Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3  (Read 827434 times)

Online CameronD

  • Full Member
  • ****
  • Posts: 1445
  • Melbourne, Australia
    • Norton Consultants
  • Liked: 470
  • Likes Given: 338
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #120 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.

With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4334
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2563
  • Likes Given: 531
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #121 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.

Offline AJW

  • Full Member
  • ****
  • Posts: 598
  • Liked: 498
  • Likes Given: 63
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #122 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?

Offline CJ

  • Full Member
  • ****
  • Posts: 887
  • Liked: 649
  • Likes Given: 180
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #123 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.


Offline llanitedave

  • Senior Member
  • *****
  • Posts: 2157
  • Nevada Desert
  • Liked: 1332
  • Likes Given: 1569
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #124 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.
"I've just abducted an alien -- now what?"

Online CameronD

  • Full Member
  • ****
  • Posts: 1445
  • Melbourne, Australia
    • Norton Consultants
  • Liked: 470
  • Likes Given: 338
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #125 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. :)
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4334
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2563
  • Likes Given: 531
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #126 on: 03/18/2016 07:36 AM »
Octaweb is (was?) probably under the white tarp, I would think.

« Last Edit: 03/18/2016 07:38 AM by Kabloona »

Offline JamesH65

  • Full Member
  • ****
  • Posts: 917
  • Liked: 606
  • Likes Given: 8
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #127 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'


Offline Hankelow8

  • Full Member
  • *
  • Posts: 164
  • UK
  • Liked: 120
  • Likes Given: 40
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #128 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.

Offline JamesH65

  • Full Member
  • ****
  • Posts: 917
  • Liked: 606
  • Likes Given: 8
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #129 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.

Offline OxCartMark

  • Full Member
  • ****
  • Posts: 1111
  • Michigan
  • Liked: 880
  • Likes Given: 910
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #130 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.

Offline John Alan

  • Full Member
  • ****
  • Posts: 781
  • Central IL - USA - Earth
  • Liked: 473
  • Likes Given: 1907
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #131 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...
« Last Edit: 03/18/2016 02:34 PM by John Alan »

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 10799
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 7722
  • Likes Given: 5579
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #132 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?
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline kevinof

  • Full Member
  • ****
  • Posts: 682
  • Antibes
  • Liked: 492
  • Likes Given: 515
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #133 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?

Offline Kabloona

  • Senior Member
  • *****
  • Posts: 4334
  • Velocitas Eradico
  • Fortress of Solitude
  • Liked: 2563
  • Likes Given: 531
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #134 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?

Offline John Alan

  • Full Member
  • ****
  • Posts: 781
  • Central IL - USA - Earth
  • Liked: 473
  • Likes Given: 1907
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #135 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...
« Last Edit: 03/18/2016 02:38 PM by John Alan »

Offline sghill

  • Full Member
  • ****
  • Posts: 1409
  • United States
  • Liked: 1576
  • Likes Given: 2312
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #136 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.
Bring the thunder!

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 2562
  • Canada
  • Liked: 401
  • Likes Given: 600
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #137 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.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 10799
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 7722
  • Likes Given: 5579
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #138 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?
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline steveholtam

  • Member
  • Posts: 2
  • United States
  • Liked: 2
  • Likes Given: 8
Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #139 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? 

Tags: