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

[Herb Schaltegger]

Just read this on USA TODAY :

SpaceX hopes to launch another commercial satellite from the Cape before the year is out, for Thaicom.
Musk said SpaceX might try to recover that rocket's first stage from the ocean, depending in part on data collected during the SES-8 mission.
Link : http://www.usatoday.com/story/tech/2013/12/04/spacex-launch-successful/3866655/

Can someone confirm this?

They might have discovered that they only broke up very close to Max-Q meaning they need very little delta-V to prevent breakup.

This has been my hope all along.  That stage break-up is a runaway process, and if the stage remains oriented right, you don't need a lot of authority to keep it there - and so it will slow down with increasing atmospheric density.

SpaceX got to test the two ends of the envelope - I am pretty sure that with CASSIOPE they did a lot of retro-burn, and with SES, they most likely did none. 

Like we always said here - the second burn is the magic sauce.  Everyone understands by now how the first and third burns go.

There something in L2 about this, I think, with regard to SES. 

[meekGee]

Just read this on USA TODAY :

SpaceX hopes to launch another commercial satellite from the Cape before the year is out, for Thaicom.
Musk said SpaceX might try to recover that rocket's first stage from the ocean, depending in part on data collected during the SES-8 mission.
Link : http://www.usatoday.com/story/tech/2013/12/04/spacex-launch-successful/3866655/

Can someone confirm this?

They might have discovered that they only broke up very close to Max-Q meaning they need very little delta-V to prevent breakup.

This has been my hope all along.  That stage break-up is a runaway process, and if the stage remains oriented right, you don't need a lot of authority to keep it there - and so it will slow down with increasing atmospheric density.

SpaceX got to test the two ends of the envelope - I am pretty sure that with CASSIOPE they did a lot of retro-burn, and with SES, they most likely did none. 

Like we always said here - the second burn is the magic sauce.  Everyone understands by now how the first and third burns go.

There something in L2 about this, I think, with regard to SES.

Cool.    Still they've explored both ends of the envelope.  This is their main learning goal right now, since GH flights take care of everything else.

If it ends up being on the lean side of the envelope, it reduces the propellant penalty, and so more power to them.  Sometimes, the universe actually IS on your side.

To continue the logic, if after the SES flight they start talking about soft landing on this flight, likely they got happy results.  The extra practice will make it easier when planning for CRS-3.

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

[Jim]

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Not really.  Unmanned missions don't generate the interest.
And there would be nothing to see.

[imspacy]

They might have discovered that they only broke up very close to Max-Q meaning they need very little delta-V to prevent breakup.

Do we know for sure that the SES booster did break up before it hit the water?

[Borklund]

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Not really.  Unmanned missions don't generate the interest.
And there would be nothing to see.

I would think that many people would want to show up to view - for the first time ever in the history of mankind - an orbital launch vehicle's first stage land on back on terra firma, intact, on legs. That would be something to behold, surely. It's just not for you Jim.

[dcporter]

They might have discovered that they only broke up very close to Max-Q meaning they need very little delta-V to prevent breakup.

Do we know whether the SES booster broke up before it hit the water?

I guess not for sure, but it's a pretty good bet.

[Lars_J]

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Not really.  Unmanned missions don't generate the interest.
And there would be nothing to see.

Nothing to see? It certainly depends on the viewing conditions - if they are like for SES-8 there should be plenty to see. (Note on YouTube how people with even crappy cell phone cameras were able to capture the fairing separation, and visible by the naked eye as well) A 1st retro and braking burn should be be quite spectacular.

[Comga]

Cool.    Still they've explored both ends of the envelope.  This is their main learning goal right now, since GH flights take care of everything else.

If it ends up being on the lean side of the envelope, it reduces the propellant penalty, and so more power to them.  Sometimes, the universe actually IS on your side.

To continue the logic, if after the SES flight they start talking about soft landing on this flight, likely they got happy results.  The extra practice will make it easier when planning for CRS-3.

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Remember, SpaceX is not going for water recovery.  The announced plan is to fly back to the launch site.  That pretty much fixes the required delta-V. For each point in the trajectory there is an optimum elevation angle for the boost-back that minimizes delta-V.  (I bet it is close to or the same as optimizing for minimum descent velocity.) The only issue seems to be whether they need a third burn to slow down before hitting the atmosphere. That is a question they could have started answering with the data from the SES launch yesterday.

[meekGee]

Cool.    Still they've explored both ends of the envelope.  This is their main learning goal right now, since GH flights take care of everything else.

If it ends up being on the lean side of the envelope, it reduces the propellant penalty, and so more power to them.  Sometimes, the universe actually IS on your side.

To continue the logic, if after the SES flight they start talking about soft landing on this flight, likely they got happy results.  The extra practice will make it easier when planning for CRS-3.

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Remember, SpaceX is not going for water recovery.  The announced plan is to fly back to the launch site.  That pretty much fixes the required delta-V. For each point in the trajectory there is an optimum elevation angle for the boost-back that minimizes delta-V.  (I bet it is close to or the same as optimizing for minimum descent velocity.) The only issue seems to be whether they need a third burn to slow down before hitting the atmosphere. That is a question they could have started answering with the data from the SES launch yesterday.

oooh - we seem to have a 0-index/1-index communication issue here 

I counted the burns excluding the initial launch.  So what I meant was:

Launch is burn 0.
Fly-back is burn 1.
Slow-down is burn 2. (magic sauce, unknown dV, hopefully minimal, so really only "keep straight")
Hover-slam is burn 3.

----

If they come back to shore, unlike a launch, you'll be looking for the incoming, without being sure where it is.
Will it have a contrail?   Will they put a bloody smoke candle on it for visual recognition?
What if it's a night launch - will they have running lights?  Strobes?

Then - Leg deployment, ignition, hover slam, landing - all within, what, 20 seconds?

Yeah, tempting.

EDIT:  Taking the second half of this over to the CRS-3 thread.

[Comga]

oooh - we seem to have a 0-index/1-index communication issue here 

I counted the burns excluding the initial launch.  So what I meant was:

Launch is burn 0.
Fly-back is burn 1.
Slow-down is burn 2. (magic sauce, unknown dV, hopefully minimal, so really only "keep straight")
Hover-slam is burn 3.

Are you a software guy, meekGee?
Only a software guy would start counting at zero, or discuss "index" on something as physical as burns.

Other than that, we might be in violent agreement.

[meekGee]

oooh - we seem to have a 0-index/1-index communication issue here 

I counted the burns excluding the initial launch.  So what I meant was:

Launch is burn 0.
Fly-back is burn 1.
Slow-down is burn 2. (magic sauce, unknown dV, hopefully minimal, so really only "keep straight")
Hover-slam is burn 3.

Are you a software guy, meekGee?
Only a software guy would start counting at zero, or discuss "index" on something as physical as burns.

Other than that, we might be in violent agreement.

Maybe that's why nobody can ever follow my driving directions...  (Take the zeroth driveway on your left) 

Otherwise, it's complicated.  (Studied EE, ended up doing some CE, mostly ME)  But I'm C Native, so zero's it.

ANYWAY.

The launch was not a "burn" in my mind.  It was, you know, THE LAUNCH. 

[Wetmelon]

Then - Leg deployment, ignition, hover slam, landing - all within, what, 20 seconds?

I haven't seen any information in particular, but I have a hunch the legs will be deployed significantly ahead of 20 seconds, to both increase control and reduce terminal velocity.

As for Thaicom - do we have orbital parameters yet?

[fatjohn1408]

Will this one go to SSTO as well? Is it known which SSTO?

[malu5531]

Will this one go to SSTO as well? Is it known which SSTO?

SSTO often stands for Single Stage To Orbit, perhaps you meant to say GTO? If so, the answer is yes and I don't believe we have information on target orbit yet, however, given the similar size/mass it will probably be a similar flight profile (my guess).

[Skyrocket]

In this case here SSTO means probably "Super-Synchroneous Transfer Orbit"

[Jim]

I would think that many people would want to show up to view - for the first time ever in the history of mankind - an orbital launch vehicle's first stage land on back on terra firma, intact, on legs. That would be something to behold, surely. It's just not for you Jim.

They wouldn't be able to see the landing.  It would be obscured.
And again, it is unmanned.  After all, the shuttle returned from space many times and its boosters too.  Most people wouldn't understand the significance, and you are overplaying the significance

[Jim]

Nothing to see? It certainly depends on the viewing conditions - if they are like for SES-8 there should be plenty to see. (Note on YouTube how people with even crappy cell phone cameras were able to capture the fairing separation, and visible by the naked eye as well) A 1st retro and braking burn should be be quite spectacular.

They wouldn't see the landing and SES-8 was because of the twilight conditions

[Joffan]

Nothing to see? It certainly depends on the viewing conditions - if they are like for SES-8 there should be plenty to see. (Note on YouTube how people with even crappy cell phone cameras were able to capture the fairing separation, and visible by the naked eye as well) A 1st retro and braking burn should be be quite spectacular.

They wouldn't see the landing and SES-8 was because of the twilight conditions

Do you have any reason to expect a different launch window for Thaicom 6? Presumably they are using a similar transfer orbit protocol to SES-8 so it might well be at twilight again.

[Avron]

I would think that many people would want to show up to view - for the first time ever in the history of mankind - an orbital launch vehicle's first stage land on back on terra firma, intact, on legs. That would be something to behold, surely. It's just not for you Jim.

They wouldn't be able to see the landing.  It would be obscured.
And again, it is unmanned.  After all, the shuttle returned from space many times and its boosters too.  Most people wouldn't understand the significance, and you are overplaying the significance

Jim, I think you may want to reevaluate that, but of for me it is. A stage that returns for re-flight (assumed) without rebuld. in 50 odd years .. that is big.. it may be huge.. time will tell but as far as I know its not happening on T-6 .. What would be nice to know first stage "tricks " are planned for T-6

[ChrisWilson68]

Pre-empting the CRS-3 viewing thread, but I am very tempted to fly down to watch.  I imagine any viewing venue will be absolutely jam packed.     *IF they indeed come back to shore on that one.

Not really.  Unmanned missions don't generate the interest.
And there would be nothing to see.

Nothing to see? It certainly depends on the viewing conditions - if they are like for SES-8 there should be plenty to see. (Note on YouTube how people with even crappy cell phone cameras were able to capture the fairing separation, and visible by the naked eye as well) A 1st retro and braking burn should be be quite spectacular.

Yeah, I think Lars makes a better case than Jim on this issue.  The actual touchdown might not be visible, but there's a decent chance with good binoculars or a telescope you could follow the first stage down to just a few hundred meters.  Even without any of that, you might be able to catch sight of it with the naked eye as it does its final burn.

I'm probably going to fly out from California to be there the first time I hear they're going to attempt a landing on land.  Even if I don't end up seeing much, I'd like to know I was there for that moment.