success, and that's what really matters !

Elon said they'd max the performance of both these flights.

Cheers, Martin

[MP99]

F9 v1.1 specs call for 4850Kg to GTO, this is a 3300Kg payload, so lots of room

iirc, the 4850 is to 27 deg. gto... they need the "room" to get the payload to a "more standard" gto (or what should i call it) - similar to the ses-8 launch

SES-8 went to 80k km to reduce GSO shortfall to 1.5 km/s. Makes the inclination change easier at higher apogee, but needs more performance from the LV.

Cheers, Martin

[Barrie]

F9 v1.1 specs call for 4850Kg to GTO, this is a 3300Kg payload, so lots of room

iirc, the 4850 is to 27 deg. gto... they need the "room" to get the payload to a "more standard" gto (or what should i call it) - similar to the ses-8 launch

SES-8 went to 80k km to reduce GSO shortfall to 1.5 km/s. Makes the inclination change easier at higher apogee, but needs more performance from the LV.

Cheers, Martin

Do we know if Thaicom 6 will follow the same strategy, or will the rocket do the whole plane change?

[aga]

@mp99:
yes, that is exactly what i meant

[oiorionsbelt]

Elon said they'd max the performance of both these flights.

Cheers, Martin

I believe he said that before the first flight of F9 v1.1 He stated after the first flight that the vehicle had better performance that expected. He also said it was operating at 85% so perhaps there is more margin than we think.