SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION

[meekGee]

My question is, are there cameras at the land landing site? Will we get a stream?

Oh there will be plenty of cameras set up covering the landing zone. But I doubt it will be live-streamed.

My money is on live-stream.  Since there will be "informal" cameras looking on, they would want to be in front of the news (good or not-so-good) rather than behind it.

Also - Landing Zone One (LZ-1) is now the official name.  "The site formerly known as Prince LC-13".

And it's a "zone", rather than a "pad", which bodes well for the interpretation that there will eventually be multiple active landing pads.

[macpacheco]

What is Go Quest used for?

Go Quest is a communications/support ship.

Now heading downrange, so she may be monitoring telelemetry from the stage during boostback.

Just idle speculation, but, if the ASDS could be positioned as a backup say, 30 miles from shore, would they need a comm/support ship ?

[Kabloona]

What is Go Quest used for?

Go Quest is a communications/support ship.

Now heading downrange, so she may be monitoring telelemetry from the stage during boostback.

Just idle speculation, but, if the ASDS could be positioned as a backup say, 30 miles from shore, would they need a comm/support ship ?

Probably, because Go Quest probably sends the remote safing/venting commands to safe the stage before the crew can approach the ASDS to hook up the tow line and tie the stage down.

But there is no need for "backup." The landing coordinates are loaded before launch and the stage has only one target, in this case LZ-1.

[cscott]

I bet the remote safing commands can be sent from LZ-1 if the ASDS is close to shore.

[JasonAW3]

Space x rockets ain't afraid of the dark.

On a more serious note, it's all about orbital timing and good lighting isn't needed for landing.

My questions is, for 2 huge events... RTF and a first time land landing attempt, why do a night launch and not a day launch?

Ought to be pretty spectacular launching and landing.  I REALLY hope they make the launch window and stick the landing. Not only would it be historic, but it's look spectacular when they have the flood lights on it!

[Johnnyhinbos]

Go Quest is beyond doubt heading to a very specific destination offshore. And I'd say the window is closed for OCISLY. This means land on land is confirmed.

[Antilope7724]

Some launch history for CCAFS LC-13

Used for 30 Atlas B, D, E & F ICBM flight tests 1958 through 1962.
Used for 21 Atlas-Agena D orbital or escape velocity launches 1963 through 1978.

-1st ICBM test launch, 1958-08-02, Atlas B - 4B, Suborbital.
- Last ICBM test launch, 1962-02-13, Atlas E - 40E, Suborbital.
-1st orbital launch, 1963-10-17, Vela 1A/1B Nuclear detonation detection satellites, Atlas-Agena D.
- Last orbital launch, 1978-04-07, reported as Aquacade-4 or Rhyolite ELINT satellite, Atlas-Agena D.

Other noteable NASA launches, Mariner 3 Mars flyby, Lunar Orbiter 1 through 5, OGO-5.

[catdlr]

Just repeating a video produced by Space X some time ago of the first stage landing at Landing Zone One (LZ-1).  This video is for a simulation of Dragon Heavy (3 core) but the process is the same.

Falcon Heavy | Flight Animation

[CyndyC]

Meaning no disrespect to SpaceX, and I might sound a little like Jim here, but are there good reasons to think that after the static fire took 3 days, next the rocket can be launched instantaneously in one evening, or even instantaneously in two evenings? To suggest an answer to my own question, maybe one of the big reasons the "dress rehearsal" went on as long as it did, even though we didn't hear about it, was because repetitions were included of new or even older procedures that went right the first time, but SpaceX wanted to put in some extra practice for the sake of speed and efficiency, or is that not unusual for static fires of a much shorter duration?

[ChrisC]

L2 now has an instantaneous T-0 of 20:29 Eastern for the attempt on the 20th. Previously was a three hour window. Next opportunity on the 22nd is showing a 15 minute window!

Press release:
HAWTHORNE, Calif.--(BUSINESS WIRE)--Today SpaceX confirmed that the company is targeting launch of the 11 ORBCOMM satellites aboard a Falcon 9 rocket from Cape Canaveral Air Force Station, Fla. on Sunday, Dec. 20. The 60-second launch window opens at 8:29 p.m. ET. If needed, a backup launch opportunity is available on Dec. 21.

Interesting that they appear to have inserted the 21st as a possibility.  What's the launch window for the 21st?

EDIT:  OK, I see L2 has it, nevermind.

[Chris Bergin]

L2 now has an instantaneous T-0 of 20:29 Eastern for the attempt on the 20th. Previously was a three hour window. Next opportunity on the 22nd is showing a 15 minute window!

Press release:
HAWTHORNE, Calif.--(BUSINESS WIRE)--Today SpaceX confirmed that the company is targeting launch of the 11 ORBCOMM satellites aboard a Falcon 9 rocket from Cape Canaveral Air Force Station, Fla. on Sunday, Dec. 20. The 60-second launch window opens at 8:29 p.m. ET. If needed, a backup launch opportunity is available on Dec. 21.

Interesting that they appear to have inserted the 21st as a possibility.  What's the launch window for the 21st?

EDIT:  OK, I see L2 has it, nevermind.

20:33 Eastern, instantaneous - for the 22nd. I've added it to the Static Fire article. The launch day article is almost ready to go on early tomorrow.

[Mike_1179]

maybe one of the big reasons the "dress rehearsal" went on as long as it did, even though we didn't hear about it, was because repetitions were included of new or even older procedures that went right the first time, but SpaceX wanted to put in some extra practice for the sake of speed and efficiency, or is that not unusual for static fires of a much shorter duration?

It probably had more to do with the need to keep the LOX cold. If they ran into a problem with a sticky valve, you can't just recycle and go, you have to drain the warm LOX and re-fill with cold LOX.

So you've got new GSE, new environmental conditions for the vehicle and a situation where any hang-ups delay the whole thing by hours.

Regarding this quote upthread:

Go Quest is beyond doubt heading to a very specific destination offshore. And I'd say the window is closed for OCISLY. This means land on land is confirmed.

Or a water "landing".

[northenarc]

   Is Falcon 9 still dependent on CCAFS radar for range tracking or have they switched over to a GPS system as Atlas and Delta have? They obviously have GPS on the first stage for landing at least. Not sure if this was covered somewhere in all the SpaceX discussion, but I couldn't find it, and I don't remember it being mentioned anywhere since a faulty radar held up a Falcon launch a while back.

[joek]

   Is Falcon 9 still dependent on CCAFS radar for range tracking or have they switched over to a GPS system as Atlas and Delta have? They obviously have GPS on the first stage for landing at least. Not sure if this was covered somewhere in all the SpaceX discussion, but I couldn't find it, and I don't remember it being mentioned anywhere since a faulty radar held up a Falcon launch a while back.

They have GPS, but that does not eliminate the need for range radar (at least not yet); e.g., the Atlas V NROL-67 launch was also delayed due to range radar issues last year. edit: Just to be clear, the range still requires those radars, regardless of the LV's capabilities.  That may change in the future with autonomous FTS (among other things).

[Herb Schaltegger]

Meaning no disrespect to SpaceX, and I might sound a little like Jim here, but are there good reasons to think that after the static fire took 3 days, next the rocket can be launched instantaneously in one evening, or even instantaneously in two evenings?

You're conflating two issues which are not necessarily dependent: 1) GSE teething troubles; and 2) short launch windows.

SpaceX has hit instantaneous launch windows before. That's not really the issue, all by itself. But when you've got changes in ground support equipment to handle a change to propellant conditions (subcooled LOX and RP1), well ... those GSE changes come with their own little niggles and things. Every single major facility that has a set of associated infrastructure (chemical refinery; large hospital; skyscraper; aircraft carrier; launch complex, etc) comes with its own set of foibles and quirks. Some generators don't power up as quickly as others; some valve cycle a tad more quickly or slowly than specified; some fans run hot or cool .... Learning all these foibles, keeping track of them and considering them properly in regular operations, is part of what has to be done to make that launch complex (or aircraft carrier, or chemical refinery, or skyscraper ....) operational and usable.

[Kabloona]

To suggest an answer to my own question, maybe one of the big reasons the "dress rehearsal" went on as long as it did, even though we didn't hear about it, was because repetitions were included of new or even older procedures that went right the first time, but SpaceX wanted to put in some extra practice for the sake of speed and efficiency, or is that not unusual for static fires of a much shorter duration?

Usually for a wet dress rehearsal/static fire you go through the pre-launch procedure exactly as written, meaning you do each step only once unless you have to recycle for contingencies. So if all goes well you only have to do each step once. Obviously SpaceX had to recycle through parts of the procedure multiple times due to the various issues that cropped up, but it probably wasn't because they wanted that "extra practice." Elon would probably have been pleased if the procedure had gone perfectly the first time through. And the team would be better rested for this launch attempt. Multiple late nights just before a launch attempt put extra stress on the launch team. They're probably all pretty wrung out by now.

[Norm38]

I wasn't aware of the new landing zone. Is there info on its size relative to the barge?
Meaning, will the landing location be more relaxed, doesn't have to try to hit the exact center.
Can focus more on staying vertical and just stick the landing?
I'm a lot more excited for this than another barge attempt.

[geza]

Even it is not larger, location of the land landing zone is fixed and known with certainty. In case of barge landing, the positioning error of the barge is additive to the navigation error of the incoming rocket.

[Ohsin]

I wasn't aware of the new landing zone. Is there info on its size relative to the barge?
Meaning, will the landing location be more relaxed, doesn't have to try to hit the exact center.
Can focus more on staying vertical and just stick the landing?
I'm a lot more excited for this than another barge attempt.

http://forum.nasaspaceflight.com/index.php?topic=36513.msg1453058#msg1453058



Note: OCISLY is ~150' wide

[LouScheffer]

Meaning no disrespect to SpaceX, and I might sound a little like Jim here, but are there good reasons to think that after the static fire took 3 days, next the rocket can be launched instantaneously in one evening, or even instantaneously in two evenings?

It shows no disrespect to be skeptical of the chances of an on-time launch, given a new rocket, a new ground infrastructure, and an instantaneous launch window.  It's a big and complex system unforgiving of errors, and it took them weeks to get it working in Texas and days to repeat this in Florida.  There are probably many hours of glitches yet to resolve, and no time to do so on these launches.

I would personally put today's attempt at 20-30% chance of launch, and 70-80% chance it turns into a WDR.  But if a bug halts today's attempt, that's one less bug to halt tomorrow's, and so on.  I'd not be surprised if this one took as many as 4 or 5 attempts, the next one 2 or 3, and so on.  Eventually the rate of scrubs should get down to the point they are dominated by weather. 

A quote from a very different context might be relevant:  "The odds of success are difficult to estimate.  But if we do not try, the odds of success are zero."