Author Topic: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video  (Read 160692 times)

Offline Llian Rhydderch

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #200 on: 07/26/2014 05:12 AM »
That's certainly better than nothing, but I don't think it's sufficient for the claim they've made here. They need to recover the stage.

In the US, that kind of a statement made by a company is known as a "forward-looking statement."  However, since SpaceX is not publically traded on the open stock exchanges, any legal and jurisprudential standards for such statements (and potentially "misleading" investors) are much lower than they are for publically-traded companies.

Overall, when Must/SpaceX speaks "confident", I think that is just vernacular English for "highly likely", or maybe P > (say) 0.9 or so.  Net:  Musk really believes his test program to date has shown him that the big hurdles can be solved by good engineering in the ongoing SpaceX reusable technology development program, and that he believes they can (eventually or soon) recover and refly a stage.

For my money, I would think they do have sufficient data from the (now) three-pronged test program (Grasshopper, F9R Dev flights in Texas; plus the three controlled descent tests from high altitude and high Mach) to say what they have said.
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Offline aero

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #201 on: 07/26/2014 05:18 AM »
I'm still wondering why we haven't seen any surface video of the return. They show surface video of the Dragon returns after all and surface video goes a long way toward proving that they know where it will touch down. Video shot from aircraft is good, (Casiope) but one could argue that an airplane could move several miles toward the touch down while the stage is returning. A boat can't move far at all during the return.

A boat with a GPS and ship to shore radio setting a sea anchored buoy then standing off and filming the buoy while the stage touches down beside (on top of) it would work. Need the radio in case of a scrub  :(
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Offline deruch

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #202 on: 07/26/2014 06:44 AM »
Decent chance of that with "sold surface" landings planned for flights 14 &15.
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Offline guckyfan

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #203 on: 07/26/2014 06:54 AM »
I'm still wondering why we haven't seen any surface video of the return.

I have wondered that too. It may be because they keep a larger distance until precision landing is proven. A rocket stage descending under engine power poses a bigger risk than a capsule under a parachute.

Offline mikelepage

I was probably too wordy in my earlier post to encourage replies (http://forum.nasaspaceflight.com/index.php?topic=35243.msg1232564#msg1232564), but I did want to make the point that any future recovery of the second stage in flights from the Cape to LEO would likely have to be on a ship-based platform off Western Australia (as opposed to a land-based platform).  Therefore, experience recovering the first stage on a ship-based platform will be useful, even if the eventual plan is to bring first stages back to the pad.  I'm looking forward to flights 14 & 15 :)

Offline guckyfan

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #205 on: 07/26/2014 08:59 AM »
I was probably too wordy in my earlier post to encourage replies (http://forum.nasaspaceflight.com/index.php?topic=35243.msg1232564#msg1232564), but I did want to make the point that any future recovery of the second stage in flights from the Cape to LEO would likely have to be on a ship-based platform off Western Australia (as opposed to a land-based platform).  Therefore, experience recovering the first stage on a ship-based platform will be useful, even if the eventual plan is to bring first stages back to the pad.  I'm looking forward to flights 14 & 15 :)

Why would you think that? More likely they will bring the second stage back to the launch pad, too. After ~12 hours it shouuld pass over that point again.

Offline douglas100

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #206 on: 07/26/2014 09:31 AM »
This post does come to the topic - bear with me :)

I know I saw somewhere (maybe for CRS-3) an exclusion zone map for the second stage coming down off the coast of Western Australia.  Being a resident of Perth WA, I began wondering if SpaceX is likely to attempt to build landing pad(s) somewhere near me, (or maybe if it will be more efficient to give the second stage just enough of an extra boost so it comes down somewhere near Florida after the first full orbit)

Any second stages returning to land on current trajectories would have to come down somewhere on the WA coast....

No they wouldn't. Just because SpaceX chose to de-orbit the second stage in that area for this flight doesn't mean a future re-usable stage would do that. Why would they ever chose to bring the stage down  in an area which has the maximum distance to transport the stage home? Bear in mind a recoverable second stage is a spacecraft. It essentially has to do what Dragon has to do for re-entry and landing. Why would they consider landing the stage on a platform at sea (extra cost and complexity of operations) when they can land it anywhere on land between the latitudes of the orbital inclination?

But I notice we're getting OT here and I'm contributing to it. I shall reprimand myself and say no more!


Douglas Clark

Offline mikelepage

This post does come to the topic - bear with me :)

I know I saw somewhere (maybe for CRS-3) an exclusion zone map for the second stage coming down off the coast of Western Australia.  Being a resident of Perth WA, I began wondering if SpaceX is likely to attempt to build landing pad(s) somewhere near me, (or maybe if it will be more efficient to give the second stage just enough of an extra boost so it comes down somewhere near Florida after the first full orbit)

Any second stages returning to land on current trajectories would have to come down somewhere on the WA coast....

No they wouldn't. Just because SpaceX chose to de-orbit the second stage in that area for this flight doesn't mean a future re-usable stage would do that. Why would they ever chose to bring the stage down  in an area which has the maximum distance to transport the stage home? Bear in mind a recoverable second stage is a spacecraft. It essentially has to do what Dragon has to do for re-entry and landing. Why would they consider landing the stage on a platform at sea (extra cost and complexity of operations) when they can land it anywhere on land between the latitudes of the orbital inclination?

But I notice we're getting OT here and I'm contributing to it. I shall reprimand myself and say no more!

Ah right, I see I was confused about why that landing zone was chosen.  My bad.

Offline cscott

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #208 on: 07/26/2014 03:09 PM »
I'm still wondering why we haven't seen any surface video of the return. They show surface video of the Dragon returns after all and surface video goes a long way toward proving that they know where it will touch down. Video shot from aircraft is good, (Casiope) but one could argue that an airplane could move several miles toward the touch down while the stage is returning. A boat can't move far at all during the return.

The NASA crew failed to obtain video: it was too hard to track the rocket.  They will reportedly try again for CRS-4.  There might be other video, but remember this is only the *first* shot they've had at capturing landing video -- the CRS-3 flight has terrible weather, so they didn't even get to try then.  Yes, we have good surface video of Dragon now --- but there have been five Dragons.  I seem to recall the first dragon didn't have great surface splashdown photos either.  And remember that parachute landings are quite leisurely compared to the propulsive landing process.

Offline Comga

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #209 on: 07/26/2014 11:50 PM »
I'm still wondering why we haven't seen any surface video of the return. They show surface video of the Dragon returns after all and surface video goes a long way toward proving that they know where it will touch down. Video shot from aircraft is good, (Casiope) but one could argue that an airplane could move several miles toward the touch down while the stage is returning. A boat can't move far at all during the return.

The NASA crew failed to obtain video: it was too hard to track the rocket.  They will reportedly try again for CRS-4.  There might be other video, but remember this is only the *first* shot they've had at capturing landing video -- the CRS-3 flight has terrible weather, so they didn't even get to try then.  Yes, we have good surface video of Dragon now --- but there have been five Dragons.  I seem to recall the first dragon didn't have great surface splashdown photos either.  And remember that parachute landings are quite leisurely compared to the propulsive landing process.

We were told that the NASA plane went to record the hypersonic retro-burn.   Where was is said that they would attempt to photograph the landing?
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline cscott

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #210 on: 07/27/2014 02:35 AM »
I didn't. Perhaps my use of the pronoun "they" confused you.

Offline PeanutGallery

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #211 on: 07/27/2014 03:53 AM »
Considering SpaceX's lawsuit against the Air Force, I guess it's very unlikely they'll agree to allowing the use of their RC-135S Cobra Ball to observe/video the booster return, even if it was available...this is their regular job...
« Last Edit: 07/27/2014 03:53 AM by PeanutGallery »

Offline Lars_J

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #212 on: 07/27/2014 05:39 AM »
Considering SpaceX's lawsuit against the Air Force, I guess it's very unlikely they'll agree to allowing the use of their RC-135S Cobra Ball to observe/video the booster return, even if it was available...this is their regular job...


The Air Force has been sued before by contractors (even current ones... hmm), but that isn't part of the picture that a certain competitor is trying to spread.

The Air Force are big boys, they can handle it.
« Last Edit: 07/27/2014 05:45 AM by Lars_J »

Online Dave G

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #213 on: 07/27/2014 10:45 AM »
Considering SpaceX's lawsuit against the Air Force, I guess it's very unlikely they'll agree to allowing the use of their RC-135S Cobra Ball to observe/video the booster return, even if it was available...this is their regular job...

Quote from Elon Musk:
Quote
"It’s not as though we’re battling the whole Air Force. That’s not the case at all.  I think we’re on very good terms with the vast majority of the Air Force. Our concern really relates to a handful of people in the procurement area of the Air Force.”

Offline GregA

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #214 on: 07/27/2014 02:54 PM »
Looking at the video, I was surprised at how late the landing legs deployed.<snip>
I've read a few comments about timing of the legs, and consistency with the CRS-3 landing. So I decided to do a split screen video on both landings and watch them side by side - and this lead to me adding one thing after another until my wife said I've spent too much time on this.

So here's a link to my 2 minute combination of 5 videos showing the reusability of the first stage. :)






Offline guckyfan

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #215 on: 07/27/2014 03:19 PM »
Looking at the video, I was surprised at how late the landing legs deployed.<snip>
I've read a few comments about timing of the legs, and consistency with the CRS-3 landing. So I decided to do a split screen video on both landings and watch them side by side - and this lead to me adding one thing after another until my wife said I've spent too much time on this.

So here's a link to my 2 minute combination of 5 videos showing the reusability of the first stage. :)

Great video. Thanks. So the legs deploy in parallel.

Offline Tuts36

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #216 on: 07/27/2014 05:43 PM »

I've read a few comments about timing of the legs, and consistency with the CRS-3 landing. So I decided to do a split screen video on both landings and watch them side by side - and this lead to me adding one thing after another until my wife said I've spent too much time on this.

So here's a link to my 2 minute combination of 5 videos showing the reusability of the first stage. :)

Great video. Thanks. So the legs deploy in parallel.

No no, you spent JUST ENOUGH time on it - thank you for this!

I notice the same "bounce" in the (edit: deployement of the) landing legs both times, and the elapsed time between leg deploy & splashdown looks VERY precise for both.  Does that imply something about how the first stage detects the landing surface?
« Last Edit: 07/27/2014 05:44 PM by Tuts36 »

Offline MTom

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #217 on: 07/27/2014 08:26 PM »
Looking at the video, I was surprised at how late the landing legs deployed.<snip>
I've read a few comments about timing of the legs, and consistency with the CRS-3 landing. So I decided to do a split screen video on both landings and watch them side by side - and this lead to me adding one thing after another until my wife said I've spent too much time on this.

So here's a link to my 2 minute combination of 5 videos showing the reusability of the first stage. :)


Very good comparison.

What I see: the last part of the landing, while the engine blows the dust/vapor away has other length at the test flights and at the ocean landings:
- 1:49-1:52 at ocean landings
- 1:49-1:57 at F9R landings

Maybe the landing speed is higher (this is my guess as explanation) at ocean landing? More aggressive deceleration in this case? Or the engine was shut down earlier because of the water?

I tried to measure the velocity of objects on the video before 1:49. The waves at CRS-3 seems to be more speedy going away from the rocket, than the object on the F9R videos, but I don't know if the video restoring was enough accurate to use for this measurement.
« Last Edit: 07/27/2014 08:30 PM by MTom »

Offline GregA

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #218 on: 07/27/2014 09:57 PM »
Thanks for the feedback I'm glad you liked it :)

Very good comparison.

What I see: the last part of the landing, while the engine blows the dust/vapor away has other length at the test flights and at the ocean landings:
- 1:49-1:52 at ocean landings
- 1:49-1:57 at F9R landings

Maybe the landing speed is higher (this is my guess as explanation) at ocean landing? More aggressive deceleration in this case? Or the engine was shut down earlier because of the water?
Yes I was wondering about the same things.

Your second guess appears correct - the engines get doused earlier in the water, at about the same time in the video as the F9R stops moving. The F9R seems to keep the engines going 5 more seconds, perhaps it's some sort of stability (slow reduction in power?) or landing checks before powering down? 

edit: I'm certainly not sure of my interpretation. The rocket may be moving slightly. In any case, if it's designed to be very slow in the last seconds, a wave would put an end to that...?

Quote
I tried to measure the velocity of objects on the video before 1:49. The waves at CRS-3 seems to be more speedy going away from the rocket, than the object on the F9R videos, but I don't know if the video restoring was enough accurate to use for this measurement.
I would say that at the beginning of the F9R descent in the video, it's moving more slowly (much more slowly?) than the water landings. By the time they reach ground/water level they all seem to move equally slowly.
« Last Edit: 07/27/2014 11:14 PM by GregA »

Offline deruch

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Re: Falcon 9 v1.1 ORBCOMM - First Stage Ocean Landing Video
« Reply #219 on: 07/28/2014 01:06 AM »
Great vid!  The only minor critique I have is that we're pretty sure that there wasn't a boost-back, just re-entry and landing burns.  So, if I was making this video (I'm in no way skilled enough to make one anywhere near as good as your is though), I don't think I would show one even in animation.  But this is a fairly minor technical point.  Great job!
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