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#860
by
OxCartMark
on 10 Dec, 2015 18:36
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Now having just read to the top of this large stack of posts I'm curious about something. -"RTF"- There have been a lot of statements in this thread stating something is the case "because its RTF" or similar phrasing. It seems from my perspective that any reference to RTF refers back to the two shuttle RTF processes with all of the political and contractor involvement and their consequent circuses. Is there an actual on the books RTF procedure that exists or is this launch just contingent on the same decision process as any other SpaceX launch which I envision as ~ the fire will be lit when Elon .and. customer .and. eastern range .and. FAA .and. orbital mechanics all simultaneously agree its a good time to do so.?. And, I'm wondering where and when the term "RTF" came into popular usage, was it during the shuttle days or prior? Does its usage go back to the airplane industry?
Yes, I realize this is probably opening a nebulous can of worms but I'm hoping some of those worms are constructive and informative.
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#861
by
Jim
on 10 Dec, 2015 19:02
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RTF is generic and not specific to shuttle.
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#862
by
WindyCity
on 10 Dec, 2015 20:15
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How would SpaceX defend a landing attempt on land for ORBCOMM-2, given the following:
1) None of the ASDS flights have landed intact (even though they reached their targets);
2) The F9 for the mission is a newly modified (as yet unproven) version of the rocket; and
3) This is a RTF mission.
What would NTSB require in terms of assurances in order to approve a landing attempt on land? Would the items I listed above factor in any way as deterrents to the board's approval? It strikes me, off-handedly and not being educated on its range safety criteria, that they would.
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#863
by
Hugo-norway
on 10 Dec, 2015 20:24
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Window is 20:25 to 23:25 local (to the launch site) time for the 19th.
That's 01:25 to 04:25 UTC (Ugg).
02:25 to 05:25 Norway Time 
nice point, it may be not much sleep that night, but since I still am young and not 50 for another month that dont matter much.
I have bought the t-shirt with X marks the spot, Spacex and you bet i will be wearing it on and cheering for a sucessfull mission. Landing will be a big bonus and land landing jackpot.
Still it will be in the dark, but will mark a start for the adventure to see "launch reload and relaunch".
A bit to young to remember much of the "golden age" with the Saturn v, but I am ready for the new golden age.
Remember back when the first shuttle flew I skipped school to see it. Told my teacher that this was important for me. Ended up skipping school two days since first day was scrubbed"?". Anyway was theachers pet since I was a good pupil.
Have to admit that at first I cind of liked ULA and Atlas V since they used the RD-180. This was since I saw the docu. about the NK-33 "The engine that came in from the cold"
But now my bias have shifted 180 degrees.
H
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#864
by
pathfinder_01
on 10 Dec, 2015 20:56
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How would SpaceX defend a landing attempt on land for ORBCOMM-2, given the following:
1) None of the ASDS flights have landed intact (even though they reached their targets);
2) The F9 for the mission is a newly modified (as yet unproven) version of the rocket; and
3) This is a RTF mission.
What would NTSB require in terms of assurances in order to approve a landing attempt on land? Would the items I listed above factor in any way as deterrents to the board's approval? It strikes me, off-handedly and not being educated on its range safety criteria, that they would.
It would be the FAA or Airforce via the range. The NTSB only gets involved in the investigation of an crash.
1. The purpose was to more to demonstrate that the thing can be controled. Landing would have been gravy.
2. Unless the modifications somehow posed an new danger, probably not.
3. How does an 2nd stage failure in flight affect an landing attempt.
What the FAA and the range want to make sure of is that this thing is not an danger to the public. They don't care why it didn't land, they just want to make sure that public safety is preserved. The range would be tracking it all the way in and the range would want self distruct features in case the booster loses control.
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#865
by
wolfpack
on 10 Dec, 2015 21:13
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3. How does an 2nd stage failure in flight affect an landing attempt.
IMO, they (SpX) might want to consider the PR of a failed landing attempt at LC-13. At least with the barge, you can impound the video. Of course, we NSFers all understand the difference, but the general public might not if the booster explodes on a flyback landing attempt. Headlines with the word "explosion" are just no good.
I'd shoot for the boat this time.
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#866
by
rsnellen4
on 10 Dec, 2015 21:16
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Ow, I am definitely a fan and do want to see this... but since I have 3 mini-me's that will furiously try to push me out of bed at ungodly hours I think I'll just have to go for whatever sleep I can get 
Hey, turnabout is fair play! :-)
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#867
by
douglas100
on 10 Dec, 2015 21:33
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IMO, they (SpX) might want to consider the PR of a failed landing attempt at LC-13. At least with the barge, you can impound the video. Of course, we NSFers all understand the difference, but the general public might not if the booster explodes on a flyback landing attempt. Headlines with the word "explosion" are just no good.
I'd shoot for the boat this time.
It's reliably reported that they want to try land landing on this flight, subject to FAA and Range approval. Assuming this is true, it would seem that they disagree with you. If they go for the barge it will be for technical or regulatory reasons. PR should be the least of their considerations when it comes to deciding. If they fail, they fail, bite the bullet and try again.
But if they succeed they will have accomplished a notable first. RTLS has never been attempted before.
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#868
by
Kabloona
on 10 Dec, 2015 21:53
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IMO, they (SpX) might want to consider the PR of a failed landing attempt at LC-13. At least with the barge, you can impound the video.
SpaceX has released video from both failed landing attempts on the barge. Elon has been remarkably and refreshingly willing to share videos that end with a "kaboom" (as he called it in one tweet). No reason to expect anything different this time (except, we hope, a successul landing).
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#869
by
nadreck
on 10 Dec, 2015 22:03
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IMO, they (SpX) might want to consider the PR of a failed landing attempt at LC-13. At least with the barge, you can impound the video.
SpaceX has released video from both failed landing attempts on the barge. Elon has been remarkably and refreshingly willing to share videos that end with a "kaboom" (as he called it in one tweet). No reason to expect anything different this time (except, we hope, a successul landing).
It is so Kerbal of him! I wonder if he wears foundation to cover the green?
But yes, SpaceX doesn't really have to worry about PR for the landings. The only PR that would be bad on this launch is a failure of the primary objective. Another landing failure, land or sea based, still gets them a step further towards their goal and ultimately any negatives from the failure add to the positive for when they are successful and there are no contracts, funding issues, investor concerns that affect them that hinge on this sort of PR.
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#870
by
WindyCity
on 10 Dec, 2015 23:44
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Thank you, pathfinder_01, wolfpack, and douglas100 for your responses.
SpaceX's decision to attempt a landing on land seems like an aggressive move, though I may not be reading it rightly. Given all the effort that the company has put into refurbishing and upgrading the drone ship, I thought that another attempt to stick a landing on that platform would have come first.
(As an aside, I wonder if Blue Origin's successful landing, albeit a less challenging accomplishment, stirred Musk's competitive juices, and he decided to skip ahead to a land landing.)
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#871
by
cscott
on 11 Dec, 2015 01:02
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Restating some facts for the record:
SpaceX already have range permission for flyback. They are waiting for an FAA permit. We have no indication that range safety is the blocking issue.
There barge will in all likelihood be deployed for this flight. They can divert to the barge "at the last minute" (for a suitable definition of last).
The barge story does not end with a land landing. There are still plans to land F9 and FH stages far out to sea on performance-critical missions. Even if spurned this month, they will return. We'll see a sea landing at some point.
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#872
by
OxCartMark
on 11 Dec, 2015 02:59
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Thought - There has only been one night time landing attempt on an ASDS and that was well illuminated so we got good video. I hope there is good lighting at X1 to get good video but at the same time I hope there are no lights above ground level to get in the way. Not sure what I mean, just thinking out loud.
Well, what I think I mean is that on the ASDS there are containers and other tall objects sticking up at the ends which present some degree of hazard to an approaching F9. Mounting flood lights up on these objects doesn't appreciably increase the potential for a collision. But in a wide open flat field there there isn't as much opportunity for light placement other than at ground level without increasing the chance of collision.
Hmmm, or perhaps if we see towers for lights and cameras relatively proximate to the pad it means that the initial targeting isn't to the center of the pad with a random circular error around the center of the pad but rather that the initial targeting is elsewhere (and if so likely to be a bit offshore as many have speculated), with a planned approach path from the initial target through the gap in the light poles to the pad.
Hmm., anyone have a current pic of the pad area?
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#873
by
WindyCity
on 11 Dec, 2015 03:49
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There barge will in all likelihood be deployed for this flight. They can divert to the barge "at the last minute" (for a suitable definition of last).
The barge story does not end with a land landing. There are still plans to land F9 and FH stages far out to sea on performance-critical missions. Even if spurned this month, they will return. We'll see a sea landing at some point.
Answers my question! Thanks! I wasn't aware that the landing site could be switched "at the last minute," suitably defined. Fascinating! The vehicle it has, apparently, a lot of built-in guidance flexibility for targeting its landing location. I wonder to what extent different mission profiles (based on the mass of satellite(s), LEO or GTO) determines which platform to target. (But that's off topic for this thread.)
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#874
by
Coastal Ron
on 11 Dec, 2015 04:00
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There barge will in all likelihood be deployed for this flight. They can divert to the barge "at the last minute" (for a suitable definition of last).
The barge story does not end with a land landing. There are still plans to land F9 and FH stages far out to sea on performance-critical missions. Even if spurned this month, they will return. We'll see a sea landing at some point.
Answers my question! Thanks! I wasn't aware that the landing site could be switched "at the last minute," suitably defined. Fascinating! The vehicle it has, apparently, a lot of built-in guidance flexibility for targeting its landing location...
I'm not sure he meant the Falcon 9 would have the flexibility to decide itself. I would imagine that at some point prior to liftoff that they will enter in the one destination the 1st stage is supposed to try to land at. And that point in the countdown might even play into how much fuel they load too, so it could be more than minutes before launch - more like hours.
Remember they should know hours in advance whether they have clearance to attempt a return to launch site landing and if the weather conditions will allow for that, and they will know the sea state and predicted weather for the barge too.
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#875
by
Johnnyhinbos
on 11 Dec, 2015 04:34
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One thing I think can never be stressed enough because it seems people easily forget it - the competition ALWAYS (stress _always_) destroys their hardware on every launch. When a company contracts, say an Atlas V to put their payload into [destination], they are paying for the entire enchilada. Engines, tanks, avionics, everything. After the proper insertion it's toast. So if SX decides they want to blow it up in a spectacular way, who cares? It's no more of a loss than every other rocket delivery system ever.
People seem to forget that point...
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#876
by
QuantumG
on 11 Dec, 2015 04:57
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Intended explosions are more common than unintended ones. That's what makes the unintended ones newsworthy.
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#877
by
Coastal Ron
on 11 Dec, 2015 05:30
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So if SX decides they want to blow it up in a spectacular way, who cares? It's no more of a loss than every other rocket delivery system ever.
Sure they could. But SpaceX has shown that they never waste an opportunity to learn. Which is why they have "landed" many stages in the ocean, even though they had no plan to recover them - real data to feed back into their simulations. And all it costs is a little extra fuel.
And no doubt SpaceX employees will be dancing in the aisles if they successfully deliver their customer payloads, yet fail to recover the 1st stage. They know what it takes to be allowed to continue experimenting...
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#878
by
the_other_Doug
on 11 Dec, 2015 12:27
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As for how quickly SpaceX can retarget the first stage to a different destination, recall that on an earlier flight, when the sea state was too rough to attempt a landing on the ASDS, the stage was re-targeted late in the count to land something like 10 km from the barge, onto the sea and away from the ASDS "flotilla".
So, I imagine they can retarget from the RTLS trajectory to one that targets the ASDS fairly late in the count, if weather or other conditions call for it.
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#879
by
Kabloona
on 11 Dec, 2015 13:09
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As for how quickly SpaceX can retarget the first stage to a different destination, recall that on an earlier flight, when the sea state was too rough to attempt a landing on the ASDS, the stage was re-targeted late in the count to land something like 10 km from the barge, onto the sea and away from the ASDS "flotilla".
So, I imagine they can retarget from the RTLS trajectory to one that targets the ASDS fairly late in the count, if weather or other conditions call for it.
In the case you cite, they may have repositioned the barge away from the landing zone at the last minute, rather than retargeting the stage itself. It may have been as simple as the support ship radioing the barge a command to maneuver itself to a pre-programmed "divert" position.
But it does make sense that eventually they would/will (maybe now with the FT upgrade) add the ability to retarget late in the count, especially when the choice is between RTLS and a barge landing.
nice point, it may be not much sleep that night, but since I still am young and not 50 for another month that dont matter much. 