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SpaceX Vehicles and Missions => SpaceX Facilities and Fleets => Topic started by: Chris Bergin on 03/10/2016 01:02 AM

Title: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris Bergin on 03/10/2016 01:02 AM
Thread 3 for the ASDS Fleet.

Honorary Thread 0:
http://forum.nasaspaceflight.com/index.php?topic=35244.0
(Topic: Where will F9 flights 14 & 15 attempt "solid surface" landings?  (Read 134296 times) )

Honorary thread 0b: http://forum.nasaspaceflight.com/index.php?topic=31452.0
(Topic: First stage recovery at down-range locations  (Read 89853 times) )

Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=36140.0

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36326.0

The small matter of 1.65 million views, for a barge, that catches rockets....not much interest there then! ;)

Total views for these three "barge" threads: 1,655,527

Main Articles:
http://www.nasaspaceflight.com/2014/11/spacex-autonomous-spaceport-drone-ship/
(Also contains links to other articles covering reusability tech).

https://www.nasaspaceflight.com/2015/06/spacex-augments-upgrades-drone-ship-armada/
(Also contain links to cover the fleet's evolution).

Other ASDS Articles (launches and such that involved the ASDS):
https://www.nasaspaceflight.com/?s=%28ASDS%29

Also:

SpaceX Articles:
http://www.nasaspaceflight.com/tag/spacex/

L2 SpaceX Section:
http://forum.nasaspaceflight.com/index.php?board=55.0

----

As noted, threads on this site's forum get a lot of views. When you post, consider a lot of people are going to read your post. As such make your post worth reading. "Barge, LOLZ" is not worth reading. ;) Images from external sources need an accreditation link. That should do it, so I'll let you get on with your business.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/10/2016 01:27 AM
I've been giving some thought to the hole in the deck. I'm not worried it holed the hill bottom too, because the ASDS was most likely ballasted (so there would have been water between the deck and hull bottom).

However... We've seen what LOX and RP1 do when they combine during other hard landings. Now, imagine that happening INSIDE the hull. I hope it didn't.

Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/10/2016 01:31 AM
Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 
I expect that depends on what the lease agreement says. Informed speculation holds that these are leased vessels, not purchased, and that they will someday perhaps be returned. The agreement may say that significant damages have to be repaired before returning, or repaired whenever damage happens (in case the return happens early, etc.)  so a patch like that might be OK for a while, or might be OK forever, or might not be OK at all because they want a real repair with replacement at the normal seams, not patching....
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/10/2016 01:33 AM
Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 
I expect that depends on what the lease agreement says. Informed speculation holds that these are leased vessels, not purchased, and that they will someday perhaps be returned. It may say that they have to be repaired before returning, or repaired whenever damage happens (in case the return happens early, eto)  so a patch like that might be OK for a while, or might be OK forever, or might not be OK at all.

Also kinda depends on when they'll need OCISLY to sail again, in terms of how quick-and-dirty the fix has to be.  As I just inquired in the CSR-8 discussion thread, if they try an RTLS on that flight, we may not have a need for OCISLY for a couple of months or more.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/10/2016 01:35 AM
I believe a skilled welder could have the deck in like new condition in a day or two. Replacing the damaged equipment will take longer.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/10/2016 01:35 AM
Thread 3 for the ASDS Fleet.

Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=36140.0

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36326.0

To this I want to add what I consider Thread 0, where NSF members first started sifting through the clues that SpaceX might have been headed toward using an ocean landing platform.

Thread 0:
http://forum.nasaspaceflight.com/index.php?topic=35244.0
or Topic: Where will F9 flights 14 & 15 attempt "solid surface" landings?  (Read 134296 times)

Total views for these three "barge" threads: 1,655,527


edit: note that it was Kabloona that started the initial thread and he's been active thorough all of this.  A fact that Elon recognized when he named the phenomenon that happens when a rocket falls over as "kaboom".   ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/10/2016 01:35 AM
I've been giving some thought to the hole in the deck. I'm not worried it holed the hill bottom too, because the ASDS was most likely ballasted (so there would have been water between the deck and hull bottom).

Good point.

However... We've seen what LOX and RP1 do when they combine during other hard landings. Now, imagine that happening INSIDE the hull. I hope it didn't.

Well, there's no evidence from the photo that it did.  One would also assume the ballast water to be relatively RP1-free, otherwise they wouldn't be pumping it over the side..

Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints?

It's really no big deal to cover the hole - cut out the daggy bits and weld a new plate in place.  The issue will be if there's any damage to the sub-structure (ribs, deck beams) and needing to repair those first ...to the satisfaction of their local USCG/ABS Inspector.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 01:52 AM
edit: note that it was Kabloona that started the initial thread and he's been active thorough all of this.  A fact that Elon recognized when he named the phenomenon that happens when a rocket falls over as "kaboom".   ::)

Thanks for the nod, but pure coincidence I assure you.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Rocket Science on 03/10/2016 01:53 AM
Great to hear that Elon wants to go for "another hole in one"... ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 01:56 AM
Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 
I expect that depends on what the lease agreement says. Informed speculation holds that these are leased vessels, not purchased, and that they will someday perhaps be returned. It may say that they have to be repaired before returning, or repaired whenever damage happens (in case the return happens early, eto)  so a patch like that might be OK for a while, or might be OK forever, or might not be OK at all.

Also kinda depends on when they'll need OCISLY to sail again, in terms of how quick-and-dirty the fix has to be.  As I just inquired in the CSR-8 discussion thread, if they try an RTLS on that flight, we may not have a need for OCISLY for a couple of months or more.

Someone just pointed out in the CRS-8 thread that the mission patch has been posted on Reddit and does not show a barge, FWIW.

And RTLS landing would give them more time to repair the barge, plus give them a higher probability of successful recovery, so I'm inclined to believe the barge will be out of action for a while.

(I had thought Elon's tweet implied next flight would be another barge landing attempt, but now I think I read too much into it.)

Quote
Elon Musk ‏@elonmusk
Rocket landed hard on the droneship. Didn't expect this one to work (v hot reentry), but next flight has a good chance.

"Next flight has a good chance" because it will be RTLS?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Wolfram66 on 03/10/2016 02:58 AM
Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines. There are a variety of reasons that SpaceX made decisions to use this design:

A closed hydraulic system separate of the main RP-1 tank would require a pump to repressurize the RP-1 for reuse. This adds weight and complexity to something which you really don't want to make much heavier or more complex.

A closed hydraulic system that uses the RP-1 from the main tank is also infeasible as it would require a pump to push RP-1 up from the tank near the engines right to the top of the vehicle. There is no easy way of doing this.

Switching to an electromechanical system would require a very large amount of power to operate, which would require an impractical amount of batteries.

All three of the above solutions require pumps to be active or some energy storage mechanism - not very attractive or really suitable for Falcon 9 as the engines are only burning over a subset of the return trajectory.

The grid fins are deployed at approximately T+5 minutes. This is before the reentry burn takes place, which does not last for very long. For the majority of the time the grid fins are deployed, Falcon 9 is in free flight. SpaceX's solution is rather clever, actually:

It does not require power from the engines to operate.

It doesn't involve a complex plumbing solution which adds weight to lift the RP-1 up from the bottom tank

It doesn't add much mass beyond the pressure vessel, since the RP-1 is "free" as it can be "reused" by the engines.

Overall, it weighs less than a similar amount of pressurized Nitrogen cold gas to steer.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/10/2016 03:15 AM
Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines. There are a variety of reasons that SpaceX made decisions to use this design:

I don't think its been established that the hydraulic fluid being used is fuel.  I don't think its been established that the expended fluid goes into the main fuel tank.  These have been speculated as likely and seem so but I don't think its been proven.  Or am I wrong?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/10/2016 03:20 AM
I believe a skilled welder could have the deck in like new condition in a day or two. Replacing the damaged equipment will take longer.

Good point. I've done some welding (I'm not good at it though) so what I'd look at first is what's damaged below the deck plate: that, IMHO, will be the hard part, because we'd be talking structural members.

It's also IMHO a question of when it needs to be done by.

As mentioned upthread, there's no ASDS on the CRS-8 mission patch, which strongly hints at a RTLS. If the F9 1.2 (or should I call it F9 FT?) has the capacity to do RTLS on a Dragon launch, my strong guess is that doing so would be the preferred option. If so,  OCISLY may have plenty of time for repairs, refurbishment, R&R, etc.   

Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 
I expect that depends on what the lease agreement says. Informed speculation holds that these are leased vessels, not purchased, and that they will someday perhaps be returned. The agreement may say that significant damages have to be repaired before returning, or repaired whenever damage happens (in case the return happens early, etc.)  so a patch like that might be OK for a while, or might be OK forever, or might not be OK at all because they want a real repair with replacement at the normal seams, not patching....
I've never dealt with a maritime lease, but I've dealt with all sorts of commercial building leases. *IF* there's a similarity, a temporary repair would be okay for a while under most, especially if it's needed to avoid any downtime. The caveats would be that the temp repair does not risk further damage, and meets codes. On the other hand, most commercial building owners would not be okay with the lessee firing enormous rockets at it. :)

However... We've seen what LOX and RP1 do when they combine during other hard landings. Now, imagine that happening INSIDE the hull. I hope it didn't.

Well, there's no evidence from the photo that it did.  One would also assume the ballast water to be relatively RP1-free, otherwise they wouldn't be pumping it over the side..


Good point; pumping water over the side is indeed a pretty clear indication of no contamination. You also raised an excellent point regarding stratifying inspectors when it comes to fixing the hole. I darkly suspect that'll take much longer than the actual repairs.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Comga on 03/10/2016 04:19 AM
Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines. There are a variety of reasons that SpaceX made decisions to use this design:

I don't think its been established that the hydraulic fluid being used is fuel.  I don't think its been established that the expended fluid goes into the main fuel tank.  These have been speculated as likely and seem so but I don't think its been proven.  Or am I wrong?

Wolfram66 is stating all this as facts.
Either its complete and detailed speculation without any statement to that effect ...
or Wolfram66 is in a position to know and to discuss it in a public thread.
I certainly hope it's the latter as this is precisely the kind of details I want to learn about and understand.


PS If SpaceX is using fuel that gets dumped into the fuel tank, why wouldn't they pressurized with Helium?
There is a large supply of He and it's the gas already being used to pressurize the fuel.
Is it because they need an even higher pressure, because the hydraulic actuators would be powered by the differential pressure, and the fuel tank drain is itself pressurized?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/10/2016 04:52 AM
Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints? 
I expect that depends on what the lease agreement says. Informed speculation holds that these are leased vessels, not purchased, and that they will someday perhaps be returned. The agreement may say that significant damages have to be repaired before returning, or repaired whenever damage happens (in case the return happens early, etc.)  so a patch like that might be OK for a while, or might be OK forever, or might not be OK at all because they want a real repair with replacement at the normal seams, not patching....
I've never dealt with a maritime lease, but I've dealt with all sorts of commercial building leases. *IF* there's a similarity, a temporary repair would be okay for a while under most, especially if it's needed to avoid any downtime. The caveats would be that the temp repair does not risk further damage, and meets codes. On the other hand, most commercial building owners would not be okay with the lessee firing enormous rockets at it. :)

Lease or no lease, the way the maritime regulations stand, that hole needs to be fixed to the satisfaction of the USCG, ABS, SpaceX, the owners, workers, insurers and any other Joe who happens by... so there really isn't any option other than to fix it properly.

At the end of the day, unless the ASDS is "in all respects fit for sea", it doesn't go anywhere.

However... We've seen what LOX and RP1 do when they combine during other hard landings. Now, imagine that happening INSIDE the hull. I hope it didn't.

Well, there's no evidence from the photo that it did.  One would also assume the ballast water to be relatively RP1-free, otherwise they wouldn't be pumping it over the side..


Good point; pumping water over the side is indeed a pretty clear indication of no contamination. You also raised an excellent point regarding stratifying inspectors when it comes to fixing the hole. I darkly suspect that'll take much longer than the actual repairs.

"Stratifying inspectors".. I like that.  Stringing 'em up and hosing 'em down doesn't work either.  ;D

Anyways, it really depends on the extent of the damage.  If whatever-it-was managed to miss anything vital (given the hole is located in the corner of one of the tanks as can be seen by following the deck-plate joins they sure came mighty close!) it could be just a quick phone call, drive down, peek in the hole, "she'll be right" and weld it all back up again.

...but if they took out a rib or deck beam or two then, yes, that could take a while.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: BlazingAngel665 on 03/10/2016 05:30 AM
Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines. There are a variety of reasons that SpaceX made decisions to use this design:

I don't think its been established that the hydraulic fluid being used is fuel.  I don't think its been established that the expended fluid goes into the main fuel tank.  These have been speculated as likely and seem so but I don't think its been proven.  Or am I wrong?

Wolfram66 is stating all this as facts.
Either its complete and detailed speculation without any statement to that effect ...
or Wolfram66 is in a position to know and to discuss it in a public thread.
I certainly hope it's the latter as this is precisely the kind of details I want to learn about and understand.


PS If SpaceX is using fuel that gets dumped into the fuel tank, why wouldn't they pressurized with Helium?
There is a large supply of He and it's the gas already being used to pressurize the fuel.
Is it because they need an even higher pressure, because the hydraulic actuators would be powered by the differential pressure, and the fuel tank drain is itself pressurized?

Most of what Wolfram66 has said meshes well with what is known for certain. Elon's tweets after the first ASDS hard landing tell us that the hydraulic system is definitely open loop. Using Nitrogen as a pressurant makes good sense based upon the location of all the components. RP-1 is used as a hydraulic fluid for TVC so it makes good sense to use it again for gridfin actuation. Finally we know that the reserve of fluid for the grid fins is separate from the normal RP-1 supply and  non replenish-able, so having a separate reservoir makes sense as well. I'd treat most of that as fairly certain.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Robotbeat on 03/10/2016 05:40 AM
I doubt you'd use RP-1 if you're using a separate reservoir.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: vanoord on 03/10/2016 07:22 AM
I doubt you'd use RP-1 if you're using a separate reservoir.

Propylene glycol and water would be sufficient - with the advantage it can be discharged overboard after use as it's non-toxic.

I don't like the idea of using RP-1 and trying to return the waste to the main tank: I doubt the pressure in the grid fin hydraulic system is higher than the tank - which would prevent it getting there after use.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 07:41 AM
Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines.

I don't believe this is correct, and in any case what does it have to do with the ASDS? Wrong thread.

Grid fin hydraulic thread is over here:

http://forum.nasaspaceflight.com/index.php?topic=36536.0

Back to ASDS topics, please...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: symbios on 03/10/2016 10:41 AM
...

Incidentally, regarding repairing the hole; assuming there's not significant damage belowdecks, wouldn't slapping a bit over-sized steel plate atop the hole (It'd protrude above deck level, but only by its thickness) and welding it in place be good enough? Especially if there are time constraints?

It is never recommended to fixing a hole by slapping a patch over it. You will get moisture in between the plates and this will cause corrosion. Always cut out the bad part and weld in a new plate. It is not like it is a lot more work; it would only be sloppy workmanship not to.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/10/2016 11:48 AM
More grid fin stuff is off topic. Take it to the thread pointed out a few posts back. Or else your posts walk the plank. Savvy?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: starhawk92 on 03/10/2016 12:38 PM
Where would the repairs to the ASDS happen?  Can they fix it where it berths, or does it go to another port with the proper equipment and materials?  I lived in Kansas for a long time, so I know nothing about the sea/am the ultimate landlubber.

Thanks!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 01:06 PM
Where would the repairs to the ASDS happen?  Can they fix it where it berths, or does it go to another port with the proper equipment and materials?  I lived in Kansas for a long time, so I know nothing about the sea/am the ultimate landlubber.

Thanks!

The barge owner, McDonough Marine, is based on the Louisiana Gulf Coast, and that's where the barges have had their wings installed.

But hopefully this damage is minor enough that it can be done at Port Canaveral.  Welding equipment and steel plate are portable, as are experienced welders, and welding can be done even underwater if necessary (I just learned this by watching "Deadliest Job Interviews."  ;))
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/10/2016 02:37 PM
And JRtI had its wings installed in port, not at the Louisiana shipbuilder.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 02:46 PM
And JRtI had its wings installed in port, not at the Louisiana shipbuilder.

Yes, good point. I forgot that minor operation.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 05:59 PM
FCC permit for CRS-8 transmitters:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=69496&RequestTimeout=1000

ASDS location is given as 30.5 degrees N, 78.5 degrees W.

Permit does not guarantee an ASDS landing attempt on CRS-8, but it is apparently an option if they can get the repairs done fast enough.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Craig_VG on 03/10/2016 07:55 PM
Here are some more photos of the ASDS I took today. Drone, Panorama, and some shots from the Exploration Tower.

Full Album:

(Also caught a delta stage rolling up to the base)

http://imgur.com/a/SHt5g
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 03/10/2016 08:02 PM
So does it have a big hole dead centre or not? Most pictures say not, the first aerial view suggests it does, but maybe a bit of photoshop?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/10/2016 08:09 PM
I was the one that speculated that there may have been a hit dead center.  Shadows from scrap that was nearby was the other possibility.  This and other pictures prove that there never was a hard hit there.

But on the other side, the newly exposed bottom side, there appear to be more barnacles than I've ever seen in one place, about 2/3 of an acre of them.

edited, meant to say "never was" not "never wasn't".
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OnWithTheShow on 03/10/2016 09:04 PM
I was the one that speculated that there may have been a hit dead center.  Shadows from scrap that was nearby was the other possibility.  This and other pictures prove that there never wasn't a hard hit there.

Do you mean "never was"?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Okie_Steve on 03/10/2016 09:53 PM
Anyone know enough about metallurgy to estimate the minimum force required to puncture the steel plating?
That and dry mass would give a lower bound on the velocity at contact.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 10:12 PM
Anyone know enough about metallurgy to estimate the minimum force required to puncture the steel plating?
That and dry mass would give a lower bound on the velocity at contact.

I think we have a reasonable idea of deck plate thickness, well enough to make a meaningful guesstimate, but the result will be strongly influenced by the assumed contact area, which in turn depends on angle of impact, how the aft end of the stage deforms on impact, etc, etc.

OxCartMark did a detailed calculation a while back assuming all the steel plate in the barge was of equal thickness, and he got a result of 1" thick all around, so I'd trust that number as being in the right ballpark.

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1341509#msg1341509
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 03/10/2016 10:33 PM
Here are some more photos of the ASDS I took today. Drone, Panorama, and some shots from the Exploration Tower.

Full Album:

(Also caught a delta stage rolling up to the base)

http://imgur.com/a/SHt5g
Thanks!  Is that a person I see inside?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AncientU on 03/10/2016 10:41 PM
Anyone know enough about metallurgy to estimate the minimum force required to puncture the steel plating?
That and dry mass would give a lower bound on the velocity at contact.

I think we have a reasonable idea of deck plate thickness, well enough to make a meaningful guesstimate, but the result will be strongly influenced by the assumed contact area, which in turn depends on angle of impact, how the aft end of the stage deforms on impact, etc, etc.

OxCartMark did a detailed calculation a while back assuming all the steel plate in the barge was of equal thickness, and he got a result of 1" thick all around, so I'd trust that number as being in the right ballpark.

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1341509#msg1341509

By the look of that tear and the possibly wood structure below, I'm wondering if the deck is some type of composite.  One inch steel would have peeled back, not torn; maybe quarter inch plate could tear... And why would you install timbers below decks?

The welding the landing legs/pads to the deck was discussed for an earlier version of the ASDS.  New tie-downs could be because deck is no longer steel.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/10/2016 10:49 PM
Quote
By the look of that tear and the possibly wood structure below, I'm wondering if the deck is some type of composite.  One inch steel would have peeled back, not torn; maybe quarter inch plate could tear... And why would you install timbers below decks?

I think it did both "peel" and "tear." It looks from that photo like a big petal of the "peeled down" steel has been cut away. Timbers may have been to support the bent "petal" from below while it was being cut out.


(After peeled steel cut out:)

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39766.0;attach=1104036)




(Before peeled steel cut out:)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/10/2016 11:19 PM
OxCartMark did a detailed calculation a while back assuming all the steel plate in the barge was of equal thickness, and he got a result of 1" thick all around, so I'd trust that number as being in the right ballpark.

True I did that based on the assumption of uniform thickness of all outer surfaces and ballast partitions and my weight numbers came out exceedingly close to the known weight but afterward someone with fewer assumptions and more naval engineering knowledge (Docmordrid??) came in and convinced us very convincingly that the deck thickness was something else.  1/2"?,  I seem to vaguely recall.  If someone wants to sort through the 300+ pages of ASDS thread 2 they could probably find it.


Anyone know enough about metallurgy to estimate the minimum force required to puncture the steel plating?
That and dry mass would give a lower bound on the velocity at contact.

There are so many problems with trying to do that with normal classroom mechanical engineering knowledge, so many.  You've got strain rate sensitivity (the material's yield strength is higher in a fast hit than in a standard tensile test), you have deformation of the plate into a partial bulge so that even knowing the area of the break you aren't able to multiply that area simply by the shear strength (if it was punched out) or tensile strength (if it was domed and the dome pulled off), and you have the force at the interface of the plate and the rocket being divided between impact (accelerating the plate) and doing work to open the hole.  Also, its not going to happen simultaneously around the perimeter of the hole but rather it would be a sequence of local actions.

I'd guess that the best answer to your question if there is one will come from the military field where I presume there are charts or formulas of projectile size or mass or energy vs. ship hole size.  Perhaps if nobody steps forward with such info we could look around at ships that have been damaged by impacts of known energy (USS Cole comes to mind but probably much thicker steel plate) and work somewhat backward to see what energy and thus speed the stage would have.

Or wait a few more days and see if we can get speed info from the video.

OK, here is a really quick but useless extrapolation to be used for entertainment purposes only:
An online chart of punch press tonnage for these assumptions [1/2" A36 steel, 1" diameter punch] shows an expected punch force of 50 tons.  Assuming the situation of a hole being punched in a machine [all sheared at once, force is proportional to perimeter which is proportional to diameter] then for a 12 foot diameter the force would be 144x 50 tons or 7200 tons, 14.4M lbf, 6M kgf.  Don't take this calculation seriously other than to say you wouldn't want to have your finger between the crashing stage and the deck plate during the event.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 03/10/2016 11:28 PM
Six portable welders and a dude.

Steel delivery?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 03/10/2016 11:34 PM
OxCartMark is correct above that there are MANY variables here. Amusingly, a lot of this kind of analysis parallels the very empirical work performed in the WWII era and earlier by the U.S. Navy Bureau of Ships with regard to armor plate penetration studies using a wide variety of projectiles. The outlines of what's involved in a full analysis of that stuff can be gleaned from reading some of those old BuShips Battle Damage Assessment Reports and books/articles by trivia-obsessed #shipnerds, who spend as much time rehashing the Battle of Jutland as we do parsing ShitElonSays and SpaceX kremlinology - more, actually, since they've been at it for almost a century now.  Google is your friend if you want to dig into that stuff.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 03/10/2016 11:50 PM
(USS Cole comes to mind but probably much thicker steel plate)
Not necessarily thicker:

http://www.military.com/Content/MoreContent?file=FL_cole_bradp

Quote
The blast ripped a 40-by-20 foot hole in the Cole's half-inch-thick hull plates below the forward smokestack,

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/11/2016 12:11 AM
Quote
By the look of that tear and the possibly wood structure below, I'm wondering if the deck is some type of composite.  One inch steel would have peeled back, not torn; maybe quarter inch plate could tear... And why would you install timbers below decks?

I think it did both "peel" and "tear." It looks from that photo like a big petal of the "peeled down" steel has been cut away. Timbers may have been to support the bent "petal" from below while it was being cut out.

There's absolutely no doubt, and never has been, that it's a steel deck.. but let's agree it's approximately 3/4" thick (give or take 1/4") shall we?? :D

The timbers could also be propping up a busted deck beam whilst they get in there and weld it back in place.

It's telling to me that they've pumped out all their ballast tanks - anti-foul (what's left of it) showing all round, spill control boom yet no evidence of hydrocarbon sheen on the water - not something they normally do after target practice.  At first I thought maybe that meant they had a smallish leak, but it's more likely they need the compartment absolutely dry to carry out the repairs and do a close inspection of the hull from inside and want the work-site as level as possible.


Adding: Welding spatter and filings plus salt water = instant rust and is a right PITA to clean up afterwards - and you can't just leave it there either.  Usual practice the world over is to put down hessian sacks or similar and vacuum up afterwards and both of those things are kinda difficult inside a wet compartment.  And that's ignoring the discomfort caused by welding (heat) inside a poorly-ventilated black steel box with condensation running all around (and on!) you whilst you try to strike a spark.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 03/11/2016 12:16 AM
3/4" thick based on what? I have seen lots of speculation about deck thickness, but no authoritative citation.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Arb on 03/11/2016 12:23 AM
Is that a landing leg?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/11/2016 12:25 AM
3/4" thick based on what? I have seen lots of speculation about deck thickness, but no authoritative citation.

Refer OxCartMark's post back 5..

FWIW, I still think it's more likely on the 1/2" side of things - but I could be wrong. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 12:35 AM
Just noticed a thing or two in the pictures that Kabloona posted above.  That hole is in one of the compartments at the edge of the Marmac barge.  Beyond that is deck extension.  Hmm.  Let's back up and think about the impact slam event.  After the rocket scrap broke through the deck it would have done essentially a belly flop into the swimming pool below which had approximately 10 feet of water standing in it.  If it hit slowly then no big deal.  But if it had substantial remaining speed then it could have generated significant hydraulic pressure bulging out the plates around the impact.  That could be the bottom plate, the plates between compartments, or now I understand it could also be the plate on the side of the hull.  That plate is at the base of a number of deck extension braces.  I tried to go back to look at the side of the hull in the images we have of it coming into port but the image quality and lighting don't allow any conclusions.  http://forum.nasaspaceflight.com/index.php?topic=36326.msg1501108#msg1501108

Then we have the tank walls themselves which could have been directly impacted by the rocket coming down on their edge.  And internal bracing / structure may have been hit.

Below I'm re-re-posting some images that have been posted here before, both by meself and Ohsin depicting the tank divisions.  These are for only the Marmac barge, not the deck extensions.  I've added an approximately 12' red circle for scale but its location in the fore-aft direction is anybody's guess.

And then there's the dark spot approximately 1' in diameter just inside the cones and tape (Kabloona's picture above).  That is at the edge of the Marmac barge.  One might just hypothesize that it too is a hole.  One of the caps to the ballast tanks has been removed, that's what I observed.

I'm thinking that its probable that there will be multiple plates and structures that need to be replaced.  But still, relatively easy going with flat rectangular low carbon steel.

As for the image of the welders and stuff on the truck, I think some of those welders are plasma cutters.  The number of them would seem to indicate that they aren't planning to replace just the deck plate.  And that bundle of other stuff being lifted off the truck, not plate, something else.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 12:39 AM
There's absolutely no doubt, and never has been, that it's a steel deck.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 01:14 AM
Hmm, I just stumbled into another predecessor to this thread

Honorary thread 0b: http://forum.nasaspaceflight.com/index.php?topic=31452.0
Topic: First stage recovery at down-range locations  (Read 89853 times)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/11/2016 01:42 AM
Below I'm re-re-posting some images that have been posted here before, both by meself and Ohsin depicting the tank divisions.  These are for only the Marmac barge, not the deck extensions.  I've added an approximately 12' red circle for scale but its location in the fore-aft direction is anybody's guess.

And then there's the dark spot approximately 1' in diameter just inside the cones and tape (Kabloona's picture above).  That is at the edge of the Marmac barge.  One might just hypothesize that it too is a hole.

OxCartMark, I think you're a compartment too far aft.

Looking at the photo again and comparing the ballast tank diagram, the last compartment is at the stern and the stage hit is 8'-10' forward of the bulkhead (the one in line with the ends of the wings).  It looks to me like the stage hit took out a deck beam - right across the center of the hole - and damaged another aft of it.

I can't see any other damage that isn't part of the one big hole..

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 01:45 AM
Like rocket catching barges?  Got some time?  Try punching in "marmac 303" or "marmac 304 in this link and hitting search.  http://www.eagle.org/safenet/record/record_vesselsearch (http://www.eagle.org/safenet/record/record_vesselsearch)

Among other things you get inspection records and the type of steel used, which is 'ABS Grade A', which itself is a search term that will send you off to some interesting reading.
__________

Six portable welders and a dude.
You're going to need more dudes.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/11/2016 02:04 AM
To try and illustrate a couple of things, I'm attaching a marked-up detail of Craig's aerial-view post.

First, the yellow lines define the distance between the aft-most extent of the hole (almost exactly at the level of the wing "roots") and the end of the barge.  Looks to me like Mark's estimate in terms of which compartment was holed is pretty good, but I would think his first marked-up diagram, showing the hole to fore of the frame between the aftmost compartment and the one to fore of it, is more correct.  I think the wall between those compartments is just aft of the wing roots, not fore of them.

The yellow lines give a really good feel for the extent of distance between the aft end of the barge and where the hole was punched.  And it looks to me like the fore line, still aft of the hole, would be fore of the first compartment bulkhead.

Second, what seems to be being referred to as "the second hole" is a very dark area, somewhat similarly shaped to the obvious hole, just across the barge from the obvious hole.  I've circled it in red.  This area was covered by debris and tarps on the earlier aerial views, and seems to be one of the foci of the tire scuffs and drag marks that result from the piling up of the debris and its subsequent removal.

I'd be willing to bet that this really dark spot is a place where the decking had been extremely thoroughly washed.  Perhaps some type of fluid came out of the debris and pooled here, and either discolored the deck or required a very thorough cleaning?

Edit to correct picture attribution (oops, sorry) and to point out that I drew the yellow lines, and yes, I know the aft yellow line is about five feet behind the barge.  It was more visible there... :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/11/2016 02:16 AM
FCC permit for CRS-8 transmitters:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=69496&RequestTimeout=1000

ASDS location is given as 30.5 degrees N, 78.5 degrees W.

Permit does not guarantee an ASDS landing attempt on CRS-8, but it is apparently an option if they can get the repairs done fast enough.

So it's back to east of Jacksonville, about 173 mi off that coast and about 192 mi from Port Canaveral.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/11/2016 02:33 AM
Like rocket catching barges?  Got some time?  Try punching in "marmac 303" or "marmac 304 in this link and hitting search.  http://www.eagle.org/safenet/record/record_vesselsearch (http://www.eagle.org/safenet/record/record_vesselsearch)

Among other things you get inspection records and the type of steel used, which is 'ABS Grade A', which itself is a search term that will send you off to some interesting reading.

Drat!  The secret is out..  :-X

Seriously though: Yes, that's the place to go for details of any ABS-approved vessel.. and that's most commercial vessels in the USA.  In the case of our target-barges however, you'll find more recent updates on the USCG PSIX site (google it) because, in the case of the Marmacs, the USCG organise the inspections on behalf of ABS.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/11/2016 02:35 AM
Quote
I'd be willing to bet that this really dark spot is a place where the decking had been extremely thoroughly washed.  Perhaps some type of fluid came out of the debris and pooled here, and either discolored the deck or required a very thorough cleaning?

Hydraulic fluid from the grid fin reservoir ?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 02:41 AM
what seems to be being referred to as "the second hole" is a very dark area, somewhat similarly shaped to the obvious hole, just across the barge from the obvious hole.  I've circled it in red.  This area was covered by debris and tarps on the earlier aerial views, and seems to be one of the foci of the tire scuffs and drag marks that result from the piling up of the debris and its subsequent removal.

That is not the potential hole I was speculating as maybe being a hole.  I've marked up the first image below to show what I thought might be a hole.  But then I had a revelation.  It isn't another rocket puncture hole, its a hole. It is one of the many small holes with removable covers that the barge has for access to the ballast tanks.  Its placement along the edge is a guarantee of that, final answer.  The last three images I'm posting are of some of these holes from previous discussion.  Case closed (before it was much open).  Even the green garden hose seems to be the same.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/11/2016 06:26 AM
Thanks for those amazing images Craig_VG :) First stage took out two ballast compartments and it did that to what I assume is second most strong region on barge deck first would be where four compartments meet.

If it lande.. I mean ploughed through middle of ballast compartment damage might have been much more.

Hole aligns to covered bollard box on sides(3rd from stern)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 12:46 PM
First stage took out...
I feel you know more about ASDS anatomy than anyone on this board so its hard to argue with you but according to your dimensioned diagram that I reposted above that cross ship bulkhead, the second from the rear that you think was hit is 79' 9" forward of the stern.  I have a hard time scaling that distance using something of known width such as the 8.0 foot wide shipping containers.

Hole aligns to covered bollard box on sides(3rd from stern)
What is a bollard box?  You might have to point this feature out.  Not knowing the answer to this it appears  to me that your line across the deck is based on following a pre-existing line across the deck, presumably a weld line?  Which would presumably be on top of a bulkhead as you say(?)

And as a reminder to everyone, the red circles I posted above are very approximate in their fore-aft placement, I'm not suggesting any accuracy there.  There may be some degree of accuracy in the diameter of the circle and its cross ship placement.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/11/2016 02:17 PM
From the exploration tower photos it appears that the on-site forensics are done and they are well into the cleanup phase.  I see wood packing crates scattered over the deck, each filled with "Falcon droppings" and then another large blue steel shipping container which appears to have the "big stuff" (tank panels, etc).  As noted above, they've already cut off some of the peeled back steel, pumped the ballast tanks dry, and ordered a bunch of welders and/or cutters for the repair work.  There are some open boxes near the "down" Thrustmaster which might be repair parts. The urgency might give us a clue as to whether OCISLY might be used for CRS-8.

I'm a little disappointed: I was hoping for some bottom hull fix-up, and that MARMAC 300 might be recalled for the job.  I was imagining MARMAC 300 getting some timbers lashed to the top, being submerged under OCISLY, and then triumphantly refloated, lifting OCISLY, to be the new temporary work area.  Aw, never mind---I can see it so clearly in my head I don't need for it to happen in real life. ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/11/2016 05:25 PM
I was imagining MARMAC 300 getting some timbers lashed to the top, being submerged under OCISLY, and then triumphantly refloated, lifting OCISLY, to be the new temporary work area

While singing "He ain't heavy...he is my brother" (https://www.youtube.com/watch?v=Jl5vi9ir49g)  ::)

@Mark

Luxury of posting here is everyone can be barge scientist till CameronD tells you how it really is  ;D I didn't get into measurements for this at all. 'Bollard box' is a technical term I just invented.. on edge there are these recessed bollards/cleats and wing covers them up. These 'boxes' are exactly where compartments meet as in the second image you posted. Using container width for reference will give more error, better would be to use whole barge length and see if hole is at 26% of it from stern. I think its close to it.

With your model what should be the length of these compartments? See if it matches to those.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/11/2016 11:13 PM
Random hypothetical question from nowhere;

If there were to be an F9 flight two days from now (surprise!) and assuming that SpaceX were willing to take the chance that one of the landing leg feet might step into the hole in the deck could ASDS OCISLY report for duty or is it legally grounded?  And if grounded is there appeal wiggle room since there is no endangerment and its such a badass program that the CG is already partway involved in?

@Mark ... With your model what should be the length of these compartments? See if it matches to those.
IIRC, the longitudinal placement of the bulkheads in my model was done with little regard to being anatomically correct as I was going for weight and (other than the front bulkhead which is on the sloping bow) the longitudinal placement has no affect on bulkhead area or weight.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 03/11/2016 11:32 PM
I take it you mean CG would insist OCISLY is repaired 100% before leaving port...
No... she could sail now if they wanted to... IMHO...

There are many stories (IIRC) of boats being patched seaworthy and going back to sea...
It was not damaged beyond use... since it relies on EIII to provide propulsion and guidance... 
My guess  ;) is CG considers if boat is a hazard or could easily become a hazard if taken out as is...

Of course I differ to those who know the regs better then me...   :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 03/11/2016 11:48 PM
Think of the Yorktown before the Battle of Midway.




Not sure this is quite as compelling...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AJW on 03/12/2016 02:43 AM
In the overhead view, there is part of the stage under a white tarp.   Any clue if this was the engines and octaweb, or could these have remained below deck?  If so, they may need to open up the hole further to extract these parts before repairs can begin.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/12/2016 03:07 AM
Random hypothetical question from nowhere;

If there were to be an F9 flight two days from now (surprise!) and assuming that SpaceX were willing to take the chance that one of the landing leg feet might step into the hole in the deck could ASDS OCISLY report for duty or is it legally grounded?  And if grounded is there appeal wiggle room since there is no endangerment and its such a badass program that the CG is already partway involved in?

I'd imagine that several of the trailers need replacing, as well as some of the cooling equipment for the Thrustmasters, etc., etc. before OCISLY would be considered capable of accomplishing a stage recovery.

However, I do recognize that your question is more about whether or not, short of wartime, a barge with a hole in its deck would be considered seaworthy than whether it could realistically be ready to depart in a day or so with all needful repairs to accomplish a stage recovery, a hole in the deck notwithstanding.  And I guess my answer to that is, well, it came back into port from 600 km out to sea, right?  I'd say that, while not happy, it was seaworthy... but without the Thrustmasters all working, and without replacing some of the apparently damaged electronics trailers, there would be far more risk than reward in a landing attempt.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 03/13/2016 08:26 PM
Hi fellow barge watchers/stalkers  :D

I am still making an model of the barge
(you can see the current state here : https://github.com/maximlevitsky/ASDS)

After last wave of images, when we found out about the hole, I found out that I didn't get the wings width correct, and I also don't know anymore the exact location of engine mounts.

If you happen to stalk the barge again, could you take a photo of the stern engine mounts directly from the side and/or from the above with drone? This will help me determine the distance between engine mount and wing.
Also obviously any closeups of the engines and engine mounts are very welcome.

Also if the barge is still in raised condition (with ballast tanks empty) I would like a closeup photo of exposed side (what appears to be white). I want to know what raised relief bars on the sides they did cut and what parts they didn't.

About the engines they are not exactly OD1000 - the autocad drawing doesn't match in the long tube section, it appears to be roughly ~10ft shorter, and not unformally conical.

You can see current status of my model here
https://twitter.com/maximlevitsky/status/706599126876684288
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 03/13/2016 09:27 PM
The barge earlier today.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 03/13/2016 09:53 PM
The barge earlier today.

Alas, the pictures aren't quite high enough resolution to resolve the deck thickness debate.
I am amused to say this of a 2000 pixel high image.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/13/2016 11:26 PM
I am still making an model of the barge
(you can see the current state here : https://github.com/maximlevitsky/ASDS)

I looked at the progress page.  I don't get it.  Why does your model of a barge look like a computer program?
edit: Now an hour or two later I look at it again and I see images of it.  Hmm, must be a browser freakout thing.

today.
Delightful, thank you.  Very resolutious.  Observations and thoughts -
- Today is a Sunday and they are busting it out.  It would seem that someone is motivated to have an ASDS as an available option for CRS-8.
- They have a substantial number of night work lights.  Looks like its urgent enough that they're working multiple shifts into the night
- There are enough LOX dewers to launch a (very) small rocket.  So they have a lot of initial cutting of scrap steel to do before the reconstruction starts.  Also gaseous oxygen and a rack of black cylinders which I assume is acetylene.
- Plenty of torch cut barge scrap in two piles (tan with singed edges) but nowhere near the quantity that I would expect based on the quantity of oxygen they have on hand.  More to come up?
- No aerospace scrap in sight.  Either SpaceX collected their scrap and moved it off before this crew started or it kept on going out the bottom.
- There is a fair sized load of fresh lumber on deck.  To make temporary holders for plate and various structures?
- Blast wall is cleaner than I remember it being and in the 6048 image you can see the clover.  You could make a song about the clover being still there after the rocket's red glare.

There is information V in L2 if you missed it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 03/14/2016 01:20 AM
On the second image it's impressive to see the cut out section of deck and the attached steel I beam stringers the are attached to the underside. I'm still amazed by the power of the impact and can only imagine just how awesome the video must be of that, uh, event.

And six generators (welders) on deck along with work lights. Someone seems in an awful hurry to effect the repairs...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/14/2016 01:40 AM
lol and how about that mine shaft type elevator basket! i guess they're lowering dudes into the hole to cut and weld.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 03/14/2016 11:10 AM
A bit higher resolution. I think I neeed to invest in longer lens...

Go Quest is now parked elsewhere:

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 03/14/2016 11:51 AM
Why so much wood on deck?  I thought the barge was all steel...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 03/14/2016 12:07 PM
Why so much wood on deck?  I thought the barge was all steel...

Probably temporary shoring while structural repairs are made; WWII warships used to keep stocks of timber aboard for the same purpose.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/14/2016 04:00 PM
How's things out JRTI way?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/14/2016 07:48 PM
Around 5 March INTL Freedom went near it then went to about a km west of Island Freeman possibly leaving JRTI there. It then berthed and then went straight out to San Diego at about 6.5 kn... Can't say if it had JRTI with it or not..on satellite imagery there are many barges around the spot it(tug) currently is.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/15/2016 02:10 AM
I take it you mean CG would insist OCISLY is repaired 100% before leaving port...
No... she could sail now if they wanted to... IMHO...

There are many stories (IIRC) of boats being patched seaworthy and going back to sea...
It was not damaged beyond use... since it relies on EIII to provide propulsion and guidance... 
My guess  ;) is CG considers if boat is a hazard or could easily become a hazard if taken out as is...

Of course I differ to those who know the regs better then me...   :)

Depends who's watching, I suppose.  ;)

The point is:  (1) The barge is leased from McDonough Marine, who, it would seem from looking through the ABS records for their rather-extensive fleet, take pride in ensuring they always comply with their obligations.  (2) The barge has then been heavily modified and re-surveyed and USCG approved again in accordance with the regs, so it would surprise many if SpaceX suddenly cut corners (pun intended) with the repairs this time around.

As mentioned above, it looks like the they've done some internal structural damage that needs fixing.  Sure, they could patch it up and head to sea right away if needed - but what if something went wrong with the repairs in some way and the ASDS either (God forbid) sank or one of their on-board crew was injured?   It doesn't look like a big fix to me and I wouldn't think they'd want to take the risk whilst the world was watching on.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/15/2016 02:15 AM
Why so much wood on deck?  I thought the barge was all steel...

Probably temporary shoring while structural repairs are made; WWII warships used to keep stocks of timber aboard for the same purpose.

I would only get worried if they start loading bags of cement.. since, traditionally, that's what's used to fix hull leaks - and cover a multitude of sins.  8)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/15/2016 08:24 PM
The barge earlier today.

Alas, the pictures aren't quite high enough resolution to resolve the deck thickness debate.


I just asked a source at McDonough Marine who told me the deck plate is 9/16" thick, so we won't have to debate that point any further.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: edkyle99 on 03/15/2016 09:32 PM
Think of the Yorktown before the Battle of Midway.

Not sure this is quite as compelling...
And, since Yorktown was sunk during the battle, we don't want the same result!

 - Ed kyle
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/16/2016 01:17 AM
I just asked a source at McDonough Marine who told me the deck plate is 9/16" thick, so we won't have to debate that point any further.  ;)

Now that's a solid report.  Case closed forever.  Thanks.

It seems as if someone else, a newer person IIRC, solved another longstanding ASDS mystery a few weeks back by just simply picking up the phone and calling the authority.  I can't recall or find it, I think it was the Eastern Range or Coast Guard??

Given these two stepwise advancements in ASDS science it seems to me that rather than filling up hundreds of additional pages of NSF server space with more speculations, calculations, and educated guesses we just need to list our questions and call the sources for answers.  Perhaps we need to print up some cool looking NSF credentials so we look official doing it. ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/16/2016 02:22 AM
Quote
It seems as if someone else, a newer person IIRC, solved another longstanding ASDS mystery a few weeks back by just simply picking up the phone and calling the authority.  I can't recall or find it, I think it was the Eastern Range or Coast Guard??

That was someone who contacted the 45th Space Wing to ask about the boat intrusion in the hazard area. Who knew you could get answers just by asking the right person?  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: NovaSilisko on 03/16/2016 02:33 AM
Given these two stepwise advancements in ASDS science it seems to me that rather than filling up hundreds of additional pages of NSF server space with more speculations, calculations, and educated guesses we just need to list our questions and call the sources for answers.  Perhaps we need to print up some cool looking NSF credentials so we look official doing it. ;D

That would be so very nice. It gets really hard to follow actual information sometimes with all of the unceasing arguments that well up everywhere.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: brettreds2k on 03/16/2016 12:15 PM
I figured by now they would have released the video of the landing attempt.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Rocket Science on 03/16/2016 12:42 PM
I just asked a source at McDonough Marine who told me the deck plate is 9/16" thick, so we won't have to debate that point any further.  ;)

Now that's a solid report.  Case closed forever.  Thanks.

It seems as if someone else, a newer person IIRC, solved another longstanding ASDS mystery a few weeks back by just simply picking up the phone and calling the authority.  I can't recall or find it, I think it was the Eastern Range or Coast Guard??

Given these two stepwise advancements in ASDS science it seems to me that rather than filling up hundreds of additional pages of NSF server space with more speculations, calculations, and educated guesses we just need to list our questions and call the sources for answers.  Perhaps we need to print up some cool looking NSF credentials so we look official doing it. ;D
Or start up your own website... "Barge Stalkers United"...BSU ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/16/2016 01:54 PM
I figured by now they would have released the video of the landing attempt.

Yeah.  Considering how long it's been, I'm seriously doubting we'll ever see it.

Maybe it happens so fast that there's really not much to see.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: clegg78 on 03/16/2016 02:11 PM
I would bet we catch a glimpse in some presentation at some point by Elon or other management from SpaceX.  They've done that in the past, where we never saw video until it was at some speech they gave.   I am guessing its pretty dramatic video, adn they want a success before they show it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MattMason on 03/16/2016 02:56 PM
I figured by now they would have released the video of the landing attempt.

Yeah.  Considering how long it's been, I'm seriously doubting we'll ever see it.

Maybe it happens so fast that there's really not much to see.

And they're trying to save some surprise for the SpaceX Christmas Party Blooper Reel. You could put these attempts to music. They'll provide their own percussion.

But I might agree. It was a night launch and the speed that the octoweb did to core-sample the barge like that probably just appears as an immediate +5 Vorpal RUD of Kaboomy Goodness.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: vanoord on 03/16/2016 08:23 PM
Is the Octaweb itself so weighty that it would be responsible for the damage alone; or is the mass of the engines as much / more of a factor?

Certainly to tear 9/16" plate there's got to have been a fair impact - the footage would be interesting; and might cast a bit of light on whether the impact speed tor the ensuing explosion caused most of the damage.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 03/16/2016 09:50 PM
Is the Octaweb itself so weighty that it would be responsible for the damage alone; or is the mass of the engines as much / more of a factor?

Certainly to tear 9/16" plate there's got to have been a fair impact - the footage would be interesting; and might cast a bit of light on whether the impact speed tor the ensuing explosion caused most of the damage.

Since several stages have blown up on the barges, seemingly without leaving a dent, the hole was punched by the speed of impact.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/16/2016 10:05 PM
Is the Octaweb itself so weighty that it would be responsible for the damage alone; or is the mass of the engines as much / more of a factor?

Certainly to tear 9/16" plate there's got to have been a fair impact - the footage would be interesting; and might cast a bit of light on whether the impact speed tor the ensuing explosion caused most of the damage.

Well, we know from past attempts that the kaboom part of the landing does very little damage to anything other than the stage itself.. but that heavy bits impacting at speed do cause the odd puncture (remember the one in the side of the hull?)

Ignoring the deck for a sec and considering the damage to the bulkhead underneath - likely a 9/16" mild steel plate on edge with a 6" (my guess) steel "I"-shaped deck beam running across the top which was sheared completely upon impact - I think it's fair to surmise the impact was caused by something solid (like the octaweb) travelling at higher-than-landing-approach speed..

As others have said, I don't think the video would show much other than a ball of light decending rapidly followed by a kaboom to finish.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 03/17/2016 02:13 AM
https://www.youtube.com/watch?v=AJNPUqHFdLg
Source: https://www.reddit.com/r/spacex/comments/4aqh3w/ocisly_today_look_at_the_huge_hole_on_the_left/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/17/2016 03:56 AM
https://www.youtube.com/watch?v=AJNPUqHFdLg
Source: https://www.reddit.com/r/spacex/comments/4aqh3w/ocisly_today_look_at_the_huge_hole_on_the_left/

That's not just any scrap - that's a piece of the deck!!  :o

You can clearly see the beams spaced a foot or so apart and part of a deck girder.  Like this example (out of the Barge Rules):
 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/17/2016 04:50 PM
The deck piece being moved in the video looks much bigger than the original hole made by the rocket. The impact must have damaged deck beams adjacent to the hole.

Too bad we can't get a drone's-eye view now, because the hole after they cut that piece out must be much larger.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: GeneBelcher on 03/17/2016 04:55 PM
They still haven't raised that one thruster. Wonder what's up with that.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: litton4 on 03/17/2016 05:48 PM
Think of the Yorktown before the Battle of Midway.

Not sure this is quite as compelling...
And, since Yorktown was sunk during the battle, we don't want the same result!

 - Ed kyle

That reminds me of a quote I read from a WW II US seaman, later in the war, when UK Aircraft Carriers were deployed in the Pacific Theater.

After a kamikaze attack, where a British Carrier had been struck on the flight deck, and just carried on with operations:

"When a US carrier is struck by a kamikaze, it's back to the 'States for 6 months R&R. When a limey carrier is struck, it's a case of 'sweepers, man your brooms'. "

British carriers had reinforced, armour plate flight decks........

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/17/2016 06:19 PM
The deck piece being moved in the video looks much bigger than the original hole made by the rocket. The impact must have damaged deck beams adjacent to the hole.

Too bad we can't get a drone's-eye view now, because the hole after they cut that piece out must be much larger.

Worse yet, the lifted piece looked to be from only one quadrant of the hole area.

Looking more closely a 2nd time full screen, there are quite a few boards covering an area much larger than the original hole, and still a larger actual hole section uncovered, although some or all of the boards may be there just to protect undamaged deck from the machinery, not to keep people or machinery from falling inside.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/17/2016 06:29 PM
They still haven't raised that one thruster. Wonder what's up with that.

Could be just an extra measure to keep the ASDS stabilized, since that thruster is too far from the hole to think it was damaged.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: robertross on 03/17/2016 07:17 PM
They still haven't raised that one thruster. Wonder what's up with that.

Could be just an extra measure to keep the ASDS stabilized, since that thruster is too far from the hole to think it was damaged.

No, but the cooler(s) on top of the containers sustained damage, and possibly some hydraulic lines. They might be waiting on technical help or parts to get that fixed before testing/operating it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/17/2016 08:51 PM
Someone on Reddit says he'll be down there Sunday with a drone to take aerial video, so maybe we'll see some footage from him this weekend.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/17/2016 09:29 PM
The deck piece being moved in the video looks much bigger than the original hole made by the rocket. The impact must have damaged deck beams adjacent to the hole.

Too bad we can't get a drone's-eye view now, because the hole after they cut that piece out must be much larger.

Worse yet, the lifted piece looked to be from only one quadrant of the hole area.

Looking more closely a 2nd time full screen, there are quite a few boards covering an area much larger than the original hole, and still a larger actual hole section uncovered, although some or all of the boards may be there just to protect undamaged deck from the machinery, not to keep people or machinery from falling inside.

That all makes sense.  The octaweb is a fairly large chunk of metal, and, at the speed it was likely going to punch a hole like that, the 'unseen' damage to structural supports like girders and deck beams could be pretty extensive.

Even if a beam is only "bent a bit" it would still have to be cut out and replaced because there'd be no way to straighten it in-situ without stressing something else and, quite frankly, it's the easiest/cheapest way to do it.  Other sections of deck might also be removed to gain better access to the part they need to fix.

In summary:  What you're looking at is the first stage of a re-build of a section of the barge deck and substructure from the inside out.  We'll know when they're nearly done when the new deck plate(s) arrive.  McD Marine likely not only know about it, but insisted it be done this way - all paid for by the insurers.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 03/17/2016 09:34 PM

In summary:  What you're looking at is the first stage of a re-build of a section of the barge deck and substructure from the inside out.  We'll know when they're nearly done when the new deck plate(s) arrive.  McD Marine likely not only know about it, but insisted it be done this way - all paid for by the insurers.


After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/17/2016 11:08 PM
Quote
In summary:  What you're looking at is the first stage of a re-build of a section of the barge deck and substructure from the inside out.  We'll know when they're nearly done when the new deck plate(s) arrive.  McD Marine likely not only know about it, but insisted it be done this way - all paid for by the insurers.

Also, my source at McDonough tells me ABS is supervising when McDonough people are not on site, so ABS will have a say too in the extent/quality of repairs.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/17/2016 11:56 PM
Quote
In summary:  What you're looking at is the first stage of a re-build of a section of the barge deck and substructure from the inside out.  We'll know when they're nearly done when the new deck plate(s) arrive.  McD Marine likely not only know about it, but insisted it be done this way - all paid for by the insurers.

Also, my source at McDonough tells me ABS is supervising when McDonough people are not on site, so ABS will have a say too in the extent/quality of repairs.

I should hope so!  That's a good move.  It's in their own best interest that ABS are okay with the repairs.. 'cause if they aren't, then for sure both the USCG and their insurers won't be either.
 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 12:01 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

I retract my later suggestion that an attempt might be understandable with 2 more SES launches planned for this year. This particular SES launch would not have set the precedent I thought, unless everyone's hoping to be able to give an orbital boost to the next 2 as well.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 12:07 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

You're right, of course.. and SpaceX must be kicking themselves for trying it now, given the extent of the damage although they've got a few weeks to fix the ASDS before the next flight.

Perhaps they were mighty confident it would (at least) soft land??

EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 03/18/2016 12:10 AM
The deck piece being moved in the video looks much bigger than the original hole made by the rocket. The impact must have damaged deck beams adjacent to the hole.

Too bad we can't get a drone's-eye view now, because the hole after they cut that piece out must be much larger.

Worse yet, the lifted piece looked to be from only one quadrant of the hole area.

Looking more closely a 2nd time full screen, there are quite a few boards covering an area much larger than the original hole, and still a larger actual hole section uncovered, although some or all of the boards may be there just to protect undamaged deck from the machinery, not to keep people or machinery from falling inside.


I don't necessarily interpret that as a sign of an enlarged damage area.  It means they aren't just patching the hole, they're replacing the rectangular plates that were damaged as entire units.  This gives them standard dimensions and framework segments to work with, and ensures that there are no hidden weak areas.


It's like replacing a windshield rather than just filling a crack in it.  You get a better repair.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Okie_Steve on 03/18/2016 12:57 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

You're right, of course.. and SpaceX must be kicking themselves for trying it now, given the extent of the damage although they've got a few weeks to fix the ASDS before the next flight.

Perhaps they were mighty confident it would (at least) soft land??

EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..

actually I think they expected it to break up in reentry, but if it made it far enough to hit and cause damage that is just the cost of doing business in a test.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 01:10 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

Gotta give them credit for not being afraid to fail spectacularly, though. Go big, or go home!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 01:32 AM
You're right, of course..
Good to know someone agrees and I'm not just being silly. All I saw in posts after the launch was, "Well, they got data."

Quote
Perhaps they were mighty confident it would (at least) soft land??
The word was that SpaceX themselves had zero confidence in the success of this landing, which became less obvious with the growing enthusiasm from others.

Quote
EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..
Isn't the rocket what's supposed to get out of the way? I think the ASDS positioning system is only set up to keep the target in one place, and the rocket carries some guidance to redirect itself.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 01:36 AM
[actually I think they expected it to break up in reentry, but if it made it far enough to hit and cause damage that is just the cost of doing business in a test.

Well if they expected it to break up on re-entry, wouldn't that be an even better reason to get the (poor little insignificant fragile) ASDS well away from the IIP??

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 01:42 AM
Quote
Isn't the rocket what's supposed to get out of the way? I think the ASDS positioning system is only set up to keep the target in one place, and the rocket carries some guidance to redirect itself.

The stage has no redirect capability. It has one programmed target, and it does its darndest to get there regardless.

The only "divert" option is to send the ASDS away from the landing zone, in case weather is too bad to attempt landing, for example. That happened once, during the storm that damaged the containers with 30-foot waves, IIRC.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 01:44 AM
EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..
Isn't the rocket what's supposed to get out of the way? I think the ASDS positioning system is only set up to keep the target in one place, and the rocket carries some guidance to redirect itself.

You mean to say, perhaps they were trying to get the rocket to get out of the way... and

(http://www.quickmeme.com/img/d1/d11d1c516380d1c6ed3da36170911e6e4c7c3683a178d1573d9f56f12fe6a193.jpg)

 ;) ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: bstrong on 03/18/2016 01:49 AM
One of the many things they're learning is how quickly an ASDS can be patched up and returned to service after sustaining a variety of different types of damage, figuring out which contractors can be relied upon to do get things done quickly, etc. This will ultimately be an important input into an analysis of how large a fleet they need to maintain on each coast, which will be one of the big cost drivers for recovery operations.

So, they're definitely learning things from putting the ASDS out there every time.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 01:56 AM
One of the many things they're learning is how quickly an ASDS can be patched up and returned to service after sustaining a variety of different types of damage, figuring out which contractors can be relied upon to do get things done quickly, etc. This will ultimately be an important input into an analysis of how large a fleet they need to maintain on each coast, which will be one of the big cost drivers for recovery operations.

So, they're definitely learning things from putting the ASDS out there every time.

SpaceX hasn't seemed to have any problems getting the right fleets together and quickly.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 01:59 AM
Gotta give them credit for not being afraid to fail spectacularly, though. Go big, or go home!

I just went big disagreeing with the actions of a company with over 4,000 employees, and I'm already at home.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 02:01 AM
Gotta give them credit for not being afraid to fail spectacularly, though. Go big, or go home!

I just went big disagreeing with the actions of a company with over 4,000 employees, and I'm already at home.

Well, like Gwynne Shotwell said of Grasshopper/F9R Dev, if they didn't crash, they weren't trying hard enough.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 02:07 AM
Well, like Gwynne Shotwell said of Grasshopper/F9R Dev, if they didn't crash, they weren't trying hard enough.  ;)

Well, right about now, McDonough Marine are probably wondering why they agreed to lease one of their newest barges to SpaceX only to have them go at it with oxy-torches and welders..
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 02:11 AM
Well, like Gwynne Shotwell said of Grasshopper/F9R Dev, if they didn't crash, they weren't trying hard enough.  ;)

Well, right about now, McDonough Marine are probably wondering why they agreed to lease one of their newest barges to SpaceX only to have them go at it with oxy-torches and welders..

Being handsomely paid on a long-term lease, plus SpaceX pays for repairs? They're smiling all the way to the bank...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 03/18/2016 02:23 AM
My initial take on the "not expected to succeed" statement while also sending the ASDS out(mixed messages), was that they did have a reasonable expectation that it would work(or not fail in an uncharacteristically spectacular way) but wanted to manage expectations on the public side, especially given recent history.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AJW on 03/18/2016 03:35 AM
I am still expecting to hear that the 9 merlins and octaweb are below the deck.  The hole is nearly the size of the octaweb, so there is reason to believe that the octaweb fully penetrated the upper deck.  The decking is bent inwards, so there is no indication that the octaweb exited through the entry wound, nor is there any reason that it should.  The stage exploding above deck would only force it further in and not pull it out.   If the octaweb had punched through both the upper and lower decks I would expect the repair to require a dry-dock.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/18/2016 03:42 AM
I don't see the damage being that bad in the big scheme.  I'm gonna guess it at $250k to fix.  Might be off by a factor of 10 on the high end but $250k feels good to me.  Actually, it seems likely that the price of this barge fixing is lower than the price to replace equipment at the ends as we've previously seen done.  Now as long as I'm guessing and speculating, what did SpaceX think the odds of a good landing were?  Hmm, 1%, 0.01   .  So what is the value of a returned stage?  $40M?  Less if its damaged from the high energy SES-9 entry, more if you consider the research value and the timing of having that research knowledge earlier rather than later in the development of downstream products.  So a 1% chance of re-collecting a $40M asset has an expected value of $400k and the damage incurred is less than that.  Sounds like they made a good bet. 

Has anyone considered the possibility that they are constructing a missile silo or launch tube rather than repairing?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Rocket Science on 03/18/2016 03:47 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

You're right, of course.. and SpaceX must be kicking themselves for trying it now, given the extent of the damage although they've got a few weeks to fix the ASDS before the next flight.

Perhaps they were mighty confident it would (at least) soft land??

EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..
Perhaps they will/can fire the FTS next time at the last moments prior to impact to reduce damage if telemetry indicates a very hard landing is about to occur...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 03:57 AM
If the octaweb had punched through both the upper and lower decks I would expect the repair to require a dry-dock.

1. There is no "upper and lower decks".. once through the "upper deck" you're heading for the bottom plating.
2. They're already prepping for damage repair by cutting out damaged sections of the deck - no dry dock is required. ..and it doesn't appear to be leaking either, since they're no longer pumping any water out.

FWIW, I would guess that they've been mighty lucky to hit that bulkhead square on like that.  If the stage had gone straight into the bilges, they might have damaged the ribs/hull stringers which would be a much more difficult fix indeed.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 04:01 AM
After which, insurance premiums will rise for either SpaceX (if they insure directly) or McD Marine (who will pass along costs to SpaceX through their leasing contract). All part of the risks of trying something new.

Call me on it if you must, and nobody likes an I-told-you-so, but I posted trying to warn against the idea of landing on the barge, and now all this for what, 1 extra minute of data? They could have landed in the ocean and still have had an extra 50 seconds of data, and a test of re-entry.

You're right, of course.. and SpaceX must be kicking themselves for trying it now, given the extent of the damage although they've got a few weeks to fix the ASDS before the next flight.

Perhaps they were mighty confident it would (at least) soft land??

EDIT:  I suppose one thing this DOES demonstrate is that, even with super-sized thrusters, they can't get the ASDS out of the way if the stage is coming in too hot..
Perhaps they will/can fire the FTS next time at the last moments prior to impact to reduce damage if telemetry indicates a very hard landing is about to occur...

This has been brought up before. Not possible. Only the MFCO can issue a destruct command. Also, IIRC, stage 1 FTS gets safed during ascent when it gets far enough downrange.

Sometime down the road, autonomous FTS will be implemented by the Range, at which point something like what you suggest would be feasible. But still unlikely to be implemented by SpaceX, because the risk of a false positive means loss of a stage that might have survived.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AJW on 03/18/2016 05:05 AM
If the octaweb had punched through both the upper and lower decks I would expect the repair to require a dry-dock.

1. There is no "upper and lower decks".. once through the "upper deck" you're heading for the bottom plating.
2. They're already prepping for damage repair by cutting out damaged sections of the deck - no dry dock is required. ..and it doesn't appear to be leaking either, since they're no longer pumping any water out.

FWIW, I would guess that they've been mighty lucky to hit that bulkhead square on like that.  If the stage had gone straight into the bilges, they might have damaged the ribs/hull stringers which would be a much more difficult fix indeed.

We appear to be in agreement that that the hull plate does not appear to have been breached.   The question remains unanswered, where did the octaweb and merlins go?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/18/2016 05:24 AM
We appear to be in agreement that that the hull plate does not appear to have been breached.   The question remains unanswered, where did the octaweb and merlins go?

I strongly suspect that most of the Merlins and octaweb ended up directly below the hole (in a non-assembled condition) but without damaging the bottom. The reason I suspect no significant damage to the hull bottom is the ASDS was most likely ballasted during the landing, so the chamber the Merlins and Octaweb entered was most likely half full of water (which would have cushioned the impact and protected the hull bottom). 

This could also explain the list noticed when OCISLY entered port; OCISLY was listing away from the hole, so they IMHO they likely, before the tow back, pumped out that chamber to check for hull bottom damage.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 03/18/2016 05:25 AM
If the octaweb had punched through both the upper and lower decks I would expect the repair to require a dry-dock.

1. There is no "upper and lower decks".. once through the "upper deck" you're heading for the bottom plating.
2. They're already prepping for damage repair by cutting out damaged sections of the deck - no dry dock is required. ..and it doesn't appear to be leaking either, since they're no longer pumping any water out.

FWIW, I would guess that they've been mighty lucky to hit that bulkhead square on like that.  If the stage had gone straight into the bilges, they might have damaged the ribs/hull stringers which would be a much more difficult fix indeed.

We appear to be in agreement that that the hull plate does not appear to have been breached.   The question remains unanswered, where did the octaweb and merlins go?


I thought we saw portions of at least one Merlin powerhead sitting on the deck when it arrived.  Considering their extended position and relatively loose connection to the octoweb, it's possible that many of them were hurled overboard.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/18/2016 05:56 AM
We appear to be in agreement that that the hull plate does not appear to have been breached.   The question remains unanswered, where did the octaweb and merlins go?

The octaweb is probably still down the hole... although now that they've cut the deck away, they should have clear access to go fish it out. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 07:36 AM
Octaweb is (was?) probably under the white tarp, I would think.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/18/2016 09:29 AM
All I'm seeing is a hole that needs to be welded up. Not a biggie. Steel is cheap, labour is cheap.

$250k to repair this? Cannot see it myself. More like $50k at most. Two weeks work for 4 workers, plus steel. Small change for SpaceX, probably less than the cost of having it loiter out at sea waiting for the stage.

Average salary for a welder, is $36,720 (2014 prices). For 4 welders, per week that only $2825. Steel is about $450/ton.  Add on a load of inspection fees, you still have 'not very much money needed'

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Hankelow8 on 03/18/2016 10:19 AM
All I'm seeing is a hole that needs to be welded up. Not a biggie. Steel is cheap, labour is cheap.

$250k to repair this? Cannot see it myself. More like $50k at most. Two weeks work for 4 workers, plus steel. Small change for SpaceX, probably less than the cost of having it loiter out at sea waiting for the stage.

Average salary for a welder, is $36,720 (2014 prices). For 4 welders, per week that only $2825. Steel is about $450/ton.  Add on a load of inspection fees, you still have 'not very much money needed'

Although I do not know how much a welder in the USA gets paid per year, I think $37 k is far to low. There must also have been specialist work needed for cutting out the sections around the impact zone.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/18/2016 12:26 PM
All I'm seeing is a hole that needs to be welded up. Not a biggie. Steel is cheap, labour is cheap.

$250k to repair this? Cannot see it myself. More like $50k at most. Two weeks work for 4 workers, plus steel. Small change for SpaceX, probably less than the cost of having it loiter out at sea waiting for the stage.

Average salary for a welder, is $36,720 (2014 prices). For 4 welders, per week that only $2825. Steel is about $450/ton.  Add on a load of inspection fees, you still have 'not very much money needed'

Although I do not know how much a welder in the USA gets paid per year, I think $37 k is far to low. There must also have been specialist work needed for cutting out the sections around the impact zone.

Specialist work? Why? I could do it with a oxy torch or plasma cutter, and I am a software guy (who spends time in the garage)

That figure came from a USA webpage about USA welding salaries from 2014 It does vary from State to State, and what particular skill set is involved.

But this sort of welding is basic ship building stuff. Not sure why people think this is such an issue. It really isn't rocket science.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/18/2016 01:20 PM
Its not just welders that have their hand in the pay stream.  Six welding machines were delivered.  The material handling lifts were rented and brought there.  Oxygen and acetylene.  The company that Spacex hired that employs the welders and rented the equipment.  Purchasing people that found the materials.  Steel to ABS-A probably costs more than the "bulk steel" rate.  Freight charges.  SpaceX employees time.  ABS.  Naval engineers.  Unballasting with rented pumps and re-ballasting.  Oil containment booms.  Divers if only for inspection. That's the obvious stuff.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 03/18/2016 01:25 PM
A welder who is damn good at welding overhead and in tight spaces commands a premium salary...
You can't teach it either... it's a skill learned from actually doing it in real life situations... for years...
A damn good welder asks for 6 figures annual and gets it from companies who values his skills...
Mainly so he can teach others and supervise their work... just saying...  ;)

On edit later...
I agree with others on the $250K cost estimate to fix this... all in costs verses it never happened...
Was just saying the annual paycheck of a welding supervisor that knows his chit is in the 100K+ range
Different skill set needed to do a repair job verses assy welding in a production setting...
For that yes the 35~40K quoted is ballpark...
For repetitive high quality welding in production settings... a robot will be used as the cost can be spread over a production run...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/18/2016 02:12 PM
I agree this isn't average welding work and that all the stuff listed by OxCartMark raises costs.... I'm still thinking 250K is a reasonable estimate here...  we did our usual good job of ballparking this.... and that it was a good bet for SpaceX. SpaceX also know that even a direct hit can make a good hole but not sink the barge, right? How much worse could it be?

Let's not go TOO far down the hole of how much welders and steel cost, though, ok?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: kevinof on 03/18/2016 02:20 PM
No way this is a 250K job. I would be surprised if it was anything more than 50k. Steel, even high quality stuff, is cheap this days. Transport is cheap. A welder for a weeks work is cheap. Welding steel plate an even repairing beams is not a complex task (I've built boats before) and doesn't require a lot of finesse. Just a good plan and a decent weld.


I agree this isn't average welding work and that all the stuff listed by OxCartMark raises costs.... I'm still thinking 250K is a reasonable estimate here...  we did our usual good job of ballparking this.... and that it was a good bet for SpaceX. SpaceX also know that even a direct hit can make a good hole but not sink the barge, right? How much worse could it be?

Let's not go TOO far down the hole of how much welders and steel cost, though, ok?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 02:29 PM
Glad we all agree SpaceX will not go bankrupt repairing the barge. The only question is, will it be ready in 2 weeks?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 03/18/2016 02:36 PM
Will it be ready in 2 weeks... I think so...
Will not surprise me if it not all done including painting in 1 week (next Friday) in fact...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: sghill on 03/18/2016 02:36 PM
We appear to be in agreement that that the hull plate does not appear to have been breached.   The question remains unanswered, where did the octaweb and merlins go?

I strongly suspect that most of the Merlins and octaweb ended up directly below the hole (in a non-assembled condition) but without damaging the bottom. The reason I suspect no significant damage to the hull bottom is the ASDS was most likely ballasted during the landing, so the chamber the Merlins and Octaweb entered was most likely half full of water (which would have cushioned the impact and protected the hull bottom). 

This could also explain the list noticed when OCISLY entered port; OCISLY was listing away from the hole, so they IMHO they likely, before the tow back, pumped out that chamber to check for hull bottom damage.

My take on the list was that they lowered that end intentionally to get water and toxic to run off away from the hole.  My evidence for this is the green firehouse and sprayer duct taped to the step ladder in the first photos. The fire supression equipment was still in place, so they were obviously hosing down the deck for an extended period to flush off the toxic liquids to have jury rigged that setup, and they wouldn't have wanted all that waste to get flushed into the hole, where they would have to pump it out before reaching port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 03/18/2016 02:42 PM
Perhaps they will/can fire the FTS next time at the last moments prior to impact to reduce damage if telemetry indicates a very hard landing is about to occur...
Rather pointless. Since the Octoweb and support structure will have the same ballistic impact on the deck. AFAIK the FTS cuts the motors and pops open the tankage, doesn't effect the structural integrity of the core below the tankage.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/18/2016 03:08 PM
No way this is a 250K job. I would be surprised if it was anything more than 50k. Steel, even high quality stuff, is cheap this days. Transport is cheap. A welder for a weeks work is cheap. Welding steel plate an even repairing beams is not a complex task (I've built boats before) and doesn't require a lot of finesse. Just a good plan and a decent weld.

250K is a reasonable (95% confidence ??? I'm guessing here, didn't do rigorous analysis)  upper bound, how about that?

My take on the list was that they lowered that end intentionally to get water and toxic to run off away from the hole.  My evidence for this is the green firehouse and sprayer duct taped to the step ladder in the first photos. The fire supression equipment was still in place, so they were obviously hosing down the deck for an extended period to flush off the toxic liquids to have jury rigged that setup, and they wouldn't have wanted all that waste to get flushed into the hole, where they would have to pump it out before reaching port.

Not to be concern trolling, but will Greenpeace eventually notice all this and complain about hosing toxic stuff off into the ocean?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: steveholtam on 03/18/2016 03:48 PM
The first stages with unspent fuel all fall back into the ocean normally anyway.  These just get smashed on a barge first.  And perhaps the ensuing explosion burns up many of the toxin that would normally get released into the ocean from a typical splashdown and breakup? 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 03:50 PM
Nate_Trost reporting that a barge landing is still "Plan A" for CRS-8:

http://forum.nasaspaceflight.com/index.php?topic=39350.msg1505239#msg1505239
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/18/2016 04:14 PM
The first stages with unspent fuel all fall back into the ocean normally anyway.  These just get smashed on a barge first.  And perhaps the ensuing explosion burns up many of the toxin that would normally get released into the ocean from a typical splashdown and breakup? 

You're being way too logical. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 03/18/2016 04:39 PM
Nate_Trost reporting that a barge landing is still "Plan A" for CRS-8:

http://forum.nasaspaceflight.com/index.php?topic=39350.msg1505239#msg1505239

I thought so... been saying RTLS will be rare for some time now...  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Hankelow8 on 03/18/2016 04:52 PM


I have just checked what the average American wage is and it comes in at 44K, if this is correct I cannot see any skilled welder working for 36K.

I would think (depending on damage) there could be support structure that will need to be replaced. Who knows  what is needed under the barge surface decking, we do not have Super Man eyes, but it does look like it's not just a patch and weld job.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/18/2016 04:56 PM
Nate_Trost reporting that a barge landing is still "Plan A" for CRS-8:

http://forum.nasaspaceflight.com/index.php?topic=39350.msg1505239#msg1505239

Loren Grush says so, too:

Quote
James Stewart  ‏@JamesStewart97  2h2 hours ago United Kingdom
@lorengrush have @SpaceX confirmed that they're going for a first stage drone ship landing rather than a RTLS?
 
Loren GrushVerified account
‏@lorengrush
@JamesStewart97 Yep! Got confirmation this morning
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/18/2016 05:05 PM
Just adding this old one to better illustrate my previous post on topic (http://forum.nasaspaceflight.com/index.php?topic=39766.msg1502618#msg1502618)

A good look at beam that aligns with 'Bollard Boxes' on sides of barge. The hole is exactly on it and damages two compartments, also you can see it is one of the stronger portion on barge. Attached one is from 303 and not the same region.
Source: http://www.worldmarine.com/projects/barges

Octaweb is (was?) probably under the white tarp, I would think.

I think it is top of stage minus interstage. Didn't blow away possibly due to less pressure, crumpled and got stuck between wing and thruster mount.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: symbios on 03/18/2016 06:24 PM
Just want to add my two cents to this.

I'm currently building a 55 fot steel trawler yacht. All the steel and work on the entire hull with peripherals does not cost 250k.

If you can not patch a 10 feet hole for less, get a new contractor.

No way this is a 250K job. I would be surprised if it was anything more than 50k. Steel, even high quality stuff, is cheap this days. Transport is cheap. A welder for a weeks work is cheap. Welding steel plate an even repairing beams is not a complex task (I've built boats before) and doesn't require a lot of finesse. Just a good plan and a decent weld.


I agree this isn't average welding work and that all the stuff listed by OxCartMark raises costs.... I'm still thinking 250K is a reasonable estimate here...  we did our usual good job of ballparking this.... and that it was a good bet for SpaceX. SpaceX also know that even a direct hit can make a good hole but not sink the barge, right? How much worse could it be?

Let's not go TOO far down the hole of how much welders and steel cost, though, ok?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 03/18/2016 06:27 PM
And for another data point, it would cost ULA about $2.5 million to fix this.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarsInMyLifetime on 03/18/2016 07:08 PM
Another metric for comparing costs is to compare this repair to the cost of a first stage. We know a full stack is priced to customers at about $60 million, so let me pull a WAG of a $20 million internal cost of a stage--this is just a guesstimate used for the sake of magnitude. Was the cost of fixing the hole close to the cost of a first stage? Not by a long shot. Was the risk worth accepting in order to recoup the ~$20 million cost of a successfully returned stage? By all means. Is some of the accounting for this work hidden in R&D or contingency funds rather than direct cost against the mission budget? Undoubtedly. So the way I look at it, whether this repair job cost $50K vs $250K is a moot point; in the bigger picture, costs of this nature are worth embracing repeatedly for the sake of getting to a sustained level of stage recovery and an improved amortization rate on launch costs. I happen to think they are very close to working out the systemic impedances.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 07:21 PM
OCISLY was listing away from the hole

Was it determined as fact that the ASDS came in listing away from the hole? I couldn't see the list then, and now what's obvious in the latest video is that there's a list towards the hole. Seems to me that means two things:

1) they didn't find any hull plate damage, or else they would be continuing to keep the hole's corner as far above the ocean surface as possible instead of letting it back down,

2) either they re-ballasted the hole's corner (after more obviously emptying the other corners) to stabilize the hole for work, OR, guess what, the dry weight of nine octaweb engines is 4.66 US tons.

My only question now is, why was the ASDS turned around to put the hole opposite the bulkhead? When it was first moored, the hole was on the same side as the bulkhead.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/18/2016 07:53 PM
A second hand (preloved) 300ft barge costs about $2.5M (very quick google).

Repairs to same barge for a small hole, $250k? No, don't think so.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: leetdan on 03/18/2016 08:07 PM
OR, guess what, the dry weight of nine octaweb engines is 4.66 US tons.

4.66 tons is just over 4 cubic meters of water displacement.  The barge hull is 91 * 30 meters.  That ain't it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/18/2016 08:52 PM
OR, guess what, the dry weight of nine octaweb engines is 4.66 US tons.

4.66 tons is just over 4 cubic meters of water displacement.  The barge hull is 91 * 30 meters. That ain't it.

I was talking about only one corner, and even smaller, only the ballast tanks underneath that one corner. That more confined area is still probably larger than 4 cubic meters though, I presume. Have to admit I wasn't quite motivated enough on top of everything else to look up the weight of water. So does that imply you agree that corner was re-ballasted to stabilize it for the work, or what else could be weighing it down more than all 3 other corners? Surely not just the equipment & supplies on the deck?

BTW, I reviewed some images and can answer one of my own questions, asking if the list first being away from the hole was fact. In the video of the ASDS coming in, the list is toward the corner opposite the hole but on the same end, and the corner with the hole is obviously up -- I don't know if that end is the bow or stern, but I mark it by a small white metal "bubble" sticking up from one of the large white containers, something that isn't duplicated on the other end. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: leetdan on 03/18/2016 09:34 PM
I don't really have an opinion on how or where or why it was ballasted.  But with all the recent talk of the ASDS moving out of the way of a falling rocket, or FTS somehow being used to prevent crash damage, etc. I thought it would be helpful to remind people of just how light aerospace hardware is on the relative scale of an oceangoing barge.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/19/2016 03:08 AM
I reviewed some images and can answer one of my own questions, asking if the list first being away from the hole was fact. In the video of the ASDS coming in, the list is toward the corner opposite the hole but on the same end, and the corner with the hole is obviously up -- I don't know if that end is the bow or stern, but
Too tired to think much maybe you've got this or maybe not - It came in bow first (of course) but then did a U turn before parking.  Bow now pointing out towards ocean.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/20/2016 12:44 AM
It came in bow first (of course) but then did a U turn before parking.  Bow now pointing out towards ocean.

Thanks for the heads up on which end is the bow, but there wasn't a U turn before mooring when she first came in, as can be seen in this picture from that day March 8th. Probably not much to chew on though, I thought later, maybe just how they had to turn to eject the ballast water into the sea instead of into the street, or whatever that is behind the bulkhead. Also could have something to do with the levels of the other corners relative to the bulkhead while the hole corner is weighed down, and getting machinery & supplies onboard more easily.

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-08%20OCISLY%20aerial%20300w.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/20/2016 08:07 AM
It came in bow first (of course) but then did a U turn before parking.  Bow now pointing out towards ocean.

Thanks for the heads up on which end is the bow, but there wasn't a U turn before mooring when she first came in, as can be seen in this picture from that day March 8th. Probably not much to chew on though, I thought later, maybe just how they had to turn to eject the ballast water into the sea instead of into the street, or whatever that is behind the bulkhead. Also could have something to do with the levels of the other corners relative to the bulkhead while the hole corner is weighed down, and getting machinery & supplies onboard more easily.

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-08%20OCISLY%20aerial%20300w.jpg)

There seems to be some confusion here (though I may be the one confused - if I'm wrong, I'd appreciate being corrected).

In that picture you posted, the bow is to the right. An easy way to determine it is the ASDSs name is on the port (left) side. The ASDS appears to be in the same orientation in later pictures.

The list seen was, as I recall, toward the forward starboard quarter (which was a bit lower in the water than the rest), so away from the hole, which is in the aft port quarter.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/20/2016 12:07 PM
Quote
There seems to be some confusion here (though I may be the one confused - if I'm wrong, I'd appreciate being corrected).

In that picture you posted, the bow is to the right. An easy way to determine it is the ASDSs name is on the port (left) side. The ASDS appears to be in the same orientation in later pictures.

The list seen was, as I recall, toward the forward starboard quarter (which was a bit lower in the water than the rest), so away from the hole, which is in the aft port quarter.

You (and Ohsin) are correct. Bow is now on right side of photo, pointing towards open sea, which means she did a U-turn before docking.

Also, this screen shot from the Port Canaveral webcam shows the list towards the bow (left side of photo) as she entered port. To my eye the bow port corner is lowest to the water, but maybe the perspective is fooling my eye.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/20/2016 12:17 PM
And for help with perspective on the orientation, here's a shot from before SES-9, with bow facing left as it would be during tow-in (in opposite direction of her current orientation). Port entrance is to the right.

(https://i.imgur.com/dZ8ypzz.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/20/2016 12:51 PM
A couple of points...

Recall that the ASDS operates with its "bollard boxes" partially flooded.  This lets it ride lower in the water and gives it great stability in an ocean-wave environment.

The list seen as OCISLY came back from SES-9 duty was down in the opposite corner of the barge from the holed compartment.  This means that OCISLY wasn't listing because of complete flooding of the compartment(s) under the hole -- it was listing because the compartment(s) under the hole had been pumped as dry as possible.

So, for the sake of illustration, if the various "bollard box" compartments normally operate half-flooded, for stability, OCISLY's list was caused by pumping water out of the affected compartment(s) and having them providing a higher level of flotation than the rest of the barge.

This speaks to the likelihood that the hull plating beneath the hole was likely not damaged (at least not holed), and the list was due the compartment(s) under the hole being emptied of their normal level of water. The opposite of the list being caused by one or more compartments being breached to the sea and flooded.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: symbios on 03/20/2016 02:31 PM
I'm sorry to be a little petty  ;D

But a bollard is something you use to tie the boat to the key. <edit> In this context a</edit> bollard box refers to a cut out section at deck level where you place the bollard out of the way. (se OxCartMark answer below)

You could call it a ballast tank. Or a water tight section of the hull used as a ballast tank. There might be a more correct technical term... English is not my first language  8)

Recall that the ASDS operates with its "bollard boxes" partially flooded.  This lets it ride lower in the water and gives it great stability in an ocean-wave environment.

Edit: Thanks OxCartMark for the clarification.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/20/2016 03:45 PM
I'm sorry to be a little petty  ;D

But a bollard is something you use to tie the boat to the key. A bollard box refers to a cut out section usually at deck level where you place the bollard out of the way.

You could call it a ballast tank. Or a water tight section of the hull used as a ballast tank. There might be a more correct technical term... English is not my first language  8)

Recall that the ASDS operates with its "bollard boxes" partially flooded.  This lets it ride lower in the water and gives it great stability in an ocean-wave environment.

"Bollard Box" is a term that Ohsin came up with to call out the rectangular hollowness space that is created around the bollards (the short posts that rope is tied to).  This allows the bollards to be below flush with the deck and inside of the side width of the barge.  AFAIK, bollard box is not an official nautical term but rather something that Ohsin came up with to explain what he was seeing.  It seems he came up with the term a year or so ago and used it here but I forgot and ~10 days ago in this thread I had to ask and he explained that term.  That's how I'm now familiar with the term.  I think ballast tank or water tight compartment may be the right term for what is below deck.

The list away from the hole seen when ASDS OCISLY came in was explained above as being due to water having been pumped out of the damaged compartment / tank(s).  That may or may not be the case.  It could also be the case that water was pumped from other compartments in that area and it may be that it wasn't possible to drain that tank if it was holed on the bottom, other than the small reduction that would come from water draining out the bottom as that side of the barge came up from draining surrounding compartments.

Quote
bol·lard
ˈbälərd
noun
1.
a short, thick post on the deck of a ship or on a wharf, to which a ship's rope may be secured.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/20/2016 06:28 PM
I may have started the confusion with my later U-turn & hole corner re-ballast ideas, and I apologize, but it was an honest mistake. In the video of the piece of deck being lifted (http://forum.nasaspaceflight.com/index.php?topic=39766.msg1504682#msg1504682), it's clear the piece is being lifted from the side opposite the bulkhead, and that it was cut from there too (latter clearer at full screen w/ zoom in about 3:18), and in the aerial from March 8th, the large hole is against the bulkhead.

So in other words, U-turn aside, unfortunately I might now have to add even more confusion. That deck piece and large hole it came from are clearly on the starboard side, using my marker for the bow, the small white metal bubble sticking up from a white container on one end, which jives with CJ's marker of name on port side, both being visible in Kabloona's photo. In addition, when I just watched the video again, that hole does not appear to be in the corner as I & others may have first assumed, but close to the center of the starboard side. In the March 8th photo, the hole we've been following is on the same side as the name, the port side, and clearly in a corner.

I don't see how anyone can guess what THAT is about, so it might help if we can hang on till this:
Someone on Reddit says he'll be down there Sunday with a drone to take aerial video, so maybe we'll see some footage from him this weekend.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/20/2016 07:11 PM
Quote
So in other words, U-turn aside, unfortunately I might now have to add even more confusion. That deck piece and large hole it came from are clearly on the starboard side, using my marker for the bow, the small white metal bubble sticking up from a white container on one end, which jives with CJ's marker of name on port side, both being visible in Kabloona's photo. In addition, when I just watched the video again, that hole does not appear to be in the corner as I & others may have first assumed, but close to the center of the starboard side. In the March 8th photo, the hole we've been following is on the same side as the name, the port side, and clearly in a corner.

If I understand correctly, you're saying you see a large hole at the center starboard side, in the video where the telehandler picked up the large piece of deck that had been cut out. But I don't think you're seeing a second hole. I believe you're seeing a dark pile of scrap steel that was cut out of the "original" hole from the impact in the stern/port corner. I think they cut several pieces of steel out of that hole and piled it on the starboard side, amidships.

Another indicator is the orange safety cones. You can see them in the far stern corner, around the "original" hole. If there were another hole on the starboard side by the debris pile, we would see cones surrounding that, too, but there aren't any cones visible there. So I believe it's just a scrap pile, not a second hole.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/20/2016 07:36 PM
I don't know Kabloona, it will be nice if you're right, but I just looked again and I still think it's a new hole they've cut. I only see flat gray plates lying around the area. I also see the orange cones on the stern after you mentioned them, but I don't think they would put them around a hole while they're working on it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: sewebster on 03/20/2016 08:44 PM
I don't know Kabloona, it will be nice if you're right, but I just looked again and I still think it's a new hole they've cut. I only see flat gray plates lying around the area. I also see the orange cones on the stern after you mentioned them, but I don't think they would put them around a hole while they're working on it.

Are you looking at that video? Seems like you can see the pieces of junk shift around when they pick up the big piece at around 1:45... https://www.youtube.com/watch?v=AJNPUqHFdLg?t=105
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 03/20/2016 10:03 PM
I don't know Kabloona, it will be nice if you're right, but I just looked again and I still think it's a new hole they've cut. I only see flat gray plates lying around the area. I also see the orange cones on the stern after you mentioned them, but I don't think they would put them around a hole while they're working on it.

They most definitely would have some kind of warning or barrier around part of an open space/fall hazard - OSHA regulations require them. I'm with Kabloona on this.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/20/2016 11:07 PM
Are you looking at that video? Seems like you can see the pieces of junk shift around when they pick up the big piece at around 1:45... https://www.youtube.com/watch?v=AJNPUqHFdLg?t=105

You're right, something black fluttered around big time for about 2-3 seconds there. It made me think of tar paper more than scrap steel, but there's a better closeup at 4:40 that could pass for the same material instead of a hole.

They most definitely would have some kind of warning or barrier around part of an open space/fall hazard - OSHA regulations require them. I'm with Kabloona on this.

There are a lot of flat pieces of gray metal lying around for protection, and companies skirt around OSHA regulations all the time when they think no one is watching, but in this case there's a good chance the repair companies can guess people are watching. So, as I said here & previously, I'm happy to be more convinced that's not a new hole after all.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/21/2016 02:14 PM
From the previous thread

Quote
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #6295 on: March 08, 2016, 09:29:58 AM »
Reddit user heading there with DSLR and drone.

The level of stalking for this barge is huge!

Did this ever happen?  Did said reddit user forget to go?  Forget to take off the lens cap?  Forget to upload?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/21/2016 06:36 PM
I noticed a new pic of OCISLY on Redit, said to be taken today.
http://i.imgur.com/O1mGlJ0.jpg

Relevant thread is;
https://www.reddit.com/r/spacex/comments/4bdo1f/im_at_the_port_could_anyone_verify_if_this_is/

Looks to me like OCISLY still has a slight list away from the hole. (the photo is from off the starboard forward quarter).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/21/2016 08:44 PM
And the guy with the drone posted about 3 hours ago saying it was too windy to fly, but that he would try again later.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/21/2016 09:02 PM
Quote
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #6295 on: March 08, 2016, 09:29:58 AM »
Reddit user heading there with DSLR and drone.

Did this ever happen?  Did said reddit user forget to go?  Forget to take off the lens cap?  Forget to upload?

The aerial image I re-posted a smaller version of just a few posts ago, on the 19th, was first posted here on March 8th, the same day as the Reddit quote. The source given here was the Spacenews page on Facebook, but the photo could have been taken by the same Reddit photographer, depending on time of day of course.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/21/2016 09:10 PM
I noticed a new pic of OCISLY on Redit, said to be taken today.
http://i.imgur.com/O1mGlJ0.jpg

So the good news is the starboard aft thruster is back up!

Quote
Looks to me like OCISLY still has a slight list away from the hole. (the photo is from off the starboard forward quarter).

Still something of a mystery why the starboard bow corner has been listing after coming in with the port bow corner listing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/21/2016 09:36 PM
Quote
Looks to me like OCISLY still has a slight list away from the hole. (the photo is from off the starboard forward quarter).

Still something of a mystery why the starboard bow corner has been listing after coming in with the port bow corner listing.

Not that much of a mystery..  They will have trimmed it like that to ensure any remaining water in the damaged ballast tank stays away from the site of the repair if they get any motion from the wake of a passing vessel.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/22/2016 01:22 AM
And the guy with the drone posted about 3 hours ago saying it was too windy to fly, but that he would try again later.

Posted here. Drone wasn't used though.

http://johnkrausphotos.com/ocisly-march-21-2016/

Edit 1:
They really opened it up. I see whole rectangular section has been removed and all these beams on deck would probably be used to fix it from inside. Also stern thruster is half up.

Edit2:
Is that tube for ventilation? Also I think we can see some beam work already in place.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/22/2016 01:50 AM
The bow bubble is gone. I'm lost.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 02:18 AM
The bow bubble is gone. I'm lost.

It's the "original" hole in the stern, port side. They cut away all around it to make a big rectangular hole so the edges are straight.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/22/2016 02:25 AM
And the guy with the drone posted about 3 hours ago saying it was too windy to fly, but that he would try again later.

Posted here. Drone wasn't used though.

http://johnkrausphotos.com/ocisly-march-21-2016/

Edited:

They really opened it up. I see whole rectangular section has been removed and all these beams on deck would probably be used to fix it from inside. Also stern thruster is half up.

Yes, the blue is likely a primer coat.  You can see the new steel angles to be used to support the deck plates and a deck girder hanging from the crane.

Note the white ventilation duct with an industrial fan on the end.  Don't see any sign of new deck plates just yet.. but they're making good progress. :)

Edit:
Edit2:
Is that tube for ventilation? Also I think we can see some beam work already in place.

Yes.. and yes - looks like they're almost half-way there.  They'll likely complete all of the beams, girders and bulkhead work then cover it up with fresh deck plates and a final inspection.  Then comes the painting.. inside and out.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/22/2016 03:46 AM
The bow bubble is gone. I'm lost.

It's the "original" hole in the stern, port side. They cut away all around it to make a big rectangular hole so the edges are straight.

Hahaha, I know I've been on the confused side lately, but not that confused. I meant it like "who moved my cheese?" Could be a problem for me if they don't put it back though, when the deck isn't visible, or worse, if someone gets tricky and moves it to the stern.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/22/2016 04:12 AM
Whoever it was that was guessing toward the $50k end of the spectrum that money looks to have been spent.  I'm not going back to Elon to ask for the rest of the money we need to get this hole filled. You go ask him.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/22/2016 05:25 AM
Whoever it was that was guessing toward the $50k end of the spectrum that money looks to have been spent.  I'm not going back to Elon to ask for the rest of the money we need to get this hole filled. You go ask him.

Well.. there are certainly cheaper ways to do a repair like this.  I know a dockyard in Malaysia...  ;D
 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 07:43 AM
The bow bubble is gone. I'm lost.

It's the "original" hole in the stern, port side. They cut away all around it to make a big rectangular hole so the edges are straight.

Hahaha, I know I've been on the confused side lately, but not that confused. I meant it like "who moved my cheese?" Could be a problem for me if they don't put it back though, when the deck isn't visible, or worse, if someone gets tricky and moves it to the stern.

Sorry. I expect the cheese will return, maybe on anti-vibration mounts. (I assume the bubble you mean is that VSAT antenna dome that gets vibrated by the exhaust noise during landing attempts and loses satellite lock, disrupting the live feed. Now would be a good time to do some acoustic tests on it in an acoustic chamber and dial in some anti-vibe mounts...)

https://www.vibrationmounts.com/uses/aerospace.htm
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Semmel on 03/22/2016 11:04 AM
New images and drone video from EverydayAstronauts images

http://i.imgur.com/E8T9pEj.jpg (same as attachment)

https://www.youtube.com/watch?v=r5bybH72JPo
posted on reddit.

Looks like the hull was breached after all, just below the wing. Makes sense to keep that side of the OCISLY out of the water in that case. Any speculation if the engine section went right through or if it got stuck inside? I cant see it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 03/22/2016 11:07 AM
Here's an overhead shot provided by Reddit user Termderd. You can see how they had to remove decking to get back to the main stringers to be able to tie in the cross trusses. I see eleven generators (welders) and one massive beam over towards the bow.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/22/2016 11:09 AM
New images and drone video from EverydayAstronauts images

http://i.imgur.com/E8T9pEj.jpg (same as attachment)

https://www.youtube.com/watch?v=r5bybH72JPo
posted on reddit.

Looks like the hull was breached after all, just below the wing. Makes sense to keep that side of the OCISLY out of the water in that case. Any speculation if the engine section went right through or if it got stuck inside? I cant see it.
I watched the vid a couple times and I'm not quite clear how you drew that conclusion... there is never an overhead view that lets us see into the hole, plus there is blue(teal??) material covering a lot of it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Semmel on 03/22/2016 11:10 AM
I watched the vid a couple times and I'm not quite clear how you drew that conclusion... there is never an overhead view that lets us see into the hole, plus there is blue(teal??) material covering a lot of it.

look at the picture.. its not visible in the video I beleave.

edit: Part of the yellow/orange background is missing where the wing attaches to the body of the barge. It looks like a section is cut out.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/22/2016 11:36 AM
That's a really interesting view into the inside of the machine.  I don't think I've ever seen the inside of an ASDS before.

Has there always been the blue tarping on the fence around the SpaceX area?  I see more portable fencing with blue tarp near the plastic outhouses, and interestingly, a section of it blocking the view that someone might have under the wing area.

Cindy's antenna bubble is immediately on shore next to the bow.  Its strapped to a pallet for shipment, either coming or going or maybe just that way to lift it off the ASDS.

Interesting singe marks on the white container behind the blast wall but I think we knew this had taken some damage.  Curious that they're not painting it.

Looks like the hull was breached after all, just below the wing. Makes sense to keep that side of the OCISLY out of the water in that case. Any speculation if the engine section went right through or if it got stuck inside? I cant see it.

look at the picture.. its not visible in the video I beleave.

edit: Part of the yellow/orange background is missing where the wing attaches to the body of the barge. It looks like a section is cut out.

When you said the hull breached I think a few folks might have taken you to be saying the bottom was holed but you are pointing to the side of the hull being apparently blown out or at least cut out.  Good observation but there may be fruit for additional observation here.

Can we get the drone down inside the hole?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: symbios on 03/22/2016 12:56 PM
Added a picture to to show what Semmel is referring to.

There must have been some serious structural damage from the impact. Buckling of stringers and load bearing beams. Definitely passing the 50 k $ mark. But I still think far from the 250 k mark.  :P

Maybe getting close with Inspections, Marine architects/engineers and their associated costs, etc...

I think that if anything below the waterline had been damage, it would have been away to the boatyard for the ASDS.  8)

I watched the vid a couple times and I'm not quite clear how you drew that conclusion... there is never an overhead view that lets us see into the hole, plus there is blue(teal??) material covering a lot of it.

look at the picture.. its not visible in the video I beleave.

edit: Part of the yellow/orange background is missing where the wing attaches to the body of the barge. It looks like a section is cut out.

Enlarge to see the encircled area more clearly:
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Retired Downrange on 03/22/2016 01:03 PM
......  I see more portable fencing with blue tarp near the plastic outhouses, and interestingly, a section of it blocking the view that someone might have under the wing area.


My guess is the blue tarp at the plastic outhouses (which blocks the view of the repair area) is there to protect the eyes of people approaching the outhouses, from direct exposure to the arc welding.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 03/22/2016 01:10 PM
Part of the yellow/orange background is missing where the wing attaches to the body of the barge. It looks like a section is cut out.

Looking at that blown up enlarged, I believe what you're seeing is an inset "bollard box" (to use the convenient, if not exactly canonical, term).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 01:15 PM
CyndyC, there's your (new?) white bubble (VSAT antenna dome) dockside on a pallet, by the bow.

The photographer (Tim Dodd according to the photo watermark, who is presumably the reddit user termderd) commented over there that he was stopped by a policeman and told that drone flying was illegal around the port. So the days of us getting new drone footage of OCISLY may be numbered...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/22/2016 01:33 PM
Still not seeing a hull breach. Still surprised how much damage was allegedly done (difficult to tell from these pictures anyway), would not have expected that at all, 1/2" steel plate reinforced by some pretty big stringers is a very strong surface, even for something travelling at 200mph. I doubt that once past the deck and the stringers there was enough energy left in the octoweb/engines to puncture the hull as well.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 03/22/2016 01:35 PM

Still not seeing a hull breach. Still surprised how much damage was allegedly done (difficult to tell from these pictures anyway), would not have expected that at all, 1/2" steel plate reinforced by some pretty big stringers is a very strong surface, even for something travelling at 200mph. I doubt that once past the deck and the stringers there was enough energy left in the octoweb/engines to puncture the hull as well.
The hull side is being repaired (post breach)

Keep in mind the the wings extend past hull sides. Therefore if you look into the hole you can see the actual hull side that's under repair.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: symbios on 03/22/2016 01:42 PM
I must agree with ClayJar after he pointed this out.  If you look at Semmels original large image you can see where the wings are attach and the "cut-in" sections evenly spaced along the line/seam of the wing for the "bollard-boxes". The "hole" in the side of the hull visible at the damaged area could mach a "bollard-box".

Part of the yellow/orange background is missing where the wing attaches to the body of the barge. It looks like a section is cut out.

Looking at that blown up enlarged, I believe what you're seeing is an inset "bollard box" (to use the convenient, if not exactly canonical, term).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/22/2016 01:45 PM
There's sidewall damage above the waterline, since the deck extends over the sidewall, but it's limited to the part right near the deck - essentially a beam at that point.

Because it is limited, I don't think it extended much lower towards the waterline - unless the sidewall itself transmitted impact further below.

Might have been cleaner if it hit more towards center deck.

I agree with other posters - that's quite an impact...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 03/22/2016 02:03 PM
I agree with other posters - that's quite an impact...

Indeed. Someone do the math - what's the kinetic energy of a returning, nearly empty S1 at 90 mph? ;)

Now, snark aside, people routinely misunderstand impact forces and the amount of damage done by even relatively low speed impacts between massive objects. And frankly, 90 mph isn't slow, and the octoweb and engine powerbeads are both strong and relatively dense.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 03/22/2016 02:07 PM
Couple of spots seem to have been marked with spray paint for repair?

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 02:09 PM
I tend not to believe the "bollard cutout" explanation for the gap in the right side of the ribbed yellow sidewall. The bollard cutouts are vertical, but that missing area we see meets the yellow sidewall at an angle, as if torched out.

Also, if that sidewall were not damaged, why would they extend the deck plate cutout beyond that area into the wing?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 03/22/2016 02:27 PM
I agree with other posters - that's quite an impact...

Indeed. Someone do the math - what's the kinetic energy of a returning, nearly empty S1 at 90 mph? ;)

Now, snark aside, people routinely misunderstand impact forces and the amount of damage done by even relatively low speed impacts between massive objects. And frankly, 90 mph isn't slow, and the octoweb and engine powerbeads are both strong and relatively dense.

High School physics tells me about 40MJ- assuming the oft quoted stage mass of 20t.

A friend of mine taught me to remember the formula by saying "eek, half my Volkswagen has vanished"...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/22/2016 02:36 PM
Cyndy's antenna bubble is immediately on shore next to the bow.  Its strapped to a pallet for shipment, either coming or going or maybe just that way to lift it off the ASDS.
CyndyC, there's your (new?) white bubble (VSAT antenna dome) dockside on a pallet, by the bow.

Yay! Thanks for that. Can't believe the both of you were able to spot it, and I didn't know what it was before this. Bow ID aside, it might help the situation if SpaceX uses more than one, and adds some of Kabloona's shock & vibration components (https://www.vibrationmounts.com/uses/aerospace.htm).

Any speculation if the engine section went right through or if it got stuck inside? I cant see it.
Can we get the drone inside the hull?
So the days of us getting new drone footage of OCISLY may be numbered...

That's disappointing, but people here don't seem to have a problem using their imaginations. Sorry to those who don't care about seeing the image below again, but it might provide some help with Semmel's & OxCartMark's questions, and help illustrate some of the comments from others, and took enough work worth a repeat from my perspective:

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-08%20OCISLY%20aerial%20corner+web%206x4.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 03/22/2016 03:58 PM
I tend not to believe the "bollard cutout" explanation for the gap in the right side of the ribbed yellow sidewall. The bollard cutouts are vertical, but that missing area we see meets the yellow sidewall at an angle, as if torched out.

Also, if that sidewall were not damaged, why would they extend the deck plate cutout beyond that area into the wing?

The bollard cutouts (or should we call them "cleat cuts", since they actually had mooring cleats in them originally, not cylindrical bollards) are trapezoidal when viewed from above.  I believe the angle you're seeing is an artifact of perspective.  I *think* I can discern the other end of the cutout, but there isn't enough resolved detail to say with any confidence.  (Attached is a crop of two cleats in the pre-Panama now-JRtI.)

The deck plate and perhaps original hull sidewall must have been compromised to require that extent of deck work, but I am reasonably confident that what we see in the image is at least primarily the original cutout and not new work.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 05:14 PM
Quote
The bollard cutouts (or should we call them "cleat cuts", since they actually had mooring cleats in them originally, not cylindrical bollards) are trapezoidal when viewed from above.  I believe the angle you're seeing is an artifact of perspective.  I *think* I can discern the other end of the cutout, but there isn't enough resolved detail to say with any confidence.  (Attached is a crop of two cleats in the pre-Panama now-JRtI.)


You know what? I think you're right, and moreover, in that aerial photo I think I see a cleat right where it should be if that were a "cleat cutout."
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 03/22/2016 05:19 PM
CyndyC, there's your (new?) white bubble (VSAT antenna dome) dockside on a pallet, by the bow.

The photographer (Tim Dodd according to the photo watermark, who is presumably the reddit user termderd) commented over there that he was stopped by a policeman and told that drone flying was illegal around the port. So the days of us getting new drone footage of OCISLY may be numbered...


Well, there's always balloons...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/22/2016 05:29 PM
I suppose its possible that if the wing took a big impact, the support struts may have been pushed in to the hull wall, which could have bent them or perhaps made a slight puncture leak. But the hole seems to indicate the main impact wasn't far enough out.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/22/2016 05:44 PM
What impressed me, seeing the extend of the work, is how quickly after getting to port actual work has begun.

There had to be damage assessment, repair planning, approval of repair plans, ordering material and equipment, etc...

Each step can be expedited, for sure, but in order to see arcs so quickly, the organization had to be really efficient.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/22/2016 06:32 PM
I suppose its possible that if the wing took a big impact, the support struts may have been pushed in to the hull wall, which could have bent them or perhaps made a slight puncture leak. But the hole seems to indicate the main impact wasn't far enough out.

So far we have seen extreme localized damage on deck and equipment but never on wings. I think this was discussed previously but can't recall much. Also estimating the nature of damage they could have a prefabricated wing section in store somewhere.. just in case.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: joncz on 03/22/2016 06:41 PM
Quote
The bollard cutouts (or should we call them "cleat cuts", since they actually had mooring cleats in them originally, not cylindrical bollards) are trapezoidal when viewed from above.  I believe the angle you're seeing is an artifact of perspective.  I *think* I can discern the other end of the cutout, but there isn't enough resolved detail to say with any confidence.  (Attached is a crop of two cleats in the pre-Panama now-JRtI.)


You know what? I think you're right, and moreover, in that aerial photo I think I see a cleat right where it should be if that were a "cleat cutout."


Like so?

(http://www.mcdonoughmarine.com/images/Marmac%2004%20Launch%20010%20eb.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/22/2016 06:58 PM
What impressed me, seeing the extend of the work, is how quickly after getting to port actual work has begun.

There had to be damage assessment, repair planning, approval of repair plans, ordering material and equipment, etc...

Each step can be expedited, for sure, but in order to see arcs so quickly, the organization had to be really efficient.

Well, since SpaceX seems to be trying for an ASDS landing on CRS-8, and since that is currently scheduled for two and a half weeks from now, I'd wager OCISLY will need to leave port in about two weeks.

So, yes, very gratifying to see the speed of the repair.  Also, though, perhaps extremely necessary...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 03/22/2016 07:22 PM
Quote
The bollard cutouts (or should we call them "cleat cuts", since they actually had mooring cleats in them originally, not cylindrical bollards) are trapezoidal when viewed from above.  I believe the angle you're seeing is an artifact of perspective.  I *think* I can discern the other end of the cutout, but there isn't enough resolved detail to say with any confidence.  (Attached is a crop of two cleats in the pre-Panama now-JRtI.)

You know what? I think you're right, and moreover, in that aerial photo I think I see a cleat right where it should be if that were a "cleat cutout."

Like so?

The first cutout at the front (pictured above, about where the hull slopes into the water on the bow when unladen) has a pair of bollards, as does the cutout directly at the stern.  Those two are about a foot "deeper" (measured from deck level) than the intervening six cutouts, each of which has a mooring cleat.

(Source: First-hand examination of MARMAC 303 while it was near Morgan City along with 300 and 304 during one of my favorite kayak excursions ever.)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/22/2016 07:35 PM
(Source: First-hand examination of MARMAC 303 while it was near Morgan City along with 300 and 304 during one of my favorite kayak excursions ever.)

You know you're a space geek when "favorite kayak excursion" involves barges and industrial snooping, rather than white water, tall pines and mountain views...

Thanks for all the info you gathered, it's still paying off...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/22/2016 10:07 PM
What impressed me, seeing the extend of the work, is how quickly after getting to port actual work has begun.

There had to be damage assessment, repair planning, approval of repair plans, ordering material and equipment, etc...

Each step can be expedited, for sure, but in order to see arcs so quickly, the organization had to be really efficient.

Yes, they didn't mess around. Very impressive indeed!  :)

One possibility is that much of the general damage assessment (photos, phone calls) happened whilst on the way back to land and, once they realised there was structural damage this time, someone-in-charge made the call for help to MD Marine.  Given the size of this operation, it would not surprise me in the least if McD Marine flew a team of barge-builders over with all their gear and were waiting dockside, barge plans in hand, ready to get stuck in as soon as the lines were secure.  There's nothing special about the steelwork - that could have been sourced from anywhere.

Don't forget:  this barge isn't very old at all and it's quite likely the guys that built it originally are still on the tools.


EDIT:  Presuming there was no structural damage to the hull/ribs/keel (and for reasons posted uphill we have no reason to think there is) this is a pretty straightforward repair.  Seriously, it is not nearly as complex as it looks.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/22/2016 10:11 PM
What impressed me, seeing the extend of the work, is how quickly after getting to port actual work has begun.

There had to be damage assessment, repair planning, approval of repair plans, ordering material and equipment, etc...

Each step can be expedited, for sure, but in order to see arcs so quickly, the organization had to be really efficient.

Yes, they didn't mess around. Very impressive indeed!  :)

One possibility is that much of the general damage assessment (photos, phone calls) happened whilst on the way back to land and, once they realised there was structural damage this time, someone-in-charge made the call for help to MD Marine.  Given the size of this operation, it would not surprise me in the least if McD Marine flew a team of barge-builders over with all their gear and were waiting dockside, barge plans in hand, ready to get stuck in as soon as the lines were secure.  There's nothing special about the steelwork - that could have been sourced from anywhere.

Don't forget:  this barge isn't very old at all and it's quite likely the guys that built it originally are still on the tools.

Agreed - It's the only scenario that I can think of that matches what we see.    (Which does hike up the repair price, but as people noted, compared to the cost of a used stage, is still not a bad trade...)

And I assume that the barge builders are pretty stoked about this project...  so the will to go the extra mile was there...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/22/2016 10:16 PM
Agreed - It's the only scenario that I can think of that matches what we see.    (Which does hike up the repair price, but as people noted, compared to the cost of a used stage, is still not a bad trade...)

And I assume that the barge builders are pretty stoked about this project...  so the will to go the extra mile was there...

I imagine you're right - this is a 'spare no expense' repair that needs to be completed, to the owner's and ABS's satisfaction, in time for the next launch.  You don't get work like that every day!

..and check out the dock-side picnic shelter for their meal-breaks.  Very civilised indeed!  ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/22/2016 10:30 PM
Maybe one of us can get in the yard if we offer to man the BBQ grill... :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/23/2016 12:28 AM
I think what we need is to modify one of those huge container unloading cranes in the background to have a bargestalker observation platform, bar & grille suspended on it.  Perhaps it would have a small section of grandstand seating in the floating patio area outside the main cabin or building.  We could hover over or around any part of the ASDS without bothering them a bit.  They'd probably actually encourage us to hover over them to provide shade in the Florida summer.  Win-win.  And we could run it all the way up to have a great view of launches.  This really isn't as far fetched as you might think since (as you can see in the latest overhead images) the tracks for those cranes go all the way to the front of the ASDS.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/23/2016 01:00 AM
lol we are spoiled rotten! drone videos and HD pictures!? back in my day you had to get your drone ship kicks from a grainy webcam video that only worked 2 days a week.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/23/2016 04:09 AM
But it was clockwork regular with 10 hrs of live feed from vantage point!  :-\
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 03/23/2016 11:55 AM
I heard Police cracked down on drone flying in Port Canaveral - people were issued tickets + reported to FAA (restricted airspace).

I was there last night watching Atlas V launch - there was a lot of activity at SpaceX barge. Cranes moving, welding etc. At 11 PM - looks like they are working 24x7.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/23/2016 01:11 PM
(restricted airspace)
Anyone care to delve into the truthiness of this restricted airspace?  Restricted by FAA?  Restricted by local ordinance? Restricted by port authority (is that possible on mostly non-port side of the waterway?) Restricted only in the minds of the police?

And what are the limits of its restrictedness?  For instance, if you moved another 100' off of that property would it be OK?

I wonder if it was SpaceX that pushed for this?.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rettenet on 03/23/2016 01:15 PM
(restricted airspace)
Anyone care to delve into the truthiness of this restricted airspace?  Restricted by FAA?  Restricted by local ordinance? Restricted by port authority (is that possible on mostly non-port side of the waterway?) Restricted only in the minds of the police?

And what are the limits of its restrictedness?  For instance, if you moved another 100' off of that property would it be OK?

I wonder if it was SpaceX that pushed for this?.

By FAA apparently. See this reddit comment:

https://www.reddit.com/r/spacex/comments/4bgxok/asds_ocisly_aerial_video_march_21_2016_pic_in/d197l6p

Quote
There's not "legislation" exactly, which is to say, congress isn't passing laws specifically blocking off each restricted airspace. That's up to the FAA (although based on authority given by congress). R-2932 is the restricted airspace block over Port/Cape Canaveral and is continuously in effect below 5000'. Above 5000' for that same block is R-2933. Then there are a couple larger zones (R-2934 to the west and north and R-2935 that forms a "C" to the N/W/S of all the above) that are enabled as needed. These would apply to everything that flies. You have to get permission from the airspace's controlling authority, which I believe is the space wing there.
Looks like tomorrow R-2933 is active from 0222 to 0417 and again from 1400 to 1800 (times are Zulu). R-2934 is active tomorrow from 0222 to 0417. I recall hearing something about R-2935 rarely being activated (only for manned flight or something like that?).
You can checkout special use airspaces at the FAA website here: https://sua.faa.gov/sua/siteFrame.app
Edit: Oh, right, Orbital is launching at 0315 tonight, so that explains 2933 and 2934 going active from 0222 to 0417.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 03/23/2016 01:21 PM
(restricted airspace)
Anyone care to delve into the truthiness of this restricted airspace?  Restricted by FAA?  Restricted by local ordinance? Restricted by port authority (is that possible on mostly non-port side of the waterway?) Restricted only in the minds of the police?

And what are the limits of its restrictedness?  For instance, if you moved another 100' off of that property would it be OK?

I wonder if it was SpaceX that pushed for this?.

By FAA apparently. See this reddit comment:

https://www.reddit.com/r/spacex/comments/4bgxok/asds_ocisly_aerial_video_march_21_2016_pic_in/d197l6p

Quote
There's not "legislation" exactly, which is to say, congress isn't passing laws specifically blocking off each restricted airspace. That's up to the FAA (although based on authority given by congress). R-2932 is the restricted airspace block over Port/Cape Canaveral and is continuously in effect below 5000'. Above 5000' for that same block is R-2933. Then there are a couple larger zones (R-2934 to the west and north and R-2935 that forms a "C" to the N/W/S of all the above) that are enabled as needed. These would apply to everything that flies. You have to get permission from the airspace's controlling authority, which I believe is the space wing there.
Looks like tomorrow R-2933 is active from 0222 to 0417 and again from 1400 to 1800 (times are Zulu). R-2934 is active tomorrow from 0222 to 0417. I recall hearing something about R-2935 rarely being activated (only for manned flight or something like that?).
You can checkout special use airspaces at the FAA website here: https://sua.faa.gov/sua/siteFrame.app
Edit: Oh, right, Orbital is launching at 0315 tonight, so that explains 2933 and 2934 going active from 0222 to 0417.


Time for the longest selfie stick:
http://www.guinnessworldrecords.com/world-records/377096-longest-selfie-stick
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/23/2016 07:58 PM
...rather than doing what-if, why not try to figure out what SpaceX is doing and why and what things they are going to try next.  Some of the best threads on the site are those kind (the barge threads in many cases are like that)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/23/2016 08:55 PM
quoting me from another thread and you didn't even like that post? ... splutter...

So are they going to make it? Right to left planning, assuming no further CRS8 slips (can't count on those) what does the timeline look like?

When does the ASDS need to leave port? (if we assume worst case distance, a mostly ballistic reentry rather than a boostback)

Given that, when does the ASDS have to have all its seaworthiness paperwork done? How much time is needed for inspections?  before that, for painting? Besides teh major steelwork, what else do we speculate is needed? one thruster repaired? comm gear repaired? Anything else?

Go!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/23/2016 09:16 PM
Quote
When does the ASDS need to leave port? (if we assume worst case distance, a mostly ballistic reentry rather than a boostback)

No assumption necessary. FCC transmitter permit gives the expected ASDS position as around 160 nmi off the Cape. At 5 knots, the ASDS can get there in around 32 hours. So they could leave port as late as 2 days prior to launch and still have plenty of time to set up at the LZ.

(For future reference, the expected ASDS position is 30.5N, 78.5W)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 03/23/2016 10:53 PM
Quote
When does the ASDS need to leave port? (if we assume worst case distance, a mostly ballistic reentry rather than a boostback)

No assumption necessary. FCC transmitter permit gives the expected ASDS position as around 160 nmi off the Cape. At 5 knots, the ASDS can get there in around 32 hours. So they could leave port as late as 2 days prior to launch and still have plenty of time to set up at the LZ.

(For future reference, the expected ASDS position is 30.5N, 78.5W)

That location anticipates a normal boostback burn and regular single-engine landing burn, as have been executed nearly perfectly on at least a couple of occasions.

I think the CRS flights are within the F9's performance range for RTLS, so an ASDS landing should be well within its envelope.

I doubt there will be any problems getting OCISLY ready for departure in time to support CRS-8.  It looked like they were making good, steady progress as of that drone flight.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/24/2016 12:22 AM
Re: the other party of Lar's question: I think we haven't been able to get a good handle on paperwork delays because the paperwork shows up online well after it must have been complete and "on file".  But I wouldn't doubt that they've got a good relationship with the inspectors and can get what they need in good time.  Can anyone do some paperwork sleuthing to put tighter bounds on the paperwork delay?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/24/2016 12:40 AM
Re: the other party of Lar's question: I think we haven't been able to get a good handle on paperwork delays because the paperwork shows up online well after it must have been complete and "on file".  But I wouldn't doubt that they've got a good relationship with the inspectors and can get what they need in good time.  Can anyone do some paperwork sleuthing to put tighter bounds on the paperwork delay?

Paperwork delays: In reality, with cost no obstacle, there are none.  They'll arrange for the inspector to come and take a final look once the work is complete and they're sweeping up ready to leave (he may even be checking daily progress already..).  He'll sign-off right then and away they go.  The paperwork gets lodged when the inspector gets around to it - maybe that day or maybe later.. it doesn't matter, just as long as he signs off (and, more importantly, that they fix anything he doesn't like) before they leave the dock.

EDIT:  Final inspection for something like this should take no longer than an hour, excluding a celebratory beer or two dockside. :)  Painting will take a couple of days because there's at least two coats to go on over that primer and it's something the inspector will want to see.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/24/2016 01:53 AM
Paperwork delays: In reality, with cost no obstacle, there are none.  They'll arrange for the inspector to come and take a final look once the work is complete and they're sweeping up ready to leave (he may even be checking daily progress already..).  He'll sign-off right then and away they go.  The paperwork gets lodged when the inspector gets around to it - maybe that day or maybe later.. it doesn't matter, just as long as he signs off (and, more importantly, that they fix anything he doesn't like) before they leave the dock.

EDIT:  Final inspection for something like this should take no longer than an hour, excluding a celebratory beer or two dockside. :)  Painting will take a couple of days because there's at least two coats to go on over that primer and it's something the inspector will want to see.
Is this inspector a government inspector (Coast Guard or similar) who would have one size fits all / fair to all ways of scheduling visits or is it a private entity such as a naval engineer that will take payment to move the inspection time to the front burner, even if that's 3:15am?  Even with the CG, I'm not meaning to imply anything negative and they are probably as much into what SpaceX has going on as we are.  Well, as close as normal people get to our level of enthusiasm at least.

I think the CRS flights are within the F9's performance range for RTLS...
Odd, but with the recent work I'm now shifted to the point that my first take on your abbreviation "CRS" is "Cold Rolled Steel".

(For future reference, the expected ASDS position is 30.5N, 78.5W)
Here plotted that is.  Its the lower lefter pin, red.  I noticed that the location is rounded to one decimal place so to see what one decimal accuracy does I've plotted another point, a smaller pin intermediate between CRS-8 and CRS-6/7 ASDS positions to show the reasonably assumable distance it might be from the point I've plotted (+0.1 lat, -0.1lon).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/24/2016 02:00 AM
Curiositization-

There are quite a few radars around a port including I assume the CG, and whoever runs the port.  These radars don't rely on transponders, they are old school primary radar.  How evident would a drone be on that radar?  Probably not much since a drone has little in the may of area or reflective materials and marine radar doesn't care about vertical motion or even speed (?).  So that's not how the police were brought in so quickly to harsh the drone is it?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/24/2016 02:04 AM
Paperwork delays: In reality, with cost no obstacle, there are none.  They'll arrange for the inspector to come and take a final look once the work is complete and they're sweeping up ready to leave (he may even be checking daily progress already..).  He'll sign-off right then and away they go.  The paperwork gets lodged when the inspector gets around to it - maybe that day or maybe later.. it doesn't matter, just as long as he signs off (and, more importantly, that they fix anything he doesn't like) before they leave the dock.

I would be surprised if anyone can pay an official agency for faster service, and in fact that might be illegal (I see OxCartMark just alluded to that before I did). I'd also be surprised if multiple inspections aren't required to coincide with the various stages of repair. I acted as contractor for a bathroom remodel in my own home, which can be done w/o a license, and multiple interim inspections were required for such as plumbing, floor structure, electric, and fireproofing. I paid a one time charge based on the estimated cost of construction, and that included all inspections. I don't recall having to wait long for an inspection before the construction could continue, but it was around Christmas when a lot of people are sitting out construction.

Quote
EDIT:  Final inspection for something like this should take no longer than an hour, excluding a celebratory beer or two dockside. :)  Painting will take a couple of days because there's at least two coats to go on over that primer and it's something the inspector will want to see.

My final was definitely brief, and even allowed me to fudge a bit (by allowing me to keep a two handle shower fixture instead of the coded single handle), the inspector said, "Because it's Christmas," haha. I don't recall drinking any beer afterwards though. Another surprise will be if an inspection of the paint is required. Really?? That seems a bit extreme. Home construction does not even require inspection of tile installations.

Edit: I will say this about the paint though. Some paint requires 48-72 hours dry time between coats, and my guess would be the tough kind of paint required on seagoing vessels would fall into that category. Also, the glazing putty that goes around window glass to waterproof windows before painting is technically supposed to be allowed to dry for a couple of weeks before painting (http://www.doityourself.com/stry/how-long-does-it-take-for-glazing-putty-to-set#b). The people I hired painted over it the same week and now a lot of it is falling off. I imagine there's plenty of waterproofing substance(s) required for this vessel.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/24/2016 02:22 AM
Curiositization-

There are quite a few radars around a port including I assume the CG, and whoever runs the port.  These radars don't rely on transponders, they are old school primary radar.  How evident would a drone be on that radar?  Probably not much since a drone has little in the may of area or reflective materials and marine radar doesn't care about vertical motion or even speed (?).  So that's not how the police were brought in so quickly to harsh the drone is it?

The guy said on Reddit that the cop told him half his time was spent busting people flying drones around the port. So he's probably got his eyes peeled for drones all the time he's on duty.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/24/2016 03:54 AM
im not familiar with ship industry but are we sure there is actually a government mandated inspection of repairs? id think theyd only have to satisfy the barge owner?

i can sorta understand that the coast gaurd would have an interest in knowning that things arnt going to sink but on the other hand this isnt a passenger vessel, worst case scenario is sinks in a shallow spot and gets in the way.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/24/2016 06:15 AM
Paperwork delays: In reality, with cost no obstacle, there are none.  They'll arrange for the inspector to come and take a final look once the work is complete and they're sweeping up ready to leave (he may even be checking daily progress already..).  He'll sign-off right then and away they go.  The paperwork gets lodged when the inspector gets around to it - maybe that day or maybe later.. it doesn't matter, just as long as he signs off (and, more importantly, that they fix anything he doesn't like) before they leave the dock.

I would be surprised if anyone can pay an official agency for faster service, and in fact that might be illegal (I see OxCartMark just alluded to that before I did). I'd also be surprised if multiple inspections aren't required to coincide with the various stages of repair. I acted as contractor for a bathroom remodel in my own home, which can be done w/o a license, and multiple interim inspections were required for such as plumbing, floor structure, electric, and fireproofing. I paid a one time charge based on the estimated cost of construction, and that included all inspections. I don't recall having to wait long for an inspection before the construction could continue, but it was around Christmas when a lot of people are sitting out construction.

My apologies - I DID NOT mean to imply an inspector could be paid off!  :o

What I mean by that comment is that, if cost is no obstacle, they (SpX, McD Marine) could afford to pay for an Inspector to stand around all day if that's what they need to do to ensure sign-off happens ASAP.  At the decent hourly rates these guys would be on, most folks can't afford that luxury.


My final was definitely brief, and even allowed me to fudge a bit (by allowing me to keep a two handle shower fixture instead of the coded single handle), the inspector said, "Because it's Christmas," haha. I don't recall drinking any beer afterwards though. Another surprise will be if an inspection of the paint is required. Really?? That seems a bit extreme. Home construction does not even require inspection of tile installations.

Edit: I will say this about the paint though. Some paint requires 48-72 hours dry time between coats, and my guess would be the tough kind of paint required on seagoing vessels would fall into that category. Also, the glazing putty that goes around window glass to waterproof windows before painting is technically supposed to be allowed to dry for a couple of weeks before painting (http://www.doityourself.com/stry/how-long-does-it-take-for-glazing-putty-to-set#b). The people I hired painted over it the same week and now a lot of it is falling off. I imagine there's plenty of waterproofing substance(s) required for this vessel.

There are pages of requirements for coatings in the Barge Rules so I won't bore you with specifics, but yes, generally final coatings must be inspected.  In some cases (eg. salt water ballast tanks) special corrosion resistant hard coatings might be required, but either way, the Inspector needs to check that the paintwork has been properly applied and the new steelwork isn't likely to rust any time soon.  These particular tanks are to be filled with water, remember?

You're right, some marine epoxy paints do require several hours to cure properly - but there's nothing I can think of in this repair that would require weeks..

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/24/2016 06:28 AM
im not familiar with ship industry but are we sure there is actually a government mandated inspection of repairs? id think theyd only have to satisfy the barge owner?

Yes.  No. 

(You guys will be calling me "Barge Jim" soon.. :))
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/24/2016 06:46 AM
im not familiar with ship industry but are we sure there is actually a government mandated inspection of repairs? id think theyd only have to satisfy the barge owner?

Yes.  No. 

(You guys will be calling me "Barge Jim" soon.. :))

could they get around this by using a flag of convenience for the barge?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/24/2016 07:07 AM
im not familiar with ship industry but are we sure there is actually a government mandated inspection of repairs? id think theyd only have to satisfy the barge owner?

Yes.  No. 

(You guys will be calling me "Barge Jim" soon.. :))

could they get around this by using a flag of convenience for the barge?

Sometimes.. in some parts of the world, including those due south of you - but last I heard the USCG were cracking down on that sort of thing.

If you're operating regularly out of an American port, it would be mighty difficult to get away with.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/24/2016 07:28 AM
found something

https://www.federalregister.gov/articles/2011/12/14/2011-32007/seagoing-barges

"In 1993, Congress exempted from inspection seagoing barges that are unmanned and not carrying hazardous material as cargo, or carrying a flammable or combustible liquid, including oil, in bulk."

https://www.gpo.gov/fdsys/pkg/USCODE-2014-title46/html/USCODE-2014-title46-subtitleII-partB-chap33-sec3302.htm

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

not a lawyer so not sure if this actually covers what it sounds like
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/24/2016 08:20 AM
found something

https://www.federalregister.gov/articles/2011/12/14/2011-32007/seagoing-barges

"In 1993, Congress exempted from inspection seagoing barges that are unmanned and not carrying hazardous material as cargo, or carrying a flammable or combustible liquid, including oil, in bulk."

https://www.gpo.gov/fdsys/pkg/USCODE-2014-title46/html/USCODE-2014-title46-subtitleII-partB-chap33-sec3302.htm

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

not a lawyer so not sure if this actually covers what it sounds like

Sounds fair enough. Don't really care if a non-toxic barge sinks through bad maintenance - that's the owners fault. Unless of course it sinks somewhere important and gets in the way.

Makes a nice reef for coral etc. Lot's of tanks and old ships out there already doing that.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: woods170 on 03/24/2016 08:37 AM
found something

https://www.federalregister.gov/articles/2011/12/14/2011-32007/seagoing-barges

"In 1993, Congress exempted from inspection seagoing barges that are unmanned and not carrying hazardous material as cargo, or carrying a flammable or combustible liquid, including oil, in bulk."

https://www.gpo.gov/fdsys/pkg/USCODE-2014-title46/html/USCODE-2014-title46-subtitleII-partB-chap33-sec3302.htm

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

not a lawyer so not sure if this actually covers what it sounds like
In that case, this barge is probably not exempted from inspection. The ASDS carries four substantial containers worth of combustible liquids.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Alastor on 03/24/2016 09:23 AM
Sounds fair enough. Don't really care if a non-toxic barge sinks through bad maintenance - that's the owners fault. Unless of course it sinks somewhere important and gets in the way.

Makes a nice reef for coral etc. Lot's of tanks and old ships out there already doing that.

As a diver, I must say, the opportunity to visit OCISLY underwater while admiring the underwater fauna that might be in the process of taking over it would most definitely both please the aerospace nerd and the diving nerd in me.

Sadly, not likely, though ...  :'(

Maybe  if we ask nicely enough, SpaceX might agree to sink the first barge-landed core along with its barge after having safed it ?
That might make for a very nice diving spot !  ;D

EDIT: Celebratory edit for my 50th post ! :P Well ... not every post can be serious !
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jet Black on 03/24/2016 01:09 PM
found something

https://www.federalregister.gov/articles/2011/12/14/2011-32007/seagoing-barges

"In 1993, Congress exempted from inspection seagoing barges that are unmanned and not carrying hazardous material as cargo, or carrying a flammable or combustible liquid, including oil, in bulk."

https://www.gpo.gov/fdsys/pkg/USCODE-2014-title46/html/USCODE-2014-title46-subtitleII-partB-chap33-sec3302.htm

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

not a lawyer so not sure if this actually covers what it sounds like
In that case, this barge is probably not exempted from inspection. The ASDS carries four substantial containers worth of combustible liquids.

depends on whether you class that as 'in bulk' though. I guess those containers are for fuel to be used, rather than stuff to be transported about the place.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 03/24/2016 01:44 PM
found something

https://www.federalregister.gov/articles/2011/12/14/2011-32007/seagoing-barges

"In 1993, Congress exempted from inspection seagoing barges that are unmanned and not carrying hazardous material as cargo, or carrying a flammable or combustible liquid, including oil, in bulk."

https://www.gpo.gov/fdsys/pkg/USCODE-2014-title46/html/USCODE-2014-title46-subtitleII-partB-chap33-sec3302.htm

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

not a lawyer so not sure if this actually covers what it sounds like
In that case, this barge is probably not exempted from inspection. The ASDS carries four substantial containers worth of combustible liquids.

But not as cargo, and not really bulk when compared to the rest of the barge. But that could be a cause for inspection.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 03/24/2016 01:55 PM
OK you ASDS sleuths..
Ready to make a prediction who is going to win this round, the Anti-ASDS missile targeting system, or the Anti-rocket repellent, or will it be a draw?

Landing Poll just out..
http://forum.nasaspaceflight.com/index.php?topic=39862.0
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/24/2016 03:04 PM
not sure the difference between what they have listed as the CFR and the eCFR. one lists 250 barrels as bulk.

https://www.law.cornell.edu/cfr/text/46/90.05-25

§ 90.05-25 Seagoing barge.

(a) Each seagoing barge, as defined in 46 CFR 90.10-36, is subject to inspection and certification; except that a seagoing barge is exempt from those requirements if it is unmanned for the purposes of operating or navigating the barge, and carries neither a hazardous material as cargo nor a flammable or combustible liquid, including oil, in bulk quantities of 250 barrels or more.

http://blog.transportbusinesslaw.com/2013/09/13/maritime-seagoing-barges-the-u-s-coast-guard-is-exempting-specified-seagoing-barges-from-its-inspection/

“The second commenter requested more detailed discussion in support of our proposed definition of a seagoing barge carrying flammable or combustible liquid, including oil ‘in bulk.” We are amending 46 CFR 90.05-25(a) to define ‘in bulk’’ as a quantity equivalent to at least 250 barrels (10,500 gallons). Some regulatory definition of ‘in bulk’ is needed so that barge operators know whether or not they are subject to the 46 U.S.C. 3302(m) exemption. The statute does not provide that definition. However, as we pointed out in the NPRM, 78 FR at 2150, col. 3, Coast Guard policy set the bulk threshold at 250 barrels in 1996. That same policy has been in place without public concern for almost two decades and so the regulatory definition follows current Coast Guard policy.”


we should start an extralegal probono NSF barge law office
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 03/24/2016 04:02 PM

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

Not sure why everyone is so focused on (2), when (1) seems so much more relevant. I expect that a rocket (or parts there of) that was launched not 10 minutes prior would certainly be classified as hazardous material. (High pressure vessels, kerosene LOX, TEA/TEB)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/24/2016 04:48 PM

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

Not sure why everyone is so focused on (2), when (1) seems so much more relevant. I expect that a rocket (or parts there of) that was launched not 10 minutes prior would certainly be classified as hazardous material. (High pressure vessels, kerosene LOX, TEA/TEB)

The TEA/TEB is probably all burned off during the landing burn ignition just for that reason, the tank pressurant is vented after landing, and the remaining LOX boils off. Kerosene is not a hazardous material.

The only remaining hazardous material on the rocket is the FTS charges, in such relatively small quantity that it's debatable whether that clause applies or not.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 03/24/2016 05:06 PM

"(m) A seagoing barge is not subject to inspection under section 3301(6) of this title if the vessel is unmanned and does not carry—
(1) a hazardous material as cargo; or
(2) a flammable or combustible liquid, including oil, in bulk."

Not sure why everyone is so focused on (2), when (1) seems so much more relevant. I expect that a rocket (or parts there of) that was launched not 10 minutes prior would certainly be classified as hazardous material. (High pressure vessels, kerosene LOX, TEA/TEB)

The TEA/TEB is probably all burned off during the landing burn ignition just for that reason, the tank pressurant is vented after landing, and the remaining LOX boils off. Kerosene is not a hazardous material.

The only remaining hazardous material on the rocket is the FTS charges, in such relatively small quantity that it's debatable whether that clause applies or not.
Try to tell TSA at the airport that it's not hazardous.  :)
But anyway, anything that happens "after landing" is too late. It's cargo at soon as it lands.
I wouldn't expect SpaceX to test the limits of what they could get away with regarding inspections. It might be considered a poor indicator of how they might treat other far more important inspections.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/24/2016 05:23 PM
restricted airspace

selfie stick:

http://www.ebay.com/itm/Will-Burt-9-5-56-Pneumatic-Mast-56-Tall-Telescoping-Mast-Broadcast-Mast-/281978116276?hash=item41a73498b4:g:i2kAAOSw0JpV6Pk7

Its common to have a camera on top of these things along with the microwave antenna but in our case I think it would be more um, interesting if we were to bolt an otherwise motionless drone to the top of it.

Edit:  The one shown is the simple American version that just goes up and down.  I think the Canadians make a version that is much longer and has articulated joints with grippers and various attachments on the end.  It used to be used to take selfies of the space shuttles.  If we were to put the Canadian version on our van it would probably reach a good portion of the way across the harbor.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/24/2016 06:56 PM
Paperwork delays: In reality, with cost no obstacle, there are none.  They'll arrange for the inspector to come and take a final look once the work is complete and they're sweeping up ready to leave (he may even be checking daily progress already..).  He'll sign-off right then and away they go.  The paperwork gets lodged when the inspector gets around to it - maybe that day or maybe later.. it doesn't matter, just as long as he signs off (and, more importantly, that they fix anything he doesn't like) before they leave the dock.

I would be surprised if anyone can pay an official agency for faster service, and in fact that might be illegal

If done informally that's a bribe. But some agencies do have provisions for paying extra for faster service. It's an option that is then open to whomever wants to pay the fee, so it's not a bribe. For example read up on US passport processing. You can pay extra for rush processing.

I have no idea if that's the case here... but did want to point out that it's not unprecedented to have two tracks, the expensive/fast track and the normal/normal track.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 03/24/2016 08:30 PM
If done informally that's a bribe. But some agencies do have provisions for paying extra for faster service. It's an option that is then open to whomever wants to pay the fee, so it's not a bribe. For example read up on US passport processing. You can pay extra for rush processing.

I have no idea if that's the case here... but did want to point out that it's not unprecedented to have two tracks, the expensive/fast track and the normal/normal track.
It's also the case that, sometimes, when one part of the government is your customer, they may have ways of encouraging other government agencies to help you out.   Years ago I heard a story about just how quickly you can get a passport if Something Is Broken on the other side of an ocean and your customer -- the US Navy -- needs your help to fix it...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: RayL2 on 03/25/2016 03:01 PM
I happened to look over the rail on Disney Dream
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: tleski on 03/25/2016 03:17 PM
Looks like a new photo was just posted in the CRS-8 party thread. No selfie stick needed.

I happened to look over the rail on Disney Dream

Edit: Removed the photo, since the original posting was moved just above. I will keep the post to celebrate my 50th post on this forum.
And congratulations to RayL2 for a very nice first post.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 03/25/2016 05:45 PM
@RayL2 Thank you very much. Yet another picture that clarified more things.
This photo finally gave me view, directly  from the side on the engines

If you happen to be able to picture the barge again from this angle, it would be pefect to have a close up of the stern engines also directly from the side, pretty much form the same angle.

(I am doing scale model of the barge and it is going to be great, hope to finish it by CRS-8 launch)

Best regards,
       Maxim Levitsky
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: RayL2 on 03/25/2016 06:56 PM
Here are 2 other Pictures from slightly different angles. This is all I have. I hope this helps. I am a very novice follower of Spaxex and was excited to happen to see OCISLY. I am spending the winter in Jupiter and have seen a couple of the launches and the successful return (or at least a partial view)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 03/25/2016 07:28 PM
Thank you very very very much  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: RayL2 on 03/25/2016 08:06 PM
I have taken advantage of the great sharing on Spaceflight.com and am glad I can contribute
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 03/25/2016 08:12 PM
This is current state of my model for reference  :)

https://github.com/maximlevitsky/ASDS

Its not yet ready to be built though. Now I am working on model for engines, and while I have exact blueprints for them, its is still hard due to many things missing in the blueprints + need to translate everything to paper.

Also engines in 1:100 scale are damn small  :) - this will soon be big challenge for me to make them out of paper.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/25/2016 09:23 PM
Can someone help me understand why in this series of images of OCISLY coming back into port on March 8th we see scattered bits of debris on deck but we don't see the large chunk (presumably interstage or top of 1st stage or octaweb) that is prominent in Marek's and other pictures in the days after being tied up in port?

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1501071#msg1501071 (http://forum.nasaspaceflight.com/index.php?topic=36326.msg1501071#msg1501071)

edit: a rathole of thought that is straightened out by others below (it was on deck).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/25/2016 10:03 PM
Can someone help me understand why in this series of images of OCISLY coming back into port on March 8th we see scattered bits of debris on deck but we don't see the large chunk (presumably interstage or top of 1st stage or octaweb) that is prominent in Marek's and other pictures in the days after being tied up in port?

http://forum.nasaspaceflight.com/index.php?topic=36326.msg1501071#msg1501071 (http://forum.nasaspaceflight.com/index.php?topic=36326.msg1501071#msg1501071)

I think this is it. Note that in both photos, it is in roughly the same rotational orientation on the ASDS. Once in port, they just dragged it forward, away from the crater.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/25/2016 11:03 PM
In Beittil's photo what I'm seeing in answer to OxCartMark's question is below. I've never understood why people have been saying anything the shape or size of an octaweb could be under that white tarp near the 'X'. To me some kind of single large glass dome appears to be peaking out, as seen again in Kabloona's photo, and I've had zero theories of my own on what it could be.

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-08%20OCISLY%20Tow%20600w%20.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/26/2016 01:30 AM
Quote
I've never understood why people have been saying anything the shape or size of an octaweb could be under that white tarp near the 'X'.

Because the diameter of its circular end is roughly twice the height of the man in the photo, or about 12 feet, which is exactly the diameter of the rocket. So it's big enough in diameter to be the octaweb or the top end of the stage.

The object you circled in the previous post is only about half the height of the blast wall, ie nowhere near 12' diameter. It might be a fragment of tank cylinder lying on its side, but it's not big enough to be an octaweb lying on its side.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/26/2016 02:03 AM
And here's an even better closeup from MarekCyzio's awesome hi-res panorama. We can even see the concave shape under the tarp, with the black hole in the center of the concavity where the propellant feeds down into the engines.

Workman in foreground gives us convenient scale. IMHO, it's the bottom end of the stage, with the engine bells facing away from us. Red circle is the diameter of the stage aft end.

CyndyC, the object you circled upthread might be the object in the lower right corner of this photo. It looks like a section of tank flattened on one side.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/26/2016 02:47 AM
I agree, it was in the pic of the ASDS coming in, I just didn't look close enough and it had been moved a bit.  But I have a hard time buying that the closeup(s) of it on deck are the bottom of the tank with the octaweb.  That octaweb is somewhere below the deck and its no longer shapely after bashing through the deck.  I think what we're looking at is the top end of the tank and the black center coloration is the area that houses the manhole / access hatch.  My visual theory for its being relatively unscathed is that the whole machine was coming down tail first at an impressive velocity (Vi) and when it hit the pressure vessel that is the tank went kaboom as we've seen and in doing so the top end of the tank and interstage were accelerated axially up relative to the stage at a speed relative to the stage of very roughly Vi while the sides of the tank departed radially (from pressure) and downward from pre-impact velocity.  This left the top of the stage somewhere above the deck with not much horizontal speed and a vertical speed much lower than it had prior to the impact, either + or -, and it fell from there.

Elon,

You'll have fools on the internet making silly speculations / assertions such as this until you release the video!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/26/2016 06:13 AM
if i had to guess i think im going with kablooma's theory on it being the bottom of the tank/top of octo web.

the engines all probably got trash compacted but the octoweb is the beefiest part and wouldnt be moving very far.

i think its possible that under the tarp one of the legs is still attached to the octoweb
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/26/2016 09:19 AM
Quote
i think its possible that under the tarp one of the legs is still attached to the octoweb

That would make sense, as the crater looks like the stage may have been tilted WRT the barge when it hit. So the leg farthest from the deck when it hit would have a chance of staying attached to the base of the stage. Meanwhile, the engines on the oppositie side took the brunt of the impact.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/26/2016 09:40 AM
Another reason I believe it's the aft end of the stage: i think we see one of the anti-vortex baffles at the center where the propellant exits the tank. Compare to the in-tank photo of the second stage LOX tank. Different tank, of course, but same design principle. Baffles highlighted in yellow.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/26/2016 12:22 PM
The piece is from top of stage it has grid fins attached and we are probably looking at the inside of LOX tank very top part of it that is still attached to interstage.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/26/2016 12:36 PM
Where are you seeing grid fins, Ohsin? Dorkmo's highlight of a leg looks like a leg:

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-09%20OCISLY%20leg%20600w.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/26/2016 12:58 PM
Grid fins in yellow?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/26/2016 01:07 PM
Grid fins, interstage seam and manhole highlighted.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 03/26/2016 01:27 PM
Ohsin is correct - definitely a grid fin on lower right. However I'm not sure this is the same piece as being discussed under light tarp.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/26/2016 02:17 PM
Dirt and sunlight making it look different. At bottom both have wall peeling off slightly and bumps under tarp are similar on both. Too good in shape to be bottom of stage and the rim should have hint of those windows/holes.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/26/2016 03:28 PM
However I'm not sure this is the same piece as being discussed under light tarp.

Below is a detail from one of Marek's first photos that shows the gray tarp covering the top of the stage w/ grid fins, and behind the rolls of black sheets is the white tarp used (later - not as large) to cover the bottom of the stage with one leg.

(http://public.cyndyclayton.fastmail.us/ASDS/2016-03-09%20OCISLY%20Tarps%20600w.jpg) 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/26/2016 04:11 PM
I'm not sure about the grid fins I'm seeing or not in these images.  But I'm still leaning toward thinking this is the top.  Because a) Kabloona's anti-swirl baffles don't convince my eyes that they are anything more than weld seams, b) Ohsin's closeup (and also kabloona's above) shows a high density circular bolt pattern which is indicative of an access hatch vs. the tank cam images of the bottom of the tank which show no such bolted joint.

Also, Kabloona's yellow lined image shows the bottom of the LOX tank which is a bit different from the bottom of the fuel tank in that the fuel tank has (at least when intact) the large diameter LOX feed tube going through it on the side we are potentially seeing.  We don't see remnants of that LOX tube in the image which may be due to tarp coverage or it may be due to that tube having been ripped cleanly off.  But the prevailing preponderance of my ponderance is that we would see something to indicate that that tube had been there if it was the bottom of the tank we are looking at and we don't.

And separately, notice in the foreground of Cindy's image (and others as well) we see a largish chunk of tank section.  Its completely black.  And certainly more blackened than any part of the exterior of the recovered O-2 booster.  That may be from post crash fire.  Or it may be a preview of how we expect to see our stages looking after a ripping hot re-entry.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 03/26/2016 05:20 PM
boy im not sure. i want to agree with johnny that these are probably two different ends of the rocket. but its hard to piece much evidence together from the one low res image with what appears to be a lighter color tarp. could be lighting? or one side is a different color than the other? the way it looks like a leg could just be it pulled taught out to cover something else. theres a little bump that could be another gridfin on top. hard to image we wouldnt have a nice picture showing both ends at the same time.

the part that oshin highlighted are for sure gridfins.

i think there might also be a piece that is a little more than half of a leg sitting out there too.

edit: thinking about it more, its hard to imagine that the octoweb bulkhead would look that good after crushing throught the deck. and perhaps wildly unlikely that it and the interstage bulkhead would look appear in similar condition. perhaps it could have been one or the other but the chances of them being mistaken for each other seems impossible.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/26/2016 09:11 PM
the part that oshin highlighted are for sure gridfins.
I had trouble seeing it in the images that Ohsin and Kabloona were pointing to but when I went back to the source image from Marek, I can't agree more, that's a grid fin for sure on the right at deck level and by logical extension what they point to on the left is a grid fin.

And they don't put grid fins on the bottom of the machine.

i think there might also be a piece that is a little more than half of a leg sitting out there too.
Yea, that was my kinda sorta thought as well.  Along with thinking that the perforated looking rectangular part near it must be for anti-slosh.

edit: thinking about it more, its hard to imagine that the octoweb bulkhead would look that good after crushing throught the deck. and perhaps wildly unlikely that it and the interstage bulkhead would look appear in similar condition. perhaps it could have been one or the other but the chances of them being mistaken for each other seems impossible.
Yep.  The octaweb area is smithereened.

Can you imagine being those upgraded leg lock collets all locked in place, proud and happy, ready to do their job right and then the surprise they must have had when they were hit with a barge at that speed?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 03/27/2016 11:03 AM
What do you think the circled feature is?
if the part we see is the bottom of the tank, the feature is the attachment of leg's telescopic cylinder.
I cannot think to another feature passing "through" the wall of the tank this way.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/27/2016 02:23 PM
LOX umbilical connection/vent?

The thing right under your circle is very very clearly a grid fin.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 03/27/2016 03:00 PM
LOX umbilical connection/vent?

The thing right under your circle is very very clearly a grid fin.

Not a LOX umbilical, propellant feeding for first stage comes from bottom; seems too low for upper vent.

The grid fin is here and very clear; does not mean it is attached to something, specially after a "landing" so hard that punched a hole in barge deck.
I believe that grid fin is a detached, collected piece.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: apirie98 on 03/27/2016 04:07 PM
Looking back at some of Marek's photos I think that we've seen both the top and bottom of the stage. I'm fairly convinced by that leg shape under the white tarp as well as the (definitely at least two) grid fins under the black tarp. I checked up on the fin orientation in the picture and it seems like it could well be attached to that part of the stage.

Looking back at the black tarp pictures I think i see more than one section of the stage under there. There's clearly what looks to be the top of the stage - annotated red in the images below - complete with what looks like some buckling  of the stage as well. Although it's really pushing it I also see a rectangular-shaped mark on the stage. Going out on a whim I think this might be the bottom stripe of the flag at the top of the stage. But i'm really not too sure. Looks too square to just be dirt, and sort of looks a bit red as well.

What I also see is another stage sectiron highlighted yellow - it definitely looks like a cylindrical section of some sort. And it's situated on/in/near the hole in the barge. It looks to me like this may be the bottom end of the stage, or at least the octoweb. Considering that it's a pretty hefty lump of metal it seems unlikely that it woud've simply disappeared off the barge into the sea. What's more I see what I believe is the raceway (the inside side?) on that piece of skin by the yellow area (highlight green.) The tarp seems to go over part of this as if it was still attached to something. Could this still have been attached to the bottom of the stage at the time?

Assuming that all the above happens to be by some miracle correct, I think the bottom of the stage bedded into the barge deck and whole stage folded in and exploded, resulting in the rocket ending as it did with octoweb in the hole, top of stage close by and parts everywhere, but more or less logo side down(ish - some of the SPACEX logo was over the broken thruster.) When in the port the wreckage was removed - the top end of the stage being craned off and taken away (seems to just disappear in the photos) and the bottom end being temporarily dragged out of the hole (see drag/scrape marks on the deck) and then covered in the white tarp, which we see in the later images.

</speculation>
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 03/27/2016 04:11 PM
Octaweb ?

https://imgur.com/a/aYUJY 1:Gif 4.5Mo 2: picture
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/27/2016 05:25 PM
Octaweb ?

Nice find.  You clearly have a case.  But its also the case that we believe the rocket was coming down tail first, the octaweb is at the tail end, and something did serious damage to the 9/16" (14mm) steel deck.  Hmmm.

Perhaps in addition to finding a way around the drone ban (such as taking Disney cruises) we also need a tarp penetrating microwave imager.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/27/2016 05:49 PM
The *nozzles and chamber and turbopumps* are at the tail end.  The octoweb is above that.  I think there's plenty of opportunity for the business end of the rocket to do serious damage to the deck without disrupting the integrity of the octoweb.  The combustion chamber has to be a pretty strong chunk of metal, considering the pressures it must contain.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/27/2016 06:37 PM
Which brings up the question, what is this octaweb we all talk of?  Images are hard to come by.  Here is the closest thing found on the first page of a google image search.  To me the octaweb is a structure consisting of plate aluminum stock which extends from the engine throat to the bottom dome of the fuel tank in which all structural members are aligned with the long axis of the rocket.  There is a circular member around the perimeter which aligns with tank walls but only goes partway down.  There are radial members which go between engines for both structure and to contain an engine failure or fire to one compartment. These go to the bottom of the octaweb at the engine throat. I presume each of these radial members align directly under one of the tank weld seams but not necessarily so.  The radial members need to join at the center for structural reasons but there is also an engine at the center and the tank bottom bulges down at the center so I expect the vertical dimension of the octaweb has been trimmed there and doublers have been added.  This is one of two reasons the center engine is lower than the other engines, the other reason being that the center one needs to gimbal fully while the others sleep.  I don't think there is much horizontal structure to it, that the engines somehow impart their thrust forces into the vertical walls directly.  The only horizontal panels I think are there are the panels at the bottom of the octaweb which probably don't have much structural function, but serve to contain fires surrounding an individual engine and to keep out re-entry heat.  In other words, I see the bottom of the octaweb as being at the throat of the engine and the top of the octaweb extending only the minimum possible distance above the tops of the engines.  With respect to the impact, I see the nozzles hitting first, then the bottom of the octaweb, followed very quickly by the combustion chambers as the octaweb shortens then the pumps.  I don't see the octaweb surviving and the engines not or the other way around.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/27/2016 06:41 PM
What do you think the circled feature is?
if the part we see is the bottom of the tank, the feature is the attachment of leg's telescopic cylinder.
I cannot think to another feature passing "through" the wall of the tank this way.

Attachment point is way above on RP1 tank from bottom it can't be that.

http://forum.nasaspaceflight.com/index.php?topic=33788.msg1370037#msg1370037

Attaching top view of stage for reference on what that feature could be. Also a relevant view from recovered stage.

https://c2.staticflickr.com/2/1476/24175842475_57833a78ff_o.jpg
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 03/27/2016 06:53 PM

Attachment point is way above on RP1 tank from bottom it can't be that.

http://forum.nasaspaceflight.com/index.php?topic=33788.msg1370037#msg1370037


Thanks, these pictures shows clearly that the attachment point is about two meters above the bottom of the tank (and no, not way above).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 03/27/2016 06:55 PM
Which brings up the question, what is this octaweb we all talk of?

This.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/27/2016 08:35 PM
Regarding the grid fin, IIRC, its outer shape is not rectangular.  The side away from the rocket is, but the side near the body (where the attachment stem is) has two large chamfers to it.

Does this match what we see under the tarp?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/27/2016 08:45 PM
Below is a classic Saturday Night Live skit from 1979 titled "What the Hell Is That?", with a much younger Bill Murray and Steve Martin. Please don't take it the wrong way, after awhile I just couldn't help but think of it, having no more theories of my own to add to the current discussion.

http://www.liveleak.com/view?i=872_1313749431
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/27/2016 10:22 PM

Attachment point is way above on RP1 tank from bottom it can't be that.

http://forum.nasaspaceflight.com/index.php?topic=33788.msg1370037#msg1370037


Thanks, these pictures shows clearly that the attachment point is about two meters above the bottom of the tank (and no, not way above).

I think its more than 3 meters which is a lot. Also don't forget the riveted seam, rest of interstage which is under tarp and the other grid fin most of which I think is sheared off. Attached a comparison with features that are somewhat similar to me(visible when enlarged).

Edit: '3' is just about part not orientation of it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/27/2016 10:52 PM
Regarding the grid fin, IIRC, its outer shape is not rectangular.  The outer side is, but the side near the body (and the near the attachment stem) has two large chamfers to it.

Does this match what we see under the tarp?

No. Ohsin's closeups don't either.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Comga on 03/27/2016 10:56 PM
Which brings up the question, what is this octaweb we all talk of?  Images are hard to come by.  Here is the closest thing found on the first page of a google image search.  To me the octaweb is a structure consisting of plate aluminum stock which extends from the engine throat to the bottom dome of the fuel tank in which all structural members are aligned with the long axis of the rocket..... (snip)

IIRC the Octoweb is made of titanium.  Musk discussed the thrust structure of the Falcon 1 as being made of titanium and being sufficiently expensive that its recovery would have by itself justified attempting to recover the first stage.

(Kudos to anyone with sufficiently heightened google-fu to be able to locate that quote, which is from more than a decade ago.

A titanium structure just might be able to survive intact, but not undamaged, from an impact with steel like this.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/27/2016 10:58 PM
Regarding the grid fin, IIRC, its outer shape is not rectangular.  The outer side is, but the side near the body (and the near the attachment stem) has two large chamfers to it.

Does this match what we see under the tarp?

No. Ohsin's closeups don't either.
So either this is a grid fin in a misleading orientation, or a partial grid fin, or something else.

One possibility is that this is a never seen before core of a composite leg sandwich....  But for the skin to be laminated like that, it would take a very odd application of force.

My money is still on a grid fin, but I'm noting the discrepancy...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 03/27/2016 11:10 PM
Regarding the grid fin, IIRC, its outer shape is not rectangular.  The outer side is, but the side near the body (and the near the attachment stem) has two large chamfers to it.

Does this match what we see under the tarp?

No. Ohsin's closeups don't either.
So either this is a grid fin in a misleading orientation, or a partial grid fin, or something else.

One possibility is that this is a never seen before core of a composite leg sandwich....  But for the skin to be laminated like that, it would take a very odd application of force.

My money is still on a grid fin, but I'm noting the discrepancy...

Grid Fin in background has its under side facing us , mangled Grid Fin under interstage is rotated 180 and folded 'up'. Another Grid Fin could be under tarp in its normal folded position. Also I have no clue about the walls of lox tank does it have layers that could peel away?

Edit: Mangled fin could have been in deployed position just jutting out when whole upper portion of stage crashed upon it that would explain it being mangled and being buried.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/27/2016 11:52 PM
So either this is a grid fin in a misleading orientation...

That's what it is, I can see it now. One of the corners of the fin that is normally lopped off at an angle closer to the rocket body is the angle top left in the wreckage photo. Looking closely you can see the actual grid that runs perpendicular to that angled edge. It helps to compare to a good closeup of a normal fin. Now I'm thinking it's still attached too. Edited to add crop of Apirie98's photo, with angle in ref at bottom of his red circle.

(http://public.cyndyclayton.fastmail.us/ASDS/fins_extended%20crop.jpg)          (http://public.cyndyclayton.fastmail.us/ASDS/fin%20extended%20wreckage.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/28/2016 02:18 AM
So either this is a grid fin in a misleading orientation...

That's what it is, I can see it now. One of the corners of the fin that is normally lopped off at an angle closer to the rocket body is the angle top left in the wreckage photo. Looking closely you can see the actual grid that runs perpendicular to that angled edge. It helps to compare to a good closeup of a normal fin. Now I'm thinking it's still attached too. Edited to add crop of Apirie98's photo, with angle in ref at bottom of his red circle.

(http://public.cyndyclayton.fastmail.us/ASDS/fins_extended%20crop.jpg)          (http://public.cyndyclayton.fastmail.us/ASDS/fin%20extended%20wreckage.jpg)

Playing with the contrast, the cross-hatch pattern is clear, as well as the two parallel long ribs.

What I perceive as lack of chamfers is perspective.  If I use the grid pattern to figure out the viewing angle (note that they are close to perpendicular, which means that find is more "face on" than I'd assumed) then suddenly the chamfer is obvious.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 03/28/2016 02:25 AM
Which brings up the question, what is this octaweb we all talk of?  Images are hard to come by.  Here is the closest thing found on the first page of a google image search.  To me the octaweb is a structure consisting of plate aluminum stock which extends from the engine throat to the bottom dome of the fuel tank in which all structural members are aligned with the long axis of the rocket.  There is a circular member around the perimeter which aligns with tank walls but only goes partway down.  There are radial members which go between engines for both structure and to contain an engine failure or fire to one compartment. These go to the bottom of the octaweb at the engine throat. I presume each of these radial members align directly under one of the tank weld seams but not necessarily so.  The radial members need to join at the center for structural reasons but there is also an engine at the center and the tank bottom bulges down at the center so I expect the vertical dimension of the octaweb has been trimmed there and doublers have been added.  This is one of two reasons the center engine is lower than the other engines, the other reason being that the center one needs to gimbal fully while the others sleep.  I don't think there is much horizontal structure to it, that the engines somehow impart their thrust forces into the vertical walls directly.  The only horizontal panels I think are there are the panels at the bottom of the octaweb which probably don't have much structural function, but serve to contain fires surrounding an individual engine and to keep out re-entry heat.  In other words, I see the bottom of the octaweb as being at the throat of the engine and the top of the octaweb extending only the minimum possible distance above the tops of the engines.  With respect to the impact, I see the nozzles hitting first, then the bottom of the octaweb, followed very quickly by the combustion chambers as the octaweb shortens then the pumps.  I don't see the octaweb surviving and the engines not or the other way around.
I think you are confusing the bottom of the containment structure with the octogrid.  The octogrid carries the thrust loads, hence the "strong part" is above the combustion chamber.

Or am I wrong? Is it actually the nozzle, not the combustion chamber, which is the source of the thrust force?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/28/2016 02:50 AM
Which brings up the question, what is this octaweb we all talk of?  Images are hard to come by.  Here is the closest thing found on the first page of a google image search.  To me the octaweb is a structure consisting of plate aluminum stock which extends from the engine throat to the bottom dome of the fuel tank in which all structural members are aligned with the long axis of the rocket.  There is a circular member around the perimeter which aligns with tank walls but only goes partway down.  There are radial members which go between engines for both structure and to contain an engine failure or fire to one compartment. These go to the bottom of the octaweb at the engine throat. I presume each of these radial members align directly under one of the tank weld seams but not necessarily so.  The radial members need to join at the center for structural reasons but there is also an engine at the center and the tank bottom bulges down at the center so I expect the vertical dimension of the octaweb has been trimmed there and doublers have been added.  This is one of two reasons the center engine is lower than the other engines, the other reason being that the center one needs to gimbal fully while the others sleep.  I don't think there is much horizontal structure to it, that the engines somehow impart their thrust forces into the vertical walls directly.  The only horizontal panels I think are there are the panels at the bottom of the octaweb which probably don't have much structural function, but serve to contain fires surrounding an individual engine and to keep out re-entry heat.  In other words, I see the bottom of the octaweb as being at the throat of the engine and the top of the octaweb extending only the minimum possible distance above the tops of the engines.  With respect to the impact, I see the nozzles hitting first, then the bottom of the octaweb, followed very quickly by the combustion chambers as the octaweb shortens then the pumps.  I don't see the octaweb surviving and the engines not or the other way around.
I think you are confusing the bottom of the containment structure with the octogrid.  The octogrid carries the thrust loads, hence the "strong part" is above the combustion chamber.

Or am I wrong? Is it actually the nozzle, not the combustion chamber, which is the source of the thrust force?

I think both.  The nozzle is pushing upwards (remember that in addition to just pressure, the flow accelerates as it expands, awkwardly, so there's got to be a reaction back on the nozzle wall to counter that) and the chamber certainly generates a force (simple vee-m-dot).  All are channeled to the engine structure though, which in turn pushes on the octoweb, which distributes it to the tank structure.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/28/2016 03:02 AM
I think you are confusing the bottom of the containment structure with the octogrid.  The octogrid carries the thrust loads, hence the "strong part" is above the combustion chamber.

Or am I wrong? Is it actually the nozzle, not the combustion chamber, which is the source of the thrust force?
Golly we're wandering from ASDSing and I think I started it.  Whether the thrust is generated here or there in the engine the engine mounts are toward the top of the chamber and their connection to the octaweb is above that level.  The interface with the throat area is only a flexible blanket material.  But what you are calling containment structure may or may not be one and the same as the octaweb and could carry load (and be containment) even if its far below the engine attachment point and far below the tank.  Or not.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/28/2016 03:42 AM
I think you are confusing the bottom of the containment structure with the octogrid.  The octogrid carries the thrust loads, hence the "strong part" is above the combustion chamber.

Or am I wrong? Is it actually the nozzle, not the combustion chamber, which is the source of the thrust force?
Golly we're wandering from ASDSing and I think I started it.  Whether the thrust is generated here or there in the engine the engine mounts are toward the top of the chamber and their connection to the octaweb is above that level.  The interface with the throat area is only a flexible blanket material.  But what you are calling containment structure may or may not be one and the same as the octaweb and could carry load (and be containment) even if its far below the engine attachment point and far below the tank.  Or not.

I believe the barge structure and the octoweb can be considered as a single entity now...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarsInMyLifetime on 03/28/2016 04:16 AM
I believe the barge structure and the octoweb can be considered as a single entity now...

Which can only remind us of these lines from Hudsucker Proxy, "Say, buddy, who's the most liquid businessman on the street? Waring Hudsucker! Say buddy, when is a sidewalk fully dressed? When it's Waring Hudsucker!" "Waring Hudsucker is abstract art on Madison Avenue."
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/28/2016 04:31 AM
All this wreckage identification stuff is fascinating[1]. But isn't tracking the barge readiness more important? How IS the barge coming along? Any new spy shots of that? How much time do they have left now and what tasks?

1 - I said that with a straight face, honest.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 03/28/2016 09:27 AM

IIRC the Octoweb is made of titanium.  Musk discussed the thrust structure of the Falcon 1 as being made of titanium and being sufficiently expensive that its recovery would have by itself justified attempting to recover the first stage.


Still available on SpaceX site, first of updates.
http://www.spacex.com/news/2004/june-2004-july-2004
Thrust Frame The engine thrust frame weight has come in significantly better than our initial baseline for Falcon I. This is due in part to switching from steel to high strength titanium and in part to a better design. Although we are spending more than planned on this piece of equipment, we expect to be able to reuse it essentially forever (i.e. thousands of flights), so long as the stage itself is recovered.

The corner fittings are precision machined and then welded under argon to the gun drilled tubes. The whole frame only weighs 74.8 lbs and is shown below going through structural qualification. We loaded it to 150,000 lbs (almost twice maximum flight load) in the axial direction and applied max gimbal and TVC loads. Nine limit and ultimate load cycles were applied with no indications of yield (strains all returned to zero).


Attached picture saved offline some time ago.

IMHO no relationship with octaweb.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/28/2016 12:54 PM
Interesting, that thrust structure was tested to 150,000 lbf back in 2004 which was then 2x Merlin thrust.  Now Merlins make more than that so it would have been redesigned a bit by now but the basic shape seems the same.  Its upside down to installed direction, the four feet would attach to the vehicle and in my opinion that connection is to the octaweb.  What else is there to connect to?  The geometry of this part is probably one of the things that was commonized when they went from tic tac toe to octaweb layout.  I figger that 8 of the engines use one design of this and the two center engines use another design.

Safe harbor statement (for Lar): The structure described does have an impact on the ASDS.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/28/2016 02:55 PM
Safe harbor statement (for Lar): The structure described does have an impact on the ASDS.

"Safe Harbor"??
"an impact" ??

I see what you did there. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 03/28/2016 10:19 PM
Golly we're wandering from ASDSing and I think I started it.  Whether the thrust is generated here or there in the engine the engine mounts are toward the top of the chamber and their connection to the octaweb is above that level.  The interface with the throat area is only a flexible blanket material.  But what you are calling containment structure may or may not be one and the same as the octaweb and could carry load (and be containment) even if its far below the engine attachment point and far below the tank.  Or not.

I believe the barge structure and the octoweb can be considered as a single entity now...

So.. if they recover a Grid Fin and re-use it on a new stage - does that count??  Maybe SpX should focus on collecting and re-using parts recovered from barge-RUD and work up to recovering a whole stage from there?!?   ::) ;D

Slow days indeed over Easter...  Hopefully someone will post some current photos showing progress sometime soon.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 03/29/2016 12:59 AM
Hopefully someone will post some current photos showing progress sometime soon.
new satellite antenna
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/29/2016 01:09 AM
new satellite antenna
s
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 03/29/2016 01:34 AM

Hopefully someone will post some current photos showing progress sometime soon.
new satellite antenna
Ah, a certain CyndyC will be delighted...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/29/2016 02:50 AM

Hopefully someone will post some current photos showing progress sometime soon.
new satellite antenna
Ah, a certain CyndyC will be delighted...

Haha, yes, I am THRILLED :)! And they have one on each end now, just as I guessed they might benefit from having. I can easily give up being able to ID the bow for more reliable landing coverage.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 03/29/2016 03:59 AM
Looks to me like they're doing some upgrades along with the repairs - two sat domes instead of one. I wonder if this will allow two video feeds?

I wonder if there will be a shakedown sortie after these repairs? My guess is they'll want one.


Hopefully someone will post some current photos showing progress sometime soon.
new satellite antenna
Ah, a certain CyndyC will be delighted...

Haha, yes, I am THRILLED :)! And they have one on each end now, just as I guessed they might benefit from having. I can easily give up being able to ID the bow for more reliable landing coverage.

A few easy ways to ID the bow are, if see from above, the name is on the port (left) side. Also, the aft blast wall is where the four leaf clover is. If seen side-on, the bow has the bow wall, which is vertical and all the way forward. And, there are two strakes (?) which look almost like large rudders under the stern. :)

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 03/29/2016 07:30 AM
Looks to me like they're doing some upgrades along with the repairs - two sat domes instead of one. I wonder if this will allow two video feeds?
He always had two antennas. ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 03/29/2016 10:31 AM

So.. if they recover a Grid Fin and re-use it on a new stage - does that count??  Maybe SpX should focus on collecting and re-using parts recovered from barge-RUD and work up to recovering a whole stage from there?!?   ::) ;D


Just a point.  RUD is only a term used for an engine coming apart and not a generic term for an accident or vehicle crash.  And it is a Spacex only term
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/29/2016 01:21 PM
He always had two antennas. ;)

So the bow VSAT is in the center and the stern VSAT is off to starboard, the latter just above the thruster lines that were damaged, and showing damage of its own in Marek's panorama. The bow VSAT appeared undamaged yet was replaced at the same time, probably meaning even though there have been two VSATs all along, there will be improved odds for unbroken reception.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 03/29/2016 03:05 PM
I can't site a source, but I remember engineers using R.U.D. in the eighties. Musk himself has used the term in a tweet to describe the fate of the returning stage that ran out of hydraulic fluid.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 03/29/2016 04:15 PM
 One antenna can have it's signal interrupted by the returning rocket. Two antenna systems can be completely independent and actually go to different suppliers, be automatically switched if one is obstructed or has other issues, or have simultaneous links on the same sat. They can also be S and Ku since KU is usually better bandwidth and S is better in bad weather. Or, they just might want redundancy. Intellian wouldn't have been my first choice for reliable gear.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: LouScheffer on 03/29/2016 06:07 PM

Just a point.  RUD is only a term used for an engine coming apart and not a generic term for an accident or vehicle crash.  And it is a Spacex only term
Here is a  quote from a government manual, using the same acronym, with the same meaning, for a gun accident (https://books.google.com/books?id=86zpYQO5yYcC&q=Rapid%20unintentional%20Disassembly&dq=Rapid%20unintentional%20Disassembly&hl=en&sa=X&ved=0CC0Q6AEwAjgKahUKEwisiKjUh_TGAhWIGx4KHYQCC-o) in 1970.  (They used "unintentional" rather than "unscheduled", but the meaning is identical.) So RUD has been around for a while, and used for other than engine accidents.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: woods170 on 03/29/2016 06:07 PM
Just a point.  RUD is only a term used for an engine coming apart and not a generic term for an accident or vehicle crash.  And it is a Spacex only term

Just a point. RUD is used by multiple folks at SpaceX to describe more than just an engine coming apart (as so aptly demonstrated by a tweet from Elon describing a landing rocket stage coming apart - not just the engine).
Also, it's a pre-existing term, adopted by SpaceX, being used in a thread where the subject is (surprise, surprise!) SpaceX.

Jim, my two cents on this: accept the fact that SpaceX sometimes does things differently (including the use of terms). You constantly pointing out that SpaceX does not (always) adhere to industry standards is symptomatic for the state of denial found in a substantial part of the OldSpace community. Like it or not: SpaceX is disrupting the old state of affairs and that disruption is highly likely to be permanent. Along come several new views and ways of doing things and even new (or, in this case, dusted-off) terminology. Only those folks clinging to the old ways too much will continue to bleat over unavoidable changes.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 03/29/2016 06:35 PM

So.. if they recover a Grid Fin and re-use it on a new stage - does that count??  Maybe SpX should focus on collecting and re-using parts recovered from barge-RUD and work up to recovering a whole stage from there?!?   ::) ;D


Just a point.  RUD is only a term used for an engine coming apart and not a generic term for an accident or vehicle crash.  And it is a Spacex only term
The U can stand for several things, but the term has been used since the 70s at least.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 03/29/2016 06:47 PM
Arguing over who said RUD first or whether it's standard or whether using it is a sign that you're not OldSpace etc etc....

Is boring.

So let's not. Thanks.

(I was wearing my mod hat when I said that and posts below this line get trimmed)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/30/2016 12:20 AM
So now we can get back to the discussion of RSR...as in the Rapid Scheduled Reassembly of OCISLY.

7 days until she needs to leave port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 03/30/2016 03:08 AM
Intellian wouldn't have been my first choice for reliable gear.

What would be your choice for reliable gear, Nomadd? Is it possible SpaceX has been using Intellian gear elsewhere and has been happy with the performance? I don't know what they use to beam down from the rocket, but have yet to see that feed go out.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 03/30/2016 03:28 AM
Intellian wouldn't have been my first choice for reliable gear.

What would be your choice for reliable gear, Nomadd? Is it possible SpaceX has been using Intellian gear elsewhere and have been happy with the performance? I don't know what they use to beam down from the rocket, but have yet to see that feed go out.
Seatel, which Intellian copied most of their gear from, but has much better technical support.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/30/2016 03:48 AM
IIRC, the first photos of the original ASDS (Just Read the Instructions) showed TracPhone VSAT antenna domes. I guess they've moved on. Maybe the new ones are more vibration-resistant.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 03/30/2016 05:12 AM
IIRC, the first photos of the original ASDS (Just Read the Instructions) showed TracPhone VSAT antenna domes. I guess they've moved on. Maybe the new ones are more vibration-resistant.

... or cheaper to replace ...  :)
(something something quantity discount)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 03/30/2016 05:21 AM
IIRC, the first photos of the original ASDS (Just Read the Instructions) showed TracPhone VSAT antenna domes. I guess they've moved on. Maybe the new ones are more vibration-resistant.
I've been out of the business for a while, but KVHs Tracphones use to be big on selling services, where Intellian or Seatels bigger Marine VSATs were more generic dishes. Lots of people use them to access the same bandwidth they get on their land VSATs, and avoid the ridiculously expensive sea based services. 3 megabits up and down is a pretty common package with 1M or 1.2M. Smaller Tracphones are pretty common for telephone, messaging and lower speed data.
 The barge looks like both antennas have 360 coverage, which makes things a helluva lot simpler than on most ships.
 Speaking of iPhones again, I used an iPhone 3s with a 3 axis vibration recorder app to OK spots for those dishes and smaller sat antennas on the masts. That and all the audio and scope apps I had saved us a fortune on test equipment.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dgates on 03/31/2016 12:00 AM
How far offshore is the ASDS expected to be?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/31/2016 01:43 AM
Anybody feel like dropping by Port Canaveral and seeing how things are going?  We're going to need that ASDS ready to go soon.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 03/31/2016 02:07 AM
How far offshore is the ASDS expected to be?
About 185 statute miles from the point of launchness and about 172 miles from nearest land.  Curiously enough, when I started swinging a Google Earth measuring radial around the ASDS hold point I found that the ASDS will be in the center of a very nice shoreline arc which extends from Charleston to the top of Cape Canaveral.  Along that stretch the distance from land to the ASDS tends to fall within a single digit (+/-) range.   That's oddly interesting.  I tried to draw a circle on the image to show this but it can't be done very well because of map projection non-linearity.  I suggest having a go at it in Go Oogle Earth, the point is 30.5 deg N, 78.5 deg W.

Here is the map I posted a few pages back
http://forum.nasaspaceflight.com/index.php?topic=39766.msg1507418#msg1507418 (http://forum.nasaspaceflight.com/index.php?topic=39766.msg1507418#msg1507418)

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dgates on 03/31/2016 07:50 PM
Darn, probably too far out to see from 8000-10000 feet I think.  I am going to be watching the launch while flying my plane.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Comga on 03/31/2016 08:08 PM
How far offshore is the ASDS expected to be?
About 185 statute miles from the point of launchness and about 172 miles from nearest land. 
Darn, probably too far out to see from 8000-10000 feet I think.  I am going to be watching the launch while flying my plane.

Correct
The horizon from 3 km = 10 kft around a 6378 km radius Earth is 197 km = 121 miles
You will only be able to see down to 4 km altitude at 185 miles distance, so the whole landing burn will be out of sight.
You would have to be ~23 kft to put the ASDS on the horizon, ~18 kft to see the start of the landing burn.

edit:  Or you have to fly more than 60 miles off-shore at 10 kft..
Kabloona has a point.  Anyone can watch a launch by driving up.
You can't get that close to the launch with an airplane anyways.  Optimize for the landing.
Just don't cause a range hold or people here and elsewhere will be .... unhappy with you.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 03/31/2016 10:23 PM
Quote
I am going to be watching the launch while flying my plane.

Heck, you can watch the launch even without a plane.

How about watching the *landing* while flying your plane? That would be more fun.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/01/2016 12:32 AM
Quote
I am going to be watching the launch while flying my plane.

Heck, you can watch the launch even without a plane.

How about watching the *landing* while flying your plane? That would be more fun.  ;)

Launches are so boring they no longer even get mentioned...   Seen one, seen them all...

But landings, man, landings!!!!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/01/2016 12:37 AM

So.. if they recover a Grid Fin and re-use it on a new stage - does that count??  Maybe SpX should focus on collecting and re-using parts recovered from barge-RUD and work up to recovering a whole stage from there?!?   ::) ;D


Just a point.  RUD is only a term used for an engine coming apart and not a generic term for an accident or vehicle crash.  And it is a Spacex only term
The U can stand for several things, but the term has been used since the 70s at least.

For the record, I typed "RUD" as an abbreviation for "rapid unplanned disassembly" to save typing it all out (like I just have!  :o) (a) not particularly caring who used it when, where or why, (b) aware you lot all know what it means and (c) not wishing to make my post unnecessarily wordy..

EDIT: Anyways, yes, who's got some photos to share?!?  They must be getting close now! :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dgates on 04/01/2016 01:19 AM
Well. Yeah, I was hoping to be able to see the landing, but hey, I will take the launch!

And yes, I intend to be VERY careful regarding airspace, including pre-coordination with Orlando Approach.  I will be actively radar tracked and if I get too close they will vector me as needed. ( IAW, yell at me to turn away).  I am NOT going to be "that guy"! Still should be a lot of fun!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: hans_ober on 04/01/2016 05:26 AM
Well. Yeah, I was hoping to be able to see the landing, but hey, I will take the launch!

And yes, I intend to be VERY careful regarding airspace, including pre-coordination with Orlando Approach.  I will be actively radar tracked and if I get too close they will vector me as needed. ( IAW, yell at me to turn away).  I am NOT going to be "that guy"! Still should be a lot of fun!

Don't cause a scrub. Doing so will result in another twitter account: Wayward plane?

Remember to post video  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mvpel on 04/01/2016 12:13 PM
"I don't want no scrubs, a scrub is a try who can't win my love from me."
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/01/2016 02:24 PM
Well. Yeah, I was hoping to be able to see the landing, but hey, I will take the launch!

And yes, I intend to be VERY careful regarding airspace, including pre-coordination with Orlando Approach.  I will be actively radar tracked and if I get too close they will vector me as needed. ( IAW, yell at me to turn away).  I am NOT going to be "that guy"! Still should be a lot of fun!
I assume you're flying vfr, hence you can't loiter 60 miles off shore?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/02/2016 02:45 PM
Its been a week since we've had any images other than the grainy ones from the port cam.  I'm withering away for lack of information.  Someone please feed us.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/02/2016 03:59 PM
Its been a week since we've had any images other than the grainy ones from the port cam.  I'm withering away for lack of information.  Someone please feed us.

At this point it might help to chip in together and offer to include a free lunch or dinner at Fishlips.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 04/02/2016 07:26 PM
Its been a week since we've had any images other than the grainy ones from the port cam.  I'm withering away for lack of information.  Someone please feed us.
https://www.reddit.com/r/spacex/comments/4d2slo/close_up_of_the_spacex_asds_of_course_i_still/
Source: https://twitter.com/Restrantek/status/716303900828164096

Direct link
Picture 1 : https://pbs.twimg.com/media/CfDSmd7WAAA0qiV.jpg:orig
Picture 2 : https://pbs.twimg.com/media/CfDR_XeWQAA985_.jpg:orig
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 04/02/2016 07:32 PM
OCISLY From a Helicopter : http://imgur.com/42k1kjY
Source : https://www.reddit.com/r/spacex/comments/4d2wk4/ocisly_from_a_helicopter/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/02/2016 07:59 PM
Hole looks like it's been completely covered; good progress.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/02/2016 08:09 PM
OCISLY From a Helicopter : http://imgur.com/42k1kjY
Source : https://www.reddit.com/r/spacex/comments/4d2wk4/ocisly_from_a_helicopter/

Hole is patched... Looks like a test run of the upper left (nearest to hole) thruster was in progress even...
All thrusters look to be down in fact... A bit of paint and she looks ready to go...  8)

On edit... also looks like re-ballasting is ongoing...  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/02/2016 08:36 PM
The scar will add character....

Awesome pic
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 04/03/2016 03:33 AM
(falcon) chicks dig scars
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 04/03/2016 03:36 AM
OCISLY From a Helicopter

"drones are outlawed? fine, we'll get a chopper"

lololol
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: NovaSilisko on 04/03/2016 04:54 PM

Direct link
Picture 1 : https://pbs.twimg.com/media/CfDSmd7WAAA0qiV.jpg:large
Picture 2 : https://pbs.twimg.com/media/CfDR_XeWQAA985_.jpg:large

Remember, you can replace :large with :orig for the highest available resolution.

https://pbs.twimg.com/media/CfDSmd7WAAA0qiV.jpg:orig
https://pbs.twimg.com/media/CfDR_XeWQAA985_.jpg:orig
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/04/2016 03:56 AM
From a document posted (in a western niche of) the Eastern Range topic...

Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Boost-Backs and Landings of Rockets at Vandenberg Air Force Base
https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to (https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to)

Quote
In the event that a contingency landing action is required, SpaceX has considered the likelihood of the First Stage missing the barge and landing instead in the Pacific Ocean, and has determined that the likelihood of such an event is so unlikely as to be considered discountable. This is supported by three previous attempts by SpaceX at Falcon 9 First Stage barge landings, none of which have missed the barge.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 08:38 AM
IMO, this is the most interesting bit from that document:

Quote
In the event of an unsuccessful barge landing, the First Stage would explode upon impact with the barge; the explosion would not be expected to result in take of marine mammals, as described below. The explosive equivalence with maximum fuel and oxidizer is 503 pounds of trinitrotoluene (TNT) which is capable of a maximum projectile range of 384 m (1,250 ft) from the point of impact. Approximately 25 pieces of debris are expected to remain floating in the water and expected to impact less than 0.46 km2 (114 acres), and the majority of debris would be recovered. All other debris is expected to sink. These 25 pieces of debris are primarily made of Carbon Over Pressure Vessels (COPVs), the LOX fill line, and carbon fiber constructed legs. During previous landing attempts in other locations, SpaceX has performed successful debris recovery. All of the recovered debris would be transported back to Long Beach Harbor for proper disposal. Most of the fuel (estimated 50-150 gallons) is expected to be released onto the barge deck at the location of impact.

So stage explosion = 500 lb bomb, more or less.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/04/2016 09:35 AM
IMO, this is the most interesting bit from that document:

Quote
In the event of an unsuccessful barge landing, the First Stage would explode upon impact with the barge; the explosion would not be expected to result in take of marine mammals, as described below. The explosive equivalence with maximum fuel and oxidizer is 503 pounds of trinitrotoluene (TNT) which is capable of a maximum projectile range of 384 m (1,250 ft) from the point of impact. Approximately 25 pieces of debris are expected to remain floating in the water and expected to impact less than 0.46 km2 (114 acres), and the majority of debris would be recovered. All other debris is expected to sink. These 25 pieces of debris are primarily made of Carbon Over Pressure Vessels (COPVs), the LOX fill line, and carbon fiber constructed legs. During previous landing attempts in other locations, SpaceX has performed successful debris recovery. All of the recovered debris would be transported back to Long Beach Harbor for proper disposal. Most of the fuel (estimated 50-150 gallons) is expected to be released onto the barge deck at the location of impact.

So stage explosion = 500 lb bomb, more or less.

No. More like a 1500 lb bomb since only a minor fraction of a bomb's mass is the explosive filler.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/04/2016 02:23 PM
No. More like a 1500 lb bomb since only a minor fraction of a bomb's mass is the explosive filler.

No.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/04/2016 03:33 PM
https://en.wikipedia.org/wiki/Mark_83_bomb

1000lb US bomb contains 445lbs of explosive... see link above as source...  :o

And now back to your regularly scheduled barge stalking type discussion...  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 04/04/2016 03:41 PM
IMO, this is the most interesting bit from that document:
<snip>
So stage explosion = 500 lb bomb, more or less.
This is assuming all of the oxidiser and fuel mix perfectly.
This is not going to happen.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/04/2016 03:43 PM
IMO, this is the most interesting bit from that document:
<snip>
So stage explosion = 500 lb bomb, more or less.
This is assuming all of the oxidiser and fuel mix perfectly.
This is not going to happen.


The oxidizer left in the tanks doesn't matter, it is exploding at sea level where there is abundant O2 available.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 03:50 PM
In any case, it's pretty clear that the blast is mostly dispersed into the atmosphere and not absorbed by the barge, unlike a direct hit from a bomb.

The only crater produced so far was probably from kinetic energy of the stage impact at high speed, not the propellants going bang...or kaboom, as Elon likes to say.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/04/2016 06:07 PM
IMO, this is the most interesting bit from that document:
<snip>
So stage explosion = 500 lb bomb, more or less.
This is assuming all of the oxidiser and fuel mix perfectly.
This is not going to happen.


The oxidizer left in the tanks doesn't matter, it is exploding at sea level where there is abundant O2 available.


If it's just burning atmospheric oxygen, then the explosion is less likely to be a detonation and more of a deflagration.  SpaceX specifically mentioned oxidizer in its report, so it stands to reason that the maximum energy blast would incorporate the remaining oxidizer contents.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 06:39 PM
Speaking of booms and marine mammals, let's pause for a moment to remember the poor seal who was subjected to the Government-mandated sonic boom experiment via headphones to see if it would interfere with his (her?) libido.

https://mobile.twitter.com/TalulahRiley/status/320422298618302464

And Elon's hilarious comment:

https://pbs.twimg.com/media/BHJd3GQCAAA5uqa.png

Can't make this stuff up. The good news is, thanks to the seal's noble sacrifice, SpaceX is on the way to obtaining permission for one year of RTLS attempts at VAFB.

Now back to regular ASDS programming...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MattMason on 04/04/2016 06:52 PM
Speaking of booms and marine mammals, let's pause for a moment to remember the poor seal who was subjected to the Government-mandated sonic boom experiment via headphones to see if it would interfere with his (her?) libido.

https://mobile.twitter.com/TalulahRiley/status/320422298618302464

And Elon's hilarious comment:

https://pbs.twimg.com/media/BHJd3GQCAAA5uqa.png

Can't make this stuff up. The good news is, thanks to the seal's noble sacrifice, SpaceX has been granted permission for one year of RTLS attempts at VAFB.

Now back to regular ASDS programming...

Made all the more humorous when you realize Talulah Riley was/is Mrs. Elon Musk. (You saw her briefly in the film "Inception").
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: starhawk92 on 04/04/2016 08:02 PM
Anyone want to estimate the time remaining for fixes and repairs to be on station and ready for a Friday launch?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/04/2016 08:19 PM
I really don't get the TNT analogy.

All we've seen so far are "soft" conflagrations, and the shock from the bursting pressure vessel.

If the rocket is falling at at some 200 m/s, and it's a 40 m stage, and it never slows down even after starting to crumple, that's still 1/5 of a second for "mix and burn" time. (a.k.a pancaking time) This is an eternity in terms of explosions.

With the rocket slowing down once the concentrated mass hits the deck, it's probably closer to 0.5 second.

If you ignore the LOX and only consider the RP1 being kicked out into the atmosphere, then most definitely you get a slow burn.  This is why fuel-air bomb have to mix first, burn later. in order to get a real explosion.

And 500 lb of TNT....   detonated in contact with the deck...   I think you'd get a bigger hole...

Almost without a doubt the hole was made by punching through, and the following fire ball did almost nothing, though potentially if fuel managed to get into the hole, it may have burned there for a while.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 08:22 PM
Quote
If you ignore the LOX and only consider the RP1 being kicked out into the atmosphere, then most definitely you get a slow burn.  This is why fuel-air bomb have to mix first, burn later. in order to get a real explosion.

And 500 lb of TNT....   detonated in contact with the deck...   I think you'd get a bigger hole...

Yes, for ease of calculation they probably assumed a limiting case of fully-mixed LOX/RP-1, knowing you'd never really get there.

It seems the real purpose of the TNT equivalent calculation was to be able to predict the maximum projectile distance of 1250 ft, probably from a look-up table or graph of max distance vs quantity of TNT.

Obviously if you put 500 lbs of TNT on deck, the *local* blast effect would be much different...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 08:31 PM
Anyone want to estimate the time remaining for fixes and repairs to be on station and ready for a Friday launch?

They'll need a little over 30 hours transit time, plus setup time on station. I'd say sometime late Wednesday is the comfortable deadline for departure, and possibly wee hours of Thursday morning if they have to cut it really close.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/04/2016 09:03 PM
I'm not used to reading these type statements but the few that I've come across on NSF seem to be not so much science as they are arguments for what the writer wants to do written in sciencey language as a tool of persuasion.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Hywel1995 on 04/04/2016 10:00 PM
Matthew Travis on Facebook is reporting activity from the support ships around the ASDS. Might be preparing to leave under the darkness.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/04/2016 10:21 PM
Matthew Travis on Facebook is reporting activity from the support ships around the ASDS. Might be preparing to leave under the darkness.

It's too soon to be heading out to the landing zone tonight. They may just be moving the support ships back over from the Fishlips side of the port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/05/2016 12:18 AM
Or a near shore test run tomorrow.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 04/05/2016 12:27 AM
just now http://www.portcanaveralwebcam.com/
https://imgur.com/uf2dreL

Edit: https://imgur.com/sRvdwO9 light on
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/05/2016 01:44 AM
Or a near shore test run tomorrow.

And they don't have to leave until after static fire, so if there's a problem with static fire that causes a launch slip, the armada can hang back in port an extra day or two instead of waiting around in the middle of the ocean like they had to do last time. So another reason not to leave until Wednesday at earliest.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/05/2016 12:01 PM
Two panoramas from yesterday around 6:30 PM. No activity - either they are done with all repairs, or they are not going to use ASDS for CRS-8.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/05/2016 12:17 PM
And GoQuest with opened containers
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Retired Downrange on 04/05/2016 01:15 PM
In the photo of OCISLY it appears that one of the thrusters is removed.

[edit] ...as eriblo points out in next post, I can see the lower unit of the thruster down at water level, my confusion stems from the fact that the view of the vertical shaft is hidden.... I didn't recall this from previous photos.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: eriblo on 04/05/2016 01:21 PM
In the photo of OCISLY it appears that one of the thrusters is removed.
Which one? I believe I can see the three that should be visible - the one to the left is deployed all the way down (look beneath the mount).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 04/05/2016 02:17 PM
Looks like all of the welding and cutting gear is off the deck, probably ready or nearly ready to hit the open sea.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/05/2016 02:46 PM
Or a near shore test run tomorrow.

Bingo. EIII headed over to OCISLY early this morning, then left port, now heading ESE (not towards landing zone). Probably towing OCISLY for test run. Port webcam shows OCISLY berth empty.

Edit: but I will add that the ESE course is following the channel leaving Port Canaveral, so they could later turn northeast toward the landing zone and head there directly. I would have thought they would wait until after stagic fire for departure, but it's *possible* this is the real thing and not just a test run, though they would get there way early.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Blizzzard on 04/05/2016 03:13 PM
If they are going for a test run, and are also cutting it fine for leaving for landing site - could they test then go straight out to the landing site from there?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/05/2016 03:17 PM
I'd expect them to wait until the static fire is complete (later today, hopefully) before leaving for the landing site.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/05/2016 04:00 PM
Someone caught departure on camera:

https://www.instagram.com/p/BD0pGX8BRj2/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: thor1872 on 04/05/2016 05:04 PM
Departure:
https://i.imgur.com/esp7xhF.gifv
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: chrisking0997 on 04/05/2016 05:34 PM
looks like they cleaned up the shamrock before leaving
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: woods170 on 04/05/2016 07:08 PM
Two panoramas from yesterday around 6:30 PM. No activity - either they are done with all repairs, or they are not going to use ASDS for CRS-8.
The images of 2 or 3 days ago showed her still sitting high on the water with a notable tilt towards the bow. The latest pictures show her level and at depth. No tilt.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Mike_1179 on 04/06/2016 01:45 PM
Elsbeth III left port about this time yesterday traveling at ~5 knots, meaning she's towing something. I always say this, but isn't that a bit early to head out?

Looks to me like she's heading toward the landing area, not just a test run off shore.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/06/2016 02:00 PM
Pics up above hint they test ran the thrusters in port using one of the GO boats to hold it back...
My opinion is they decided, based on that all was good, any "test run" off shore was likely to be fine...
Go to sea it was decided... EIII headed out...  8)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/06/2016 02:48 PM
Is it just EIII or is there a "fairing recovery" ship this time as well?  (That one might leave later, since it doesn't have to tow a barge.)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/06/2016 03:11 PM
Is it just EIII or is there a "fairing recovery" ship this time as well?  (That one might leave later, since it doesn't have to tow a barge.)

Since Dragon doesn't have fairings, that would be rather odd.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: southshore26 on 04/06/2016 03:52 PM
Is it just EIII or is there a "fairing recovery" ship this time as well?  (That one might leave later, since it doesn't have to tow a barge.)

Go Quest departed Port Canaveral at 10:40pm last night... not fairing recovery but support ship to the ASDS.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/06/2016 03:58 PM
Go Searcher is stationary on the Fishlip side next to American Champion.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/06/2016 04:01 PM
Is it just EIII or is there a "fairing recovery" ship this time as well?  (That one might leave later, since it doesn't have to tow a barge.)

Since Dragon doesn't have fairings, that would be rather odd.

GO Searcher is still in port, and that fact combined with the lack of fairings on this flight is consistent with our suspicion that Searcher was indeed tracking/chasing fairings on previous flights.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/06/2016 04:25 PM
Is it just EIII or is there a "fairing recovery" ship this time as well?  (That one might leave later, since it doesn't have to tow a barge.)

Since Dragon doesn't have fairings, that would be rather odd.

GO Searcher is still in port, and that fact combined with the lack of fairings on this flight is consistent with our suspicion that Searcher was indeed tracking/chasing fairings on previous flights.
Thanks for turning my stupid question into real insight.  I agree, this is good circumstantial evidence for a fairing chaser role for Go Searcher.

PS. And reasonable evidence *against* that theory if Go Searcher stirs herself to dash out and join the flotilla before the launch.  Good theories are falsifiable!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/06/2016 04:55 PM
From a document posted (in a western niche of) the Eastern Range topic...

Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Boost-Backs and Landings of Rockets at Vandenberg Air Force Base
https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to (https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to)

Quote
In the event that a contingency landing action is required, SpaceX has considered the likelihood of the First Stage missing the barge and landing instead in the Pacific Ocean, and has determined that the likelihood of such an event is so unlikely as to be considered discountable. This is supported by three previous attempts by SpaceX at Falcon 9 First Stage barge landings, none of which have missed the barge.

That would be a pretty big miss...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/06/2016 04:58 PM
From a document posted (in a western niche of) the Eastern Range topic...

Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Boost-Backs and Landings of Rockets at Vandenberg Air Force Base
https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to (https://www.federalregister.gov/articles/2016/03/31/2016-07191/takes-of-marine-mammals-incidental-to-specified-activities-taking-marine-mammals-incidental-to)

Quote
In the event that a contingency landing action is required, SpaceX has considered the likelihood of the First Stage missing the barge and landing instead in the Pacific Ocean, and has determined that the likelihood of such an event is so unlikely as to be considered discountable. This is supported by three previous attempts by SpaceX at Falcon 9 First Stage barge landings, none of which have missed the barge.

That would be a pretty big miss...
for Cape launches yes, but this was from a doc about Vandy...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 04/06/2016 10:12 PM
Searcher has been known to leave later though right?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/06/2016 11:35 PM
Searcher has been known to leave later though right?

Yes, Searcher left about 2 days after Quest last time around.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/07/2016 01:42 AM
Searcher has been known to leave later though right?

Yes, Searcher left about 2 days after Quest last time around.

IIRC, one of the key "fixes" following the CRS-7 attempt was changes to the flight software to allow Dragon to free itself from a failing stack on the ride uphill and splashdown under it's own parachutes into the keep-out zone near shore.

Perhaps potential 'early' Dragon recovery operations (if required)?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/07/2016 01:52 AM
(Technically the Dragon _does_ have fairings, but not the kind worth recovering...)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: woods170 on 04/07/2016 08:28 AM
(Technically the Dragon _does_ have fairings, but not the kind worth recovering...)
More specifically: they are un-recoverable, as those fairings (for the solar arrays) burn-up upon reentry.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/07/2016 11:20 AM
(Technically the Dragon _does_ have fairings, but not the kind worth recovering...)
More specifically: they are un-recoverable, as those fairings (for the solar arrays) burn-up upon reentry.

And to be pedantic: They simply aren't worth something more complicated money-wise, whether that be fixed doors that actuate(or something else that never detaches from the dragon) or fairings with an ACS and/or whatever else may be required to survive re-entry and subsequently be recovered.

Edit - Also, does DV2 even have solar fairings?  Aren't all of the solar panels on the trunk?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 04/07/2016 11:43 AM
I bet the drone crews are packing more spare underwear this time around!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/07/2016 03:11 PM
So---is Go Searcher still in port?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/07/2016 03:13 PM
So---is Go Searcher still in port?

Yup. Brunching at Fishlips.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/07/2016 03:25 PM
So---is Go Searcher still in port?

Yup. Brunching at Fishlips.
So "fairing recovery role" theory not disproven yet.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/07/2016 07:55 PM
Hans just said in presser they are looking to refine their drone ship landing as it is part of their long term plan also next 2-3 flights will go for drone ship landing. He also mentioned it is harder compared to land landings due to movements.

Edit1: Also said a third of future missions could land on land.

Edit2: Hans said operating Drone ship is expensive. Also adds to refurbishment work "Wash off the salt".
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 04/07/2016 08:24 PM
Hmm, "refine", now there's a word. Trying to eliminate those last pesky traces of exploding on impact, falling over and exploding, punching big holes in the deck, and other miscellaneous minor refinements.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/07/2016 09:01 PM
Hmm, "refine", now there's a word. Trying to eliminate those last pesky traces of exploding on impact, falling over and exploding, punching big holes in the deck, and other miscellaneous minor refinements.

With apologies, from Butch Cassidy and the Sundance Kid:

OCISLY: What's the matter with you?!
Falcon 9: I can't swim!
OCISLY: [laughing] Why, you crazy — the fall'll probably kill ya!

But this time I bet they both survive the fall, just like in the movie.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ronsmytheiii on 04/08/2016 01:38 AM
Out to sea

https://www.facebook.com/SpaceX/posts/10157299547390131
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/08/2016 04:56 AM
Such a tiny vessel, such a big ocean!  I'm always amazed that the booster finds it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/08/2016 05:09 AM
Out to sea

Looks like a nice day for a landing.  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/08/2016 09:24 AM
Such a tiny vessel, such a big ocean!  I'm always amazed that the booster finds it.

It doesn't. The droneship finds the booster.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 04/08/2016 10:11 AM
Such a tiny vessel, such a big ocean!  I'm always amazed that the booster finds it.

It doesn't. The droneship finds the booster.
No, they set a date for a specific time and place, and then both keep it.  In this case, though, you really want the Falcon to "stand up" the date.   ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Mader Levap on 04/08/2016 10:34 AM
Such a tiny vessel, such a big ocean!  I'm always amazed that the booster finds it.
It doesn't. The droneship finds the booster.

Er, no. Both of them want to reach certain coordinates very, very much. If both of them are at those coordinates with correct speed and other parameters, it results in stage standing on barge.

They managed to do just exactly that already once. And then leg gave up (https://www.youtube.com/watch?v=jshk8ZVIgdI)...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/08/2016 01:00 PM
Er, no.

The booster has a predefined landing point (based mostly on launch mass)*. The barge has to make it to that point. The booster has no option but to hit the predefined landing point. If the barge isn't there, splash. The booster has no option but to hit its predefined landing point (if you want to land correctly). Therefor its the barges responsibility to be at that point.


* this can be varied of course, there is some cross range capability due to grid fins etc. But the point IS predefined.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ChrisC on 04/08/2016 01:14 PM
Can we just skip the inevitable semi-informed bickering about this that will take up three pages, and then peter out or get shut down by a mod?

Oh, wait, this is a discussion thread.  Carry on.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/08/2016 01:21 PM



* this can be varied of course, there is some cross range capability due to grid fins etc. But the point IS predefined.
I trust you understand that your postscript undermines your whole point.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/08/2016 01:52 PM
Ahem. On another subject, GO Searcher is still in port. So it's fairly certain she will not be joining the armada at sea. We think because there's no payload fairing to track/chase on this flight.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/08/2016 01:57 PM
If Go Searcher had been launched would it have had to find the fleet out at sea or would the fleet find it or would they have met at a designated spot?   ::)


Going crosspostal for a moment, here is a nice summary of the ASDS landing attempts so far:

All of the 4 barge landing attempts would have failed on land, too.

1) Came in hot, no directional control (grid fins ran out of hydraulic fluid)
2) Came in hot, little directional control (sticky engine/TVC valve)
3) Came in perfectly, toppled over (leg didn't latch)
4) Came in incandescent, poked hole in barge (low thrust on one engine)

So, the barge appears to be concentrating on eliminating failure modes.......
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 04/08/2016 02:27 PM
If Go Searcher had been launched would it have had to find the fleet out at sea or would the fleet find it or would they have met at a designated spot?

A relative of mine was once granted the use of a Royal Navy vessel so he could meet up with a ship from another territory for a "diplomatic handover".

He gave the Captain the agreed coordinates and asked how long the trip would take. On being told "just over seven hours" he did what any Brit would do under the circumstances and went to bed for a nice long sleep.

The next day, he was tucking into breakfast when it struck him that the ship was very quiet and surrounded by nothing but blue sea. He casually asked if there was any sign of the other party and someone speculated with a smirk that it was more than likely that the other party was at the agreed coordinates.

It seems that military types don't like being messed around by government types, and if you tell them to go somewhere, then they'll do exactly that. What they won't do without being asked is to hold station, so they'd been drifting with the wind and waves for an hour or so while said relative was performing his morning ablutions and tucking into his breakfast.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: billh on 04/08/2016 06:15 PM
Out to sea

Looks like a nice day for a landing.  :)
Partly cloudy and a chance of boosters!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/08/2016 06:27 PM
Ahem. On another subject, GO Searcher is still in port. So it's fairly certain she will not be joining the armada at sea. We think because there's no payload fairing to track/chase on this flight.

If Go Searcher had been launched would it have had to find the fleet out at sea or would the fleet find it or would they have met at a designated spot?   ::)

Could be SpaceX is wanting to keep Go Searcher hanging back and on alert in case Dragon itself needs recovering, within the 20 mile range approved by FAA for emergency landing with the new parachutes. Easy to see why SpaceX might want to take such a precaution, with CRS-7 probably re-echoing somewhere in their minds about now.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 04/08/2016 07:43 PM
Quoting from the Launch Viewing thread:
Just chatted with Secretary of the Interior Sally Jewel and SpaceX BD Josh Brost about launch costs.

ASDS can tilt up to six degrees and still support a landing. Million pounds of ballast water also means that the rate of change is dwarfed by the speed of the landing.
That gives us a bit more to go by when we're debating how flat and quiescent an ASDS must be for landing.  A bit over a 10% grade is a decent tilt for a football field/pitch.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/08/2016 08:20 PM
Quote
Screen cap from the stern cam of droneship "Of Course I Still Love You"
https://twitter.com/elonmusk/status/718532302154833920
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mvpel on 04/08/2016 08:31 PM
Score.


Sent from my iPhone using Tapatalk
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/08/2016 08:53 PM
ASDS OCISLY: Worlds Raddest Barge!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/08/2016 08:58 PM
 :-*

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/08/2016 09:01 PM
Great video from the camera drone showing OCISLY wallowing in the waves. Definitely not perfectly stable, but she caught the rocket anyway. Strike!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/08/2016 09:12 PM
What? No kaboom?  :o

A superb landing!!! Way to go OCISLY!

And, to make this post not quite entirely worthless, a note on the sea state; it's very windy out there - those kind of whitcaps only occur when you've got strong surface winds. I'd say right on the edge of gale force.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 04/08/2016 09:26 PM
I'm looping the landing, and it really looks to me as if it bounced/scooted just a bit on landing.  (As in, it looked like the initial landing point was actually closer to the center than the final resting point.)  Obviously, it would've been built for that, and it didn't hurt, but if it did translate just a bit, the targeting may actually be a smidge *better* than the resting stage makes it look.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: longboard1210 on 04/08/2016 09:32 PM
amazing amazing

should we now get the name changed to of course i caught it!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/08/2016 09:45 PM
When do you guys estimate it will come back to the port? I need to be at Jetty park for that!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/08/2016 10:13 PM
When do you guys estimate it will come back to the port? I need to be at Jetty park for that!

I figure at a minimum, around 36 hours from now...which is early Sunday morning. But that assumes a fairly quick securing process for the stage. If it takes longer to tie the stage down, maybe later Sunday morning or early afternoon.

Since you are local you can wake up early Sunday morning and check MarineTraffic. They'll show up offshore on AIS at least an hour before reaching port.

Update: Elon confirmed Sunday arrival at press conference.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/08/2016 10:20 PM
Looks like the support ships weren't hesitating to get there, unless they anchor that close the whole time anyway. I can see why they would need or want to get there quickly, with surface winds so strong, but assume the remote safing can't be avoided, and would take an hour or two before approach.

:-*

(http://public.cyndyclayton.fastmail.us/ASDS/Gotcha%202016-04-08%20600w.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: longboard1210 on 04/08/2016 10:23 PM
so they are welding her down directly to the deck  elon just confirmed
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/08/2016 10:26 PM
When do you guys estimate it will come back to the port? I need to be at Jetty park for that!

I figure at a minimum, around 36 hours from now...which is early Sunday morning. But that assumes a fairly quick securing process for the stage. If it takes longer to tie the stage down, maybe later Sunday morning or early afternoon.

Since you are local you can wake up early Sunday morning and check MarineTraffic. They'll show up offshore on AIS at least an hour before reaching port.

Update: Elon confirmed Sunday arrival at press conference.


Thank you. I guess I will be spending my Sunday at the beach ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/08/2016 10:27 PM
Looks like the support ships weren't hesitating to get there, unless they anchor that close the whole time anyway. I can see why they would need or want to get there quickly, with surface winds so strong, but assume the remote safing can't be avoided, and would take an hour or two before approach?

Hans said some time ago the support ships wait about 10 miles away and it takes them an hour or two to get back on board the barge.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/08/2016 10:34 PM
Cross-posting from abaddon, quoting Elon at the press conference:

Quote
OCISLY was maintaining within a meter of targeted position today.

One meter position accuracy on the barge...just like we said was possible... ;)

Awesome for those wind and sea conditions. Which means GPS "knowledge" accuracy was probably even better...most error probably from thruster control loop conteracting wind/wave action.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/08/2016 11:20 PM
Update: Elon confirmed Sunday arrival at press conference.


Thank you. I guess I will be spending my Sunday at the beach ;)

Wouldn't Fish Lips have a better view, or not? I finished my taxes after working all week on them, so might be a good way to reward myself. It would be about a 2 hr drive from Jacksonville.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Tuts36 on 04/08/2016 11:25 PM
Cross-posting from abaddon, quoting Elon at the press conference:

One meter position accuracy on the barge...just like we said was possible... ;)

Awesome for those wind and sea conditions. Which means GPS "knowledge" accuracy was probably even better...most error probably from thruster control loop conteracting wind/wave action.

He also pointed out in the press conference that, since it has 4 engines & other equipment installed, we really shouldn't be calling it a barge anymore as he now considers it a ship  ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/08/2016 11:27 PM

ASDS OCISLY: Worlds Raddest Barge!
(Ship!)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/08/2016 11:30 PM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.

@17m42s mark (https://www.youtube.com/watch?v=VNygOavo2mY#t=1062&feature=youtu.be)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/08/2016 11:47 PM
Looks like the support ships weren't hesitating to get there, unless they anchor that close the whole time anyway.
  Huh?  No?  What do you think you are seeing?

Hans said some time ago the support ships wait about 10 miles away and it takes them an hour or two to get back on board the barge.
Yes, I remember that it seems that it was a year back, at the CRS-7 pre-launch conference?  But in the time since (and before) then we've had a tremendous demonstration of the F9's accuracy in smart bomb mode.  I would think they would have relaxed their standoff distance by now.


I suspect that those barge fixer guys are really having a career high feel good moment now, the kind that has them cutting pictures out of newspapers to be preserved.

I think we need to be looking in the next few months for additional Marmac conversions. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Space Opera on 04/08/2016 11:58 PM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.
What could be this initial destination ?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 04/09/2016 12:00 AM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.
What could be this initial destination ?

bahamas?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 12:15 AM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.
What could be this initial destination ?

bahamas?

Doubt it, because launch azimuth is much farther north for ISS than it was for SES-9 when they did support ship runs into Bahamas. This time I think Bahamas is farther than the Cape from the LZ. My guess would be Jacksonville as the shortest run to the coast for a temporary layover.

But then they would have to go back out for a run down the coast to the Cape, and that's more exposure at sea... Hoping they opt for a straight shot into Canaveral.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mlow on 04/09/2016 12:28 AM
Yeah I'm a bit confused as to the reasoning of taking a pit-stop somewhere. Perhaps something to do with the winds Elon mentioned in the post-launch conference. Maybe they want to weld shoes and get to a port and dock ASAP, idk. The winds cant be that bad close to shore as they are out there.(he mentioned 50mph winds)

I would think the safest thing would be to weld shoes and get back to the dock where they have the equipment to remove the stage from the barge. Less time in salt spray, less time bobbing around with the shoes/legs taking extra stress. That is unless they use jacks to take some strain off. But alas Elon did not make mention of jacks, only shoes. That doesn't remove them from the equation but seems like he would have made mention of them at the same time wrt the question from a reporter of the exact process the stage has ahead.

At any rate, we will know come Sunday I suppose. I'm sure more than a few people will be on-site to report and take pics/video. I look forward to that. I am also a member of the club that wishes to see Elon standing proud on the bow as it comes into port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/09/2016 12:34 AM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.

@17m42s mark (https://www.youtube.com/watch?v=VNygOavo2mY#t=1062&feature=youtu.be)


I was puzzled by that -- unless it's taking a victory lap up and down the coast I can't imagine where else it would be more likely to go.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 12:52 AM
For reference, here is repost of map by OxCartMark. Jacksonville is almost due west of LZ, but it looks only marginally nearer to the LZ than the Cape, so it hardly seems worth a detour.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39766.0;attach=1106693)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 01:02 AM
Yeah I'm a bit confused as to the reasoning of taking a pit-stop somewhere

Perhaps Amazon has a large facility near the ocean that they want to float it past?


edit: Elon's words on the subject:
"Actually I'm not certain about that I think certainly is where it will ultimately be.  I'm not sure that is the original destination"
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 01:18 AM
I'm looping the landing, and it really looks to me as if it bounced/scooted just a bit on landing.  (As in, it looked like the initial landing point was actually closer to the center than the final resting point.)  Obviously, it would've been built for that, and it didn't hurt, but if it did translate just a bit, the targeting may actually be a smidge *better* than the resting stage makes it look.

https://twitter.com/SpaceX/status/718605741288894464

Ooh they were right on the 'X' at beginning and then as you said moved away slightly.

Edit: I still think shoes and jacks are same thing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ericspittle on 04/09/2016 01:38 AM
Edit: I still think shoes and jacks are same thing.
Why would one weld a jack over the landling legs though? I suspect they'll do both, weld shoes over the feet of the legs so it can't move, and then put jacks under it (using the same aircraft style jacks they used for the RTLS in December) to take the stress off the legs.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/09/2016 01:53 AM
Um, it's my supposition that they'd head in to nearest port that can handle the barge (strike that, ship) - I.E., Jax, and offload their precious cargo. I suspect that when OCISLY returns to Port Canaveral it'll be sans cargo...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 02:06 AM
Um, it's my supposition that they'd head in to nearest port that can handle the barge (strike that, ship) - I.E., Jax, and offload their precious cargo. I suspect that when OCISLY returns to Port Canaveral it'll be sans cargo...
Um, no Falcon perch in Jacksonville.  Falcon perch and yellow crane are at Port Canaveral.

Theory (if you are not already bought into my Amazon theory above): Stop at VAB pond or elsewhere for employee celebration on ASDS and some folks remain onboard for triumphant public return to Port Canaveral.  Hmm, after looking at maps that seems vastly impractical and it almost certainly isn't certified for passengers.

Is this event historic enough that they should eventually hang ASDS OCISLY from the ceiling of the Smithsonian A&S museum?    ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 02:10 AM
Jacks have been spotted so many times but never mentioned 'shoes' have been mentioned by Elon himself but never seen. Jack adapter goes over and secures the hold down lug and jacks could be welded to the deck. Where are these 'shoes' on deck ? Can't be in containers in my opinion very less space around them. Jacks are simply rolled out on their wheels, put under and then firmly placed. Apart from jacks so far the only leg related thing we have seen are these.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36326.0;attach=631534;image)

Shoes IF they go over leg tips need to be something more rigid and possibly attach.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 02:16 AM
Quote
Where are these 'shoes' on deck ? Can't be in containers in my opinion very less space around them.

Shoes need only be maybe 2 feet square, smaller than the size of the welder. Should be enough storage space  for them in the containers, no? Or on GO Quest.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 02:18 AM
We've never seen shoes because they are small, only need to go over feet.  Probably stored in containers.
We've never seen shoes because shoes need to be welded to a steel deck and there has never been a F9 standing on a steel deck before.
We've never seen shoes because we've never been in a situation where the F9 landed at sea and needed to be secured very quickly and easily and it was acceptable to cause more work on the receiving end (see also short list of recovered F9s)

Jacks are big because they need to reach up quite a ways to the hold down clamp attach points. 

edit:
Elon's comment from the reddit AMA 1/2015: "Mostly gravity. The center of gravity is pretty low for the booster, as all the engines and residual propellant is at the bottom.
We are going to weld steel shoes over the landing feet as a precautionary measure."

edit2:
Elon's comment on shoes today: (about 20% into the video, not possible for me to get a time)
"That's what's happening, we're welding it down.  Yea.  Make sure it doesn't tip over.  There's potentially some heavy winds coming.  We've got these steel shoes that we put over the landing feet and weld it to the deck"
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/09/2016 02:30 AM
...
Is this event historic enough that they should eventually hang ASDS OCISLY from the ceiling of the Smithsonian A&S museum?    ::)

The OCISLY will make a great lawn monument at the A&S museum, especially with a flown Falcon 9 as the centerpiece on it. :D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/09/2016 02:35 AM
Is this event historic enough that they should eventually hang ASDS OCISLY from the ceiling of the Smithsonian A&S museum?    ::)

Not anymore than Sea Launch Odyssey.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 02:46 AM
Is this event historic enough that they should eventually hang ASDS OCISLY from the ceiling of the Smithsonian A&S museum?    ::)

Not anymore than Sea Launch Odyssey.
I doubt that ranks anywhere near what happened today.  All Sea Launch Odyssey did is launch rockets.  People have been launching rockets for longer than most of us here have been alive.  And if you classify launching rockets from water as the qualifying category there'd be a large number of submarines in line in front of it.

edit: And... Sea Launch Odyssey is too tall to fit into the room.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 02:59 AM
For those of you that have been snooping ocean landing platforms for as long as some of us have recall that there were endless pages of discussion about the steel deck being unable to handle the rocket exhaust, warping, etc.  Well today we have a solid answer to that and I note after watching the video a few more times that they don't even seem to be running the red spray nozzle to wet the deck on this landing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 03:04 AM
Aware of all those Mark. Again looking at tips (http://forum.nasaspaceflight.com/index.php?topic=33788.msg1147688#msg1147688) and not seeing anything to hook up to. Also why would they need tie downs back then when shoes were there? About the space problem I imagine something that is stored partly disassembled beam frame like thing that attaches to cylinders...but then again I think jacks are enough. :-X

Edit: Replying to shoe thingy not above.

Also on Jason-3 attempt they were spraying away from deck.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 03:07 AM
Aware of all those Mark. Again looking at tips (http://forum.nasaspaceflight.com/index.php?topic=33788.msg1147688#msg1147688) and not seeing anything to hook up to. Also why would they need tie downs back then when shoes were there? About the space problem I imagine something that is stored partly disassembled beam frame like thing that attaches to cylinders...but then again I think jacks are enough. :-X

Edit: Replying to shoe thingy not above.

Shoes don't need to hook to anything. They can go over the leg tips, preventing side-slipping and overturning. Just make them long enough so they cover a foot or two of leg tip.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 03:12 AM
Aware of all those Mark. Again looking at tips (http://forum.nasaspaceflight.com/index.php?topic=33788.msg1147688#msg1147688) and not seeing anything to hook up to. Also why would they need tie downs back then when shoes were there? About the space problem I imagine something that is stored partly disassembled beam frame like thing that attaches to cylinders...but then again I think jacks are enough. :-X

Edit: Replying to shoe thingy not above.

Shoes don't hook to anything. They go over the leg tips, preventing side-slipping and overturning.

Yes I understand that assumption I don't know how to say but doesn't sit well with me. Such shoes just appear unnecessary. Jacks are like those hold downs but movable.

Edit: Adding what little attachables (http://forum.nasaspaceflight.com/index.php?topic=33788.msg1147660#msg1147660) leg tips have
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: NovaSilisko on 04/09/2016 03:26 AM
So we're back to the good old pasttime of arguing about all the minutia SpaceX is doing wrong, eh?

Welding is cheap and quick. Just a loop of metal that sits over the very end of the leg and stops it from skidding or lifting up. I'm more worried about skidding than tipping. If it's tilting to the point that it actuall falls over, we're talking Poseidon Adventure level wave action, and you've probably got bigger issues (like the entire thing sinking)

Also, I'm pretty sure we saw the shoes before, somewhere. Buried in one of the old ASDS threads, no doubt.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 04:25 AM
Quote
Also, I'm pretty sure we saw the shoes before, somewhere. Buried in one of the old ASDS threads, no doubt.

No we would know that. Also the idea of shoes going over tips and being welded isn't lost on me in fact it is intuitive just like for everyone else after listening and reading to Elon ... 'Steel' 'Over legs' 'Welded to deck' yep even more obvious I just find it odd that rocket sitting on jacks isn't worth mentioning..It is not something obvious and they visibly put work into it and stuck with them for many attempts. Mind it only one person here predicted them before they were seen on DSCVR attempt. So just trying to pick holes in the 'obvious' anyways..

To divert subject Mark mentioned in discussion thread that first stage maintains its roll such that the sides of square formed by joining leg tips are parallel to sides of deck. On Jason3 attempt this was true as well. So stage is simply adjusting its roll to reduce chances of one leg going overboard? If yes how does it determine orientation of ASDS?

Or ASDS is maintaining predetermined position as well as orientation? What factor decides what orientation ASDS should maintain? Is it something related to waves like aligning to have them along length than width.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 04/09/2016 04:46 AM
Quote
Also, I'm pretty sure we saw the shoes before, somewhere. Buried in one of the old ASDS threads, no doubt.


Or ASDS is maintaining predetermined position as well as orientation? What factor decides what orientation ASDS should maintain? Is it something related to waves like aligning to have them along length than width.
That's a good question. And a complicated one. Boats sitting still act nothing like boats moving. Bow into the waves on a still barge could make the thing pitch more than side to the waves. And, do they worry more about pitching and rolling or sliding sideways? Those Thrustmasters aren't instantaneous.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 04:56 AM
My guesses on how shoes would look;
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/09/2016 05:10 AM
Or ASDS is maintaining predetermined position as well as orientation? What factor decides what orientation ASDS should maintain? Is it something related to waves like aligning to have them along length than width.
That's a good question. And a complicated one. Boats sitting still act nothing like boats moving. Bow into the waves on a still barge could make the thing pitch more than side to the waves. And, do they worry more about pitching and rolling or sliding sideways? Those Thrustmasters aren't instantaneous.

Maintaining position would be priority and they have less error margin along width.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 09:30 AM
Quote
I just find it odd that rocket sitting on jacks isn't worth mentioning..It is not something obvious and they visibly put work into it and stuck with them for many attempts.

Maybe leg piston locks have been beefed up to the point they think legs alone can support the stage safely during transit with no need for jacks now.

Or maybe Elon just didn't bother to mention because in this case jacks won't be weighted down and thus are not really contributing to stability, just protecting against leg collapse.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/09/2016 10:34 AM
Update: Elon confirmed Sunday arrival at press conference.


Thank you. I guess I will be spending my Sunday at the beach ;)

Wouldn't Fish Lips have a better view, or not? I finished my taxes after working all week on them, so might be a good way to reward myself. It would be about a 2 hr drive from Jacksonville.


Any place in the port will be good.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/09/2016 10:39 AM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.


SpaceX installed special "rocket mount" in Port Canaveral. I suspect this mount may be required to unload the rocket. So I doubt SpaceX would divert to any other port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 04/09/2016 11:07 AM
Also Elon said ultimately it'll be at Port Canaveral but not sure if it is initial destination.


SpaceX installed special "rocket mount" in Port Canaveral. I suspect this mount may be required to unload the rocket. So I doubt SpaceX would divert to any other port.

IMHO needed to remove the legs.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gadgetmind on 04/09/2016 11:07 AM
Hmm, "refine", now there's a word. Trying to eliminate those last pesky traces of exploding on impact, falling over and exploding, punching big holes in the deck, and other miscellaneous minor refinements.

OK, now they can refine their landings!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris Bergin on 04/09/2016 12:37 PM
Set up a specific thread for the return to port tomorrow:
https://forum.nasaspaceflight.com/index.php?topic=40002.0
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 04/09/2016 12:41 PM
Word is it may come back to JAX, not to the cape

I can see they might have wanted to get close to shore for overnight and/or ASAP, to get out of the higher winds offshore, and JAXPORT would have been closest to their position at the landing site, but why go to the trouble of offloading and trucking the stage from there when it's already loaded for transport on the drone ship. I think when when the stage comes in close to it's final resting place, it will be on the drone ship, not a truck.

They have experience of trucking the stage for thousand of km, they never experienced vertical barge transport.
That said, I don't put a dime on a JAX stop.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: litton4 on 04/09/2016 01:45 PM
I'm looping the landing, and it really looks to me as if it bounced/scooted just a bit on landing.  (As in, it looked like the initial landing point was actually closer to the center than the final resting point.)  Obviously, it would've been built for that, and it didn't hurt, but if it did translate just a bit, the targeting may actually be a smidge *better* than the resting stage makes it look.

I noticed this, too - very apparent in the 4K version. Wind taking it a metre or 3 to the left. Scary stuff.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 01:58 PM
Regarding that bounce - If we knew the coefficient of friction between the deck and the foot pads we could use that to determine what that slide demonstrated in terms of tip over angle (assuming that there wasn't still any significant thrust at that time).  It wouldn't tell us the maximum angle that the stage could be at without tipping over but it would set a lower bound that we know we can survive, at least statically.  But seat of the pants, I think it demonstrates what they've been telling us all along, that the CG is way down low and we shouldn't worry about it.  Elon in the press conference said 6-8 degrees is OK and 8-9 was maybe possible.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 04/09/2016 02:03 PM
Regarding that bounce - If we knew the coefficient of friction between the deck and the foot pads we could use that to determine what that slide demonstrated in terms of tip over angle (assuming that there wasn't still any significant thrust at that time).  It wouldn't tell us the maximum angle that the stage could be at without tipping over but it would set a lower bound that we know we can survive, at least statically.  But seat of the pants, I think it demonstrates what they've been telling us all along, that the CG is way down low and we shouldn't worry about it.  Elon in the press conference said 6-8 degrees is OK and 8-9 was maybe possible.

I wonder how much of the "skid" on touchdown was due to wind on the settling stage, and how much due to motion of the barge from the sea state? At first blush it looks to me more that the deck of the barge moves under the stage (pitch and roll) as much as the stage moves while it settles.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gongora on 04/09/2016 02:13 PM
Do we know if a stand for the rocket is still in place at JAX?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/09/2016 02:18 PM
Do we know if a stand for the rocket is still in place at JAX?

Last we saw, stands had been moved to Port Canaveral. But here they are, as originally installed in JAX.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36326.0;attach=629332)

Photo below taken by MarekCyzio at Port Canaveral. You can see they are the same stands, by the "ears" projecting from the top corners of the 2 stands on the left.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: hans_ober on 04/09/2016 02:45 PM
Regarding that bounce - If we knew the coefficient of friction between the deck and the foot pads we could use that to determine what that slide demonstrated in terms of tip over angle (assuming that there wasn't still any significant thrust at that time).  It wouldn't tell us the maximum angle that the stage could be at without tipping over but it would set a lower bound that we know we can survive, at least statically.  But seat of the pants, I think it demonstrates what they've been telling us all along, that the CG is way down low and we shouldn't worry about it.  Elon in the press conference said 6-8 degrees is OK and 8-9 was maybe possible.

Check out the barge around 30 seconds into https://www.youtube.com/watch?v=sYmQQn_ZSys (https://www.youtube.com/watch?v=sYmQQn_ZSys).
(After the stage has landed).

The barge sways A LOT, definitely more than 10 degrees, but the stage seems pretty stable, no signs of movement, which is impressive. Looked close to 20 degrees.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gongora on 04/09/2016 03:03 PM
Do we know if a stand for the rocket is still in place at JAX?

Last we saw, stands had been moved to Port Canaveral. But here they are, as originally installed in JAX. Second photo shows them in Port Canaveral.

Finally found picture from JAX where they had removed stands (only 227 pages into the previous thread).  Was wondering if they had just left stands in both places, if you already have to build 4 stands then building a 5th doesn't seem like a big deal.
Quote
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #5656 on: 12/19/2015 04:24 PM »
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 03:12 PM
The barge sways A LOT, definitely more than 10 degrees, but the stage seems pretty stable, no signs of movement, which is impressive. Looked close to 20 degrees.
  No.  Elon addresses this in the press conference.  He said they were seeing 2-3 degrees.

The pictures are very definitive as to the history of the crane and Falcon Perch.  Both were at Jacksonville.  Both were gone from Jax on the next Carnival Fascination images we had after the ASDS departed.  Both have been seen in Port Canaveral since at least the beginning of March and in all probability back into February though I've not traced them back that far.  There isn't much wiggle room for other versions of reality on this.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/09/2016 04:04 PM
Quote
Also, I'm pretty sure we saw the shoes before, somewhere. Buried in one of the old ASDS threads, no doubt.


Or ASDS is maintaining predetermined position as well as orientation? What factor decides what orientation ASDS should maintain? Is it something related to waves like aligning to have them along length than width.
That's a good question. And a complicated one. Boats sitting still act nothing like boats moving. Bow into the waves on a still barge could make the thing pitch more than side to the waves. And, do they worry more about pitching and rolling or sliding sideways? Those Thrustmasters aren't instantaneous.
How would a boat know if it is "standing still", GPS wise...

I think the difference is between "free drifting boats" and "thrusting boats" (whether stationary or not", and also "moored boats".
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/09/2016 04:06 PM
Word is it may come back to JAX, not to the cape

I can see they might have wanted to get close to shore for overnight and/or ASAP, to get out of the higher winds offshore, and JAXPORT would have been closest to their position at the landing site, but why go to the trouble of offloading and trucking the stage from there when it's already loaded for transport on the drone ship. I think when when the stage comes in close to it's final resting place, it will be on the drone ship, not a truck.

They have experience of trucking the stage for thousand of km, they never experienced vertical barge transport.
That said, I don't put a dime on a JAX stop.
Deleted...   New "triumphant barge return" thread!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 04/09/2016 04:07 PM
Word is it may come back to JAX, not to the cape

I can see they might have wanted to get close to shore for overnight and/or ASAP, to get out of the higher winds offshore, and JAXPORT would have been closest to their position at the landing site, but why go to the trouble of offloading and trucking the stage from there when it's already loaded for transport on the drone ship. I think when when the stage comes in close to it's final resting place, it will be on the drone ship, not a truck.

They have experience of trucking the stage for thousand of km, they never experienced vertical barge transport.
That said, I don't put a dime on a JAX stop.
They have to go to JaX first.  There is an outstanding $20 bet between Elon and someone about whether the stage will fit under that bridge.
You've got to be kidding...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: apirie98 on 04/09/2016 04:23 PM
The barge sways A LOT, definitely more than 10 degrees, but the stage seems pretty stable, no signs of movement, which is impressive. Looked close to 20 degrees.

I noticed that the RCS thrusters are still firing after the stage is landed. I'm wondering if that is actually helping to keep the stage upright, or if it's not doing anything much to help but it's just the control system firing as the stage tilts, because that's what the control system does.

If it were keeping the stage upright and stable, how long would the RCS system be able to sustain this (i.e. in strong winds/waves)?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: gospacex on 04/09/2016 04:42 PM
A non-trivially off-center landing. I think we will see somewhat bigger barges in the future.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 04:44 PM
I noticed that the RCS thrusters are still firing after the stage is landed
They are firing N2 in all four directions simultaneously with a net thrust of zero just to get rid of the potential energy in the pressure vessels as part of safing the stage.  This happened on their momentarily successful previous landing as well.  The time that they landed with way too much sideways motion it was different, there was just one thruster at the top fighting to keep it upright.

If it were keeping the stage upright and stable, how long would the RCS system be able to sustain this (i.e. in strong winds/waves)?
The thrust isn't that significant.  You'd be better off having a pelican land on one of the legs.  The duration would be 4x the duration you see in this video.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 04/09/2016 05:12 PM
A non-trivially off-center landing. I think we will see somewhat bigger barges in the future.
Disagree...
I think we will see bullseye landing in the future!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ronsmytheiii on 04/09/2016 05:14 PM
Latest Terraserver update of Port Canaveral Shows "Of Course I still Love you" in port:

http://bit.ly/1N1dzeb
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: 411rocket on 04/09/2016 05:22 PM
Latest Terraserver update of Port Canaveral Shows "Of Course I still Love you" in port:

http://bit.ly/1N1dzeb

It also looks like, there is a hole in the deck too. We know that hole, has since been repaired.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: georgegassaway on 04/09/2016 05:32 PM
FWIW, here is an image I modified to show an estimated CG location of the F9 core after landing. I’m not claiming this is the real CG, it may well be lower than this, just that from old discussions on the forum that it would be pretty low down with nearly all of the fuel gone (And thruster gases vented shortly after landing).  So, it is easier to visualize how hard it would be for it to fall over, once you see how low the CG is relative to the legspan.

(http://i.imgur.com/Q9xXS8Z.jpg)

The off’center landing, I do not think is random, I think it is directly related to the high wind and the fact that it had to stop tilting to fight the wind to be level at touchdown, so it drifted off-center in that brief time.  Here is an edited version of a post I made elsewhere:

The tilt seen early as it was coming down, I thought at first it had been off course horizontally and was trying to maneuver a bit laterally during the descent to make up for an error. So I was relieved (and super excited) to see it landed safely.

Turned out that it was coming down pretty much vertically.... but it was VERY windy. Musk said 50 mph, not sure of that though SpaceX had said it could land in winds as high as 50 mph. Anyway, the tilt was needed to fly it "into the wind", so the net descent path seemed pretty vertical (If the wind was say 40 mph, then it would need to tilt to fly laterally 40 mph into the wind so as not to drift downwind).

But for landing it needs to be level, the legs are not designed for one to land first and for one leg to support the landing loads of the whole booster (never mind rocking moments that would be generated as a result of that).

So, it had to straighten up at the last moment to land level. And in that time, the wind started to move it downwind. The off-center location seems to be pretty much aligned with the wind direction, so it may have bene dead center until it leveled off for touchdown. Also, the video shows how, as it is landing, the steam (water sprayed on deck) from the exhaust moves quickly from right to left, showing how fast the wind was and the direction that matches the tilt direction the core was doing to fight that wind during descent.

IIRC, the Orbcomm-2 landing in December (RTLS back to the Cape) also was "downwind" of the center of the circle. Was not as windy, was not off by much, but notably the location was downwind (Later there was a great fixed near-pad camera that showed the landing closeup, where it was visibly obvious it was descending vertically, then as it straightened up 2-3 seconds before touchdown it drifted horizontally a bit).

Maybe sometime they will tweak the landing software to "lead" the targeted landing spot to be a few feet upwind of center, so the descent will be "over" that upwind spot and try to land a few feet upwind, but when it levels out to point vertically, the wind will push it closer to the center. Of course if it really was 50 mph wind.... then it works without the need for doing that. But inevitably there'd be some day with even higher wind, where such a landing software tweak might allow it to land safely without drifting too far and put a leg over the side, leading to it falling overboard.

An update I’ll add to the last paragraph, is that on rematching a HD view of the landing, it looks like the core might have been a little bit upwind of center as it came down. So possibly the landing software DID “lead” some of the landing to be somewhat upwind of center. Of course with winds that high, there would likely be gusts, including gusts at different altitudes.  As well, the issue of vertical Wind Gradient, wind velocity is lower closer to the surface.
https://en.wikipedia.org/wiki/Wind_gradient

- George Gassaway
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: alang on 04/09/2016 05:42 PM
Could a mechanical engineer here say if that skid might be a good thing, to reduce the bending stress on the stage?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/09/2016 05:54 PM
...

Yes!  Exactly as you said from beginning to end.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cambrianera on 04/09/2016 05:59 PM
That CG is too low.
Right position is about 12-13 m high.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: StuffOfInterest on 04/09/2016 06:01 PM
Maybe sometime they will tweak the landing software to "lead" the targeted landing spot to be a few feet upwind of center, so the descent will be "over" that upwind spot and try to land a few feet upwind, but when it levels out to point vertically, the wind will push it closer to the center. Of course if it really was 50 mph wind.... then it works without the need for doing that. But inevitably there'd be some day with even higher wind, where such a landing software tweak might allow it to land safely without drifting too far and put a leg over the side, leading to it falling overboard.

Something I put in the mission discussion thread, rather than changing the rocket landing target why not just shift the barge a couple meters downwind a few minutes before landing?   The rocket isn't going to change in real time but the barge can do a readjustment and the wind measurement tools are right there.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/09/2016 06:02 PM
A non-trivially off-center landing. I think we will see somewhat bigger barges in the future.
Maybe they will make bigger barges, but I don't think that is the "next step."

It touched down pretty darn close to center in a stiff wind with 50 mph gusts (it looks like a couple of meters off to me, max).  Then it "bounces" a couple times and scoots downwind. There may be ways to mitigate the "bounce."  There are definitely ways for the rocket to programmatically adjust it's target point to adjust for "fighting" the wind.  It can estimate how far it will drift in the last moments when it has to "get vertical" for the landing.

I'm not saying it "easy", but refining landing software and dampening the bounce is where to start, IMO.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/09/2016 06:17 PM
Maybe sometime they will tweak the landing software to "lead" the targeted landing spot to be a few feet upwind of center, so the descent will be "over" that upwind spot and try to land a few feet upwind, but when it levels out to point vertically, the wind will push it closer to the center. Of course if it really was 50 mph wind.... then it works without the need for doing that. But inevitably there'd be some day with even higher wind, where such a landing software tweak might allow it to land safely without drifting too far and put a leg over the side, leading to it falling overboard.

Something I put in the mission discussion thread, rather than changing the rocket landing target why not just shift the barge a couple meters downwind a few minutes before landing?   The rocket isn't going to change in real time but the barge can do a readjustment and the wind measurement tools are right there.
My only concern is that the amount of drift for the touch down point is related to when the rocket "goes vertical" for the landing.  So changes to the flight software/timing would require changes to the barge offset calculation.  Possible, but my gut is to let the rocket figure out how to hit the target.  It doesn't know the airspeed directly, but it has a good idea what the wind speed is based on how much it has to gimbal and "lean in" to the wind.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/10/2016 04:41 AM
From the Return of OCISLY thread;

We saw the support ship approaching the ASDS soon after the landing.
You are the second person that I've heard say that.  Perhaps I need to consider that its true.  What did you see to suggest that (what did I miss?)?

I know saw a smudge/water drop on the on-board view that I briefly thought looked like a ship. Can someone provide a picture of anything more definitive?

Do you mean this shot?

It started with a photo Ohsin attached at 4:58pm yesterday and then I embedded it, again below. There's a hazy outline or two and a light in the background to the right, but clearer in this shot than in Bargemanos'.

(http://public.cyndyclayton.fastmail.us/ASDS/Gotcha%202016-04-08%20600w.jpg)

Cindy, I have utterly no clue what that light is (though if anyone has any ideas, please enlighten) but those things on what looks like the horizon that look like ships, aren.t. IMHO, the forward blast wall top is in line with the horizon, so in that area you're looking over the top of the blast wall, and the things we see there are IMHO parts of OCISLY; the generator exhaust stacks, and, I think, the satcom dome.



Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Comga on 04/10/2016 04:53 AM
We saw the support ship approaching the ASDS soon after the landing.
Cindy, I have utterly no clue what that light is (though if anyone has any ideas, please enlighten) but those things on what looks like the horizon that look like ships, aren.t. IMHO, the forward blast wall top is in line with the horizon, so in that area you're looking over the top of the blast wall, and the things we see there are IMHO parts of OCISLY; the generator exhaust stacks, and, I think, the satcom dome.

Gosh I'm sorry.  CJ is obviously correct.  My statement was wrong.
But it was a minor point.  The ship is somewhere maybe an hour or two away. 
The basic conclusion remains.  The first stage was probably secured within hours of landing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/10/2016 05:32 AM

Cindy, I have utterly no clue what that light is (though if anyone has any ideas, please enlighten) but those things on what looks like the horizon that look like ships, aren.t. IMHO, the forward blast wall top is in line with the horizon, so in that area you're looking over the top of the blast wall, and the things we see there are IMHO parts of OCISLY; the generator exhaust stacks, and, I think, the satcom dome.

Gosh I'm sorry.  CJ is obviously correct.  My statement was wrong.
But it was a minor point.  The ship is somewhere maybe an hour or two away. 
The basic conclusion remains.  The first stage was probably secured within hours of landing.

IMHO, you are quite correct that the ships are somewhere fairly close (an hour or less IMHO). Five miles (about half an hour at ten knots) should be enough - it's enough for RTLS (It's about 6 miles from LC-13 to the restaurants and cruise terminals at Port Canaveral).

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/10/2016 07:49 AM
A non-trivially off-center landing. I think we will see somewhat bigger barges in the future.
I think the barge will stay the same size and the landings will improve.

Also: some of the bounce might be velocity overshoot---getting to positive a few fractions of a meter per second up, instead of precisely to zero.  Engine shutdown transient might do that, it's notoriously difficult to predict the amount of thrust from the shutdown transient.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/10/2016 10:02 PM
Over in the CRS-8 discussion thread, there's quite a bit of concern regarding the off-center location where the stage ended up after some downwind sideways motion on landing.

My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two upwind of the coordinates for touchdown.

So my question here is, is there anything known about the ASDS control system that would preclude making such a simple adjustment in case of need? My guess as to how they could do it is simply change the ASDS's target coordinates by a yard ot two in the appropriate direction.

Doing the above just seems, to me, vastly simpler and cheaper than some of the proposed (in that thread and others) changes to the ASDS and the F9, to fix a problem that we don't, yet, know is actually a problem or not.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Mongo62 on 04/10/2016 10:54 PM
My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two upwind of the coordinates for touchdown.

I assume you mean downwind? Being upwind of the GPS location would make the stage's final stopping point even further from the center of the deck.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/10/2016 11:17 PM
My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two upwind of the coordinates for touchdown.

I assume you mean downwind? Being upwind of the GPS location would make the stage's final stopping point even further from the center of the deck.

And this is why SpaceX would never be crazy enough to hire me; a goof like I made there would turn a successful landing into a kaboom.

Thanks for the correction.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/10/2016 11:55 PM
Over in the CRS-8 discussion thread, there's quite a bit of concern regarding the off-center location where the stage ended up after some downwind sideways motion on landing.

My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two updownwind of the coordinates for touchdown.

So my question here is, is there anything known about the ASDS control system that would preclude making such a simple adjustment in case of need? My guess as to how they could do it is simply change the ASDS's target coordinates by a yard ot two in the appropriate direction.

Doing the above just seems, to me, vastly simpler and cheaper than some of the proposed (in that thread and others) changes to the ASDS and the F9, to fix a problem that we don't, yet, know is actually a problem or not.

It would be really very easy to tweak the location reference in the Thustmaster's position system to do this, but I, for one, don't think they would do it for the following reasons:
1. A barge moving in any direction has significant momentum - it can't stop instantly - and presumably they want it stationary at the moment of impact (jumping onto a moving platform is more hazardous than jumping onto a stationary one - try it at home!).
2. If something went screwy with the comms link at the last second, the barge could start driving off underneath the landing stage, which would be a bad day all around.
3. The landing deck is big enough - it's simply not worth the risk.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/11/2016 12:02 AM
Also: some of the bounce might be velocity overshoot---getting to positive a few fractions of a meter per second up, instead of precisely to zero.  Engine shutdown transient might do that, it's notoriously difficult to predict the amount of thrust from the shutdown transient.

I can't see them eliminating the bounce entirely in anything other than calm seas - because it's impossible for anyone to predict the exact vertical position of the barge deck at the exact moment of touchdown whenever you have waves striking the hull.  It's a far easier engineering ask to put design constraints on the amount of bounce..
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: sewebster on 04/11/2016 12:49 AM
To me, it seems like if this "skidding off the deck" thing were a real problem, then it would be easiest to get a bigger boat. Unless they are currently at some particular width limit etc...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/11/2016 01:15 AM
To me, it seems like if this "skidding off the deck" thing were a real problem, then it would be easiest to get a bigger boat. Unless they are currently at some particular width limit etc...

Bigger deck cargo barges do exist (Marmac 400, for example) but 300' is the largest most folks need for the sort of transportation tasks these barges are used for and increasing size does increase handling and berthing costs.  This means there aren't so many to choose from, berthing options become limited and costs increase... so it's not an option they'll want to entertain unless they have to.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: robertross on 04/11/2016 01:49 AM
Also: some of the bounce might be velocity overshoot---getting to positive a few fractions of a meter per second up, instead of precisely to zero.  Engine shutdown transient might do that, it's notoriously difficult to predict the amount of thrust from the shutdown transient.

I can't see them eliminating the bounce entirely in anything other than calm seas - because it's impossible for anyone to predict the exact vertical position of the barge deck at the exact moment of touchdown whenever you have waves striking the hull.  It's a far easier engineering ask to put design constraints on the amount of bounce..

Maybe they can build and float a moving wall around the barge. It would be buoyant on the trip out, filled with water to partially submerge it, and that would become a circular wall around the barge to reduce wave impact during landings.

(They could also erect it on station & then fill it to submerge it, taking it off the barge via the support ship). There are a few ways to do this.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/11/2016 01:50 AM
Over in the CRS-8 discussion thread, there's quite a bit of concern regarding the off-center location where the stage ended up after some downwind sideways motion on landing.

My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two updownwind of the coordinates for touchdown.

So my question here is, is there anything known about the ASDS control system that would preclude making such a simple adjustment in case of need? My guess as to how they could do it is simply change the ASDS's target coordinates by a yard ot two in the appropriate direction.

Doing the above just seems, to me, vastly simpler and cheaper than some of the proposed (in that thread and others) changes to the ASDS and the F9, to fix a problem that we don't, yet, know is actually a problem or not.

It would be really very easy to tweak the location reference in the Thustmaster's position system to do this, but I, for one, don't think they would do it for the following reasons:
1. A barge moving in any direction has significant momentum - it can't stop instantly - and presumably they want it stationary at the moment of impact (jumping onto a moving platform is more hazardous than jumping onto a stationary one - try it at home!).
2. If something went screwy with the comms link at the last second, the barge could start driving off underneath the landing stage, which would be a bad day all around.
3. The landing deck is big enough - it's simply not worth the risk.

Regarding point #1, I didn't mean to imply any momentum. I was thinking something like this; ten minutes or so before launch, check wind speed an direction (I'm assuming the ASDS has an anemometer). If needed, command the ASDS to move a yard or two downwind. That (a movement of 6 feet or less) wouldn't take long, and it should be at a relative standstill again by launch.

As for trying it at home; I steadfastly refuse to try jumping on a moving ASDS at home - I live 7000 feet up a mountain, so getting an ASDS here would be a tad problematic.  :)

Points 2 and 3 are very valid IMHO. Of course, the only reason to try something like this is if there's a problem that needs fixing. My guess is that for the conditions we saw, there isn't one, but stronger winds might change the equation on that and thus might make trying something along these lines worthwhile. At least, that's my guess as to what they might have in their high winds contingency folder.   

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/11/2016 02:00 AM
Over in the CRS-8 discussion thread, there's quite a bit of concern regarding the off-center location where the stage ended up after some downwind sideways motion on landing.

My suggestion in that thread was that if SpaceX is concerned about this, they might address it by, for future windy landings, positioning the ASDS so it's centered a yard or two updownwind of the coordinates for touchdown.

So my question here is, is there anything known about the ASDS control system that would preclude making such a simple adjustment in case of need? My guess as to how they could do it is simply change the ASDS's target coordinates by a yard ot two in the appropriate direction.

Doing the above just seems, to me, vastly simpler and cheaper than some of the proposed (in that thread and others) changes to the ASDS and the F9, to fix a problem that we don't, yet, know is actually a problem or not.

It would be really very easy to tweak the location reference in the Thustmaster's position system to do this, but I, for one, don't think they would do it for the following reasons:
1. A barge moving in any direction has significant momentum - it can't stop instantly - and presumably they want it stationary at the moment of impact (jumping onto a moving platform is more hazardous than jumping onto a stationary one - try it at home!).
2. If something went screwy with the comms link at the last second, the barge could start driving off underneath the landing stage, which would be a bad day all around.
3. The landing deck is big enough - it's simply not worth the risk.

Regarding point #1, I didn't mean to imply any momentum. I was thinking something like this; ten minutes or so before launch, check wind speed an direction (I'm assuming the ASDS has an anemometer). If needed, command the ASDS to move a yard or two downwind. That (a movement of 6 feet or less) wouldn't take long, and it should be at a relative standstill again by launch.

They may well be doing this already.. but I guess we will never know unless someone for SpX pipes up here.

Points 2 and 3 are very valid IMHO. Of course, the only reason to try something like this is if there's a problem that needs fixing. My guess is that for the conditions we saw, there isn't one, but stronger winds might change the equation on that and thus might make trying something along these lines worthwhile. At least, that's my guess as to what they might have in their high winds contingency folder.

The entire barge-landing scenario is a series of engineering compromises.  Stronger winds result in larger seas which would quickly reach the point where a repeat of previous attempts is likely.  Now that they've had a success, my guess is they'll compare the environmental (wind/waves) conditions and telemetry present this time with previous attempts and determine what conditions are "go" and which aren't, so repositioning the barge due to wind conditions alone rapidly becomes unnecessary.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 04/11/2016 03:59 AM
Regarding point #1, I didn't mean to imply any momentum. I was thinking something like this; ten minutes or so before launch, check wind speed an direction (I'm assuming the ASDS has an anemometer). If needed, command the ASDS to move a yard or two downwind. That (a movement of 6 feet or less) wouldn't take long, and it should be at a relative standstill again by launch.
seems simpler to send the same wind data to the landing stage and have it adjust its aim to maximize the likelihood that during both the initial touch and any subsequent dancing all four feet are on or above the barge deck.

of course that requires a model (with things like sea state and wind velocity as input) for how the stage dances after landing. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 04:02 AM
Upthread(or maybe on the live thread) somebody brought up the concern of the sheer number of cycles that the structure within the stage will have to endure during this return trip - which raises the obvious question - is any structure that is able to handle the bending structural loads of flight and return more or less impervious to this type, magnitude, frequency and duration of repetitive cycling, full stop?  Or is this something worth digging into?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Elmar Moelzer on 04/11/2016 05:28 AM
Hmmmm, maybe they could just make some sort of retractable or unfold- able deck extension to give the stage just a few more yards to land on. Maybe with an inflatable floatation device of sorts to give it a tiny bit of extra stability underneath. Not sure if that would make sense.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 05:48 AM
Hmmmm, maybe they could just make some sort of retractable or unfold- able deck extension to give the stage just a few more yards to land on. Maybe with an inflatable floatation device of sorts to give it a tiny bit of extra stability underneath. Not sure if that would make sense.

Let's not forget that any extendable/modular extensions to the deck size will also require something on the barge that is able to transport the stage back to center so that they can then be detached(re-sunk, whatever)/retracted before the trip home.

Edit - On to a totally different topic from earlier in the thread, but since I looked it up - As far as rocking induced by an off-center landing, a falcon 9 S1 dry mass is estimated to be less, but in the same ballpark as the standard maximum load for a single full-size cargo container.  Just for visualization/reference.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Hankelow8 on 04/11/2016 08:26 AM
At Elon's pass conference after the CRS-8 launch,he commented that they are expecting to be able to launch every 2/3 weeks.

I think they will have to build an extra drone ship to cover the possibility of a hard landing, especially when attempting the more extreme conditions. The repair times and turnaround to be ready for the next launch would be very difficult to meet, if the next launch was just a couple of weeks way.

The cost of building an extra drone ship to be on standby for such a situation has to be cost effective. One saved Falcon first stage  alone could be worth the cost of a standby drone ship.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/11/2016 08:45 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jarnis on 04/11/2016 09:44 AM

What, exactly do they need to change? Accuracy? Why?

Yes, gotta get it closer to center so I win the landing bingo next time. This one was way to the side and totally fouled my chances :(

 :P
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: miki on 04/11/2016 10:08 AM
It's interesting to note that on every ASDS landing, landing legs are parallel to the sides of the deck. If they weren't one leg could end up over the edge and the stage would tip over. They thought of everything. Great job...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: FutureSpaceTourist on 04/11/2016 10:22 AM
seems simpler to send the same wind data to the landing stage

But I thought the stage has no mechanism to receive such data. Isn't the range safety termination signal (which I believe is completely separate from the rest of the avionics) the only thing the stage can receive, as the stage is fully autonomous?

Ok so something could be added to the stage but I'm really not sure that's warranted. If any adjustment is needed I think it's simpler to get the ASDS to do it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: The Amazing Catstronaut on 04/11/2016 10:30 AM
I feel the more we complicate the guidance system the greater the danger of feedback loops. Accuracy has never really been the primary problem with ASDS, it's always been a propulsion related issue, a control surfaces issue or an issue with the landing legs which have caused stages to avoid ending up where we want them. Each time those issues get iterated out (or, at least, we haven't seen them again).

The bounce this time was due to windsheer, not guidance - and hey, they recovered it.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 10:53 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

"Extreme conditions" is highly debatable.  Estimates here on this very forum bound the winds to under 25kn(look at how fast the exhaust cloud moves).  Nothing terribly out of the ordinary.  And in any case, if it's a barge landing, they have to work with what the conditions are or delay the launch, it's not like there's much wiggle room.

That said, it wouldn't surprise me if they have done all of the modelling and everything will work great no matter what, even if a stage ends up bouncing off of the railing.  It also wouldn't surprise me if they haven't.

Put simply, the problem DOES exist.  This stage came too close for comfort to the edge for such a more or less nominal mission(let's not forget that they DID actually do a boost-back burn, just not a full one - this mission was as "controlled" as any other mission will be);  If they expect to successfully launch ~66% of their missions on-time and then recover them with barges going forward, then something will need to change.  I have full confidence in them to make the appropriate adjustments, though.  And my personal WAG is that they won't need a larger barge, or any type of uplink system between the barge and the stage, or to move the barge 10 minutes before landing - it'll just be updates to the software on the stage itself. (I understand where the "move the barge 10 minutes before landing" idea comes from, but if you're going to invest money in that accuracy, obviously you want to invest it in the stage.  It's just better to have the stage land on target from a system level, that's obviously where you want to put your effort - do you plan on having mobile landing platforms on Mars that can move 10 minutes before you land an MCT?  Full accuracy is pretty much on the critical path)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jet Black on 04/11/2016 10:59 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

indeed, and also how would they do it?  Those 50mph winds are fairly close to the surface, you can't see them and there are changes in wind speed all the way up. What they've achieved is tremendous, but it also shows the massive challenges they face.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/11/2016 11:39 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

"Extreme conditions" is highly debatable.  Estimates here on this very forum bound the winds to under 25kn(look at how fast the exhaust cloud moves).  Nothing terribly out of the ordinary.  And in any case, if it's a barge landing, they have to work with what the conditions are or delay the launch, it's not like there's much wiggle room.

That said, it wouldn't surprise me if they have done all of the modelling and everything will work great no matter what, even if a stage ends up bouncing off of the railing.  It also wouldn't surprise me if they haven't.

Put simply, the problem DOES exist.  This stage came too close for comfort to the edge for such a more or less nominal mission(let's not forget that they DID actually do a boost-back burn, just not a full one - this mission was as "controlled" as any other mission will be);  If they expect to successfully launch ~66% of their missions on-time and then recover them with barges going forward, then something will need to change.  I have full confidence in them to make the appropriate adjustments, though.  And my personal WAG is that they won't need a larger barge, or any type of uplink system between the barge and the stage, or to move the barge 10 minutes before landing - it'll just be updates to the software on the stage itself. (I understand where the "move the barge 10 minutes before landing" idea comes from, but if you're going to invest money in that accuracy, obviously you want to invest it in the stage.  It's just better to have the stage land on target from a system level, that's obviously where you want to put your effort)

Er, I not sure anyone outside of SpaceX is in a position to say there is even a problem here. My opinion, no there isn't one, and nothing written above seems to say otherwise.

25knts of wind is actually pretty windy. It's at the high end of a Force 6, which is bordering on gale force. That classes as pretty damn high. And that, I suspect is a conservative guess at speed, at sea level, speeds further up will be much higher.

The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.

So, since this came in within 5m accuracy wise, how do you propose a 'software fix' is going to make it more accurate? The barge is unable to tell the stage the wind conditions, and since they vary rapidly anyway, this would appear to be irrelevant.

I'm still not seeing any sort of problem here.

EDIT: taken another look at the video. Wave state is pretty indicative of force 6, with some streaks possibly indicating close to a 7. Looking closely at the way the stage moves' as it touches down and the angle of the barge, indicated it landing first on the right leg (as seen from video) on a slightly sloping deck, This caused it to hop slightly to the left, which is pretty much what you would expect when coming down on a sloping deck. And I'm pretty damn sure there's nothing you can do about a sloping deck, except avoid flying when the sea state means it's likely to be too angled.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 11:49 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

"Extreme conditions" is highly debatable.  Estimates here on this very forum bound the winds to under 25kn(look at how fast the exhaust cloud moves).  Nothing terribly out of the ordinary.  And in any case, if it's a barge landing, they have to work with what the conditions are or delay the launch, it's not like there's much wiggle room.

That said, it wouldn't surprise me if they have done all of the modelling and everything will work great no matter what, even if a stage ends up bouncing off of the railing.  It also wouldn't surprise me if they haven't.

Put simply, the problem DOES exist.  This stage came too close for comfort to the edge for such a more or less nominal mission(let's not forget that they DID actually do a boost-back burn, just not a full one - this mission was as "controlled" as any other mission will be);  If they expect to successfully launch ~66% of their missions on-time and then recover them with barges going forward, then something will need to change.  I have full confidence in them to make the appropriate adjustments, though.  And my personal WAG is that they won't need a larger barge, or any type of uplink system between the barge and the stage, or to move the barge 10 minutes before landing - it'll just be updates to the software on the stage itself. (I understand where the "move the barge 10 minutes before landing" idea comes from, but if you're going to invest money in that accuracy, obviously you want to invest it in the stage.  It's just better to have the stage land on target from a system level, that's obviously where you want to put your effort)

Er, I not sure anyone outside of SpaceX is in a position to say there is even a problem here. My opinion, no there isn't one, and nothing written above seems to say otherwise.

25knts of wind is actually pretty windy. It's at the high end of a Force 6, which is bordering on gale force. That classes as pretty damn high. And that, I suspect is a conservative guess at speed, at sea level, speeds further up will be much higher.

The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.

So, since this came in within 5m accuracy wise, how do you propose a 'software fix' is going to make it more accurate? The barge is unable to tell the stage the wind conditions, and since they vary rapidly anyway, this would appear to be irrelevant.

I'm still not seeing any sort of problem here.

It was obviously aware of the wind conditions because it came in at a higher angle than usual.  Simple refinements to the model given the high quality telemetry from this landing and others in the future.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/11/2016 11:54 AM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

"Extreme conditions" is highly debatable.  Estimates here on this very forum bound the winds to under 25kn(look at how fast the exhaust cloud moves).  Nothing terribly out of the ordinary.  And in any case, if it's a barge landing, they have to work with what the conditions are or delay the launch, it's not like there's much wiggle room.

That said, it wouldn't surprise me if they have done all of the modelling and everything will work great no matter what, even if a stage ends up bouncing off of the railing.  It also wouldn't surprise me if they haven't.

Put simply, the problem DOES exist.  This stage came too close for comfort to the edge for such a more or less nominal mission(let's not forget that they DID actually do a boost-back burn, just not a full one - this mission was as "controlled" as any other mission will be);  If they expect to successfully launch ~66% of their missions on-time and then recover them with barges going forward, then something will need to change.  I have full confidence in them to make the appropriate adjustments, though.  And my personal WAG is that they won't need a larger barge, or any type of uplink system between the barge and the stage, or to move the barge 10 minutes before landing - it'll just be updates to the software on the stage itself. (I understand where the "move the barge 10 minutes before landing" idea comes from, but if you're going to invest money in that accuracy, obviously you want to invest it in the stage.  It's just better to have the stage land on target from a system level, that's obviously where you want to put your effort)

Er, I not sure anyone outside of SpaceX is in a position to say there is even a problem here. My opinion, no there isn't one, and nothing written above seems to say otherwise.

25knts of wind is actually pretty windy. It's at the high end of a Force 6, which is bordering on gale force. That classes as pretty damn high. And that, I suspect is a conservative guess at speed, at sea level, speeds further up will be much higher.

The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.

So, since this came in within 5m accuracy wise, how do you propose a 'software fix' is going to make it more accurate? The barge is unable to tell the stage the wind conditions, and since they vary rapidly anyway, this would appear to be irrelevant.

I'm still not seeing any sort of problem here.

It was obviously aware of the wind conditions because it came in at a higher angle than usual.  Simple refinements to the model given the high quality telemetry from this landing and others in the future.

It knows the wind conditions from it's change in GPS positioning, but that doesn't indicate what the conditions are like close to the surface. And as we have been told multiple times, there is apparently NO communications from the barge to the stage, so there's nothing being sent to tell it of the conditions on the surface.

They MIGHT preprogram approximate conditions in to the stage before flight, to give it a hint on how to deal with them, but on  the whole it seems like a closed loop system that knows where it is and where it has to go, and compensates for conditions on the way down.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 12:03 PM
I understand that it only has it's own GPS and/or intertial reference to work with.

I've written quite a few closed-loop systems in my time, and I refuse to believe that they can't just make it land on target rather than hopping and skidding, now that they know that can happen and have high quality telemetry of exactly that happening.  At least for this case - They may also need high quality telemetry from an actual ~50MPH winds landing to refine the closed-loop code to nail that landing as well.

Edit - I can't find the exact abort criteria for this mission, but would just like to point out that going from memory, 25kn is either below or close to typical green launch criteria for the stage itself.  Characterizing that as "extreme conditions" is a bit of a stretch if you want to be realistic about launching 66% of your missions on-time, because off-shore landing conditions seem to be characteristically worse than launch conditions, at least so far.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Citabria on 04/11/2016 01:01 PM
As pilot of a light plane, I am the closed-loop system. A smooth landing requires bringing 6 parameters to zero all at the same instant: height; vertical speed; distance from centerline; sideways speed; yaw; and yaw rate. Doing that in variable, gusty winds is quite a challenge. If any of those has to be sacrificed for the sake of the others, it's probably distance from centerline, within limits of runway width.

Falcon has 12 to zero simultaneously:  height; vertical speed; distance from center in two axes; sideways speed in two axes; and pitch, yaw, and roll, plus their rates. That's why it's so impressive when it works, even if a few meters off center.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 01:05 PM
As pilot of a light plane, I am the closed-loop system. A smooth landing requires bringing 6 parameters to zero all at the same instant: height; vertical speed; distance from centerline; sideways speed; yaw; and yaw rate. Doing that in variable, gusty winds is quite a challenge. If any of those has to be sacrificed for the sake of the others, it's probably distance from centerline, within limits of runway width.

Falcon has 12 to zero simultaneously:  height; vertical speed; distance from center in two axes; sideways speed in two axes; and pitch, yaw, and roll, plus their rates. That's why it's so impressive when it works, even if a few meters off center.

There does, however, exist closed-loop software that can do things like land an X-47B(which is an aerodynamically unstable airframe in it's own right) on an aircraft carrier in a comms contingency situation.  I have some insight into that particular software.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/11/2016 01:16 PM
Edit - I can't find the exact abort criteria for this mission, but would just like to point out that going from memory, 25kn is either below or close to typical green launch criteria for the stage itself.  Characterizing that as "extreme conditions" is a bit of a stretch if you want to be realistic about launching 66% of your missions on-time, because off-shore landing conditions seem to be characteristically worse than launch conditions, at least so far.

For past ASDS landings, the criterion was 20 kts wind max. For the OG2 landing at LZ-1, it was 50 mph wind max.

Judging from the well-damped pitch motion of the stage during the landing, staying pitched into the wind then righting itself pefectly with no overshoot, it looks like they've got the attitude control loop dialed in perfectly for wind compensation, and I wouldn't be surprised if a limit higher than 20 kts is now the "new normal" for the stage landing limit.

But winds a bit above that are going to make ASDS grappling/towing dangerous, with high waves as we saw during the "storm" launch that banged up the ASDS.

So we may have reached the point where the limiting factor for landing is no longer the effect of winds on the stage autopilot, but the sea conditions caused by high winds and the resulting operational difficulties.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 01:21 PM
Edit - I can't find the exact abort criteria for this mission, but would just like to point out that going from memory, 25kn is either below or close to typical green launch criteria for the stage itself.  Characterizing that as "extreme conditions" is a bit of a stretch if you want to be realistic about launching 66% of your missions on-time, because off-shore landing conditions seem to be characteristically worse than launch conditions, at least so far.

For past ASDS landings, the criterion was 20 kts wind max. For the OG2 landing at LZ-1, it was 50 mph wind max.

Judging from the well-damped pitch motion of the stage during the landing, staying pitched into the wind then righting itself pefectly with no overshoot, it looks like they've got the attitude control loop dialed in perfectly for wind compensation, and I wouldn't be surprised if a limit higher than 20 kts is now the "new normal" for the stage landing limit.

But winds a bit above that are going to make ASDS grappling/towing dangerous, with high waves as we saw during the "storm" launch that banged up the ASDS.

So we may have reached the point where the limiting factor for landing is no longer the effect of winds on the stage autopilot, but the sea conditions caused by high winds and the resulting operational difficulties.

Out of curiosity, what makes you think it wouldn't skid twice as far in 50MPH winds?  Not trying to be confrontational at all.  To me it looks like the system didn't take any translation after MECO(?) into account at all despite doing admirably well up to that point.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/11/2016 01:43 PM
Quote
Out of curiosity, what makes you think it wouldn't skid twice as far in 50MPH winds?  Not trying to be confrontational at all.  To me it looks like the system didn't take any translation after MECO(?) into account at all despite doing admirably well up to that point.

The stage landed successfully despite the skidding, and I guess we could quibble about whether that makes the wind compensation "perfect," which I assume is your point. Could they refine the control loop even further to eliminate skidding? Maybe.

But my point was that barge landings in 50 mph winds (or therabouts) are not even going to be possible because of the operational difficulties. So why bother worrying about more skidding at 50 mph? And 50 mph winds at LZ-1 at the Cape will violate LCC's and cause a scrub anyway.

So if the autpilot's wind compensation is not yet "perfect," it's quite good enough, and now the limiting factors are probably ASDS ops in high winds, and launch wind constraints.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/11/2016 02:17 PM
I think the skid was more to do with the 'right' leg landing before the others, making it momentarily susceptible to wind pressure, with only one leg down. As soon as all legs were on deck it stopped moving. *

There's not a lot you can do about that since the barge orientation is unpredictable/unfollowable, ie you cannot reorient the stage angle to match the barge.


* This is presumably why there is an upper limit of deck angle - the legs can only absorb so much, so need to get all legs down before the absorption capacity of any one leg is exceeded.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/11/2016 02:37 PM
There's a control inversion issue once one leg is touching.  That's actually probably the cause of the bump.  Solution is either to explicitly model the control inversion in software, or else just come down a little "harder" to minimize it.  The legs can probably take a bit harder landing.  My opinion is still that we are seeing a little bounce due to the shutdown transient, and that can be modelled away.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/11/2016 03:03 PM
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/11/2016 03:05 PM
The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.


It is highly relevant.
The stage would have been, in effect, ballasted by the additional remaining propellants. This would ease up the constraints on the final burn by lowering the thrust to weight ratio and giving the engine and guidance system more leeway to set down safely.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/11/2016 03:42 PM
The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.


It is highly relevant.
The stage would have been, in effect, ballasted by the additional remaining propellants. This would ease up the constraints on the final burn by lowering the thrust to weight ratio and giving the engine and guidance system more leeway to set down safely.

Make no difference. Stage knows how much fuel it has, compensates. There is no leeway. There is simply stage weight vs engine thrust.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Comga on 04/11/2016 04:17 PM
Why are people trying to solve a problem that doesn't appear to exist?

It landed, in fairly extreme conditions.

What, exactly do they need to change? Accuracy? Why?

I agree, but let's add some numbers.
Here is an image from the CRS-8 Barge Bingo thread. (http://forum.nasaspaceflight.com/index.php?topic=39977.msg1513562#msg1513562)
Scaling from a 53 meter width of the ASDS, the legs spread across ~16.5 m.
If it comes down at the center, and square to the deck, there are 18 m left on each side.
The CRS-8 first stage came to rest with about 9.5 m from the rail.
That means it used up about half the margin in a 23 knot wind. 
We can (probably can't resist the urge to) debate whether or not that qualifies as "extreme" but twice that would definitely be extreme.
They will continue to refine the control system.
It remains hard to make the case that a more complex system is required.

edit: OxCartMark:  "I feel your pain" but it's hopeless.  I will not make the excuse that people discussing adding windage to the ASDS location makes this relevant to the thread title.
In which thread would you have us discuss landing dynamics?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/11/2016 04:23 PM
The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.


It is highly relevant.
The stage would have been, in effect, ballasted by the additional remaining propellants. This would ease up the constraints on the final burn by lowering the thrust to weight ratio and giving the engine and guidance system more leeway to set down safely.

Make no difference. Stage knows how much fuel it has, compensates. There is no leeway. There is simply stage weight vs engine thrust.

On SES-9, it wasn't even known whether the stage would structurally survive re-entry, much less with all of it's critical components intact.  It's critical components WEREN'T intact, and it under-thrusted.  Could this be because of physical deformation(or full-on detachment) of an expansion nozzle?  SpaceX will probably never tell us.

Anyway, I mentioned that it was a normal profile for that reason.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/11/2016 04:36 PM
The fact this was a mission with plenty of fuel is completely irrelevant. It makes no difference to the end result whether this was an easy boostback or a hard one, the accuracy has been shown to be there in all the attempts so far.


It is highly relevant.
The stage would have been, in effect, ballasted by the additional remaining propellants. This would ease up the constraints on the final burn by lowering the thrust to weight ratio and giving the engine and guidance system more leeway to set down safely.

Make no difference. Stage knows how much fuel it has, compensates. There is no leeway. There is simply stage weight vs engine thrust.

In an ideal world, yes. But in that ideal world there are no unknown thrust transients at startup and shutdown, there are no variable crosswinds, or slight inaccuracies in positioning data.
Fact is, a ballasted stage is going to be easier to land than an empty one. Look at the early GH flights- a much heavier vehicle that could actually hover. Of course that is going to be easier to fly, you have a wider range of control authority.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/12/2016 06:14 AM
Shoes.  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/12/2016 06:38 AM
Shoes.  :)

The position of those jack-stands makes the NSF Bingo winner beyond doubt.

And these are the shoes..  more like sandals, really :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: ClayJar on 04/12/2016 01:53 PM
Even looking at the little tiny people on deck, it's a bit hard to get a true feel of how massive everything is when you have an ASDS with a Falcon 9 first stage landed on it.  To try to put it in a little perspective, perhaps someone should post a photo of what an ASDS looks like close up...

Okay, maybe that doesn't really help.  ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/12/2016 03:18 PM
Port Canaveral VHF traffic was reporting an overturned kayak somewhere out there...glad it wasn't you.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 04/12/2016 04:58 PM
@ClayJar this is new photo?  :D

If you happen to take photos of this barge, it would be usefull for my scale model. Closer the better  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/12/2016 10:35 PM
SpaceX now has (or will soon have), for the first time, hard data on what a successful landing does to an ASDS.

My guess is there might be a few very minor changes (both physical and procedural) to the ASDS as a result - the kind of minor fine-tuning that can only come with practice.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/13/2016 03:32 AM
SpaceX now has (or will soon have), for the first time, hard data on what a successful landing does to an ASDS.

My guess is there might be a few very minor changes (both physical and procedural) to the ASDS as a result - the kind of minor fine-tuning that can only come with practice.
Like a giant hand or lobster claw that grabs the stage to keep it from toppling over or fences that come up from all sides or a swirling lassoo or welders on the tips of the landing feet (no, neodymium magnets!) or maybe super huge airbags, that's what I think the changes will be from what I read earlier in the ASDS threads and elsewhere.  Or maybe stick some hydrofoils under the ASDS so that it can come back quicker.

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.

It seems like a long time back now that we were rooting for the barge fixers to get it done so that we had a hope of catching the CRS-8 core.  Just a few days back but easy to forget with the recent happy events.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 04/13/2016 04:05 AM
 I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/13/2016 05:44 AM
SpaceX now has (or will soon have), for the first time, hard data on what a successful landing does to an ASDS.

My guess is there might be a few very minor changes (both physical and procedural) to the ASDS as a result - the kind of minor fine-tuning that can only come with practice.
Like a giant hand or lobster claw that grabs the stage to keep it from toppling over or fences that come up from all sides or a swirling lassoo or welders on the tips of the landing feet (no, neodymium magnets!) or maybe super huge airbags, that's what I think the changes will be from what I read earlier in the ASDS threads and elsewhere.  Or maybe stick some hydrofoils under the ASDS so that it can come back quicker.

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.

It seems like a long time back now that we were rooting for the barge fixers to get it done so that we had a hope of catching the CRS-8 core.  Just a few days back but easy to forget with the recent happy events.

Hey, you forgot the Merlins, so the ASDS can fly back. :)

I do agree that they would wait until one or more landings to see what's really needed before spending a lot of money.
My wild guesses as to the short-term upgrades would be things like considering a panable camera for having a remote look-around at a landed stage (especially in cases of difficulty), upgrading the nav lights with metal instead of plastic covers if there was heat damage, that sort of thing (if deemed needful, of course). One other upgrade I'm looking for *IF* they are troubled by wind-caused movement of a landing F9 downwind; an anemometer (which I'm rather surprised the ASDS does not have already). And... given the need to get personnel (who might not be used to boats) on board the ASDS, as we saw at the harbor mouth, perhaps a rope ladder.     

Not exactly big ticket items, but they are the kind of minor tweaking I'll be keeping an eye out for in the short term. My basis for this is having seen many people make similar small usability tweaks after acquiring a new house, yacht, fishing trawler, 18 wheeler, etc. They see what's needed in practice, then start making small improvements. (and of course, I may be comparing apples to oranges here and be totally wrong).

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/13/2016 06:01 AM
Folly - Not for serious comment.  I can think of as many reasons this is a bad idea as you can, probably more.




Ladies and gentlemen, I give you the Falcon Heavy Spaceport Drone Ship;
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: darkenfast on 04/13/2016 06:10 AM
Even looking at the little tiny people on deck, it's a bit hard to get a true feel of how massive everything is when you have an ASDS with a Falcon 9 first stage landed on it.  To try to put it in a little perspective, perhaps someone should post a photo of what an ASDS looks like close up...

Okay, maybe that doesn't really help.  ;D
"It's no use, Mr. Bond.  We were watching you and your little cockleshell the entire time!"
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/13/2016 11:30 AM
I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.

I think whizzing along at 25knots with a F9 on top would be rather a foolish endeavour. It looks like they came back slower than they could have done anyway. Speed doesn't appear to be an issue.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/13/2016 12:19 PM
It might help, though, to get the ASDS out on station a bit quicker.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/13/2016 01:02 PM
It might help, though, to get the ASDS out on station a bit quicker.

Why would they need that? I suspect it would be cheaper and more convenient to have multiple converted barges that have a custom made catamaran hulled landing pad. (since barges seem to be fast enough for the return trip already)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 04/13/2016 01:41 PM
I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.

I think whizzing along at 25knots with a F9 on top would be rather a foolish endeavour. It looks like they came back slower than they could have done anyway. Speed doesn't appear to be an issue.

Oh come on, sporty!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Nomadd on 04/13/2016 04:05 PM
I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.

I think whizzing along at 25knots with a F9 on top would be rather a foolish endeavour. It looks like they came back slower than they could have done anyway. Speed doesn't appear to be an issue.
They didn't come back slow because they didn't care about time. They came back slow because it was a little boat towing a big barge. Empty barges tend to lift up and slam down while under tow even at low speed and mild seas. They're not made for a gentle ride. A high speed cat or trimaran type hull would be a much more stable, able to go around weather and probably increase success rate from it's greater stability during landing and greater availability from being able to get places faster. Once they get going, a single lost stage would be considerable money.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: muazcatalyst on 04/13/2016 04:44 PM
Once they get going, a single lost stage would be considerable money.

What do you mean by this phrase?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JamesH65 on 04/13/2016 06:19 PM
I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.

I think whizzing along at 25knots with a F9 on top would be rather a foolish endeavour. It looks like they came back slower than they could have done anyway. Speed doesn't appear to be an issue.
They didn't come back slow because they didn't care about time. They came back slow because it was a little boat towing a big barge. Empty barges tend to lift up and slam down while under tow even at low speed and mild seas. They're not made for a gentle ride. A high speed cat or trimaran type hull would be a much more stable, able to go around weather and probably increase success rate from it's greater stability during landing and greater availability from being able to get places faster. Once they get going, a single lost stage would be considerable money.

Sorry, my post read wrong. I meant that the barge could return faster, but they didn't because they have an F9 sitting on it, not that they came in slow because they were not in a hurry.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Wolfram66 on 04/13/2016 06:59 PM
SpaceX could have Austral build a larger version of the Spearhead-class expeditionary fast transport ships.
or like the Sea Slice demonstrator, but utilizing an updated version of Hughes Surge compensator.

The Surge Compensator worked a lot like a video camera steady cam system.

see this historical document to see how it worked for Hughes Glomar Explorer/ CIA USSR sub retrieval ship

http://www.maritime.org/doc/glomarexplorer/index.htm (http://www.maritime.org/doc/glomarexplorer/index.htm)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/13/2016 07:18 PM
I'm still waiting for them to contract Austal to make a 400 foot cat. Much more stable and 25 knots in rough seas.

SpaceX could have Austral build a larger version of the Spearhead-class expeditionary fast transport ships.
or like the Sea Slice demonstrator, but utilizing an updated version of Hughes Surge compensator.
...
My only concern about these (besides initial investment) is that the beauty of the barge is it's so easy to fix.  Outboard motors, equipment containers, a flat deck and no cabin.  Rockets may not be LEGO elements, but the current ASDS is.

But maybe once they get all the kinks worked out, who knows.  It would be super cool.  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 04/13/2016 07:46 PM
SpaceX now has (or will soon have), for the first time, hard data on what a successful landing does to an ASDS.

My guess is there might be a few very minor changes (both physical and procedural) to the ASDS as a result - the kind of minor fine-tuning that can only come with practice.
Like a giant hand or lobster claw that grabs the stage to keep it from toppling over or fences that come up from all sides or a swirling lassoo or welders on the tips of the landing feet (no, neodymium magnets!) or maybe super huge airbags, that's what I think the changes will be from what I read earlier in the ASDS threads and elsewhere.  Or maybe stick some hydrofoils under the ASDS so that it can come back quicker.

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.

It seems like a long time back now that we were rooting for the barge fixers to get it done so that we had a hope of catching the CRS-8 core.  Just a few days back but easy to forget with the recent happy events.

Don't forget the ball pit!  ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/13/2016 07:54 PM

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.


No, not really.  Most of the landings are going back to land and not barges.  Ocean landings will be an exception and not the rule.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: KSHavre on 04/13/2016 08:14 PM

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.


No, not really.  Most of the landings are going back to land and not barges.  Ocean landings will be an exception and not the rule.

According the Elon in the post launch press conference, about half will be at sea; anything more than LEO...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AnalogMan on 04/13/2016 11:59 PM

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.


No, not really.  Most of the landings are going back to land and not barges.  Ocean landings will be an exception and not the rule.

According the Elon in the post launch press conference, about half will be at sea; anything more than LEO...

The fuller answer to how often SpaceX planned to do ground landings was:

"Right now we expect about half our landings to be ground and then half to be ocean landings.  And then over time as we refine the performance of the rocket and it can improve the ... just all the elements of flight ... and its amazing how a few percent improvement here and there sorta adds up and then you are able achieve enough margin to bring it back all the way to land.

"So we're hopeful that in the long run we'll move from say half of our missions being ocean landing to maybe a third of them or a quarter - 'cause it certainly is a lot easier to re-fly the rocket if comes back to land."


Can be found at at 26:00 in the video of the press conference posted here:
http://forum.nasaspaceflight.com/index.php?topic=39537.msg1513775#msg1513775 (http://forum.nasaspaceflight.com/index.php?topic=39537.msg1513775#msg1513775)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/14/2016 01:09 AM

More seriously, I think they have probably known for months what their likely progression path is and wanted to see a landing to confirm that they were on the right path before investing the money.  Short of the longer term refuel and flyback upgrades I think most of the revisions we see will be in the areas of capacity and speed.  More ASDSs , possibly 3 ASDS (per launch site? hmm, nah) to extend FH capacity, or just 2 to cover transit times and occasional kaboom fixup, and some TBD way to get the landed stage back to shore.


No, not really.  Most of the landings are going back to land and not barges.  Ocean landings will be an exception and not the rule.

According the Elon in the post launch press conference, about half will be at sea; anything more than LEO...

The fuller answer to how often SpaceX planned to do ground landings was:

"Right now we expect about half our landings to be ground and then half to be ocean landings.  And then over time as we refine the performance of the rocket and it can improve the ... just all the elements of flight ... and its amazing how a few percent improvement here and there sorta adds up and then you are able achieve enough margin to bring it back all the way to land.

"So we're hopeful that in the long run we'll move from say half of our missions being ocean landing to maybe a third of them or a quarter - 'cause it certainly is a lot easier to re-fly the rocket if comes back to land."


Can be found at at 26:00 in the video of the press conference posted here:
http://forum.nasaspaceflight.com/index.php?topic=39537.msg1513775#msg1513775 (http://forum.nasaspaceflight.com/index.php?topic=39537.msg1513775#msg1513775)

A shift in a larger proportion of landings by SpaceX flights back to the launch site is unlikely IMO. Since the Satcom operators will just increase their birds' mass to take advantage of any excess performance from the SpaceX launchers.


But to get more on topic. The current ASDS barge conversions will have to be replaced with something bigger and more speedy eventually. Recovering the FH center core from further out in the ocean with the current set up will take at least 48 hours each on the outbound leg  and return leg.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/14/2016 02:27 AM
They didn't come back slow because they didn't care about time. They came back slow because it was a little boat towing a big barge.

Sorry, my post read wrong. I meant that the barge could return faster, but they didn't because they have an F9 sitting on it, not that they came in slow because they were not in a hurry.


I think it was sometime after I read mvpel's post below (from the launch viewing thread) that I theorized w/o saying so earlier, I think they were stalling, instructed to time their arrival when huge crowds wouldn't be as likely to overrun the area again so soon. Even the Space Coast probably has their limits.


A record-territory crowd yesterday at the visitor center in excess of 14,000 I heard from the KSC director, and stuffed causeways and beach parking all up and down the Cape I heard from someone ahead of me in line at the grocery store who got stuck in mind-boggling traffic jams.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/14/2016 03:43 AM
But to get more on topic. The current ASDS barge conversions will have to be replaced with something bigger and more speedy eventually. Recovering the FH center core from further out in the ocean with the current set up will take at least 48 hours each on the outbound leg  and return leg.

In the approximate direction of on-topic.. I assume you're forgetting SpX's stated original plan was to prep the stages out there and fly them back Grasshopper (would that be Sea-hopper?) -style??

The ASDS can then, potentially, wait around out there for the next one.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/14/2016 09:18 AM
But to get more on topic. The current ASDS barge conversions will have to be replaced with something bigger and more speedy eventually. Recovering the FH center core from further out in the ocean with the current set up will take at least 48 hours each on the outbound leg  and return leg.

In the approximate direction of on-topic.. I assume you're forgetting SpX's stated original plan was to prep the stages out there and fly them back Grasshopper (would that be Sea-hopper?) -style??

The ASDS can then, potentially, wait around out there for the next one.

No I didn't forget the hop back to launch site idea.

The current ASDS is just too small to act as launch platform or to be on station in the middle of the Atlantic for weeks at a time. IMO

Something like a 10000 tons Landing ship dock variant with flat top armored landing deck and well deck capable of 15 knot cursing cruising speed.


edit: auto-correct, sigh.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/14/2016 02:07 PM
I think SpaceX has found their "barge with stuff bolted on" model working well so far.  I wouldn't be surprised if the first "hop back" attempts used another barge fitted as a launch platform, with integrated transporter erector and tankage.  As we're seeing with the dockside work on the CRS-8 stage, though, there's currently a lot of involved crane and cherry-picker work involved in recycling a stage (although maybe some of the tank flushes and leg work wouldn't be needed if it were to hop back?).  I suspect we'd see some sort of automated handling ground-side first, and then that same automated handler/Transporter/Erector would show up integrated with a barge.

Best to keep launch and landing barges separate, at least for the initial experimentation phase.  IMO.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: starhawk92 on 04/14/2016 05:12 PM
But to get more on topic. The current ASDS barge conversions will have to be replaced with something bigger and more speedy eventually. Recovering the FH center core from further out in the ocean with the current set up will take at least 48 hours each on the outbound leg  and return leg.

In the approximate direction of on-topic.. I assume you're forgetting SpX's stated original plan was to prep the stages out there and fly them back Grasshopper (would that be Sea-hopper?) -style??

The ASDS can then, potentially, wait around out there for the next one.

No I didn't forget the hop back to launch site idea.

The current ASDS is just too small to act as launch platform or to be on station in the middle of the Atlantic for weeks at a time. IMO

Something like a 10000 tons Landing ship dock variant with flat top armored landing deck and well deck capable of 15 knot cursing speed.

I have an idea which should fit the bill!  She's an oldie but a beauty!!
http://www.nimitz.navy.mil/ (http://www.nimitz.navy.mil/)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/14/2016 11:45 PM
I think SpaceX has found their "barge with stuff bolted on" model working well so far.  I wouldn't be surprised if the first "hop back" attempts used another barge fitted as a launch platform, with integrated transporter erector and tankage.  As we're seeing with the dockside work on the CRS-8 stage, though, there's currently a lot of involved crane and cherry-picker work involved in recycling a stage (although maybe some of the tank flushes and leg work wouldn't be needed if it were to hop back?).  I suspect we'd see some sort of automated handling ground-side first, and then that same automated handler/Transporter/Erector would show up integrated with a barge.

Best to keep launch and landing barges separate, at least for the initial experimentation phase.  IMO.

There is the small matter of transferring the F9 core from the landing barge to the launching barge in the middle of the Ocean. ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/15/2016 12:36 AM
Cranes are routinely fitted to barges.  Now, I'm sure the actual transfer at sea would be anything but routine.  But I think it would be worthwhile to keep the tall crane-y bits well away from the landing barge during the hoverslam.  Or not---maybe the precision is such that they could stick a crane in one corner of the landing barge and not worry.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jakusb on 04/15/2016 06:54 AM
But to get more on topic. The current ASDS barge conversions will have to be replaced with something bigger and more speedy eventually. Recovering the FH center core from further out in the ocean with the current set up will take at least 48 hours each on the outbound leg  and return leg.

In the approximate direction of on-topic.. I assume you're forgetting SpX's stated original plan was to prep the stages out there and fly them back Grasshopper (would that be Sea-hopper?) -style??

The ASDS can then, potentially, wait around out there for the next one.

No I didn't forget the hop back to launch site idea.

The current ASDS is just too small to act as launch platform or to be on station in the middle of the Atlantic for weeks at a time. IMO

Something like a 10000 tons Landing ship dock variant with flat top armored landing deck and well deck capable of 15 knot cursing speed.

I guess this would be a relative low speed launch an transfer trajectory. Would it not be possible to simply launch from its own legs it landed on? Like grasshopper? One engine, low altitude.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/15/2016 07:12 AM

There is the small matter of transferring the F9 core from the landing barge to the launching barge in the middle of the Ocean. ::)

Exactly!
Crane mounted barges are used in harbours for construction work etc. The relative motion between two vessels at sea would make offloading something the size of a F9 first stage more than sporty...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Okie_Steve on 04/15/2016 02:18 PM
Taking the state horizontal on an ASDS would also be a sort of tight fit given it's about 150 feet tall and they only have a square about 180 feet on a side to work with given the blast walls and containers etc on the long axis.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/15/2016 02:25 PM
You've convinced me: no horizontal processing, no T/E, and no cranes.  Just "gas and go", taking off from the legs where it's sitting.  Hence no hold downs, either!  F9dev flew this way (which is why it was lost...). Still might be worth having an extra vessel for the propellant tanks, pumps, and chillers.  Just tie it up alongside and run some umbilicals to the base to fuel 'er up, then back off a safe distance and launch.

And I still say that any extra utility vessels are likely to be converted barges.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/15/2016 02:56 PM
F9dev flew this way

It was launched from a stand
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/15/2016 06:57 PM
You've convinced me: no horizontal processing, no T/E, and no cranes.  Just "gas and go", taking off from the legs where it's sitting.  Hence no hold downs, either!  F9dev flew this way (which is why it was lost...). Still might be worth having an extra vessel for the propellant tanks, pumps, and chillers.  Just tie it up alongside and run some umbilicals to the base to fuel 'er up, then back off a safe distance and launch.

And I still say that any extra utility vessels are likely to be converted barges.

The GH flights were very short, and towards the end (GH2) they used a stand (though no hold downs yet)

Remember the legs can't fold themselves in flight...

A fly-back shot is much more substantial - while suborbital, it is quite a bit more serious than the "Karman Line" shots.  We're talking traveling 1000 km here, going up to about 500...

It is not an easy task at all.  You'd want to have the rocket achieve a very high degree of reusability before you start doing fly-backs.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/17/2016 03:16 AM
I have an idea which should fit the bill!  She's an oldie but a beauty!!
http://www.nimitz.navy.mil/ (http://www.nimitz.navy.mil/)

Of course you were kidding with the Nimitz still in service (your current or former ship I take it), but your post brought to mind the USS Saratoga (CV-60 Supercarrier). Too bad SpaceX didn't grab it before it was sold for scrap for one penny just 2 years ago (http://www.foxnews.com/us/2014/05/09/uss-saratoga-destined-for-dismantling-after-one-cent-deal-with-texas-firm.html), after sitting mothballed for 20 years. It went to be dismantled in of all places, Brownsville Texas, the future site of new SpaceX launch facilities.

Edit: The article from 2014 did say the Saratoga was the 2nd of 3 carriers planned for scrap, but they didn't name the 3rd, so it might still be around.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 04/17/2016 09:15 AM
I have an idea which should fit the bill!  She's an oldie but a beauty!!
http://www.nimitz.navy.mil/ (http://www.nimitz.navy.mil/)

Of course you were kidding with the Nimitz still in service (your current or former ship I take it), but your post brought to mind the USS Saratoga (CV-60 Supercarrier). Too bad SpaceX didn't grab it before it was sold for scrap for one penny just 2 years ago (http://www.foxnews.com/us/2014/05/09/uss-saratoga-destined-for-dismantling-after-one-cent-deal-with-texas-firm.html), after sitting mothballed for 20 years. It went to be dismantled in of all places, Brownsville Texas, the future site of new SpaceX launch facilities.

Edit: The article from 2014 did say the Saratoga was the 2nd of 3 carriers planned for scrap, but they didn't name the 3rd, so it might still be around.
There are two full sized aircraft carriers in process of decommissioning right now at Newport News, Virginia.  One of them is the USS Enterprise.  I don't know offhand which is the other one.

Look here (https://www.google.com/maps/place/Newport+News,+VA/@36.9810205,-76.440627,642m/data=!3m1!1e3!4m2!3m1!1s0x89b07b82704d56d9:0xec7e55ec03c8cb1b).  I believe the one on the south is the USS Enterprise.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: RotoSequence on 04/17/2016 09:22 AM
I have an idea which should fit the bill!  She's an oldie but a beauty!!
http://www.nimitz.navy.mil/ (http://www.nimitz.navy.mil/)

Of course you were kidding with the Nimitz still in service (your current or former ship I take it), but your post brought to mind the USS Saratoga (CV-60 Supercarrier). Too bad SpaceX didn't grab it before it was sold for scrap for one penny just 2 years ago (http://www.foxnews.com/us/2014/05/09/uss-saratoga-destined-for-dismantling-after-one-cent-deal-with-texas-firm.html), after sitting mothballed for 20 years. It went to be dismantled in of all places, Brownsville Texas, the future site of new SpaceX launch facilities.

Edit: The article from 2014 did say the Saratoga was the 2nd of 3 carriers planned for scrap, but they didn't name the 3rd, so it might still be around.
There are two full sized aircraft carriers in process of decommissioning right now at Newport News, Virginia.  One of them is the USS Enterprise.  I don't know offhand which is the other one.

Look here (https://www.google.com/maps/place/Newport+News,+VA/@36.9810205,-76.440627,642m/data=!3m1!1e3!4m2!3m1!1s0x89b07b82704d56d9:0xec7e55ec03c8cb1b).  I believe the one on the south is the USS Enterprise.

I think the other carrier is the John F Kennedy (CV-67); I don't think SpaceX has a shot at that one.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rds100 on 04/17/2016 09:26 AM

What about lifting the stage with a helicopter and transporting it to ground this way? No need to fold the legs.
But they would have to find a way to install that load bearing cap while on the ASDS.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cavok on 04/17/2016 10:18 AM
no way with a helicopter.
even the biggest (Mi-26) can barely lift 20t. and the stage is more like 25t+ according to what i've picked up here on the boards.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rds100 on 04/17/2016 10:35 AM

Well, Mi-26 is more than 30 years old helicopter. And according to wikipedia it has already been tested to lift 56+ tonnes in 1982.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/17/2016 05:38 PM

What about lifting the stage with a helicopter and transporting it to ground this way? No need to fold the legs.
But they would have to find a way to install that load bearing cap while on the ASDS.
I'm not understanding the benefit.  They eventually have to fold the legs, they can't integrate or launch with the legs deployed.  And a crane has to be cheaper to operate than a helicopter.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cavok on 04/17/2016 06:13 PM

Well, Mi-26 is more than 30 years old helicopter. And according to wikipedia it has already been tested to lift 56+ tonnes in 1982.

Well, that record is for total mass uplift for a helicopter,  including its own weight/mass and certainly leaves no room for maneuvering! Considering the gearbox itself weighs almost 4t!
And so the design may be 30 years old, it's still going to be the biggest chopper. And probably will remain as it's kind of in an An-225/An-124 niche...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rds100 on 04/17/2016 06:52 PM

What about lifting the stage with a helicopter and transporting it to ground this way? No need to fold the legs.
But they would have to find a way to install that load bearing cap while on the ASDS.
I'm not understanding the benefit.  They eventually have to fold the legs, they can't integrate or launch with the legs deployed.  And a crane has to be cheaper to operate than a helicopter.

The benefit would be not having to wait 3 days for the ASDS to arrive at the predetermined point at sea, then not having to wait 3 days for it to return to shore.

Stage lands on ASDS, a helicopter comes to pick it up and bring it to shore. This happens with the legs unfolded - they will be folded during the processing that would be done on shore. The ASDS stays at sea, waiting for the next launch / stage.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 04/17/2016 06:59 PM

Well, Mi-26 is more than 30 years old helicopter. And according to wikipedia it has already been tested to lift 56+ tonnes in 1982.

Well, that record is for total mass uplift for a helicopter,  including its own weight/mass and certainly leaves no room for maneuvering! Considering the gearbox itself weighs almost 4t!
And so the design may be 30 years old, it's still going to be the biggest chopper. And probably will remain as it's kind of in an An-225/An-124 niche...
Well, there was also the Mil V-12, which was more or less a 2xMi-6.   Its intended niche was shuttling ICBMs around the Soviet Union - not all that different from what SpaceX needs.   Two prototypes were built but then the Soviets changed their minds about the flying ICBM thing and cancelled the program.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 04/17/2016 07:51 PM
I think the other carrier is the John F Kennedy (CV-67); I don't think SpaceX has a shot at that one.

Are you saying that with it in mind that JFK was the president who got us to the moon? SpaceX would be ideal to inherit the legacy. A new JFK carrier is under construction, but SpaceX would do fine giving the old one a fitting and interesting new name I'm sure.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/17/2016 08:36 PM
The Navy retired the JFK because it was the most expensive carrier in the fleet to operate.  That wouldn't be too helpful for SpaceX.


Granted, they wouldn't have to maintain the catapults or the weapons systems, but still...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/17/2016 09:31 PM
Please go back and re read the previous discussion we had about lifting rockets with helicopters.  It's like groundhog day around here sometimes.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/17/2016 11:08 PM
I have an idea which should fit the bill!  She's an oldie but a beauty!!
http://www.nimitz.navy.mil/ (http://www.nimitz.navy.mil/)

Of course you were kidding with the Nimitz still in service (your current or former ship I take it), but your post brought to mind the USS Saratoga (CV-60 Supercarrier). Too bad SpaceX didn't grab it before it was sold for scrap for one penny just 2 years ago (http://www.foxnews.com/us/2014/05/09/uss-saratoga-destined-for-dismantling-after-one-cent-deal-with-texas-firm.html), after sitting mothballed for 20 years. It went to be dismantled in of all places, Brownsville Texas, the future site of new SpaceX launch facilities.

Edit: The article from 2014 did say the Saratoga was the 2nd of 3 carriers planned for scrap, but they didn't name the 3rd, so it might still be around.
There are two full sized aircraft carriers in process of decommissioning right now at Newport News, Virginia.  One of them is the USS Enterprise.  I don't know offhand which is the other one.

Look here (https://www.google.com/maps/place/Newport+News,+VA/@36.9810205,-76.440627,642m/data=!3m1!1e3!4m2!3m1!1s0x89b07b82704d56d9:0xec7e55ec03c8cb1b).  I believe the one on the south is the USS Enterprise.

I think the other carrier is the John F Kennedy (CV-67); I don't think SpaceX has a shot at that one.

SpaceX don't have a shot at any of them.  Ignoring the (non-trivial) extremely limited berthing opportunities for a sec, can you imagine what it would cost to berth, crew and operate something like that??  As mentioned countless times before on this thread, there are other classes of vessel far better suited so it simply isn't going to happen.

Move along, nothing to see here..  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/18/2016 02:00 AM
How's about we (allow me some slack with the "we" here please) start the tradition of painting F9 outline symbols on the blast wall near the clover leaf for each of the successful returns?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Avron on 04/18/2016 02:08 AM
F9dev flew this way

It was launched from a stand

launches need a pad/stand, legs are not an option unless you use Grasshopper type legs . Flyback under own power, is a very log ways off, easier to turn horizontal and ship back on a ship, vs barge
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/18/2016 03:25 AM
Moved from the other thread, 'cause it seemed more relevant here:

1. Here's a great shot of an engine-driven pump for draining the ballast tanks - plus an open inspection hatch for the hose.

2. They've added Plimsoll marks to the side of the wings.  That load limit line doesn't leave them very much freeboard, so they must be planning to carry significantly more load/ballast than just an empty stage!

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 04/18/2016 07:53 AM
That Plimsoll mark was always there.
This reminds me to model it in my model  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/18/2016 07:59 AM
That Plimsoll mark was always there.
This reminds me to model it in my model  :)

I've checked back and you're quite correct.  Not sure how I didn't notice it before - perhaps because it wasn't in that position on the good 'ol JRtI, I didn't think to look for it on the wings.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 04/18/2016 02:42 PM
2. They've added Plimsoll marks to the side of the wings.  That load limit line doesn't leave them very much freeboard, so they must be planning to carry significantly more load/ballast than just an empty stage!

I'm a little surprised by how high they are but I get the impression that they're positioned based entirely on the vessel's geometry and have nothing to do with the intended use of the owner.    So it's more how much they *could* carry than how much they intend to carry.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/19/2016 02:59 AM
2. They've added Plimsoll marks to the side of the wings.  That load limit line doesn't leave them very much freeboard, so they must be planning to carry significantly more load/ballast than just an empty stage!

I'm a little surprised by how high they are but I get the impression that they're positioned based entirely on the vessel's geometry and have nothing to do with the intended use of the owner.    So it's more how much they *could* carry than how much they intend to carry.

Right.  Still, if it was me standing at the rail with the ASDS down to her lines, I'm sure I'd think she was about to sink..  ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: georgegassaway on 04/19/2016 05:06 AM

What about lifting the stage with a helicopter and transporting it to ground this way? No need to fold the legs.
But they would have to find a way to install that load bearing cap while on the ASDS.
I'm not understanding the benefit.  They eventually have to fold the legs, they can't integrate or launch with the legs deployed.  And a crane has to be cheaper to operate than a helicopter.
All SpaceX needs to do is to get Stark Industries to build them THIS so they can fly to an Equatorial launch site, launch the Falcon, then do a mid-air "catch" of the booster on the deck, and fly back.

Who needs "Sea Launch" and Elsbeth III when you can do Air Launch and Air Catch, anywhere,  with "Of Course I Still Have Not Just Read The Instructions"?   

Wee bit of an issue with the theoretical cost, and even more than just a bit of an issue with reality.....   :)

(http://www.extremetech.com/wp-content/uploads/2014/11/avengers-helicarrier-640x353.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/19/2016 02:12 PM

All SpaceX needs to do is to get Stark Industries to build them THIS so they can fly to an Equatorial launch site, launch the Falcon, then do a mid-air "catch" of the booster on the deck, and fly back.

Who needs "Sea Launch" and Elsbeth III when you can do Air Launch and Air Catch, anywhere,  with "Of Course I Still Have Not Just Read The Instructions"?   

Wee bit of an issue with the theoretical cost, and even more than just a bit of an issue with reality.....   :)


If that could be built, then there is no need for Falcon.  Just use its power system on winged vehicles to go into orbit. In fact, it probably could go into orbit itself.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 04/19/2016 03:24 PM

All SpaceX needs to do is to get Stark Industries to build them THIS so they can fly to an Equatorial launch site, launch the Falcon, then do a mid-air "catch" of the booster on the deck, and fly back.

Who needs "Sea Launch" and Elsbeth III when you can do Air Launch and Air Catch, anywhere,  with "Of Course I Still Have Not Just Read The Instructions"?   

Wee bit of an issue with the theoretical cost, and even more than just a bit of an issue with reality.....   :)


If that could be built, then there is no need for Falcon.  Just use its power system on winged vehicles to go into orbit. In fact, it probably could go into orbit itself.
There are a lot of neat gadgets in the alternate worlds of science fiction.  Some of them actually become true, but that generally only happens when said gadgets don't violate the laws of physics.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 04/20/2016 07:38 PM
There are a lot of neat gadgets in the alternate worlds of science fiction.  Some of them actually become true, but that generally only happens when said gadgets don't violate the laws of physics.
Several dozen Raptors on a launch platform wouldn't violate the laws of physics.
Economics, maybe.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/20/2016 08:37 PM
Well that escalated quickly.

(insert generic admonition to stay on topic here, although with JIM talking science fiction, my heart just isn't in it)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/21/2016 04:10 PM
Meanwhile, how are things in the port of LA / Long Beach?

And (this is such a long shot I shouldn't even be writing this) - I don't suppose there's any activity around the Sea Launch ships?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/22/2016 01:03 AM


I may have to report myself if you guys (and gals) can't stay more on topic.  Don't make me turn this barge around.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/22/2016 06:52 AM
Sorry to ask an apparently off-topic (it has nothing to do with flying aircraft carriers  :P) question, but does anyone happen to know if the two ASDS's, in their current configuration, have anemometers and wind direction indicators?  I've been looking at photos and can't see them, though I foggily recall seeing one in the past.

I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/22/2016 07:11 AM
Sorry to ask an apparently off-topic (it has nothing to do with flying aircraft carriers  :P) question, but does anyone happen to know if the two ASDS's, in their current configuration, have anemometers and wind direction indicators?  I've been looking at photos and can't see them, though I foggily recall seeing one in the past.

I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

It's at the top of the tower - port side, aft forward:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=40002.0;attach=1111368;image)

(Image credit te_atl: https://forum.nasaspaceflight.com/index.php?topic=40002.msg1520225)


Whew!! We're back on board and I can breathe again..   :)

Edit:  Got the front and back of this thing mixed up again.   :-[
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/22/2016 02:22 PM
It's at the top of the tower - port side, aft:

I'm no sailor, but that's not the port side, aft.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 04/22/2016 06:23 PM
I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

I've wondered about 'perfect' 5s weather forecasts.

A cylinder of 30 or so cheap drones 200m in radius, launched a couple of minutes before landing, or doppler LIDAR/RADAR.
Being able to perfectly predict the weather for 5s as you're measuring a complete shell at the wind velocity seems in principle interesting at least.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/22/2016 07:21 PM
I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

I've wondered about 'perfect' 5s weather forecasts.

A cylinder of 30 or so cheap drones 200m in radius, launched a couple of minutes before landing, or doppler LIDAR/RADAR.
Being able to perfectly predict the weather for 5s as you're measuring a complete shell at the wind velocity seems in principle interesting at least.

Admit it.  You bought 30 cheap drones on an impulse (I can relate!) and now you're looking for an offloader.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris_Pi on 04/22/2016 08:50 PM
I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

I've wondered about 'perfect' 5s weather forecasts.

A cylinder of 30 or so cheap drones 200m in radius, launched a couple of minutes before landing, or doppler LIDAR/RADAR.
Being able to perfectly predict the weather for 5s as you're measuring a complete shell at the wind velocity seems in principle interesting at least.

Admit it.  You bought 30 cheap drones on an impulse (I can relate!) and now you're looking for an offloader.

Alcohol+Amazon can be a weird combination sometimes. Who knows what shows up a few days later!  :o

That might actually be useful especially if it extended up a thousand feet or two. Doesn't take much to fly out and just hold position for a minute or two, then come back down.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/22/2016 08:59 PM
The thing about well-tuned control loops is: you don't need perfect information about the environment.  It's magic.

In order to justify this, you'd need to show that perfect forecast actually saved fuel or increased landing reliability.  I think any such effects would be far down in the noise: you're competing with the control loop gain, which pushes any benefits down a couple of orders of magnitude.

Simplified hand-wavy example: with a control loop gain of (say) 100 and a very simple proportional control loop, every one unit improvement in your feedback parameter just giving you .01 unit less in your error term, which is what modulates your thrust.  So 1m better position accuracy is only 1cm less error term, and very little fuel saved.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: acsawdey on 04/22/2016 09:23 PM
I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

I've wondered about 'perfect' 5s weather forecasts.

A cylinder of 30 or so cheap drones 200m in radius, launched a couple of minutes before landing, or doppler LIDAR/RADAR.
Being able to perfectly predict the weather for 5s as you're measuring a complete shell at the wind velocity seems in principle interesting at least.

Well, if you put 30 or more drones in a circle and they have cameras, that opens the way to:

Bullet-time Falcon 9 (http://petapixel.com/2012/12/24/freezing-time-and-space-using-a-bullet-time-rig-of-100-digital-cameras/)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/22/2016 10:01 PM
Sorry to ask an apparently off-topic (it has nothing to do with flying aircraft carriers  :P) question, but does anyone happen to know if the two ASDS's, in their current configuration, have anemometers and wind direction indicators?  I've been looking at photos and can't see them, though I foggily recall seeing one in the past.

I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

It's at the top of the tower - port side, aft:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=40002.0;attach=1111368;image)

(Image credit te_atl: https://forum.nasaspaceflight.com/index.php?topic=40002.msg1520225)


Whew!! We're back on board and I can breathe again..   :)

Thank you!

That rohn tower does indeed have a combined anemometer/direction indicator, and it's ultrasonic.

Looks very similar to this one.
http://www.kintech-engineering.com/media/uploads/image/178.jpg
(I'm using a link rather than attaching the pic, because it may well be copyrighted due to being a commercial product and I am guessing this is NSF's preferred method in that case?).

Ultrasonic anemometers aren't anywhere near as cheap as the old cups-on-a-spindle style, but they are more suitable for the salt air environment (no moving parts). Something like this would run around $2000 retail.

I'm a bit confused as to the placement though; there's nothing similar on the port forward rhon tower, so it looks like the only one is the one you found, on the starboard aft tower. I'd have thought that placing it forward rather than aft would be preferred for accuracy (drag effects of the forward structures). Edit: it actually is on the bow, I goofed.

I'd also be willing to bet that somewhere aboard is an accelerometer/tiltmeter, to give them data on the exact attitude and motion of the ASDS at the moment of touchdown (for later analysis, not realtime use).  Might also be useful to know before launch if conditions are marginal (assuming they'd delay a launch for a landing issue). 

Edit: fixed my mistaking the bow for the stern. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/22/2016 11:41 PM
Accelerometer/tilt meter is probably part of the position-hold package already.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CuddlyRocket on 04/23/2016 02:18 AM
It's at the top of the tower - port side, aft:

I'm no sailor, but that's not the port side, aft.

Yep, if that tower is at the stern, it's on the starboard side! (Alternatively, it's on the port bow.)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/23/2016 03:30 AM
It's at the top of the tower - port side, aft:

I'm no sailor, but that's not the port side, aft.

Yep, if that tower is at the stern, it's on the starboard side! (Alternatively, it's on the port bow.)

I'm afraid I've added to the confusion here. That (in the photo CameronD included) is definitely the bow, so the tower is on the port bow. I'll go edit my post. Thanks.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/23/2016 04:33 AM
To all the regular people out there:

Port is Left  ("the ship just left port")
Bow is front (you bow forward, right?)

On ASDS, the side with one row of containers and two walls (blast wall and wave wall) is the front.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 04/23/2016 06:00 AM
I'm thinking that knowing wind speed and direction at the ASDS would be important, but can't imagine why they would not have not have an anemometer and wind vanes for that purpose?

I've wondered about 'perfect' 5s weather forecasts.

A cylinder of 30 or so cheap drones 200m in radius, launched a couple of minutes before landing, or doppler LIDAR/RADAR.
Being able to perfectly predict the weather for 5s as you're measuring a complete shell at the wind velocity seems in principle interesting at least.

Well, if you put 30 or more drones in a circle and they have cameras, that opens the way to:

Bullet-time Falcon 9 (http://petapixel.com/2012/12/24/freezing-time-and-space-using-a-bullet-time-rig-of-100-digital-cameras/)

The landing sequence is such a good fit for this.  It would be stunning.  no need for drones though.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: sanman on 04/23/2016 09:32 AM

All SpaceX needs to do is to get Stark Industries to build them THIS so they can fly to an Equatorial launch site, launch the Falcon, then do a mid-air "catch" of the booster on the deck, and fly back.

Who needs "Sea Launch" and Elsbeth III when you can do Air Launch and Air Catch, anywhere,  with "Of Course I Still Have Not Just Read The Instructions"?   

Wee bit of an issue with the theoretical cost, and even more than just a bit of an issue with reality.....   :)


Sounds like you really want...

http://forum.nasaspaceflight.com/index.php?topic=39944.0

A large floating airship could be beneficial. Not only could the airship act as a landing pad, but it could later even act as a launch pad, perhaps allowing rockets to be launched from upto 20 miles above sea level.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: catdlr on 04/23/2016 09:40 AM

All SpaceX needs to do is to get Stark Industries to build them THIS so they can fly to an Equatorial launch site, launch the Falcon, then do a mid-air "catch" of the booster on the deck, and fly back.

Who needs "Sea Launch" and Elsbeth III when you can do Air Launch and Air Catch, anywhere,  with "Of Course I Still Have Not Just Read The Instructions"?   

Wee bit of an issue with the theoretical cost, and even more than just a bit of an issue with reality.....   :)


Sounds like you really want...

http://forum.nasaspaceflight.com/index.php?topic=39944.0

A large floating airship could be beneficial. Not only could the airship act as a landing pad, but it could later even act as a launch pad, perhaps allowing rockets to be launched from upto 20 miles above sea level.

in addition, here are some concepts developed from Phillip Bono: 
https://www.flickr.com/photos/sdasmarchives/26415430231/in/album-72157666706198030/

https://www.flickr.com/photos/sdasmarchives/26481550175/in/album-72157666706198030/

https://www.flickr.com/photos/sdasmarchives/26389227292/in/album-72157666706198030/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/23/2016 12:55 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/23/2016 01:57 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

Why? They have one for each launch site, and Boca Chica won't be ready for years.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 04/23/2016 01:59 PM
The thing about well-tuned control loops is: you don't need perfect information about the environment.  It's magic

"The thing about well-tuned control loops with adequate control authority".

Over the last several seconds, many things get lots harder, probably to the point that there is not as much control authority as you'd like.
This is for several reasons:
Speed is dropping off sharply, meaning that body 'lift' and grid fins become less useful.
The body has to be approximately vertical as it hits the deck.

At the last second or two, there isn't enough time to counteract unexpected gusts fully, all you can do is to hit vertically.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/23/2016 02:31 PM
The thing about well-tuned control loops is: you don't need perfect information about the environment.  It's magic

"The thing about well-tuned control loops with adequate control authority".

Over the last several seconds, many things get lots harder, probably to the point that there is not as much control authority as you'd like.
This is for several reasons:
Speed is dropping off sharply, meaning that body 'lift' and grid fins become less useful.
The body has to be approximately vertical as it hits the deck.

At the last second or two, there isn't enough time to counteract unexpected gusts fully, all you can do is to hit vertically.
Naw, I don't believe it.  In the last seconds they have a Merlin firing at half thrust and a near-empty stage.  If anything there too much control authority.

Grid fins and body lift are for high altitude aiming.  If you said they needed to have better environment modeling of high altitude winds, I'd be on board.  At that stage of flight small improvements could indeed be compounded into significant savings.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/23/2016 02:35 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

Why? They have one for each launch site, and Boca Chica won't be ready for years.
I think the thinking is that they will eventually need two more ASDSes for downrange recovery of Falcon Heavy side cores and/or another ASDS for missions at a fast cadence without enough time for a single ASDS to return to port and redeploy.

I don't buy it, necessarily (at least not in the near term).  But it would be good to have antennae in the air just in case MARMAC 300 (say) disappears suddenly after finishing its wind turbine job.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/23/2016 03:03 PM
Quote
I don't buy it, necessarily.  But it would be good to have antennae in the air just in case MARMAC 300 (say) disappears suddenly after finishing its wind turbine job.

Will check with my source and see if he's heard anything.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/23/2016 03:38 PM
The thing about well-tuned control loops is: you don't need perfect information about the environment.  It's magic

"The thing about well-tuned control loops with adequate control authority".

Over the last several seconds, many things get lots harder, probably to the point that there is not as much control authority as you'd like.
This is for several reasons:
Speed is dropping off sharply, meaning that body 'lift' and grid fins become less useful.
The body has to be approximately vertical as it hits the deck.

At the last second or two, there isn't enough time to counteract unexpected gusts fully, all you can do is to hit vertically.

This quote from Jeff Bezos about how their autpoilot works is relevant:

Quote
One of the software improvements related to the landing approach.

“Rather than the vehicle translating to land at the exact center of the pad, it now initially targets the center, but then sets down at a position of convenience on the pad, prioritizing vehicle attitude ahead of precise lateral positioning,” added Mr. Bezos.

"It’s like a pilot lining up a plane with the centerline of the runway. If the plane is a few feet off center as you get close, you don’t swerve at the last minute to ensure hitting the exact mid-point. You just land a few feet left or right of the centerline.


https://www.nasaspaceflight.com/2016/01/blue-origin-successful-reuse-test-new-shepard/

Which is exactly what we saw on the CRS-8 landing. In the last few seconds the stage righted itself and did not try to correct for being a few meters off target.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/23/2016 06:27 PM
Well I see this thread took a hard turn into the weeds...   ???

On topic... a question or two...  ;)
They get OCISLY cleaned up and ready to go catch another stage?
I have not seen any pics of her since they left the I-beams tack welded to the deck...

When will EIII be headed out again with OCISLY in tow to catch the next one?
I see the dates slipped a bit... but this is coming up sooner then later...

Next launch in 10 days or so by my count...
SO... Headed out in less then a week... going where?... how far?...  :-\
 :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/25/2016 11:47 AM
Quote
SO... Headed out in less then a week... going where?... how far?... 

This appears to be the FCC transmitter permit for the ships on the JCSAT-14 mission. The permits are a bit tricky to decipher because they don't specify the mission, only a 6-month range of operations dates. But the permit previous to this one appeared to be for the CRS-8 ASDS location. So I think this one is for JCSAT-14. The ASDS location appear to be consistent with a low launch azimuth for GTO.

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=69736&RequestTimeout=1000

ASDS coordinates:

28 11 30 N
73 50 15 W

(Degrees-minutes-seconds)

That is 409 statute miles from the launch site, and within a few miles of the SES-9 location. So this mission will be almost identical to the SES-9 recovery profile.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/25/2016 01:14 PM
Whoo-hoo, another exciting recovery then!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 04/25/2016 01:19 PM
That is 409 statute miles from the launch site, and within a few miles of the SES-9 location. So this mission will be almost identical to the SES-9 recovery profile.
Then shouldn't the ASDS be heading out soon?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/25/2016 01:29 PM
That is 409 statute miles from the launch site, and within a few miles of the SES-9 location. So this mission will be almost identical to the SES-9 recovery profile.
Then shouldn't the ASDS be heading out soon?

For SES-9 they left almost exactly 5 days before the launch window opened. So if the 3 May launch date holds, OCISLY would probably leave this Thursday, 4/28.

Update: now NET 4 May, so Friday departure at earliest...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/25/2016 01:59 PM
Whoo-hoo, another exciting recovery then!
That doesn't follow. It's possible that they're going to do a ballistic reentry but not use the super max gonzo 3 engine landing option...  see this speculation on performance margins.

http://forum.nasaspaceflight.com/index.php?topic=33778.msg1516813#msg1516813

JCSat isn't as heavy and they aren't trying to do quite as aggressive of a GTO orbit (is the thinking)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/25/2016 02:22 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/25/2016 04:29 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

Interesting... What is the lead time for new construction of this class of barge? And if new construction were commissioned, would it be this class or would SpaceX start applying learnings (integrated shielding instead of tacked on.. special thruster housings, etc... there are dozens of things one COULD do...)? It's possible it's too early to start customizing much, so by going for another Marmac 300 class, the barge could be returned to the lessor more easily...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 04/25/2016 04:32 PM
Landing poll available for JCSat-14
(or given this forum... the anti-ASDS missile system if you prefer...)

http://forum.nasaspaceflight.com/index.php?topic=40146.0
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: starhawk92 on 04/25/2016 05:18 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

Why? They have one for each launch site, and Boca Chica won't be ready for years.
I think the thinking is that they will eventually need two more ASDSes for downrange recovery of Falcon Heavy side cores and/or another ASDS for missions at a fast cadence without enough time for a single ASDS to return to port and redeploy.

I don't buy it, necessarily (at least not in the near term).  But it would be good to have antennae in the air just in case MARMAC 300 (say) disappears suddenly after finishing its wind turbine job.

"We're gonna need a bigger boat . . . . . "
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/25/2016 08:01 PM
Whoo-hoo, another exciting recovery then!
That doesn't follow. It's possible that they're going to do a ballistic reentry but not use the super max gonzo 3 engine landing option... 
By "exciting" I mean, "not yet successful".  ASDS landing after GTO mission has not yet been successfully demonstrated.


PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

And does its next job require adding wings?

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/25/2016 08:43 PM


PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

And does its next job require adding wings?

No, it just got an ABS inspection and is being repaired after a dockside "hit and run" mishap. But no wings in its future.  :(
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/25/2016 08:49 PM
Meanwhile, how are things in the port of LA / Long Beach?

Members of the ASDS nation should be scanning the shores around Amelia and Morgan City La. for the possible construction of additional ASDS(s) now that there is proof that the concept works.  Where are the Marmacs?

My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

Interesting... What is the lead time for new construction of this class of barge? And if new construction were commissioned, would it be this class or would SpaceX start applying learnings (integrated shielding instead of tacked on.. special thruster housings, etc... there are dozens of things one COULD do...)? It's possible it's too early to start customizing much, so by going for another Marmac 300 class, the barge could be returned to the lessor more easily...

Lead time for modifying an existing 300' x 100' barge would be 5-7 months according to my source. A new purpose-built barge could be around 12 months or more, depending on their specs.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: abaddon on 04/25/2016 09:33 PM
I wonder if SpaceX will at some point try and juggle their schedule to alternate ASDS and RTLS flights.  If we imagine the once every two week cadence they hope to hit (at least some of the time) later this year, back-to-back ASDS recoveries might be impossible, even with no damage to the drone ship.  I guess you can also start adding JRTI to the mix as VAFB flights start coming on-line later in the year.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/25/2016 11:42 PM
Thank you!

That rohn tower does indeed have a combined anemometer/direction indicator, and it's ultrasonic.
.......
I'd also be willing to bet that somewhere aboard is an accelerometer/tiltmeter, to give them data on the exact attitude and motion of the ASDS at the moment of touchdown (for later analysis, not realtime use).  Might also be useful to know before launch if conditions are marginal (assuming they'd delay a launch for a landing issue). 

The high-res photos aren't quite high-res enough to work out exactly what they're using, but for completeness it is probably what is technically known as a "marine weather station", similar to this one:

(http://www.fondriest.com/news/wp-content/uploads/2015/11/airmar_diagram.jpg)

These units use on-board GPS and gyros to compensate for movement of the platform giving precise true wind speed and direction - something I presume they'd need to know in the final seconds before touchdown - and the gyro outputs can be useful for motion recording also.  They're extraordinarily accurate.. to tenths of a knot!


PS:  Apologies for the viewing angle mix-up.  I've edited my original post accordingly.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/26/2016 12:32 AM
My source at McDonough Marine says all their big barges are rented out and he hasn't heard or seen anything locally to suggest SpaceX is expanding their ASDS fleet. If they did, it would have to be with a different company, elsewhere.

PS...the original ASDS, Marmac 300, is done with wind farm construction duty and is being repaired/refit for its next job.

Interestingly, the USCG never wiped their "Research Vessel" listing for MARMAC 300 - their Certificate of Documentation is valid to April 2017.  I'm not saying that implies anything.. only that, from a pure paperwork stand-point, it wouldn't be difficult to apply for this classification to be reinstated, should they choose to do so.

Personally, I can't see them increasing the SpaceX Navy for some time yet - the cost of barge upgrades, maintenance, berthing, man-power and tug support just does not seem to be warranted at this point.


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Herb Schaltegger on 04/26/2016 12:47 AM

Personally, I can't see them increasing the SpaceX Navy for some time yet - the cost of barge upgrades, maintenance, berthing, man-power and tug support just does not seem to be warranted at this point.


Agreed. Once they reach a sustainable cadence, perhaps. But look at JCSAT-14 - the anticipated launch date has slipped approximately a week just since the CRS-8 flight. Until they need to sortie more than once every three - four weeks, there's no need for another barge, absent any SES-9 style rocket-punching through the deckplates.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/26/2016 03:03 AM
I agree with those above who say they don't see the ASDS fleet increasing soon.

My take is it's way too soon; they're going to want to learn operational lessons, and also wait until they actually need more ASDS (that way, any new ones can be designed with lessons learned in mind).

Is one ASDS enough for the Cape? I think it is, even for FH - it looks like the early FH flights will have the side cores doing RTLS, leaving only the center core for ASDS to worry about.  As for F9 launches, the ASDS operational cadence could be increased in case of need (unless there are reasons why not?). The next flight, for example, has the ASDS approx 400 miles  offshore - further than usual. But, let's assume that's average. That's 69 hours one way from Canaveral at 5 knots. Let's say 12 hours on station, then 69 hours back.  150 hours round trip - 6.25 days. Is it reasonable to say an operational ASDS, after plenty of practice, could be unloaded and prepped for another mission in 3/4 of a day? If so, you've got an ASDS capability to support launches a week apart. If for some reason (say, launch dates 5 days apart) you need to do better on occasion, make sure of of them (the first one) has enough margin for a partial boostback burn to cut the distance offshore, or, temporarily hire a larger, faster tug that could handle the ASDS at, say, 8 knots, cutting outbound transit time down 43 hours.

IMHO, it'll be a long time before launch cadence (even if we assume no RTLS, ever) exceeds the capacity of one ASDS - and SpaceX has a track record of not completing new things before they are needed - why make a capital expenditure before it's needed?   

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/26/2016 03:19 AM
Quote
?...and SpaceX has a track record of not completing new things before they are needed - why make a capital expenditure before it's needed?   

Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: miscme on 04/26/2016 03:33 AM
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/26/2016 03:44 AM
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.

OK, one attempt in a year. "Almost" nothing.

Point remains, the asset has been, shall we say, extremely underutilized.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: The Amazing Catstronaut on 04/26/2016 04:41 AM
Whoo-hoo, another exciting recovery then!
That doesn't follow. It's possible that they're going to do a ballistic reentry but not use the super max gonzo 3 engine landing option...

Lar, can I report you if your comment made me spill my hard-earned five AM hot chocolate on my crotch?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: timverhoeven on 04/26/2016 11:39 AM
Yes, and they're probably feeling a bit burned by JRtI sitting out there out West doing nothing for what...almost a year now?

I recall JRtI trying to catch the Jason-3 booster just 3 months ago.

OK, one attempt in a year. "Almost" nothing.

Point remains, the asset has been, shall we say, extremely underutilized.

Accorinding to the manifest on http://forum.nasaspaceflight.com/index.php?topic=40049.msg1523417#msg1523417 there are 3 flights from the West coast planned for the remainder of this year. And the 6 months downtime because of CRS-7 didn't help of course.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Scylla on 04/26/2016 01:42 PM
Go Quest has moved near OCISLY.
http://portcanaveralwebcam.com/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: the_other_Doug on 04/26/2016 02:48 PM
Hypothetically, if launch cadence ramps up like the manifest says it might, could we get into a position where there is another GTO (or even FH) launch approaching and the drone ship is still carrying a stage back from the last launch attempt?

To put it more bluntly, what do we think is the fastest launch cadence we could see for launches which cannot use an RTLS trajectory for stage recovery?  Is three weeks between GTO launches too little time, or plenty?  Is two weeks pushing it too much?  Is a single week between GTO launches even do-able without designating the second GTO launch in a row as expendable, simply because the ASDS isn't ready to sail yet?

I'm thinking that SpaceX won't delay a launch just because the ASDS is still making its way back to Port Canaveral.  So, at what launch cadence will SpaceX require a second ASDS to be available on the ETR?  (Obviously, the WTR is not so much of an issue, as the launch cadence from Vandenberg isn't projected ot be nearly as busy as that from the Cape.)

Since moving JRtI from California to Florida would seem to require removing its wings before it will fit through the Panama Canal, I'm assuming in the question above that there is no operational flexibility available by using one of the current fleet of two as a "swing barge," able to pop over to the ETR when the cadence demands and pop back over to the WTR when it's needed.  In other words, I'm assuming that, for any kind of short-term planning purposes, an ASDS asset on one coast is unavailable for use on the other coast.  Unless Musk fits out one of them with Merlins, as he joked a couple of years ago...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/26/2016 03:18 PM
Doug, your question was answered a few posts above yours.  And yes, our observations confirmed that Panama canal transit is a huge time (and money) sink in addition to the wing mods required; I think we can safely assume JRtI will not taste the Atlantic again.

Others: I agree with the general sentiment "too soon to massively increase ASDS fleet".  I wouldnt be too surprised to see *one* more ASDS on the east coast in the next, say, one to three years.  I suspect three-ASDS landings for FH will be pushing the limits of center core reentry speed and downrange distance for some time yet, so (in my possibly-crazy opinion) after the "easy" all-RTLS and side-RTLS/center-ASDS missions the next increment of performance would be side-ASDS/center-expendable.  That would only require a single new ASDS, and I think there are two MARMAC class barges still unaccounted for?  That extra ASDS could cover Boca Chica and provide some operational flexibility---the two/three year time frame is about when I'd expect the launch cadence to have come up and Boca Chica getting near completion.  As calculated above, a single ASDS is good for approximately weekly flights, and I don't see SpaceX achieving that (or anything other than RTLS of FH side cores) in less than a year.

(On the other hand, I wonder if they'll have dialed in landing accuracy enough in the two-ish year time frame that they feel comfortable landing both side cores on a single barge?  There is space along the long axis.  But if so that also enables them to try all-ASDS missions with a two-barge fleet, so maybe that's another reason the eventual Atlantic fleet size could grow to two?)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Alastor on 04/26/2016 03:33 PM
what do we think is the fastest launch cadence we could see for launches which cannot use an RTLS trajectory for stage recovery?

As far as we have seen, assuming that ASDS does not sustain damage on landing (as seems to have happened last time), there is not much needed for the ASDS to be ready to sail again.

Coming back to shore did take less than a week, and as it was the first ASDS landing, we can assume that as was the case for port operations, they may have deliberately taken their time with it, in order to be sure they didn't make any mistakes.
Unloading operations did take no more than a few hours, once they arrived to port.
Preparing the ship to be ready to sail must be what, 1 or 2 days at most, I'd say.
Going from port to the landing zone is usually about 4 days.

In short, ASDS should be able to be recycled in about 10 days, maybe a bit more.
Going down to 7 days may be asking too much, since it would require the ASDS to go faster on the return trip than to go there, and would leave no margin. So it seems that this is definitely a no go for 7 days recycle.

So I'd say they will need a second ASDS on this coast at about the time when there will be an ASDS landing required once every two weeks. Two should be enough to be good for an ASDS landing once every week, maybe a bit less if they rush it. So it will be a long time before they need more than two (if ever).
Then, let's not forget that they can always decide to go expandable once in a while. I know it's tempting to believe that from now on, they will catch every single first stage they launch, and in the long run, that may be the aim, but until they can "safely" reuse a first stage, and until they seriously ramp up the storage capability, trying to catch every first stage they launch may cause them some serious logistics headaches, that may be solved by going expandable sometimes.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 03:35 PM
Then, let's not forget that they can always decide to go expandable once in a while. I know it's tempting to believe that from now on, they will catch every single first stage they launch, and in the long run, that may be the aim, but until they can "safely" reuse a first stage, and until they seriously ramp up the storage capability, trying to catch every first stage they launch may cause them some serious logistics headaches, that may be solved by going expandable sometimes.

Oh what exciting times we live in... "guys... splash this next one, we have too many first stages in the barn right now..."
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Scylla on 04/26/2016 05:28 PM
Spotted some workers on OCISLY. Possibly begining preperations for next launch.
http://portcanaveralwebcam.com/

Since we have this handy webcam, might be time to create a stand alone update/discussion thread for OCISLY.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/26/2016 05:29 PM
Oh what exciting times we live in... "guys... splash this next one, we have too many first stages in the barn right now..."

I still don't see that you'd really want to splash it on purpose. Why not try a really aggressive landing attempt with the first of the pair; something you expect to fail (like SES-9). If you pull it off then maybe you splash the second, but if you fail as expected then you've at least learned something from the lost S1. Sure you might damage the ASDS, but you could stage some steel and welders on Go _____ for on-site repair.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 05:37 PM
Alternatively (and this is really crazy) land one in one corner of the ASDS and the other one in the opposite corner.

That's such a silly idea I should self report...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/26/2016 05:50 PM
Wow, lots of good discussion here.  Hopefully our discussion on the need for more ASDSs is being done on a time available basis and doesn't cut into our staying on top of the real time ASDS events that Scylla is pointing out. 

I agree its not likely that the ASDS fleet is going to grow soon, particularly in light of abaddon's suggestion to juggle the launch schedule to have RTLS and ASDS alternate, its just that we're all here on this ASDS thread and it would be good for us to be ahead of whatever may be happening if it does so keep your eyes open.  As for Cameron's comment that the ASDS fleet is expensive I respond yes, but a) Part of that expense is Go Quest & Searcher, Port facility, crane, equipment rental, personnel that are not utilized much of the time with one ASDS, those expenses wouldn't increase appreciably with a 2nd ASDS, b) Having to juggle the launch schedule if a second ASDS becomes useful isn't an inexpensive option c) If the current ASDS becomes damaged which I've seen happen 4 times now out of ?6? you'd want another ASDS c) (somewhat indirictly related) The scale of expenses run up by the SpaceX navy is light compared to the cost of one lost stage.

Kabloona, good work in keeping in touch with your inside contact.

Hmm, now with a bit of time since writing above I am leaning a bit in favor of thinking a second east coast ASDS may be coming sooner rather than later.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 06:04 PM
Has anyone plotted the location of all ASDS landing attempts so far? Do we have a pattern developing? (perhaps factor out some of the early ones that had high margins and were almost standins for RTLS) My thinking here is that even with two ASDSii[1], you don't need a full complement of support ships IF two successive landings are fairly closeish together... you have a fast tug shoot out bringing an empty ASDS, and turning around to tow one ASDS back with stage, while the flotilla and empty ASDS decamp to the next location. Sucks to be the guys on board the flotilla as they don't get as much shore leave but they can handle it...

(this is a cheaper (temporary??) variant of the "purpose built fast ship with crane to return stages to land leaving the ASDS at sea" idea)

1 - obviously the plural of ASDS is ASDSii ...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/26/2016 06:10 PM
Would you really need a full up 2nd ASDS and host of associated equipment? Or could you possibly use an unmodified crane barge?
Lift the landed stage off the ASDS with the crane barge while on station. Crane barge with possibly it's own tug (or not depending on timing) would lift the S1 off the ASDS and return separately while the ASDS awaited the next landing, moving if necessary.

Edit: Ninja'd by the Mod.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/26/2016 06:19 PM
I've got this silly picture running through my head that I need to vent out.

One way to land multiple multiple cores on a barge without having to return would be to cover the deck with conveyor belt material.  Conceptually Rexnord tabletop chain.  ...Which would be in constant motion from fore to aft.  The stages would touch down in the center or forward center part of the deck and be conveyed rearward by the conveyor action until coming to a stop against a modified higher blast wall at the rear.  Perhaps with some side guides as well.  You could probably get 50 or so of them to stack up back there before the ASDS would need to come in to be unloaded, assuming the legs nested well.

Check 1:43 of this video for the general concept - https://www.youtube.com/watch?v=LwPJHVvvcZk
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rsdavis9 on 04/26/2016 06:20 PM
How about refuel on barge and hop? Maybe in a year?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/26/2016 06:25 PM
The stages would touch down in the center or forward center part of the deck and be conveyed rearward by the conveyor action until coming to a stop against a modified higher blast wall at the rear.  Perhaps with some side guides as well.  You could probably get 50 or so of them to stack up back there before the ASDS would need to come in to be unloaded, assuming the legs nested well.

Check 1:43 of this video for the general concept

What I don't understand is... why would you skip the rinse stage at 0:50?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CT Space Guy on 04/26/2016 06:27 PM
Maybe SpaceX could buy a couple of these?

https://www.tuwien.ac.at/en/news/news_detail/article/10060/ (https://www.tuwien.ac.at/en/news/news_detail/article/10060/)

http://www.heliofloat.com/ (http://www.heliofloat.com/)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 06:29 PM
Would you really need a full up 2nd ASDS and host of associated equipment? Or could you possibly use an unmodified crane barge?
Lift the landed stage off the ASDS with the crane barge while on station. Crane barge with possibly it's own tug (or not depending on timing) would lift the S1 off the ASDS and return separately while the ASDS awaited the next landing, moving if necessary.

Edit: Ninja'd by the Mod.
Who me? No, your idea is different... I think more expensive, barge mounted cranes are presumably more expensive than  the whole rest of the ASDS but i could be wrong.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: envy887 on 04/26/2016 06:31 PM
I've got this silly picture running through my head that I need to vent out.

One way to land multiple multiple cores on a barge without having to return would be to cover the deck with conveyor belt material.  Conceptually Rexnord tabletop chain.  ...Which would be in constant motion from fore to aft.  The stages would touch down in the center or forward center part of the deck and be conveyed rearward by the conveyor action until coming to a stop against a modified higher blast wall at the rear.  Perhaps with some side guides as well.  You could probably get 50 or so of them to stack up back there before the ASDS would need to come in to be unloaded, assuming the legs nested well.

That's $2 billion worth of rockets sitting out on a barge in the Atlantic for many weeks...  :o
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 06:36 PM
That canning line thing was amusing but let's stick to halfway realistic ideas for how to handle increased cadence.... Or the thread might be canned.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/26/2016 06:38 PM
Would you really need a full up 2nd ASDS and host of associated equipment? Or could you possibly use an unmodified crane barge?
Lift the landed stage off the ASDS with the crane barge while on station. Crane barge with possibly it's own tug (or not depending on timing) would lift the S1 off the ASDS and return separately while the ASDS awaited the next landing, moving if necessary.

Edit: Ninja'd by the Mod.
Who me? No, your idea is different... I think more expensive, barge mounted cranes are presumably more expensive than  the whole rest of the ASDS but i could be wrong.

I'm thinking standard COTS stuff. 14 day rental or whatever it needs. No long term lease, no wing mods, no thrustmasters, no mm precision automated positioning, etc. Rent it, go pick up the stage, fill the gas tank, and return it. Hertz/Avis style. I don't see how it would be more expensive than modifying and maintaining a 2nd ASDS. (All uninformed opinion, I could easily be wrong.) Something like...
https://www.dnlsalvage.com/services/crane-barges/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Arb on 04/26/2016 07:44 PM
Occasional sailor here.

There's a huge difference between craning from ship to ship in the calm sheltered waters of a harbour and out in the open ocean where there are significant waves almost all the time. Consider what happens if a hoisted first stage starts to pendulum...

Not saying it couldn't be done (the USN have researched crane designs that counteract wave motion for according to Google) but not going to be easy or cheap, IMO.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/26/2016 08:39 PM
Thank you!

That rohn tower does indeed have a combined anemometer/direction indicator, and it's ultrasonic.
.......
I'd also be willing to bet that somewhere aboard is an accelerometer/tiltmeter, to give them data on the exact attitude and motion of the ASDS at the moment of touchdown (for later analysis, not realtime use).  Might also be useful to know before launch if conditions are marginal (assuming they'd delay a launch for a landing issue). 

The high-res photos aren't quite high-res enough to work out exactly what they're using, but for completeness it is probably what is technically known as a "marine weather station", similar to this one:

(http://www.fondriest.com/news/wp-content/uploads/2015/11/airmar_diagram.jpg)

These units use on-board GPS and gyros to compensate for movement of the platform giving precise true wind speed and direction - something I presume they'd need to know in the final seconds before touchdown - and the gyro outputs can be useful for motion recording also.  They're extraordinarily accurate.. to tenths of a knot!


PS:  Apologies for the viewing angle mix-up.  I've edited my original post accordingly.

I think you've hit the nail on the head; that sort of data station would provide a lot that they need.

I don't see any need to know the precise wind speed in the final moments before touchdown except for after-the-fact analysis (which IMHO they would need) because there's no way to make use of the data in real time.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 04/26/2016 09:01 PM
Not saying it couldn't be done (the USN have researched crane designs that counteract wave motion for according to Google) but not going to be easy or cheap, IMO.
Motion-compensating technology is apparently deployed in production in the North Sea for the offshore energy industry (oil/gas/wind).

Here's video of a motion-compensated crane in operation:

https://www.youtube.com/watch?v=ggIDaBMbhUE&t=37m10s

(see 37 minutes 10 seconds in; I attempted to link directly there but the embed is losing the time offset somehow).

They also have a motion-compensated walkway allowing workers to "walk to work" across the North Sea.   This video shows it compensating for ship-to-fixed-platform motion but other videos show it doing ship-to-ship adjustments.

I agree that it's not going to be cheap, but it might be cheaper than maintaining a large fleet of ASDS's and continuously towing them back & forth between the port and the landing zones.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: LastStarFighter on 04/26/2016 09:16 PM
That canning line thing was amusing but let's stick to halfway realistic ideas for how to handle increased cadence.... Or the thread might be canned.

My vote (if they need more east coast help) would be to bring JRtI back from the west coast once VAFB RTLS is approved. I don't see anything on the manifest for the West Coast that would really require a barge landing. Maybe I'm over looking some larger payload missions though.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/26/2016 09:19 PM
That's amazing. However their target is a fixed platform. Transferring a stage from one barge to another would require a different sort of compensation...

When hooking the stage, the crane has to move in concert with the tip of the stage, but when setting the stage down the crane has to avoid penduluming but also get the stage to actually set down when the deck isn't moving under it a lot. Doable but a fun motion control problem to program.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: acsawdey on 04/26/2016 10:03 PM
When hooking the stage, the crane has to move in concert with the tip of the stage, but when setting the stage down the crane has to avoid penduluming but also get the stage to actually set down when the deck isn't moving under it a lot. Doable but a fun motion control problem to program.

A fun motion control problem indeed -- reminds me of how a double-pendulum is a classic chaotic physical system. If you squint at it right, you could convince yourself a stage hanging from a crane boom would behave this way too.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 04/26/2016 10:49 PM
That's amazing. However their target is a fixed platform.

Not always!  Ship-to-ship motion compensation is demonstrated here:

https://www.youtube.com/watch?v=oVonK9utYSc

(skip ahead to 3:00 or so).   They do mention "constant force" so they're likely using force-feedback control; they'd clearly need to integrate other sensors to do more general ship-to-ship motion compensation. 

Quote
When hooking the stage, the crane has to move in concert with the tip of the stage, but when setting the stage down the crane has to avoid penduluming but also get the stage to actually set down when the deck isn't moving under it a lot. Doable but a fun motion control problem to program.
No doubt!  Though if deck motion on the destination was a problem they could put the stage stand onto another motion-compensated platform.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/26/2016 11:02 PM
That's amazing. However their target is a fixed platform. Transferring a stage from one barge to another would require a different sort of compensation...

When hooking the stage, the crane has to move in concert with the tip of the stage, but when setting the stage down the crane has to avoid penduluming but also get the stage to actually set down when the deck isn't moving under it a lot. Doable but a fun motion control problem to program.


If they were going to do a ship to ship transfer, I believe they'd be better off with, rather than craning from one barge to another, creating a system that can lay the stage horizontal and set it on a faster, narrower boat with proper cradling.  Maybe that would allow them to remove the legs in transit, and they'd have much of the reprocessing one by the time they offloaded the stage in port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/26/2016 11:17 PM
That's amazing. However their target is a fixed platform.

Not always!  Ship-to-ship motion compensation is demonstrated here:

Makes you sea-sick just watching it.  :D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/26/2016 11:22 PM
Has anyone plotted the location of all ASDS landing attempts so far? Do we have a pattern developing? (perhaps factor out some of the early ones that had high margins and were almost standins for RTLS) My thinking here is that even with two ASDSii[1], you don't need a full complement of support ships IF two successive landings are fairly closeish together... you have a fast tug shoot out bringing an empty ASDS, and turning around to tow one ASDS back with stage, while the flotilla and empty ASDS decamp to the next location. Sucks to be the guys on board the flotilla as they don't get as much shore leave but they can handle it...

Note that, if money is no object, there's nothing stopping them using a ship-carrier to get the ASDS out on station a fair bit quicker than any "fast tug" could tow it.

(http://worldmaritimenews.com/wp-content/uploads/2013/02/Dockwise-Supports-Combination-with-Boskalis.jpg)

Float-on, float-off..

EDIT:  If they sent a maintenance crew along with it, they could clean the barnacles off of the hull and refresh the anti-foul whilst they're on the way out.  ;D


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 04/26/2016 11:48 PM
Go Sisters are near Droneship. When it all nears departure we should tweet to PTZtv folks.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Alastor on 04/27/2016 09:47 AM
That's amazing. However their target is a fixed platform. Transferring a stage from one barge to another would require a different sort of compensation...

When hooking the stage, the crane has to move in concert with the tip of the stage, but when setting the stage down the crane has to avoid penduluming but also get the stage to actually set down when the deck isn't moving under it a lot. Doable but a fun motion control problem to program.

Well, if the crane is compensated for six degrees of freedom, you can theoretically keep the hook immobile in the referential of the barge ship, with proper instrumentation (I don't say its easy, but after all, they manage to land a stick on top of a single booster). Even in the referential of the top of the stage, it's not that much harder (since the stage is immobile on the ASDS).

Now, if they have a lifting fixture on the end of this hook, as we have seen before, that is a problem, since the fixture will try to stay more or less vertical when the stage is not. So the fixture has to be changed, and now, you need something that also controls its motion at the end of the crane (2 to 3 additional degrees of freedom : the rotations), to match the axis of the fixture with the ones of the stage. That's pretty complicated, but I think it would be still doable.

Then (once you have lifted it), you can use this same system to slowly dampen the pendulum effect and bring the stage back to a stop relative to the transporting ship.

I do like this idea. although it would certainly not be cheap, it might be cheaper than operating another ASDS, to have an integrated support ship capable of starting work on reconditioning the stage while still at sea.

But still. As long as there is no consistent need of a second ASDS, I say they probably will try to catch every stage they can with JRtI in order to get the maximum amount of data on returned stages. Then if they start having too many stages in storage, either they start to put older ones in museums or scrap them. And if the ASDS is not available, because of repairs or because it's busy with an other stage, no big deal just go expandable.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: speedevil on 04/27/2016 01:47 PM
I don't see any need to know the precise wind speed in the final moments before touchdown except for after-the-fact analysis (which IMHO they would need) because there's no way to make use of the data in real time.

With adequate measurement upwind, you can get a complete picture of the wind and gusts in the next 5 seconds.
This means that there are never any unexpected gusts, or winds in the last 5 seconds. (Or more strictly, the unknown magnitude is vastly smaller)
You measure the wind environment in a shell around the craft, and build in these expected forces into your landing model, instead of assuming a simple constant wind field at the same value you measured 5s before landing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/27/2016 02:07 PM
using a ship-carrier to get the ASDS out on station a fair bit quicker than any "fast tug" could tow it.
Once the ASDS was on that ship carrier then there would be no ship to ship motion so a crane mounted on the ship carrier could pluck the stage off the ASDS then return the empty ASDS to the water to catch another.  BUT a) would still have pendulum motion to deal with while its hanging from the crane, b) initial contact between the ASDS and ship carrier would be hellatious since they'd be moving in the waves differently (vs.normal loading in a calm harbor), c) this is the max $$$$$ solution.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/27/2016 02:24 PM
Why are we making a big of this?
A.  The flight rate isn't going to be that high (for ASDS missions) to need the transfer.
b.  The problem was fixed long ago (it was designed for the open sea)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/27/2016 03:47 PM
No activity visible on OCISLY.

Ready for Friday night departure?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/27/2016 04:07 PM
Why are we making a big of this?
A.  The flight rate isn't going to be that high (for ASDS missions) to need the transfer.
b.  The problem was fixed long ago (it was designed for the open sea)
That looks like a really expensive solution.  I'll bet if someone tried it using such fancy and expensive equipment they'd go out of business.  Needs to be a SpaceX budget(able) solution.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/27/2016 04:44 PM
My humble opinion...  ???
The cheapest solution here... is start the ball rolling on the OCISLY barge copy to be built for the upcoming Texas need...
And charter much more powerful tugs to do "fast drags" of barges to where they are needed...  as needed...
Base whole east coast fleet out of Port Canaveral...
For Texas launches... drag one down south of Miami and do a small boost forward if need be to reach it...
Mix in some RTLS at both pad sites...
Job Done...
Just my opinion...  ;)

edit... spelling
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/27/2016 05:09 PM
I don't see any need to know the precise wind speed in the final moments before touchdown except for after-the-fact analysis (which IMHO they would need) because there's no way to make use of the data in real time.

With adequate measurement upwind, you can get a complete picture of the wind and gusts in the next 5 seconds.
This means that there are never any unexpected gusts, or winds in the last 5 seconds. (Or more strictly, the unknown magnitude is vastly smaller)
You measure the wind environment in a shell around the craft, and build in these expected forces into your landing model, instead of assuming a simple constant wind field at the same value you measured 5s before landing.

True, they theoretically might be able to generate something like that with enough data points, but being able to put it to use (other than for later analysis) is another matter; there isn't currently a way to do so, because there's no way to uplink the data to the F9, and no way for the F9's flight control program to make use of it.

It's also worth bearing in mind that gusts are less of an issue at sea than on land (on average, there's far less variance between maximum and minimum wind speeds except in major storms). It's the same dynamic that gives us far steadier winds on flat plains than in the mountains; a flat surface vs. an uneven one.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/27/2016 06:39 PM
Why are we making a big of this?
A.  The flight rate isn't going to be that high (for ASDS missions) to need the transfer.

Sorry, Jim, but that's just too rational for this thread.  :)

By my way of figuring, one ASDS means a capability to handle launches a week apart - less, if a faster tug is used. So, if we assume 50% ASDS landings, one ASDS could handle a flight rate approaching 80 launches a year (40 to ASDS) - and thus worrying about it now is rather akin to worrying about the demise of the sun in a few billion years. If there are launches scheduled too close together, say two days apart, IMHO it'd be easier and far cheaper to adjust the schedule slightly than to create a transfer capability or expand the ASDS fleet. 

The spirit of Rube Goldberg does not merely walk through this thread, it parades in grand style.   ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/27/2016 06:53 PM
The spirit of Rube Goldberg does not merely walk through this thread, it parades in grand style.   ;)
Fanciful stuff has always been unwelcome... Jim's example, and the example of the crane that can handle movement of the ship it's mounted on... are real things that real people built and put into service to solve real problems.  I'm inclined to let those slide, but fanciful stuff? No. there are other threads for that.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cuddihy on 04/27/2016 09:43 PM
Also, what US Navy does, for example, to crane on/ off missiles from one ship to another is just separate the crane platform from either ship... i.e. use an aircraft. For missiles, a helicopter works.

I'm not sure a helicopter big enough for F9 exists, but there are airships in planning that would be big enough.

You'd really need a substantial flight rate to justify it, and at that point the economics probably point to it being more effective to either take them straight off the barge and fly to the hangar at the launch pad, or build a refueling/ sea launch platform to fly themselves back to the pad.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Brian45 on 04/27/2016 10:29 PM
Given the inherently dangerous act of landing a rocket on a moving platform, I would think that the risk of having a barge get taken out and have no sea landing capability for a few weeks/months while it is repaired/replaced would motivate SpaceX to have at least some sort of contingency barge plan on stand-by that could be rapidly put into service.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/27/2016 11:37 PM
using a ship-carrier to get the ASDS out on station a fair bit quicker than any "fast tug" could tow it.
Once the ASDS was on that ship carrier then there would be no ship to ship motion so a crane mounted on the ship carrier could pluck the stage off the ASDS then return the empty ASDS to the water to catch another.  BUT a) would still have pendulum motion to deal with while its hanging from the crane,

I wouldn't suggest doing this.. but that doesn't stop you from doing so. :)

b) initial contact between the ASDS and ship carrier would be hellatious since they'd be moving in the waves differently (vs.normal loading in a calm harbor),

Wrong.  Obviously they don't load in a typhoon, but there are plenty of videos on-line of ship loading at sea so I won't try to post one here (Dockwise are the biggest in this game, so start there).  Essentially the ship-carrier submerges and moves slowly (1-5 kts depending on conditions) to windward whilst the barge/ship comes in behind.  The wide front of the carrier creates a calm essentially wave-free area behind and once the barge/ship is tied off they blow ballast tanks and increase speed.. 

c) this is the max $$$$$ solution.

I'm not so sure about that.  It's certainly cheaper than Jim's solution and you pay per trip.  There aren't many crew required either since it's a straightforward operation.  If they didn't need the support ships for other reasons, I expect it would be far cheaper than having the ASDS towed out there the way they currently do. Heck, if they were really concerned about there-and-back man/hour costs (and they may not be) they could carry the support tugs out also.  8)

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/28/2016 01:29 AM
Given the inherently dangerous act of landing a rocket on a moving platform, I would think that the risk of having a barge get taken out and have no sea landing capability for a few weeks/months while it is repaired/replaced would motivate SpaceX to have at least some sort of contingency barge plan on stand-by that could be rapidly put into service.

The risk of rendering an ASDS nonoperational for the next launch via a landing anomaly (one that ends with a kaboom) IMHO increases as the launch tempo increases (less time between sorties to effect repairs). My guesstimate is that SpaceX has, or will have, some sort of near-term contingency plans. My guess as to what they might be would be a kit to make seaworthiness repairs; a slab of deck plate (perhaps thicker than the current deck plate) to be welded over a hole for a temporary but seaworthy repair to damage like we saw recently, and perhaps more importantly, pre approval to do that sort of repair from both the hull owner and the Coast Guard inspector. Also, to speedily replace components such as we see in the modular gear on deck, the thrusters, etc, a written plan to remove those components (whatever is needed) from the ASDS on the opposite coast and air ship them to the one in need. Just having a plan in place would speed the process enormously.

Or, if the hull damage was such that it couldn't be fixed in time, a company that once famously re-purposed a pizza pan as an airborne directional antenna might rush into service a temporary ASDS; any flat-topped barge (or anything else with a large flat area that's strong enough) it could find, and send it out as-is (with the jacks and straps needed to secure the landed F9). The only absolutely necessary thing (IMHO) it couldn't do that an ASDS can is station keep, and that could be addressed via deep sea anchoring (regular anchors with very long anchor line, dropped well off each corner of the barge (about three times the depth) to keep it in place. This can be done in deep water (2000 or so feet is common in the usual recovery zone). It'd be very imperfect and ad-hoc, but might be worth the try vs. certain loss of the stage.   

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/28/2016 02:15 AM
The only absolutely necessary thing (IMHO) it couldn't do that an ASDS can is station keep, and that could be addressed via deep sea anchoring (regular anchors with very long anchor line, dropped well off each corner of the barge (about three times the depth) to keep it in place. This can be done in deep water (2000 or so feet is common in the usual recovery zone). It'd be very imperfect and ad-hoc, but might be worth the try vs. certain loss of the stage.   


Not even enough to work.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/28/2016 03:49 AM
The only absolutely necessary thing (IMHO) it couldn't do that an ASDS can is station keep, and that could be addressed via deep sea anchoring (regular anchors with very long anchor line, dropped well off each corner of the barge (about three times the depth) to keep it in place. This can be done in deep water (2000 or so feet is common in the usual recovery zone). It'd be very imperfect and ad-hoc, but might be worth the try vs. certain loss of the stage.   

Not even enough to work.

I'm not questioning that it won't work, but I'm curious to know why it won't work?

One big issue even I can see is you'd need approx 5 miles of zero buoyancy anchor line (with enough strength to hold a barge against current and seas), which is both bulky and rather pricy in that quantity, as well as a major job to deploy and recover.

Having personally dropped a lot of anchors for four-point anchoring, I'm moderately sure that four anchors as described could hold a barge in a sufficiently fixed position in fairly calm conditions (assuming the wind and sea direction don't change), BUT, placing it exactly at a per-determined set of coordinates is probably near impossible; it's going to end up fixed by up to a hundred yards off center in any direction (once the anchors are set and the rodes are trimmed) and I have no clue whatsoever if an F9, before launch but on the pad, could be programmed with a new aim point a hundred yards or so from the original one.  EDIT: Just did some calculations and I'm flat out wrong on anchoring; even with weighted rodes well trimmed for slack, that kind of length would have enough play in it to allow the barge to move by a width or more with even slight changes in current wind, and sea and sea.

What else did I miss?
Thanks!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 04/28/2016 03:57 AM
My humble opinion...  ???
The cheapest solution here... is start the ball rolling on the OCISLY barge copy to be built for the upcoming Texas need...
And charter much more powerful tugs to do "fast drags" of barges to where they are needed...  as needed...
Base whole east coast fleet out of Port Canaveral...
For Texas launches... drag one down south of Miami and do a small boost forward if need be to reach it...
Mix in some RTLS at both pad sites...
Job Done...
Just my opinion...  ;)

edit... spelling


Wouldn't a boost forward increase the re-entry velocity?  Heating is critical enough as it is.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/28/2016 06:22 AM
Deep sea anchoring (as used in oceanography buoys) is not like conventional anchoring, you don't want or need 3x scope.
The only realistic way of holding station is if the barge is self propelled, ideally using multiple thrusters. SpaceX have already got this one right.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/28/2016 10:17 AM
So we're expecting OCISLY to depart sometime tomorrow (Friday), correct?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/28/2016 01:04 PM
So we're expecting OCISLY to depart sometime tomorrow (Friday), correct?


Yes, late Friday night if they follow the same script as SES-9.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/28/2016 01:08 PM
I always expect to see the ASDS leave port around the time of a successful static fire, although I think they left port shortly before the successful static fire of ses-9 (but after the start of the scheduled static fire window, IIRC; the static fire came late on the window).  I haven't heard anything about static fire timing for this one.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/28/2016 01:15 PM
I always expect to see the ASDS leave port around the time of a successful static fire, although I think they left port shortly before the successful static fire of ses-9 (but after the start of the scheduled static fire window, IIRC; the static fire came late on the window).  I haven't heard anything about static fire timing for this one.

Probably will have to leave before static fire, again.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/28/2016 01:31 PM
My humble opinion...  ???
The cheapest solution here... is start the ball rolling on the OCISLY barge copy to be built for the upcoming Texas need...
And charter much more powerful tugs to do "fast drags" of barges to where they are needed...  as needed...
Base whole east coast fleet out of Port Canaveral...
For Texas launches... drag one down south of Miami and do a small boost forward if need be to reach it...
Mix in some RTLS at both pad sites...
Job Done...
Just my opinion...  ;)

edit... spelling


Wouldn't a boost forward increase the re-entry velocity?  Heating is critical enough as it is.

How about call it upward boost... loft it a bit to add some downrange to the ballistic arc it's on...
Once the S2 has gone on... adding some loft to S1 to increase downrange should use little fuel margin...
Lofting burn...
Reentry burn...
Landing burn...

Think RTLS... but going the wrong way on the first burn...  :o

Again just thinking out loud...  ;)

On edit...
To clarify my original thought...
Two barges at Port Canaveral implies you now have flexibility and a spare on hand...
Worst case is one down south catching one from Texas and one out east catching one from the Cape at the same time...
Otherwise you have just built in some flexibility to fix or unload one while the other is busy... into your process...
Having them based together gives you options that splitting them up takes away...
Since SpaceX has indicated IIRC Texas is to be mostly Geo orbits... then my suggestion fits the need...
Just saying...  ;)

More edit...
Sure... your going for about 1100 miles downrange to catch S1 out of Texas... bit of a loft ok
BUT, your only dragging a barge less then 400 miles south to pull it off...
Just suggesting one idea... and a cheap and flexible one...  ;)

Even more edit...
Go catch two stages going two directions from 39A and 40 from the Cape same day even...
Catch a FH booster close in and the core far downrange... with the other booster to LZ1...
Like I said... lots of cheap options basing two barges at the Cape and none in Texas...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/28/2016 04:18 PM
Regarding the suggestions to get a larger / faster tug to give faster turnaround on 1 ASDS, two thoughts / suggestions for comment -
a) Are multiple tugs an option?  Seems like E3 is already at the large end of the spectrum though certainly not the biggest.
b) It seems to me that the easiest way to speed up the tugging is to have the ASDS unballasted during towing.  IIRC, there is 12' of water in the tanks to enhance stability during landing.  Or was it enough water to cause 12' of draft?  Whichever way, without ballast the ASDS drafts about 3'.  That's a lot less drag and a lot more speed.  Is this ballast needed for towing?  Assuming that the F9 can handle more rocking motion during tow?  If yes to all of the above then fit the ASDS with a built in ballast pumping system.

Regarding the proposals for deep sea anchoring -
Perhaps that scheme would benefit from having the anchor lines connected to 4 autonomous drone winches?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/28/2016 04:37 PM
EDIT: Just did some calculations and I'm flat out wrong on anchoring; even with weighted rodes well trimmed for slack, that kind of length would have enough play in it to allow the barge to move by a width or more with even slight changes in current wind, and sea and sea.


Bingo
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/28/2016 07:37 PM
Regarding the suggestions to get a larger / faster tug to give faster turnaround on 1 ASDS, two thoughts / suggestions for comment -
a) Are multiple tugs an option?  Seems like E3 is already at the large end of the spectrum though certainly not the biggest.
b) It seems to me that the easiest way to speed up the tugging is to have the ASDS unballasted during towing.  IIRC, there is 12' of water in the tanks to enhance stability during landing.  Or was it enough water to cause 12' of draft?  Whichever way, without ballast the ASDS drafts about 3'.  That's a lot less drag and a lot more speed.  Is this ballast needed for towing?  Assuming that the F9 can handle more rocking motion during tow?  If yes to all of the above then fit the ASDS with a built in ballast pumping system.

Regarding the proposals for deep sea anchoring -
Perhaps that scheme would benefit from having the anchor lines connected to 4 autonomous drone winches?

Mark, IMHO that's an excellent point on ballasting; taking the ASDS out ballasted absolutely increases drag, and thus reduces speed.

My question is, do we know whether it's salt or fresh water? If it's salt water, there's IMHO no reason why it would be hard to give the ASDS the capability to self-ballast on location (if it does not already have it). If that ballast water is fresh water (and also the source for the deck water cannons) then it becomes a bit harder, depending on the reasons. If the ASDS holds can't handle salt water due to corrosion concerns, then enabling it to do so would be harder (perhaps as hard as painting the interior with the same sort of paint as used on the exterior underwater areas). As for the water cannon, if those are fresh water, perhaps the ASDS could sortie with only one or two compartments ballasted with fresh water, and the rest empty (to be ballasted on location).

Hrmmm. I wonder what the towing speed difference is with an unballasted ASDS vs. a ballasted one? Elsbeth III is small for an oceangoing tug, but not underpowered (5000HP). but the real number we're looking for is bollard pull (the actual amount of force applied via the towline). That varies with tug engine, powertrain, and prop design so it's not a straight conversion from horsepower, but I'm lazy and just looking for a ballpark figure so... turns out Smith Marine has the answer; 50 tons. The tow line is 2 1/4 inch steel, which can easily handle that kind of load.

As for the ASDS... we need to calculate drag. So, I'm going to pretend the ASDS is just a barge (the only parts in the water essentially are). I'm way the heck out of my depth (pun intended) here, because I know how to do this for yachts, not barges, so I may be way the heck off. Okay, the two main factors are skin friction and wave (wake) making. Skin friction increases linearly with wetted area (so doubling the wetted hull area via ballasting or loading doubles skin friction) but speed increases drag by the square of the speed. So, doubling the speed doesn't double the drag, it squares it. Therefor, to go faster, you really, really need smaller wetted area vs. more power - so your point about ballasting is spot on; getting rid of the ballast (and halving the wetted area) would have far more impact on potential speed than getting a larger tug with twice the bollard pull.

I really should give calculating the actual potential speeds a try, but I need to look up some formulas for that, so I'll need some free time and coffee, neither of which are available to me at the moment. If I can, I'll give it a whirl later.
   

 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/28/2016 07:48 PM
Old small powerboat driver here (in my misspent youth) and I remember the faster you could get on plane[1], the faster you could reach top speed. I also remember  that we got on plane faster if there weren't a lot of people in the bow seats, thus improving the angle of attack.

So if we're talking about manipulating ballast, any merit in having the front of the ASDS ride higher so it would plane easier? I don't know if it's even feasible to speak of getting a barge on plane.. how much more powerful of a tug is needed?

I also remember that the ride was rougher when you're on plane, especially when the waves were certain unfortunate heights/periods, so that there would be a perodic oscillation that would build up. (which you addressed by changing speed slightly) So maybe even if you COULD get on plane you might not WANT to, as it would damage the equipment. (maybe you plane on the way out but return more slowly so as not to damage the stage??)

Note that once you are on plane your wetted area (and thus, drag) goes way down. This is why getting on plane is key for a floatplane that wants to actually take off. As long as it's wallowing it'll never get up enough speed to get airborne. It takes more power to GET on plane than it does to STAY on plane so the excess power then can be used to accelerate further.

1 - https://en.wikipedia.org/wiki/Planing_%28boat%29
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/28/2016 08:06 PM
Quote
So if we're talking about manipulating ballast, any merit in having the front of the ASDS ride higher so it would plane easier? I don't know if it's even feasible to speak of getting a barge on plane.. how much more powerful of a tug is needed?

A million-pound barge on a plane? Shirley, you jest.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/28/2016 08:23 PM
Quote
So if we're talking about manipulating ballast, any merit in having the front of the ASDS ride higher so it would plane easier? I don't know if it's even feasible to speak of getting a barge on plane.. how much more powerful of a tug is needed?

A million-pound barge on a plane? Shirley, you jest.  ;)
On plane, not on *A* plane. And don't call me Shirley. :) I trust you did read the WP article I linked...

Although it does seem unlikely, the ASDS does have one thing going for it, the aft end is flat, which helps to achieve planing. But the power required to overcome the hull speed might be immense.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/28/2016 08:32 PM
Lar,

Kabloona is right.  It'll be best if you cop to a jesting charge.

There are planing hulls and there are displacement hulls.  Barges and tug boats have displacement hulls.

CJ,

Yes, the fresh vs. salt question is a large question and I don't know the answer.  The other question that figures large into my unballasting suggestion is whether the towing of CRS-8 back to port was done at a reduced speed because they felt the stage couldn't handle more boaty motion than it was getting at the reduced speed....or not.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 04/28/2016 08:43 PM
Regarding the suggestions to get a larger / faster tug to give faster turnaround on 1 ASDS, two thoughts / suggestions for comment -
a) Are multiple tugs an option?  Seems like E3 is already at the large end of the spectrum though certainly not the biggest.
b) It seems to me that the easiest way to speed up the tugging is to have the ASDS unballasted during towing.  IIRC, there is 12' of water in the tanks to enhance stability during landing.  Or was it enough water to cause 12' of draft?  Whichever way, without ballast the ASDS drafts about 3'.  That's a lot less drag and a lot more speed.  Is this ballast needed for towing?  Assuming that the F9 can handle more rocking motion during tow?  If yes to all of the above then fit the ASDS with a built in ballast pumping system.

Regarding the proposals for deep sea anchoring -
Perhaps that scheme would benefit from having the anchor lines connected to 4 autonomous drone winches?

Mark, IMHO that's an excellent point on ballasting; taking the ASDS out ballasted absolutely increases drag, and thus reduces speed.

My question is, do we know whether it's salt or fresh water? If it's salt water, there's IMHO no reason why it would be hard to give the ASDS the capability to self-ballast on location (if it does not already have it). If that ballast water is fresh water (and also the source for the deck water cannons) then it becomes a bit harder, depending on the reasons. If the ASDS holds can't handle salt water due to corrosion concerns, then enabling it to do so would be harder (perhaps as hard as painting the interior with the same sort of paint as used on the exterior underwater areas). As for the water cannon, if those are fresh water, perhaps the ASDS could sortie with only one or two compartments ballasted with fresh water, and the rest empty (to be ballasted on location).

Hrmmm. I wonder what the towing speed difference is with an unballasted ASDS vs. a ballasted one? Elsbeth III is small for an oceangoing tug, but not underpowered (5000HP). but the real number we're looking for is bollard pull (the actual amount of force applied via the towline). That varies with tug engine, powertrain, and prop design so it's not a straight conversion from horsepower, but I'm lazy and just looking for a ballpark figure so... turns out Smith Marine has the answer; 50 tons. The tow line is 2 1/4 inch steel, which can easily handle that kind of load.

As for the ASDS... we need to calculate drag. So, I'm going to pretend the ASDS is just a barge (the only parts in the water essentially are). I'm way the heck out of my depth (pun intended) here, because I know how to do this for yachts, not barges, so I may be way the heck off. Okay, the two main factors are skin friction and wave (wake) making. Skin friction increases linearly with wetted area (so doubling the wetted hull area via ballasting or loading doubles skin friction) but speed increases drag by the square of the speed. So, doubling the speed doesn't double the drag, it squares it. Therefor, to go faster, you really, really need smaller wetted area vs. more power - so your point about ballasting is spot on; getting rid of the ballast (and halving the wetted area) would have far more impact on potential speed than getting a larger tug with twice the bollard pull.

I really should give calculating the actual potential speeds a try, but I need to look up some formulas for that, so I'll need some free time and coffee, neither of which are available to me at the moment. If I can, I'll give it a whirl later.
   

Won't make any difference you are fighting two facing two large limiting factors:

1) Drag- goes up exponentially till it starts to plane---Not going to happen   ::)
Don't need to do the math typical drag plot attached.

2) Propeller efficiency.  Propellers are designed for specific working limits. See the Wageningen B series curves below. We call these the fishhook curves. (thrust & torque-vertical axis, and speed-horizontal are dimensionless coefficients) Back in the day you could figure out which pitch by looking at you motor torque and drag numbers to match them to the best pitch on this chart. If you have controllable pitch propeller you get all the curves just set you operating point.  Notice how the lines drop sharply after they reach a maximum; these correspond to the torque coefficient.  This is what happens when you over power a propeller;  it cavitates and stops pulling.

The fastest we have seen the tugs is about 7 Kts(J=1.0). So Assuming these curves and controllable pitch propeller ( we get all the pitch lines) J / speed maxes out at 1.2 or 8.4 Kts.  Less than a knot and a half.
That's if you have enough power to overcome the drag.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/28/2016 08:50 PM
Next mod to the ASDS... more power...  :o
Add a 20,000+hp gas turbine stern drive to the hull...
Give the tug a remote control to the powerplant...
Tell em to dial it up till it tries to pass you...  ;D

on edit...
I'm kidding of course...  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: acsawdey on 04/28/2016 08:53 PM
https://twitter.com/elonmusk/status/565637505811488768?lang=en (https://twitter.com/elonmusk/status/565637505811488768?lang=en)

Elon mentioned giving it a Merlin. How fast would that go?  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/28/2016 08:54 PM
Doesitfloat-

- Is ballasting with sea water OK?
- If the ASDS were easier to tow couldn't the propellers on the tug be changed to be efficient at a higher speed?
- What do you think of towing the ASDS unballasted?
- Built in ballasting / unballasting system feasible?  Rapid?


edit: I don't think a Merlin or a 20,000 hp gas turbine would be a productive modification.  Look at the drag curve.  Need to do something to create a different curve.  Thus my inquiry on unballasting.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rds100 on 04/28/2016 08:54 PM
It can work, if the stage is towing the ASDS, should have enough power  ;) Just kidding.
I'm still for "pickup the stage with a sufficiently large helicopter and bring it to shore this way, leave the ASDS in place waiting for the next stage". Unfortunately i was told that such a helicopter doesn't exist today.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 04/28/2016 08:58 PM
Next mod to the ASDS... more power...  :o
Add a 20,000+hp gas turbine stern drive to the hull...
Give the tug a remote control to the powerplant...
Tell em to dial it up till it tries to pass you...  ;D

on edit...
I'm kidding of course...  ;)

But You're right it will fit on an LCAC


****Elon---We need a Hovercraft****
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/28/2016 09:08 PM
Kabloona is right.  It'll be best if you cop to a jesting charge.

I'll plead ignorance but not jesting. I never jest. Honest. :)

I bet there's a way to get that barge on plane.  Just not a practical way.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 04/28/2016 09:12 PM
Doesitfloat-

- Is ballasting with sea water OK?
- If the ASDS were easier to tow couldn't the propellers on the tug be changed to be efficient at a higher speed?
- What do you think of towing the ASDS unballasted?
- Built in ballasting / unballasting system feasible?  Rapid?


edit: I don't think a Merlin or a 20,000 hp gas turbine would be a productive modification.  Look at the drag curve.  Need to do something to create a different curve.  Thus my inquiry on unballasting.

Ballasting with seawater is normal.  Most ports require ships to exchange ballast water 15-20 miles out to limit invasive marine species.

Very difficult to change to high speed propellers.  Whole boat/engine/ gearbox set up to pull/push at slow speed.

Easier to tow ballasted.  Less movement on the end of a long towline.

Built in ballasting is possible not usually done on a deck cargo barge. Just tanks below the deck; no machinery per classification.  We have seen pictures using the Marmac barges as dry-dock equipped with external piping to ballast tanks.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/28/2016 09:18 PM
Kabloona is right.  It'll be best if you cop to a jesting charge.

I'll plead ignorance but not jesting. I never jest. Honest. :)

I bet there's a way to get that barge on plane.  Just not a practical way.

To be serious, no. Power requirement for a displacement hull that size to plane approaches infinity, more or less.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/28/2016 09:54 PM
***Hydrofoil Barge***
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/28/2016 09:58 PM
Quote
***Hydrofoil Barge***
Get real.


Does anyone have an app or such that will send (me) a message when a ship that is stationary for a long period of time moves?  Or when an AIS transponder is turned on?  I'm thinking currently of EIII, which is by Fishlips and off the grid, but this functionality would be useful in other cases as well, particularly in monitoring the west coast fleet.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/28/2016 10:46 PM
Regarding the suggestions to get a larger / faster tug to give faster turnaround on 1 ASDS, two thoughts / suggestions for comment -
a) Are multiple tugs an option?  Seems like E3 is already at the large end of the spectrum though certainly not the biggest.
b) It seems to me that the easiest way to speed up the tugging is to have the ASDS unballasted during towing.  IIRC, there is 12' of water in the tanks to enhance stability during landing.  Or was it enough water to cause 12' of draft?  Whichever way, without ballast the ASDS drafts about 3'.  That's a lot less drag and a lot more speed.  Is this ballast needed for towing?  Assuming that the F9 can handle more rocking motion during tow?  If yes to all of the above then fit the ASDS with a built in ballast pumping system.

1.  IIRC from the same discussion we had last thread, the ASDS is ballasted with fresh water and it's the same water that's used to hose down the deck during landing.  There was some talk around them not wanting to hose down the stage with salt..  ::)

2.  For all the reasons recently posted, the only practical way to get the ASDS out there faster than towing it is to pick the whole lot up, tugs and all, and carry it - hence my earlier suggestion re. Dockwise.  With cruising speeds around 15-20kts their entire business model is based around getting barge and tugs (and ships too, I guess) from Point 'A' to Point 'B' as quickly as possible.

https://en.wikipedia.org/wiki/Dockwise

(https://upload.wikimedia.org/wikipedia/commons/3/32/MV_Blue_Marlin_carrying_USS_Cole.jpg)


EDIT: ..and, before anyone asks, no, you couldn't land an F9 stage on the deck of the transporter.  They don't use (or need) any kind of active positioning system and, with hulls optimised for speed, roll like pigs when lightly loaded..
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/28/2016 11:05 PM
...ya but can they get on plane to go faster? :)

Actually 15kt is significantly fast.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/28/2016 11:17 PM
...ya but can they get on plane to go faster? :)

Actually 15kt is significantly fast.

Remember that to carry another vessel, they're all pretty decent-sized ships.. and displacement hull speed increases proportional to water line length.

Eg.: Without wanting to go too far off-topic, below is a pic of a Pilot boat holding station with a cruise ship we were on last year.  Needless to say, we were plodding slowly along and he was trying his hardest to keep up! :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/29/2016 01:15 AM
@ Cameron D; thanks for the fresh water info; I'd forgotten that, and it makes sense they'd use fresh water.

Won't make any difference you are fighting two facing two large limiting factors:

1) Drag- goes up exponentially till it starts to plane---Not going to happen   ::)
Don't need to do the math typical drag plot attached.

2) Propeller efficiency.  Propellers are designed for specific working limits. See the Wageningen B series curves below. We call these the fishhook curves. (thrust & torque-vertical axis, and speed-horizontal are dimensionless coefficients) Back in the day you could figure out which pitch by looking at you motor torque and drag numbers to match them to the best pitch on this chart. If you have controllable pitch propeller you get all the curves just set you operating point.  Notice how the lines drop sharply after they reach a maximum; these correspond to the torque coefficient.  This is what happens when you over power a propeller;  it cavitates and stops pulling.

The fastest we have seen the tugs is about 7 Kts(J=1.0). So Assuming these curves and controllable pitch propeller ( we get all the pitch lines) J / speed maxes out at 1.2 or 8.4 Kts.  Less than a knot and a half.
That's if you have enough power to overcome the drag.

Thanks, you saved me from some research and math.

The props on Elsebeth III are 3 Bird-Johnson props in Kort nozzles (in other words, ducted props, not variable pitch, and that type of nozzle is often used on low speed craft, as it loses its usefulness at about 9 knots).

The tugs have been seen towing an ASDS at 7 knots? Any idea where? If it's in a strong favoring current, that's not a true speed, but if that's actual speed through the water, that's actually quite an improvement from 5 knots. To go out 400 standard miles, 69 hours at 5 knots, 49 hours at 7kt. Shaving off 20 hours each way might be quite useful in case of a scheduling bottleneck necessitating a fast ASDS turnaround.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 04/29/2016 02:29 AM
The tugs have been seen towing an ASDS at 7 knots? Any idea where? If it's in a strong favoring current, that's not a true speed, but if that's actual speed through the water, that's actually quite an improvement from 5 knots. To go out 400 standard miles, 69 hours at 5 knots, 49 hours at 7kt. Shaving off 20 hours each way might be quite useful in case of a scheduling bottleneck necessitating a fast ASDS turnaround.

Nope.  The issue, pure an simply, is fuel economy.

From Doesitfloat's graphs we see drag increases exponentially with speed and, generally speaking, fuel consumption follows a similar curve.  There is a limit to the amount of fuel each of the Support Tugs can carry (ASDS on-station duration is similarly constrained), so whether or not they can do the tow at 7kts becomes kinda irrelevant if they'll run out of fuel when they get there and need to call the USCG to tow them back.

I wonder how fast a Coast Guard Cutter could tow an ASDS??  ;D
 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/29/2016 05:22 AM
I wonder how fast a Coast Guard Cutter could tow an ASDS??  ;D
 

USCG cutters are just frigate size units that can keep pace with Amphibious units.

A lot more interesting is how fast a Burke class Destroyer can towed the ASDS. Considering they are fitted to tow an active sonar array.  ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: The Amazing Catstronaut on 04/29/2016 06:15 AM

A lot more interesting is how fast a Burke class Destroyer can towed the ASDS. Considering they are fitted to tow an active sonar array.  ;D

Don't destroyers create a lot of wake for their size when moving at speed?  The sonar array is suspended under the waterline whilst towed so it's not all that vulnerable to wave action. The barge doesn't have that luxury.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/29/2016 07:57 AM
The tugs have been seen towing an ASDS at 7 knots? Any idea where? If it's in a strong favoring current, that's not a true speed, but if that's actual speed through the water, that's actually quite an improvement from 5 knots. To go out 400 standard miles, 69 hours at 5 knots, 49 hours at 7kt. Shaving off 20 hours each way might be quite useful in case of a scheduling bottleneck necessitating a fast ASDS turnaround.

Nope.  The issue, pure an simply, is fuel economy.

From Doesitfloat's graphs we see drag increases exponentially with speed and, generally speaking, fuel consumption follows a similar curve.  There is a limit to the amount of fuel each of the Support Tugs can carry (ASDS on-station duration is similarly constrained), so whether or not they can do the tow at 7kts becomes kinda irrelevant if they'll run out of fuel when they get there and need to call the USCG to tow them back.

I wonder how fast a Coast Guard Cutter could tow an ASDS??  ;D
 

Going from 5 to 7 knots looks like it increases drag by a factor of 3. So, let's factor in some guesses at reduced efficiency and say that it'll increase fuel consumption by a factor of 4, which is probably too high, but let's use it. That's not a problem (except for cost, so they'd only do it in case of need); Elsbeth III carries 80,000 gallons of diesel, and has towed a (on a normal speed run, not 7 knots) a 400 foot barge from Norfolk, Virginia, to Seattle, Washington (via Panama) on 70,000 gallons. That's about 7000 miles, so even if we divide that by 4 for a 7 knot tow, it's still a lot more than an ASDS sortie (max about 400 out, 400 back, plus some use on station). 

Uhoh, I feel a bit of a Rube Goldberg mood coming on, which is compelling me to ponder using one ASDS to recover two Falcon Heavy side cores... can it be done? The ideal way was one Lar came up with; land the cores on towards the opposite ends. But, if that's not viable (not enough accuracy) then... could an ASDS be joined by a deck barge, lashed stern to stern once on station  and the ASDS positioning system keep both of them on station? I'm assuming light seas here... so the ASDS thrusters should have the capacity, and the ASDS bow will be into the wind. I'm betting the ASDS positioning software would need some changes - but are there other reasons this wouldn't work?

 If there isn't a way to make an ASDS do double duty, they may need 3 ASDS for a non-RTLS FH launch; one for each side core and one further downrange for the center core.   
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: RobLynn on 04/29/2016 10:37 AM
Pitch and roll stabilisation can be done with a heavy concrete weight suspended 100's of meters below the barge by 4 equal length cables from each corner of the barge.  Because the cables are always in tension it behaves like an enormously long keel to transfer weight to whichever side is highest.

And for convenience you can leave it on the seabed between missions, only winching it up and attaching it to the barge when a mission with rough weather happens (though likely just as easy to fit a winch in middle of barge to haul it up on a 5th central cable).

Taken to the limit the concrete weight could be transported while the ASDS has no ballast water then lowered and rested on the bottom (which takes some of the weight) before pumping in water ballast so that you could also use the keel to eliminate heave and so have a perfectly stable platform.

Might save a bit on leg loads/mass.  And might also reduce the required leg length slightly.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jet Black on 04/29/2016 10:57 AM
I expect that if the reuse stuff works (we still don't know if those stages are reusable many times or not) and they get a decent launch cadence, they'll have to go for something much more custom than a jury rigged marmac barge, perhaps with separate landing/shipping elements so the large, unweildy landing element doesn't have to move far. What they have at the moment is ok for eperimentation, but not terribly efficient.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Semmel on 04/29/2016 12:29 PM
OK spacefans...er, barge fans...get ready for OCISLY to head out tonight.

So soon?

Anyway, I sincerely hope that this will bring back this thread to the quality of the old one. Since resetting, this thread has become way worse than the old one. First time I see that happening on this forum, usually its the other way around.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 04/29/2016 12:29 PM
OK spacefans...er, barge fans...get ready for OCISLY to head out tonight.

I will be in the port this afternoon, will check what's going on.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/29/2016 12:34 PM
OK spacefans...er, barge fans...get ready for OCISLY to head out tonight.

So soon?

Correction:

I'm expecting OCISLY to depart almost exactly 5 days (120-ish hours) before launch time based on SES-9 operations.

But the latest published launch NET was early morning hours of May 4th, and we've already passed that L-120 hours mark, with OCISlY still in port and no sign of activity. (Sorry, my math was off about expected departure tonight).

So this make me wonder if the launch date is slipping again and we just haven't heard yet. I expect we may hear a new NET today...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/29/2016 01:16 PM
As I mentioned earlier, usually we have a static fire schedule (even if only in L2) before the ASDS leaves port.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/29/2016 01:24 PM
As I mentioned earlier, usually we have a static fire schedule (even if only in L2) before the ASDS leaves port.

There is one scheduled in L2. Don't know why it's not also on the public side.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/29/2016 01:33 PM
OK spacefans...er, barge fans...get ready for OCISLY to head out tonight.

So soon?

Anyway, I sincerely hope that this will bring back this thread to the quality of the old one. Since resetting, this thread has become way worse than the old one. First time I see that happening on this forum, usually its the other way around.

Maybe we need to split into operational, with no future speculation at all (not even capacity calculations) and future speculation? I will ponder and then ask the big boss what he thinks. (says the guy who's part of the problem)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/29/2016 01:37 PM
Question... to steer this thread back to topic...  ;D

What would be the estimated cost (we think) to replicate OCISLY class ship as a new build...???

Right now... it's a leased asset with all kinds of add on (but removable) items...

Cost (all in) to build a clone to own...  ???

My WAG... $25 mil... I may be way off however...  :P
Those here with a better number based on experience... your thoughts?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: kevinof on 04/29/2016 01:51 PM
Divide by 10!  The barge itself is not a complicated build and therefore not a very high cost. Doesn't have a powerplant, rudders or anything fancy.

Not sure about the cost of the add-ons.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/29/2016 02:06 PM
Anyway, I sincerely hope that this will bring back this thread to the quality of the old one. Since resetting, this thread has become way worse than the old one. First time I see that happening on this forum, usually its the other way around.

I think the phenomenon you have seen is not related to this being thread 3 but rather that it coincided with the hugely successful thread chronicling the triumphant return to port.  That thread created some new ASDS fans or at least turned some new people onto this thread.  So now here we have not only the crusty old ASDS watchers that have seen every posting of every bit of ASDS news from beginning to end and can tell you the polar moment of inertia of the ASDS to within 1%, but also a fair portion of new blood who don't know it in that detail.  Some questions that have been answered will get re-asked.  It would be nice if we had a "what is known & resources" page to help out newer ASDS groupies.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/29/2016 02:11 PM
Is that a tug backing up to OCISLY on http://www.portcanaveralwebcam.com/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/29/2016 02:24 PM
Divide by 10!  The barge itself is not a complicated build and therefore not a very high cost. Doesn't have a powerplant, rudders or anything fancy.

Not sure about the cost of the add-ons.

Ok... so I am way off... lets say $3 mil for the hull with enclosed wings and thruster mounts... WAG
The rest... to own... $1+ mil... maybe $2 mil...
So $5 million (all in) to own an OCISLY clone...???

If so... catch one stage and bring it back... it's paid for...  :o
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 04/29/2016 02:27 PM
I have a spreadsheet for quick cost estimate.
Came up with 11 million.  If it was built in a shipyard.  McDonough Marine is not a shipyard so they will probably be cheaper.
In addition the cost of steel is currently at very low price. I gave $100 ton but it has fluctuated between 500-50 per ton since 2013.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 04/29/2016 02:30 PM
Way back in the ancient history of this thread we had links to the various sites where barges are listed for purchase or lease.  That would probably be a reasonable way to estimate value/cost.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/29/2016 02:36 PM
I have a spreadsheet for quick cost estimate.
Came up with 11 million.  If it was built in a shipyard.  McDonough Marine is not a shipyard so they will probably be cheaper.
In addition the cost of steel is currently at very low price. I gave $100 ton but it has fluctuated between 500-50 per ton since 2013.

Ok... lets say $10 mil for the hull... and $5 mil for all the rest... $15 mil all in to own a clone...
Still in the... catch one and it's paid for range...  :o
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: KSHavre on 04/29/2016 02:39 PM
As I mentioned earlier, usually we have a static fire schedule (even if only in L2) before the ASDS leaves port.

There is one scheduled in L2. Don't know why it's not also on the public side.

I do not want to break L2 rules. So I will say, no need to watch the webcam today, but hang in there!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris Bergin on 04/29/2016 03:19 PM
Yeah, was going to be tomorrow, but more likely Sunday or Monday (we're waiting for an updated schedule).

Anyhoo....barges. ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 04/29/2016 03:31 PM
Yeah, was going to be tomorrow, but more likely Sunday or Monday (we're waiting for an updated schedule).

Anyhoo....barges. ;D
ASDSssss (stamps foot!)

Seems to me that with the current slump in shipping, now is a good time to be negotiating long term leases or even new construction (or a lease of new construction that is purpose built)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 04/29/2016 05:58 PM
My opinion...  ;)
I'm starting to think "Semi trucks and trailers" to use an analogy...

ASDS's are the trailers... cheap (relatively) and can be spread around and left idle unmanned...
Tugs and Go boats... they are the costly items... Semi tractors and the crews to man them...

Build more Trailers (ASDS's) and spread them around to add capacity...
Have enough Tractors (Tugs / Go boats) to tend to active trailers to fit the pace...

Active ASDS's are really only active when they catch a stage at sea... other wise they are only in transit or being loaded/unloaded... (or sitting idle)

Go boats... really a little bigger boat that can stay at sea a while and tow a ASDS in a pinch would be ideal...
Same idea, same uses... just enough balls and fuel to also act as ASDS tugboat when the need is there...
Also... can stay out 30+ days and the crew have a comfortable stay while out on duty...

Tugs... hired help... I would not own tugs... but I would hire the best and use them to shuttle ASDS's in and out of ports...

I hope you see where this is going... this idea...
Tug#1 and ASDS#1 leaves port and slowly heads to drop zone...
Go+ boat goes on duty and catches up at sea with pair at the drop zone...
Go+ takes the ASDS in tow/control and Tug returns to port bareback
Go+ and ASDS separate on time and catches S1... secures and make ready to travel...
Tug#2 comes out towing ASDS#2 and they swap loads in tow...
Tug#2 brings S1 into port... Go+ takes ASDS#2 to next drop zone and repeats process...

Anyway... cost wise, this idea seems to make the most sense if things get real busy downrange...  ;)

On edit...
Go+ equals purpose made ship with helipad, a modest crane, deck storage, towing winches...
Purpose is an 'at sea' mother ship 'tender' to watch over and herd up to three ASDS+ barges at once within a 10 mile radius...
Has on board amenities to support a crew for up to 45 days on duty (max) on station...
Can tow a ASDS+ at modest speeds as needed...

ASDS+ equals new build unmanned normally drone ship with better integrated and larger thrusters and much more fuel capacity built into the hull...
Needs to be new build, purpose built, yet low cost, durable, easy to fix if crashed into, and normally unmanned...
Designed to be towed for distance moves... yet can station keep under Go+ control for days if need be...
Maybe can even follow along behind/beside the Go+ in open seas to move a grouping to a new drop zone...

Tugs equals hired 50+ton bollard pull ships to shuttle ASDS+ ships out to Go+ and back to port as needed..

Speed is not the concern... process constraint is overcome with numbers inbound and outbound...

With the above... you could scale up to a crazy fast launch cadence with a two Go+ ship fleet and a small herd of ASDS+ ships...

later edit... spelling...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/29/2016 10:54 PM
The tug and support boats were milling about in the harbor and then redocked
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 04/29/2016 10:57 PM
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 04/30/2016 01:05 AM
From the CRS-8 update thread;
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

https://www.youtube.com/watch?v=KDK5TF2BOhQ

it looks to me as if the F9 was moving upwind on approach. I wonder if this is coincidence, or a planned act? If the latter, it implies that the F9 guidance system can be updated just prior to launch in order to optimize for wind direction (whatever wind direction the ASDS or support ship are reporting near launch). 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 04/30/2016 01:28 AM
From the CRS-8 update thread;

it looks to me as if the F9 was moving upwind on approach. I wonder if this is coincidence, or a planned act? If the latter, it implies that the F9 guidance system can be updated just prior to launch in order to optimize for wind direction (whatever wind direction the ASDS or support ship are reporting near launch).
Musk said in the post-launch presser that the F9 was leaning into the wind. So maybe the ASDS was broadcasting real-time weather data.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/30/2016 02:11 AM
Has anyone seen a recent AIS position report for Elsbeth III? My MarineTraffic feed says her AIS was last updated 17 days ago. So either the app/data feed is wonky (though other ships like Go Quest have current position report updates), or her AIS transponder is turned off...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/30/2016 02:15 AM
From the CRS-8 update thread;

it looks to me as if the F9 was moving upwind on approach. I wonder if this is coincidence, or a planned act? If the latter, it implies that the F9 guidance system can be updated just prior to launch in order to optimize for wind direction (whatever wind direction the ASDS or support ship are reporting near launch).
Musk said in the post-launch presser that the F9 was leaning into the wind. So maybe the ASDS was broadcasting real-time weather data.
I don't know if it was upwind but I don't think that implies that the rocket required any external information prior to launch nor from external sources to know which way the wind is blowing.

The F9 knows it's orientation.  It knows its instantaneous position.  It knows the actions it is taking to target it's intended goal.  My guess is if SpaceX tries to adjust for wind in any sort of predictive way, then the first pass at doing so will be using information that the rocket can derive in realtime.

Like Bob Dylan said, you don't have to be a weatherman to know which way the wind is blowing. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Tuts36 on 04/30/2016 03:15 AM
From Elon Musk's twitter:

Quote

Phil Jackson ‏@phillipcjackson 5h5 hours ago Maryland, USA

[email protected] once it lands on the drone ship how do you secure it so it doesn't tip over? #SpaceX #model3reserved
1 retweet 0 likes

Elon Musk Verified account
‏@elonmusk

@phillipcjackson turns out it doesn't need securing


After all those lengthy discussions...!
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/30/2016 03:39 AM
From Elon Musk's twitter:

Quote

Phil Jackson ‏@phillipcjackson 5h5 hours ago Maryland, USA

[email protected] once it lands on the drone ship how do you secure it so it doesn't tip over? #SpaceX #model3reserved
1 retweet 0 likes

Elon Musk Verified account
‏@elonmusk

@phillipcjackson turns out it doesn't need securing


After all those lengthy discussions...!

Well, let's point out the obvious: the CRS-8 stage *was* in fact secured to OCISLY, but probably to prevent sliding around on deck (and guard against leg collapse) rather than "tipping over," which many of us here argued was never a real concern due to low CG. Good to hear Elon agrees with us.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/30/2016 03:44 AM
Has anyone seen a recent AIS position report for Elsbeth III? My MarineTraffic feed says her AIS was last updated 17 days ago. So either the app/data feed is wonky (though other ships like Go Quest have current position report updates), or her AIS transponder is turned off...

Probably just turned off while she's idle. We've seen her go dark in the past.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: tadaniels on 04/30/2016 05:41 AM
Isn't that Elsbeth III moored outboard of the GO twins in Jim's post #751?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/30/2016 09:17 AM
Isn't that Elsbeth III moored outboard of the GO twins in Jim's post #751?

Yup, that's her.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 04/30/2016 09:28 AM
Public reports elsewhere that launch has slipped until the 5th, which makes OCISLY departure probable early Sunday morning.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 04/30/2016 10:05 AM
Just wanted to say thanks to CameronD for having the patience to inject some realism into this discussion. As someone who works at sea I find some of the more outlandish questions and suggestions hilarious and/or exasperating.

SpaceX have got this right- off the shelf dynamic positioning system, barge, tug. Repeat as necessary for multiple recoveries.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: JeffinLondon on 04/30/2016 02:15 PM
Dumb question ya'll


Can someone say just how far the tugs are stationed away from the drone ship during a landing attempt?

Many thanks in advance.

 - Jeff
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: woods170 on 04/30/2016 03:24 PM
Dumb question ya'll


Can someone say just how far the tugs are stationed away from the drone ship during a landing attempt?

Many thanks in advance.

 - Jeff
Not a dumb question at all. The answer is: a few miles. Someone here is bound to have an exact number of miles for you.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/30/2016 05:39 PM
Quote
Dumb question ya'll
Are the Go * ships which I know have bow thrusters able to self park or do they need tugs?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: majormajor42 on 04/30/2016 05:59 PM
From the CRS-8 update thread;
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

https://www.youtube.com/watch?v=KDK5TF2BOhQ



wasn't there water being sprayed on deck during the landing on previous attempts? I don't see them doing this in the newest video.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 04/30/2016 06:20 PM
Thanks for the explanation of how the 3D view works.  I watched the video from a desktop yesterday and was puzzled by the 3D description.

As for the water spray, yes, that's been known from the previous overhead video.  One take on it is that they only used the water on the first few times because they were reacting to the deck doom scenarios posted on NSF and the proposed solutions.  Now that they see they don't need it they know not to take advice from NSF postings.  They'll probably go with engineering analysis from now on.   ;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: sewebster on 04/30/2016 06:30 PM
Thanks for the explanation of how the 3D view works.  I watched the video from a desktop yesterday and was puzzled by the 3D description.

FYI you can click and drag on the video when using a desktop to look around...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 04/30/2016 06:34 PM

Dumb question ya'll


Can someone say just how far the tugs are stationed away from the drone ship during a landing attempt?

Many thanks in advance.

 - Jeff
Not a dumb question at all. The answer is: a few miles. Someone here is bound to have an exact number of miles for you.
IIRC, when examining the FCC permits for transmission, the support ships are positioned roughly 10 (statute?) miles from the ASDS.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Hankelow8 on 04/30/2016 06:52 PM

Dumb question ya'll


Can someone say just how far the tugs are stationed away from the drone ship during a landing attempt?

Many thanks in advance.

 - Jeff






Not a dumb question at all. The answer is: a few miles. Someone here is bound to have an exact number of miles for you.
IIRC, when examining the FCC permits for transmission, the support ships are positioned roughly 10 (statute?) miles from the ASDS.



Now that Space X have proven their accuracy for landing  on ASDs, I wonder if they will be allowed to stand off at a much closer distance. 10 miles distance now seems way over the top for safety constraints.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: mme on 04/30/2016 08:13 PM

Dumb question ya'll

Can someone say just how far the tugs are stationed away from the drone ship during a landing attempt?

Many thanks in advance.

 - Jeff
Not a dumb question at all. The answer is: a few miles. Someone here is bound to have an exact number of miles for you.
IIRC, when examining the FCC permits for transmission, the support ships are positioned roughly 10 (statute?) miles from the ASDS.
Now that Space X have proven their accuracy for landing  on ASDs, I wonder if they will be allowed to stand off at a much closer distance. 10 miles distance now seems way over the top for safety constants.
I don't know for a fact but I think the safety concern is the IIP of debris and/or the rocket if something goes horribly wrong.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: IntoTheVoid on 04/30/2016 11:03 PM
OCISLY leaving the dock. Still in frame at http://www.portcanaveralwebcam.com/
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 04/30/2016 11:10 PM
Camera operator is on point with Ocisily views.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 04/30/2016 11:19 PM
Tug called Stephanie S pushing.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: acsawdey on 04/30/2016 11:22 PM
What is the yellow apparatus at the starboard rear of OCISLY? Seems like it has two vertical bars in back, a cylinder inside, and perhaps a ladder on the deck side? It seems to be overhanging the stern slightly.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 04/30/2016 11:26 PM
I noticed that thing too, I think it may be new. Got good screen shots of it, but don't think I can post them for IP reasons. On the other hand, it is not an angle we usually see Ocisly from.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jeff Lerner on 04/30/2016 11:53 PM
Kind of like watching paint dry...slow transit of Ocisly and tug...


......Aaannnnd we are done...web cam now showing another ship...hopefully the next time we see Ocisly there is another Falcon 9 standing tall on her deck....
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: MarekCyzio on 05/01/2016 12:27 AM
(http://uploads.tapatalk-cdn.com/20160501/17926c1e2e02f72a5259cf46e466dce6.jpg)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/01/2016 12:34 AM
I saw nothing on Marinetraffic for EIII today or yesterday when the three ships were splashing around the harbor.  Kinda odd considering Marinetraffic has a receiver bolted to Fishlips.  I only see one current hit and no path / track from EIII on Vesselfinder.  Is anyone seeing better with the other services?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: AnalogMan on 05/01/2016 12:53 AM
I saw nothing on Marinetraffic for EIII today or yesterday when the three ships were splashing around the harbor.  Kinda odd considering Marinetraffic has a receiver bolted to Fishlips.  I only see one current hit and no path / track from EIII on Vesselfinder.  Is anyone seeing better with the other services?

I see a track on both vesselfinder.com and marinetraffic.com

Position data seems to have been available since 00:28 UTC.  Currently heading about 120 degrees at 5 knots.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 05/01/2016 03:31 AM
Yes! Our girl Elsbeth III now transmitting and outbound. I hope her crew is even half as interested in her activity as we are...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/01/2016 11:45 PM
From the CRS-8 update thread;
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

It's a shame they didn't leave the camera running..  What would have been even more interesting in 360deg would be the sight of the safing crew coming aboard and doing their thing.
 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Zed_Noir on 05/02/2016 01:17 AM
From the CRS-8 update thread;
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

It's a shame they didn't leave the camera running..  What would have been even more interesting in 360deg would be the sight of the safing crew coming aboard and doing their thing.
 

Maybe they have the footage, just no released yet.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 05/02/2016 01:26 AM
From the CRS-8 update thread;
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

It's a shame they didn't leave the camera running..  What would have been even more interesting in 360deg would be the sight of the safing crew coming aboard and doing their thing.
 

And since this was a topic elsewhere - no sonic boom in the video...  Obvious why, but still cool.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ronsmytheiii on 05/02/2016 01:37 AM
Go Quest heading out to sea:

http://www.marinetraffic.com/en/ais/details/ships/shipid:450521/mmsi:367564890/imo:1155515/vessel:GO_QUEST

Edit: Same for Go Searcher

http://www.marinetraffic.com/en/ais/details/ships/shipid:426008/mmsi:366584000/imo:9591648/vessel:GO_SEARCHER
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/02/2016 02:46 AM
Go Quest heading out to sea:

http://www.marinetraffic.com/en/ais/details/ships/shipid:450521/mmsi:367564890/imo:1155515/vessel:GO_QUEST

Edit: Same for Go Searcher

http://www.marinetraffic.com/en/ais/details/ships/shipid:426008/mmsi:366584000/imo:9591648/vessel:GO_SEARCHER

Interesting to note that Marinetraffic's reporting AIS source in this instance is operated by "PTZtv and Fishlips".  Sounds like they've more invested in Port Canaveral than just a few cameras.


EDIT:  Go Searcher increasing speed..
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/02/2016 02:51 AM
if both Go sisters are going does that mean fairing recovery work?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/02/2016 03:39 AM
if both Go sisters are going does that mean fairing recovery work?

That's our working thoery, at least for fairing tracking if not yet recovery.

So far, GO Searcher has been dispatched on missions only with fairings, and stayed at home for CRS-8 (carrying Dragon instead of payload fairing).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 05/02/2016 06:13 AM
What is the yellow apparatus at the starboard rear of OCISLY? Seems like it has two vertical bars in back, a cylinder inside, and perhaps a ladder on the deck side? It seems to be overhanging the stern slightly.

I noticed that thing too, I think it may be new. Got good screen shots of it, but don't think I can post them for IP reasons. On the other hand, it is not an angle we usually see Ocisly from.

Matthew

I couldn't see departure so all I have are these still frames...anyway.

http://www.portfever.com/webcam_player_pcw.php?date=20160430&start=1141&end=1200

Frame 1159 onwards. Yes a ladder and guard rails on top. What could be its function? Also there is a roof shielding over space behind blast shield at stern where they keep jacks, gas cylinders, work platform and cherry picker etc . Nice to see Droneship evolution after every attempt! they have colored the mini shields protecting the hydraulic lines to thrusters as yellow too.

Adding an image I found on Instagram by user '_adamgoodwin'

https://www.instagram.com/p/BE0DaEmBzPM/

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: leetdan on 05/02/2016 06:22 AM
And since this was a topic elsewhere - no sonic boom in the video...  Obvious why, but still cool.

Except there was a sonic boom... Did you watch the same video?  Check your volume maybe ;)  There's ambient noise from the gensets, then three quick pops immediately followed by rocket sounds that persist until cutoff.  The mic on this setup lacks sufficient dynamic range, so the boom and thrust sounds don't sound much louder than the ambient noise on the recording.  I'm sure it's quite different in person :)

I can believe there being three pops at minimum range... During Orbcomm I heard two from State Road 3, and Jim heard 1 from wherever he was.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 05/02/2016 07:04 AM
And since this was a topic elsewhere - no sonic boom in the video...  Obvious why, but still cool.

Except there was a sonic boom... Did you watch the same video?  Check your volume maybe ;)  There's ambient noise from the gensets, then three quick pops immediately followed by rocket sounds that persist until cutoff.  The mic on this setup lacks sufficient dynamic range, so the boom and thrust sounds don't sound much louder than the ambient noise on the recording.  I'm sure it's quite different in person :)

I can believe there being three pops at minimum range... During Orbcomm I heard two from State Road 3, and Jim heard 1 from wherever he was.
Yes  - but not very boom like...  Could be the mikes.  Or that along the flight axis you get a much weaker "boom".

EDIT:
It took 17 seconds from that ratatat to touchdown.   If that happened at 340 m/s, then the stage was accelerating at 20 m/s, so had a T/W = 3.0, on average.

right?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 05/02/2016 08:08 AM
https://www.youtube.com/watch?v=FdYGu9bTLhQ

Posted by ugordan https://forum.nasaspaceflight.com/index.php?topic=38149.msg1464456#msg1464456

Had boom hit 13 sec before lights out so sonic boom hitting 17 seconds earlier on bulls eye sounds right and that is when Mr Seagull hitching a free ride on droneship decided not to be roasted so nothing too bothersome happened before the beginning of 360 video.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 05/02/2016 12:17 PM
if both Go sisters are going does that mean fairing recovery work?

That's our working thoery, at least for fairing tracking if not yet recovery.

So far, GO Searcher has been dispatched on missions only with fairings, and stayed at home for CRS-8 (carrying Dragon instead of payload fairing).
I'm a fan and proponent of that working theory.  Just to play devil's advocate, though: all the "with fairing" missions have been GTO attempts, right?  It's *possible* that the second Go * ship is there for some other GTO-related reason, maybe even just downrange distance, say.  We'll really get confirmation if we see it going out for a LEO-with-fairing mission... or if it comes back with bits of fairing on deck. ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/02/2016 01:39 PM
if both Go sisters are going does that mean fairing recovery work?

That's our working thoery, at least for fairing tracking if not yet recovery.

So far, GO Searcher has been dispatched on missions only with fairings, and stayed at home for CRS-8 (carrying Dragon instead of payload fairing).
I'm a fan and proponent of that working theory.  Just to play devil's advocate, though: all the "with fairing" missions have been GTO attempts, right?  It's *possible* that the second Go * ship is there for some other GTO-related reason, maybe even just downrange distance, say.  We'll really get confirmation if we see it going out for a LEO-with-fairing mission... or if it comes back with bits of fairing on deck. ;)

Yes, Searcher has done only GTO missions so far.

But hopefully they can perfect fairing recovery on GTO launches, not just LEO, otherwise there's really no point in trying since vast majority of fairings used will be on GTO's.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: leetdan on 05/02/2016 01:57 PM
Rewatching my landing video, I remembered wrong, it was also 3 pops in about the same cadence as this new video.

Here's how the Orbcomm landing's sonic boom was modeled; obviously the boom for an ASDS landing could be different for any number of reasons, but I'd say there's no chance of there not being a boom at ground zero.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 05/02/2016 03:13 PM
Rewatching my landing video, I remembered wrong, it was also 3 pops in about the same cadence as this new video.

Here's how the Orbcomm landing's sonic boom was modeled; obviously the boom for an ASDS landing could be different for any number of reasons, but I'd say there's no chance of there not being a boom at ground zero.
Yes, agreed.

So if a vehicle is moving towards you at some constant supersonic speed, how far ahead is the sonic boom?

(Then we can talk about a decelerating vehicle)

We should take this to a different thread, but if this is a way to figure out the deceleration during final approach, that will be cool.

EDIT:
https://en.m.wikipedia.org/wiki/Sonic_boom
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cscott on 05/02/2016 03:23 PM
The sonic boom travels at the speed of sound, naturally.  Typically it would be behind you; the only way it can arrive *before* you is if you are decelerating, such that the sonic boom catches up to you and passes you.  I think someone upthread already did the math assuming constant deceleration.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 05/02/2016 03:25 PM
Rewatching my landing video, I remembered wrong, it was also 3 pops in about the same cadence as this new video.

Here's how the Orbcomm landing's sonic boom was modeled; obviously the boom for an ASDS landing could be different for any number of reasons, but I'd say there's no chance of there not being a boom at ground zero.
Yes, agreed.

So if a vehicle is moving towards you at some constant supersonic speed, how far ahead is the sonic boom?

(Then we can talk about a decelerating vehicle)

We should take this to a different thread, but if this is a way to figure out the deceleration during final approach, that will be cool.

EDIT:
https://en.m.wikipedia.org/wiki/Sonic_boom
So as I remembered (see picture), a sonic boom is only heard behind the vehicle, along a cone whose angle depends on the speed of the vehicle (and the speed of sound).   So for every speed you get a different angle, but it's always backwards of the vehicle.

But, if you look at the illustrations, there's another degenerate case - exactly at Mach 1.0  Then you get a boom directly in front of the vehicle, but only during the moment of crossing the speed of sound.

Remember that a sonic boom is not a "thing".  It's just the place where a bunch of shock fronts have constructive interference.  It doesn't "propagate" because it doesn't exist outside of that location.

I am not sure what we're hearing at ground level.  Maybe it's a shock wave from the stage doing Mach>1 while still having a horizontal component...
 
But the most curious thing here is that 2g average deceleration.  I thought our estimate for the "slam" in hoverslam was about 1g.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/02/2016 06:27 PM
Quote
So as I remembered (see picture), a sonic boom is only heard behind the vehicle, along a cone whose angle depends on the speed of the vehicle (and the speed of sound).   So for every speed you get a different angle, but it's always backwards of the vehicle.

That is true only for a body which continues on at M>1 or M=1.  cscott is correct above that if the vehicle is decelerating, the shock waves it created at supersonic speed *can* pass ahead of it. So the sonic boom *can* be heard directly "ahead" of a body decelerating below supersonic.

This is analogous to your M>1 diagram in which the point source (the center of the circles) suddenly slows below M=1 and stops creating more shock "circles." But the existing shock "circles" continue to propagate outward in all directions, including "ahead" of the last point where the body was supersonic.

This is why the sonic boom could be heard right on the landing pad, directly "ahead" of the incoming, now-subsonic stage...if only there were someone on the pad to actually hear it...  :)


Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: meekGee on 05/02/2016 07:10 PM
Quote
So as I remembered (see picture), a sonic boom is only heard behind the vehicle, along a cone whose angle depends on the speed of the vehicle (and the speed of sound).   So for every speed you get a different angle, but it's always backwards of the vehicle.

That is true only for a body which continues on at M>1 or M=1.  cscott is correct above that if the vehicle is decelerating, the shock waves it created at supersonic speed *can* pass ahead of it. So the sonic boom *can* be heard directly "ahead" of a body decelerating below supersonic.

This is analogous to your M>1 diagram in which the point source (the center of the circles) suddenly slows below M=1 and stops creating more shock "circles." But the existing shock "circles" continue to propagate outward in all directions, including "ahead" of the last point where the body was supersonic.

This is why the sonic boom could be heard right on the landing pad, directly "ahead" of the incoming, now-subsonic stage...if only there were someone on the pad to actually hear it...  :)

Right - I'm aware of that - which is why it is interesting...

Let's assume the vehicle is decelerating along a straight line.

In all the "cone" section, the wavefronts at each point are moving at different directions (each originating from the vehicle when it was at a different position) and so the shock doesn't "move".  There's just "wave group" information there.

But in the front of the vehicle, at mach 1.0, all those shocks are moving in the same direction - forward.  And at the same velocity...  Which means that there is a real propagating "boom" just along the axis.

I want to use this to estimate the amount of slam in the hoverslam.  It's a really good data point.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/02/2016 08:06 PM
What is the yellow apparatus at the starboard rear of OCISLY? Seems like it has two vertical bars in back, a cylinder inside, and perhaps a ladder on the deck side? It seems to be overhanging the stern slightly.

I noticed that thing too, I think it may be new. Got good screen shots of it, but don't think I can post them for IP reasons. On the other hand, it is not an angle we usually see Ocisly from.

Matthew

I couldn't see departure so all I have are these still frames...anyway.

http://www.portfever.com/webcam_player_pcw.php?date=20160430&start=1141&end=1200

Frame 1159 onwards. Yes a ladder and guard rails on top. What could be its function?
A similar feature has appeared on the back of Go Quest in the last set of images I saw.  I'll leave that to you as an exercise to look it up  ;)   My first thought was that the ladder on the stern of GQ would be butted up against the ladder on the stern of OCISLY and they would form a continuous ladder but on second thought that doesn't make much sense as the ladder on OCISLY starts at deck level and goes up to a useless height.  So here is my current thought for bunking or debunking as you prefer:  Both are commercial off the shelf ladders that have the ladder inset from two stout vertical bumpers so that the person on the ladder has some protection from being pinched between two hulls.  There is a fixed portion and a vertically displaceable portion.  That displaceable portion would go up in the case of the one on GQ to get to the deck height of OCISLY (forming a ladder twice the collapsed height) and the displaceable portion would go down in the case of the one on OCISLY to reach (approximately) the deck of GQ.  Either ladder would get the job done, no need for both simultaneously.

EDIT: Using Doesitfloat's search term below here you can see the how the bumper protection works:
https://www.youtube.com/watch?v=20G8lDzJWAo
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 05/02/2016 08:21 PM
off shore crew transfer
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/03/2016 04:43 AM
off shore crew transfer

IMHO, it's a bit soppy really.  What's wrong with using a rope ladder?  Either that or they should learn to jump just like everyone else..  ::)

;D
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/03/2016 05:11 AM
If it was hard to land on, it should be hard to board???
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/03/2016 05:15 AM
If it was hard to land on, it should be hard to board???

Not at all.. but it seems likely that some well-meaning Health & Safety Rep may have paid a visit to poor unloved OCISLY during recent deck repairs and.. well... made a few suggestions.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: llanitedave on 05/03/2016 05:34 AM
The most important question for OCISLY is, have they renewed the 4-leaf clover?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 05/03/2016 10:54 AM
off shore crew transfer

From that video Mark posted it really looks like it but I doubt this is to board the Droneship for accessing deck as after climbing that they would have to go over the guard rails and then clumsily hop to deck it has some other specific purpose. It is also not high enough to have a good view of deck and far from HPU to have anything to do with it.

They board the Droneship from stern where generators are as we saw when OCISLY arrived with trophy and was being berthed. Perimeter fence there is also chained not wired.

The most important question for OCISLY is, have they renewed the 4-leaf clover?

Yup it is there :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/03/2016 11:20 AM
Sitting on deck, the ladder and bumpers are too high to do any good. Looks like they just put it on board temporarily and didn't have time to weld it into final position before leaving port.

It may go here when they have time to weld it on. Don't know if that's their usual boarding point, but it looks like there's a removeable safety chain there for crew boarding, suspended between the stanchions.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 05/03/2016 12:42 PM
Yes those are the chains I mentioned and yes that crew transfer thing is very last moment addition as it is not there on instagram image and the bumpers should rest against fendering like what Elsbeth III has on front (tyre stack). For Go Quest it would be metal vs metal pinching situation and its fendering is sparse so this isn't for GQ.

On a separate note  according to latest Terraserver imagery JRTI isn't at Long Beach at its usual location, not near Island Freeman where I expected it (but there is hole in imagery there) or where INTL Freedom is at the moment..

Edit:
Quote from: OxCartMark
A similar feature has appeared on the back of Go Quest in the last set of images I saw.  I'll leave that to you as an exercise to look it up

Found a link to the past. Compare the stern of Go Quest and NRC Quest. NRC Quest went without it on Jason 3 but GQ is going with it I assume.

Attached images are by /u/TheKrimsonKing (iwrRqdy.jpg 1 Jan 2016, hlOucpz.jpg 15 Jan 2016)
and Jim
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kaputnik on 05/03/2016 01:32 PM
In those pictures you can see the fast boat that will be used for ship-to-ship passenger transfer at sea.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Doesitfloat on 05/03/2016 01:43 PM
off shore crew transfer

From that video Mark posted it really looks like it but I doubt this is to board the Droneship for accessing deck as after climbing that they would have to go over the guard rails and then clumsily hop to deck it has some other specific purpose. It is also not high enough to have a good view of deck and far from HPU to have anything to do with it.

They board the Droneship from stern where generators are as we saw when OCISLY arrived with trophy and was being berthed. Perimeter fence there is also chained not wired.

The most important question for OCISLY is, have they renewed the 4-leaf clover?

Yup it is there :)

The thing about the Marine Industry is humans have been on the water for 10,000 years and someone has, "done it before." (Sarcarm__ And they screwed up and died.) So rules are written to prevent accidents. As a bonus it prevents internet experts from making Rube Goldberg contraptions for tasks.
See IMCA  SEL 25 - 4.2
And it's yellow for a reason
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: matthewkantar on 05/03/2016 02:00 PM
When Ocisly was leaving port, the zoomed in Port Canaveral webcam showed personel going between the ASDS and a tug. They used the break in the life lines circled in red above. If there had been 10 foot seas, I believe the new yellow gear would be used.

Matthew
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/03/2016 02:14 PM
Sitting on deck, the ladder and bumpers are too high to do any good. Looks like they just put it on board temporarily and didn't have time to weld it into final position before leaving port.

It may go here when they have time to weld it on. Don't know if that's their usual boarding point, but it looks like there's a removable safety chain there for crew boarding, suspended between the stanchions.
My original thought was that the ladder was telescoping / vertically sliding so that when in use it would extend down below the deck height but upon further review of your zoomed image I agree with your assessment.

Is there any reason that a yellow protrusion from the back of the ASDS would be a hindrance to barge usefulness?  Why is the back flat?  I suppose for connecting multiple barges together (which won't happen in ASDS use)?

Not of importance to this ASDS discussion but from looking at the images of these ladder & bumper devices in use it seems to me that there is a disconnect between the design intent and the way that they are used.  It appears to my eyes that the ladder is inset from the bumpers so that a person on the ladder won't be wiped out by a straight section of the boat moving up or down past them on waves.  But in the images and videos we've seen its not a straight section of the side of the boat but rather a protrusion of the boat side or the pointy bow of the boat that's nesteled into the gap toward the ladder ~thus decreasing 'man clearance'.  Hmmm, I suppose you could always be mashed through the ladder rungs if push comes to shove.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ohsin on 05/03/2016 02:30 PM
@Doesitfloat

Let me rephrase I am not disputing its utility which was clear from the video but purpose.

Part of it is not visible another ladder should be there to descend if its main purpose is to have many people on deck and as Kabloona pointed why is it not at that much better place near generators. Also trying to figure if GQ gangway would be used on it or Elsbeth III front like Figure 5 on that document.

I assume GQ has main crew that handles deck operation related to stage while ElsbethIII crew are just responsible for handling Droneship.

Another very bothersome thing is this crew transfer apparatus is plopped right in front of the emergency towline! Well at least it is not ON it Almost on it but I guess line is well clear.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 05/03/2016 03:23 PM
Not that it really matters, but is there going to be a BINGO thread this flight?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: cro-magnon gramps on 05/03/2016 03:39 PM
Not that it really matters, but is there going to be a BINGO thread this flight?

perhaps one for where we expect the "HOLE" in the deck to be  ??? :o ::) :-X
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/03/2016 03:52 PM
Not that it really matters, but is there going to be a BINGO thread this flight?

perhaps one for where we expect the "HOLE" in the deck to be  ??? :o ::) :-X
If its like the last bingo or two it'll happen suddenly and without warning and (since we're all trained to go for the center now) if you miss the start by enough time to say, have gotten a burrito, then you are relegated to the outer perimeter.

I suggest that to further the bingo game on these potentially high impact landings we add additional information to our votes such that multiple people can be on the same square with different bets.  For instance, one person could bet U19 (for conventional landing) and one person could bet U19- (for a subsurface landing or a dented surface that requires plate replacement).
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: dorkmo on 05/03/2016 05:36 PM
Not that it really matters, but is there going to be a BINGO thread this flight?

perhaps one for where we expect the "HOLE" in the deck to be  ??? :o ::) :-X
If its like the last bingo or two it'll happen suddenly and without warning and (since we're all trained to go for the center now) if you miss the start by enough time to say, have gotten a burrito, then you are relegated to the outer perimeter.

I suggest that to further the bingo game on these potentially high impact landings we add additional information to our votes such that multiple people can be on the same square with different bets.  For instance, one person could bet U19 (for conventional landing) and one person could bet U19- (for a subsurface landing or a dented surface that requires plate replacement).

this is starting to sound suspicously like roulette
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/03/2016 05:40 PM
Not that it really matters, but is there going to be a BINGO thread this flight?
I consulted my magic 8 ball and got "all indications are yes"...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CJ on 05/03/2016 08:42 PM
Regarding the new gear (ladder); when OCISLY was returning with the F9, OCISLY was boarded (this was heard on the radio, apparently) by some SpaceX personnel just off Canaveral harbor. Some of these are speculated to have been VIP types, and thus high up in the company. They, even moreso than general SpaceX crew, would tend to be unaccustomed to the normal methods for ship to ship boarding - jumping/climbing. I also suspect that Cameron D is right regarding a safety inspector, especially if said inspector was aware that OCISLY had been boarded by novices (Novices at boarding ships at sea). That's a very different thing than being boarded only by a tug crew. 

In general, changes like this are what I expect to see for the ASDS; small changes based upon operational experience.

I'll also make a purely speculative (based in no evidence) prediction for another such change; a tarp for the lower portions of the F9 will be added to OCISLY's gear (it it hasn't already) and used to protect the F9 engine area from spray during transit.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: iamlucky13 on 05/03/2016 10:09 PM
off shore crew transfer

IMHO, it's a bit soppy really.  What's wrong with using a rope ladder?  Either that or they should learn to jump just like everyone else..  ::)


Horatio Hornblower certainly would not have approved. I recall he had pretty strong disdain for use of the bosun's chair. A sailor uses the ropes only. Ahh...I need to read those books again.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Arb on 05/03/2016 11:14 PM
off shore crew transfer

IMHO, it's a bit soppy really.  What's wrong with using a rope ladder?  Either that or they should learn to jump just like everyone else..  ::)


Horatio Hornblower certainly would not have approved. I recall he had pretty strong disdain for use of the bosun's chair. A sailor uses the ropes only. Ahh...I need to read those books again.

Patrick O'Brian 's Aubrey–Maturin series (Master and Commander, etc) is way better IMO; spend your time on those instead.

But we're way off topic.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/03/2016 11:42 PM
off shore crew transfer

IMHO, it's a bit soppy really.  What's wrong with using a rope ladder?  Either that or they should learn to jump just like everyone else..  ::)

Horatio Hornblower certainly would not have approved. I recall he had pretty strong disdain for use of the bosun's chair. A sailor uses the ropes only. Ahh...I need to read those books again.

Patrick O'Brian 's Aubrey–Maturin series (Master and Commander, etc) is way better IMO; spend your time on those instead.

I disagree with both those statements: (a) that there was any suggestion they use a bosun's chair and (b) that Patrick O'Brian's series comes anywhere close to CS Forester's..

But we're way off topic.

..but on this I do agree.  Here's hoping something happens soon - before we all go overboard!  :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/04/2016 12:00 AM
The most important question for OCISLY is, have they renewed the 4-leaf clover?

Yup it is there :)

The be quite honest, given the years of valuable arm-chair engineering design critique NSF has provided (in this thread alone) I'm a bit surprised no-one has yet scrawled "We love NasaSpaceFlight" right beside it...  Hell, they know we're looking!!!
 
..and on that note, I'm even more surprised SpaceX hasn't chosen to deliberately install some obscure urban artwork on deck someplace just to give us something else to feed on.  ::)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Bargemanos on 05/04/2016 08:39 AM
The most important question for OCISLY is, have they renewed the 4-leaf clover?

Yup it is there :)

The be quite honest, given the years of valuable arm-chair engineering design critique NSF has provided (in this thread alone) I'm a bit surprised no-one has yet scrawled "We love NasaSpaceFlight" right beside it...  Hell, they know we're looking!!!
 
..and on that note, I'm even more surprised SpaceX hasn't chosen to deliberately install some obscure urban artwork on deck someplace just to give us something else to feed on.  ::)

i'd prefer a NSF bumper sticker we can search for in high res images!  ;D 8)

Just i case, here you go boys  ;)  :P
http://www.cafepress.com/nasasf.1330453213
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Ludus on 05/04/2016 01:11 PM
Is the plan to eventually leave the ASDS on station and transfer the booster to a horizontal cradle on a GO ship with a crane?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rpapo on 05/04/2016 01:33 PM
Is the plan to eventually leave the ASDS on station and transfer the booster to a horizontal cradle on a GO ship with a crane?
None of the three different helper ships is even remotely big enough to do that.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/04/2016 02:54 PM
Is the plan to eventually leave the ASDS on station and transfer the booster to a horizontal cradle on a GO ship with a crane?
There has been prior discussion of many variants on this approach.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: John Alan on 05/04/2016 06:55 PM
Is the plan to eventually leave the ASDS on station and transfer the booster to a horizontal cradle on a GO ship with a crane?

Be aware... that getting the "beanie cap" swinging from a crane lined up with the top of the stage...
...while both the stage and crane are moving about on the open seas...
... will be almost 'mission impossible'...  :P
It took a long time with the crane on dry land and the stage on a ship in port...  :-\
Just saying...  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: launchwatcher on 05/04/2016 07:05 PM
Is the plan to eventually leave the ASDS on station and transfer the booster to a horizontal cradle on a GO ship with a crane?

Be aware... that getting the "beanie cap" swinging from a crane lined up with the top of the stage...
...while both the stage and crane are moving about on the open seas...
... will be almost 'mission impossible'...  :P
It took a long time with the crane on dry land and the stage on a ship in port...  :-\
Just saying...  ;)
See the discussion about 10 pages back about active stabilization for cranes.   Offshore energy development in the North Sea has advanced the state of the art.   Doesn't look cheap, though; until the launch rate increases it likely won't save them any money over bringing the barge back to port.

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: maximlevitsky on 05/04/2016 07:49 PM
Please don't read this post.
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Since you didn't listen, here is awsome barge landing game on android:
https://play.google.com/store/apps/details?id=com.ween.rocket

From:
https://www.reddit.com/r/spacex/comments/4hk1k6/rocket_landing_game_android/

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/04/2016 10:26 PM
So that got me looking at my phone.  Its black with a flat screen.  When I lay it down face up it has some resemblance to an ASDS.  Perhaps someone could market a case that has bow angle, containers, blast wall etc., and an app that puts the circles and "X" on the screen?
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris_Pi on 05/04/2016 11:11 PM
Shapeways probably has a case design that would fit whatever phone you have. Add the containers/blastwalls and the other bits to the model and do a multi-color print. Then all you need is a screen wallpaper to match. No app needed. Can probably hire out the design work for not too much - Low detail and not too much of it. Plenty of reference photos to work from, Too.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: DatUser14 on 05/04/2016 11:24 PM
Id buy one, if it was IPad size. It could be more detailed, as there would be more room to work
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: OxCartMark on 05/05/2016 01:28 AM
So now I've got interest in two of them in two sizes and one of them is potentially a paying customer.  Hmm...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/05/2016 03:50 AM
I want one... or two. I have two Galaxy S5s

spawn a subthread? somewhere in the modeling/recreation section? we can carve out the posts, if desired. PM me.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/05/2016 12:17 PM
Elsbeth III speed plot from Reddit user robbak:

http://i.imgur.com/846I7uy.png?1

The dip at the "4 May" tick mark is about 96 hours after leaving port and likely represents the "drop off" operation where EIII cut OCISLY loose at the landing zone.

So they reached the LZ about 24 hours before the planned launch time.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CyndyC on 05/05/2016 01:39 PM
This might be mission update level, but when in doubt as they say, notification option under free services at Marine Traffic is "Sailing in high winds", you set the speed (I'm using 30 knots), which apparently includes areas beyond the coastal receivers.

ELSBETH III is reported to be sailing in high winds (34 knots, 208°) at: 
Time: 2016-05-05 07:59 UTC 
Position: 27.98077, -73.69197 
Speed/Course: 1.9 knots / 85° 

ELSBETH III is reported to be sailing in high winds (39 knots, 206°) at: 
Time: 2016-05-05 10:06 UTC 
Position: 28.16415, -73.71335 
Speed/Course: 6.6 knots / 316° 

GO QUEST is reported to be sailing in high winds (34 knots, 208°) at: 
Time: 2016-05-05 08:17 UTC 
Position: 28.12847, -73.75204 
Speed/Course: 0.7 knots / 109° 

GO SEARCHER is reported to be sailing in high winds (39 knots, 206°) at: 
Time: 2016-05-05 09:03 UTC 
Position: 28.20389, -73.79446 
Speed/Course: 4.7 knots / 351° 

Please note that the above Wind Data relies on weather forecasts that can be up to 24 hours old. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Kabloona on 05/05/2016 03:51 PM
Those high winds were probably the last storm front passing through.

Fortunately, winds near the LZ are at 20 knots now and falling. By midnight they are forecast to be 13 knots, so the weather for landing will be near perfect.

https://www.windyty.com/?28.217,-73.806,6

(The above are not the exact landing coordinates, but close enough for weather purposes)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: rsdavis9 on 05/05/2016 04:13 PM
Here is the closest buoy I could find. about 120nm too far out.
http://www.ndbc.noaa.gov/station_page.php?station=41047
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Chris Bergin on 05/06/2016 06:32 AM
Looks like we'll need to set up another stage returning to port thread....let's get people out there taking photos, before we suffer the supplemented wrath of the webcam guy after he gets upset with social media ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/06/2016 06:33 AM
Yep.. they nailed this one.  :D

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39843.0;attach=1114325;image)

..although what they were doing with that remotely-controlled fire sprinkler is anyone's guess.

Such a shame it was in the dark, so we didn't get to see any bounce... but the landing lights on the legs are pretty cool.  Better watch out for UFO reports about the time the stage was coming down.  ;)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 05/06/2016 06:37 AM

Yep.. they nailed this one.  :D

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39843.0;attach=1114325;image)

..although what they were doing with that remotely-controlled fire sprinkler is anyone's guess.
Wind was doing that...

And dang! This just spelled a massive amount of future wasted time watching the port Canaveral webcam...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/06/2016 06:38 AM
And dang! This just spelled a massive amount of future wasted time watching the port Canaveral webcam...
hopefully not as much as last time, this time I think they probably know which end of the stage to hook the crane to first try...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CameronD on 05/06/2016 06:39 AM
And dang! This just spelled a massive amount of future wasted time watching the port Canaveral webcam...
hopefully not as much as last time, this time I think they probably know which end of the stage to hook the crane to first try...

*YAWN*  Wake me up when something happens..

Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Req on 05/06/2016 07:14 AM
Crossposting from the discussion thread:
Here's the money shots for the hosted and technical webcasts:

Hosted:
https://www.youtube.com/watch?v=L0bMeDj76ig&feature=youtu.be&t=38m00s (https://www.youtube.com/watch?v=L0bMeDj76ig&feature=youtu.be&t=38m00s)

Technical:
https://www.youtube.com/watch?v=1lYZLxr3L4E&feature=youtu.be&t=38m10s (https://www.youtube.com/watch?v=1lYZLxr3L4E&feature=youtu.be&t=38m10s)

The technical link has a better view of the events.

Edit - It's always been a bit of an open question whether the vibrations from the acoustic environment alone would cause the satlink to temporarily lose sync, because the radomes have been blown away every time we had real-time video from the deck during descent.  We now know that the vibrations do indeed cause it to temporarily lose sync, but not drop frames.  It just spent some time paused, it didn't skip anything.

And we'll get to see any bounces that may have happened, once they get the video directly from the go-pros(and/or the 3D video) CameronD. :)
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: CraigLieb on 05/06/2016 08:32 AM
I think the time may be coming that this whole section of the forum needs to be renamed to remove 'reusable' from the title because "of course rockets are reusable" ! It's the throw away stages which are rapidly becoming the quaint buggy-whip type story. It will soon be considered an unusual waste.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jim on 05/06/2016 10:58 AM
I think the time may be coming that this whole section of the forum needs to be renamed to remove 'reusable' from the title because "of course rockets are reusable" ! It's the throw away stages which are rapidly becoming the quaint buggy-whip type story. It will soon be considered an unusual waste.

No, the title can only be changed to recoverable at this time. 
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Jet Black on 05/06/2016 11:26 AM
I think the time may be coming that this whole section of the forum needs to be renamed to remove 'reusable' from the title because "of course rockets are reusable" ! It's the throw away stages which are rapidly becoming the quaint buggy-whip type story. It will soon be considered an unusual waste.

No, the title can only be changed to recoverable at this time.

Quite right. There are a few people who seem to be treating three very different landings as if the whole thing is a done deal. It still remains to be seen if these rockets can be reliably reused at a cost that is commercially beneficial. There are still a large number of unknowns to be overcome.
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Lar on 05/06/2016 11:56 AM
Keep us exuberant types honest, Jim and company... but so far indications are pretty promising, I'd say...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: Johnnyhinbos on 05/06/2016 12:32 PM
I think I'm going to send Jim his very own monogrammed bucket...
Title: Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
Post by: montyrmanley on 05/06/2016 12:41 PM
Keep us exuberant types honest, Jim and company... but so far indications are pretty promising, I'd say...

The Shuttle SRB's were "recoverable" -- they were jettisoned after powered flight, and came down on parachutes into the water, and had to be recovered and extensively rebuilt after every flight.

What SpaceX has done is a difference in kind. Their boosters landed under their own power on a floating barge. IIRC the booster from the Orbcomm mission has already been test-fired. There will no doubt be a certain amount of maintenance required between flights, but all indications are that the turnaround will be far shorter -- and much less expensive -- than with the SRB's. Blue Origin's recent adventures with the New Shepard vehicle are also pretty incredible, but much less challenging than what SpaceX has done. Prior to SpaceX and Blue Origin, the only real analogue would be the DCX/Delta Clipper, and that was never anything more than a fringe project that NASA funded only grudgingly and cancelled as soon as the craft was damaged in a landing attempt.

I agree that we can't claim "reusability" until SpaceX reflies a recovered stage, but they've already done the hard part in getting the booster back. I think the "reuse" part is only a matter of weeks, or a few months at most.
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