Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2  (Read 2418052 times)

Offline Barrie

  • Full Member
  • ****
  • Posts: 440
  • Planets are a waste of space
  • Liked: 212
  • Likes Given: 2776
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #480 on: 01/04/2015 10:56 AM »
"AIS Source: 1142 Charleston Pilots"

Ah, yes, and now there is an updated position for Elsbeth III from the same source.  Status is 'Restricted Manoeuvrability', consistent with towing a BFB  :)

Offline speedevil

  • Senior Member
  • *****
  • Posts: 3187
  • Fife
  • Liked: 1629
  • Likes Given: 1956
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #481 on: 01/04/2015 01:03 PM »
"AIS Source: 1142 Charleston Pilots"

Ah, yes, and now there is an updated position for Elsbeth III from the same source.  Status is 'Restricted Manoeuvrability', consistent with towing a BFB  :)

And now properly out of range I think.

Offline Ohsin

  • Full Member
  • ****
  • Posts: 1469
  • Liked: 1451
  • Likes Given: 2380
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #482 on: 01/04/2015 01:59 PM »
Looking at Google Maps, I noticed something.  For the ASDS to dock where it does, it must first pass under I-295 on the St. John's River.  While obviously the Carnival Cruise ships pass under that bridge, and they are tall by any normal standards for ships, does that bridge provide the approximately 160' clearance that the ASDS with a Falcon 9 first stage standing up on it would need to pass underneath? 

Answered my own question: Wikipedia tells me that the bridge has 175 feet (53m) clearance below.

http://en.wikipedia.org/wiki/Dames_Point_Bridge

Now that would be quite a photo-op.  And imagine the traffic jam on the bridge from the rubber-neckers as the barge passes by.




And that Ship is Carnival Miracle it passed with 6ft to spare and traffic was halted on bridge...

Cruise ship operators could pull out business so to ensure safe passage of these ships NOAA installed Air
 Gap System on Dames point bridge it gives very accurate water level readings. And you can monitor those here.

http://tidesandcurrents.noaa.gov/ports/ports.html?id=8720376&mode=airgap

http://tidesandcurrents.noaa.gov/ports/ports.html?id=8720376&mode=threedaysag

And are we sure about 160' figure? Marmac 300 has 18' height how long is falcon 9 first stage + I/E when on its legs? I think it should be ~47m any good source?

172ft Max. now how much ASDS can adjust its buoyancy with ballast is out there. By the way http://www.mcdonoughmarine.com/assets/pdf/MARMAC-300.pdf shows all tanks on MARMAC300 and their capacity.
"Well, three cheers to Sharma, but our real baby is INSAT."

Offline speedevil

  • Senior Member
  • *****
  • Posts: 3187
  • Fife
  • Liked: 1629
  • Likes Given: 1956
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #483 on: 01/04/2015 02:13 PM »

172ft Max. now how much ASDS can adjust its buoyancy with ballast is out there. By the way http://www.mcdonoughmarine.com/assets/pdf/MARMAC-300.pdf shows all tanks on MARMAC300 and their capacity.

From memory, the sum of those ballast tanks is 13000 tons of fresh water.
The marmac 300 hull footprint is about 80m*50m (several meters of hull at the ftront and back will be out of the water - it's quite steep).
This is about 4000m^2.
With fresh water, this can depress the ship by about 3m.
With seawater, a little more.

And if they have done their sums, and for example - done some light modifications and poured gravel into the ballast tanks to the same as nominal cargo weight - it could be even lower.

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4330
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2558
  • Likes Given: 530
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #484 on: 01/04/2015 02:41 PM »
Ballast capacity is 4,105,360 gallons. With sea water, that's about 17,550 tons.

http://cfpub2.epa.gov/npdes/vessels/vesselsnoidetail.cfm?PermitId=131541&status=Active
« Last Edit: 01/04/2015 02:47 PM by Kabloona »

Offline Nomadd

  • Senior Member
  • *****
  • Posts: 3361
  • Boca Chica, Texas
  • Liked: 6016
  • Likes Given: 361
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #485 on: 01/04/2015 02:49 PM »
 Listed ballast refers to tanks set up for properly monitored and filtered for legal discharge. They can also flood cargo holds, like they did to raise the Delta Conveyor, and bring that deck so low it looks like a raft. They just couldn't discharge the water at will without proper procedures. Part of the modifications could have been lining the cargo holds and setting them up as ballast tanks.
« Last Edit: 01/04/2015 02:50 PM by Nomadd »

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4330
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2558
  • Likes Given: 530
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #486 on: 01/04/2015 02:56 PM »
Would be interesting to know how much of the ballast capacity, if any, they will use at sea. The downside of ballast is that it lowers freeboard and makes the deck more likely to be swept by waves in heavy seas. I guess there's happy medium somewhere.

Offline OxCartMark

  • Full Member
  • ****
  • Posts: 1109
  • Michigan
  • Liked: 879
  • Likes Given: 908
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #487 on: 01/04/2015 03:43 PM »
Listed ballast refers to tanks set up for properly monitored and filtered for legal discharge. They can also flood cargo holds, like they did to raise the Delta Conveyor, and bring that deck so low it looks like a raft. They just couldn't discharge the water at will without proper procedures. Part of the modifications could have been lining the cargo holds and setting them up as ballast tanks.
I'm not an expert, but I believe that this being a deck barge from initial design there are no cargo holds.  Lots of internal space which can be ballasted and maybe some which was not initially set up for ballast water that may have now been converted to water ballast but I think there are no holds which were intended for cargo.  Now that I've said that, the end conclusion is the same as yours, that they may have modified it to add additional ballast capacity beyond that originally designed.  But my opinion is that extreme and unusual ballasting (or even full ballasting) won't be in the program.

Mark

Online cartman

  • Full Member
  • ****
  • Posts: 507
  • Greece
  • Liked: 488
  • Likes Given: 2685
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #488 on: 01/04/2015 04:03 PM »
Apparently Go Quest and Elsbeth III are still being tracked by vesselfinder.com!
http://www.vesselfinder.com/?mmsi=367564890

Go Quest seems to have almost stopped and turned southwards, while Elsbeth III is still continuing past it, at a 80-90 degree heading. On the third image in green is their current position on the CRS-5 Broadcast Warning Map, so they are past the midpoint towards the landing site.
« Last Edit: 01/04/2015 04:38 PM by cartman »

Offline docmordrid

  • Senior Member
  • *****
  • Posts: 5105
  • Michigan
  • Liked: 2245
  • Likes Given: 1
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #489 on: 01/04/2015 06:47 PM »
Go Quest is classed a cargo/supply ship and has a large deck with heavy hold downs. What are the odds they'll transfer the stage to her for an upright ride back?
« Last Edit: 01/04/2015 06:52 PM by docmordrid »
DM

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 3811
  • Sunnyvale, CA
  • Liked: 2459
  • Likes Given: 3191
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #490 on: 01/04/2015 06:51 PM »
Go Quest is classed a cargo/supply ship and has a large deck with heavy hold downs. What are the odds they'll transfer the stage to her for an upright ride back?

Sounds like a risky move to me, dangling a tall rocket from a crane on a pitching deck and trying to lower it onto a different pitching deck.  Why bother?  Why not just tie it down to the ASDS deck?

Offline MTom

  • Full Member
  • ***
  • Posts: 378
  • EU / Hungary
  • Liked: 107
  • Likes Given: 435
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #491 on: 01/04/2015 06:57 PM »
Go Quest is classed a cargo/supply ship and has a large deck with heavy hold downs. What are the odds they'll transfer the stage to her for an upright ride back?

Sounds like a risky move to me, dangling a tall rocket from a crane on a pitching deck and trying to lower it onto a different pitching deck.  Why bother?  Why not just tie it down to the ASDS deck?

Actually the ship's deck isn't empty, there are some containers on it (comm., etc.).

See this pictures.
http://forum.nasaspaceflight.com/index.php?topic=36326.msg1308396#msg1308396
« Last Edit: 01/04/2015 07:00 PM by MTom »

Offline docmordrid

  • Senior Member
  • *****
  • Posts: 5105
  • Michigan
  • Liked: 2245
  • Likes Given: 1
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #492 on: 01/04/2015 06:57 PM »
Ahh...was tying to parse why that kind of ship vs. another tug. Seemed a tad excessive.
« Last Edit: 01/04/2015 06:58 PM by docmordrid »
DM

Offline dorkmo

  • Full Member
  • ****
  • Posts: 690
  • Liked: 318
  • Likes Given: 824
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #493 on: 01/04/2015 07:09 PM »
Ahh...was tying to parse why that kind of ship vs. another tug. Seemed a tad excessive.

probably tug captains just like to tug, rather not have other stuff happening on their boats.

Offline ChrisWilson68

  • Senior Member
  • *****
  • Posts: 3811
  • Sunnyvale, CA
  • Liked: 2459
  • Likes Given: 3191
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #494 on: 01/04/2015 07:10 PM »
Ahh...was tying to parse why that kind of ship vs. another tug. Seemed a tad excessive.

Maybe they want to be able to land Elon's helicopter on the support ship.

Offline cscott

  • Senior Member
  • *****
  • Posts: 2949
  • Liked: 2056
  • Likes Given: 664
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #495 on: 01/04/2015 07:35 PM »
I think go quest is better set up for fishing pieces out of the water if it comes to that.

Offline rpapo

  • Cybernetic Mole
  • Full Member
  • ****
  • Posts: 1198
  • Michigan, USA
  • Liked: 632
  • Likes Given: 486
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #496 on: 01/04/2015 08:01 PM »
And are we sure about 160' figure? Marmac 300 has 18' height how long is falcon 9 first stage + I/E when on its legs? I think it should be ~47m any good source?
SpaceFlight 101 has 42m for the first stage.  When standing on its legs, it should be about 2m taller.  Plus you have to count the height of the interstage.  Judging by proportions, it appears to be 4-5 meters in length.  That's 49 meters, which is about 160 feet.

Add to that the height of the landing deck above the water, and it's mighty close.  They may need to do it at low tide, or at least avoid high tide.

If anybody has better numbers, feel free to correct my guesstimate.
« Last Edit: 01/04/2015 08:48 PM by rpapo »
An Apollo fanboy . . . fifty years ago.

Offline OxCartMark

  • Full Member
  • ****
  • Posts: 1109
  • Michigan
  • Liked: 879
  • Likes Given: 908
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #497 on: 01/04/2015 08:13 PM »
SpaceFlight 101 has 42m for the first stage.  When standing on its legs, it should be about 2m taller.  Plus you have to count the height of the interstage.  Judging by proportions, it appears to be 4-5 meters in length.  That's 49 meters, which is about 160' feet.

Turning the barge sideways (rocket horizontal) would seemingly be worse, with the barge then being 170 feet tall, but if you folded one of the side wings on the deck it would only be 135 feet tall and with both wings folded only 100 feet tall.  Easy passage.

Mark

Offline IslandPlaya

  • Full Member
  • ****
  • Posts: 582
  • Outer Hebrides
  • Liked: 163
  • Likes Given: 166
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #498 on: 01/04/2015 10:04 PM »
Ah, yes...
Very funny.
Should that not be in the party thread?

Not much value will be lost, agreed, but between now and Tuesday, what else are we to do but party?

The joking gets in the way of obsessing over every movement of an empty barge and capturing webcam output every seven seconds of a scene that isn't changing for hours.
Indeed why would anyone want to watch a rocket take-off. Seen it all before...

Online meekGee

  • Senior Member
  • *****
  • Posts: 8783
  • N. California
  • Liked: 4969
  • Likes Given: 904
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 2
« Reply #499 on: 01/04/2015 10:15 PM »
Ah, yes...
Very funny.
Should that not be in the party thread?

Not much value will be lost, agreed, but between now and Tuesday, what else are we to do but party?

The joking gets in the way of obsessing over every movement of an empty barge and capturing webcam output every seven seconds of a scene that isn't changing for hours.

I was using a very loose definition of the word "party"...
ABCD - Always Be Counting Down

Tags: