Author Topic: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3  (Read 603341 times)

Offline rsdavis9

That thought actually occurred to me too.
Moveable landing socket is what the roomba is.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
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Online CameronD

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1821 on: 02/28/2017 11:34 PM »
Anyways, I still don't get it.  Three reasons:
a) There's been no evidence (that we've seen to date) of a properly-landed-on-all-four-legs stage moving anywhere in the time taken to get the Barge Crew aboard, and
b) the non-zero risk of a moving Roomba colliding with and injuring one of the barge crew is non-zero - especially in a heavy swell... or are the Barge Crew not allowed to board until the Roomba's are secure?  What if one of them can't secure (wet slippery deck, etc.)?? and then
c) The non-zero risk of a Roomba collision with one of the legs affecting the integrity of the landed stage makes the whole concept rather implausible. 

By doing this I'd think you were adding to the dangers the Barge Crew need to deal with.. not making it safer.  Plus, I'm not sure you make the entire process any quicker given that the ASDS will surely be on it's way back to port under it's own steam the moment the stage has landed, whilst the crew/tug catch up, secure and complete the tow - only a couple of knots faster.

All of the risks you identify are related to crew on the deck at the same time as the robot mooving.

No... the ASDS is out on the open ocean - not some factory floor. There's still a risk of the robot(s) driving out of the garage straight into one of the legs after a mistimed wave (wave impacts can be quite random) sends it off course. Problem (c) above. The bigger the robot, the bigger the impact on a fragile carbon-fibre leg.  As we've seen already, loss of one leg generally means loss of the rocket.
 
Now there are the edge cases where you potentially couldn't secure the robot nor bring it back to the garage. I see 2 possibilities :
 - You identify the usability limits of the robot beforehand through testing, and if not usable, you don't even try to let the robot out.
 - If it's not safe for the robot, is there really any chance that it's not a deathwish to send crew on board ? You might be talking about the cases where they'd rather ditch the stage into the ocean than try to catch it.

In my mind it comes down to how they might guide the thing.  I have some experience with wheeled vehicles on ship decks in the open ocean and can say you generally avoid it if you can.  There are ways to increase deck friction using non-skid rubber compounds, but I have yet to find a deck coating that wouldn't get removed instantly by the landing burn.  That leaves you with a slippery steel deck and no way (remotely) to determine how much traction you actually have until you take the thing for a drive.  The term "loose cannon" is the one most often used.

These same conditions are not "a deathwish to send crew on board" -  seaboot-wearing crew would have no trouble at all keeping their footing in situations that would have a rubber-tracked vehicle of any kind sliding all over the deck.  To suggest anything else is an insult to fishermen everywhere.

I commend the Roomba idea, but as I posted, I just can't see the risk/return indicating money well spent and I do think that in my experience, until you can teach a robot situational awareness on the high seas, for reasons of safety of both crew and rocket the decision to move anything out of the garage and around the deck would be better taken by a human on-board, making the entire exercise rather pointless.
 
« Last Edit: 02/28/2017 11:44 PM by CameronD »
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 JamesH65

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1822 on: 03/01/2017 11:27 AM »
Anyways, I still don't get it.  Three reasons:
a) There's been no evidence (that we've seen to date) of a properly-landed-on-all-four-legs stage moving anywhere in the time taken to get the Barge Crew aboard, and
b) the non-zero risk of a moving Roomba colliding with and injuring one of the barge crew is non-zero - especially in a heavy swell... or are the Barge Crew not allowed to board until the Roomba's are secure?  What if one of them can't secure (wet slippery deck, etc.)?? and then
c) The non-zero risk of a Roomba collision with one of the legs affecting the integrity of the landed stage makes the whole concept rather implausible. 

By doing this I'd think you were adding to the dangers the Barge Crew need to deal with.. not making it safer.  Plus, I'm not sure you make the entire process any quicker given that the ASDS will surely be on it's way back to port under it's own steam the moment the stage has landed, whilst the crew/tug catch up, secure and complete the tow - only a couple of knots faster.

All of the risks you identify are related to crew on the deck at the same time as the robot mooving.

No... the ASDS is out on the open ocean - not some factory floor. There's still a risk of the robot(s) driving out of the garage straight into one of the legs after a mistimed wave (wave impacts can be quite random) sends it off course. Problem (c) above. The bigger the robot, the bigger the impact on a fragile carbon-fibre leg.  As we've seen already, loss of one leg generally means loss of the rocket.
 
Now there are the edge cases where you potentially couldn't secure the robot nor bring it back to the garage. I see 2 possibilities :
 - You identify the usability limits of the robot beforehand through testing, and if not usable, you don't even try to let the robot out.
 - If it's not safe for the robot, is there really any chance that it's not a deathwish to send crew on board ? You might be talking about the cases where they'd rather ditch the stage into the ocean than try to catch it.

In my mind it comes down to how they might guide the thing.  I have some experience with wheeled vehicles on ship decks in the open ocean and can say you generally avoid it if you can.  There are ways to increase deck friction using non-skid rubber compounds, but I have yet to find a deck coating that wouldn't get removed instantly by the landing burn.  That leaves you with a slippery steel deck and no way (remotely) to determine how much traction you actually have until you take the thing for a drive.  The term "loose cannon" is the one most often used.

These same conditions are not "a deathwish to send crew on board" -  seaboot-wearing crew would have no trouble at all keeping their footing in situations that would have a rubber-tracked vehicle of any kind sliding all over the deck.  To suggest anything else is an insult to fishermen everywhere.

I commend the Roomba idea, but as I posted, I just can't see the risk/return indicating money well spent and I do think that in my experience, until you can teach a robot situational awareness on the high seas, for reasons of safety of both crew and rocket the decision to move anything out of the garage and around the deck would be better taken by a human on-board, making the entire exercise rather pointless.
 

Remote control- you don't need anyone within 5 miles. You don't need complete autonomy. Seems to work for Drones. Decent set of cameras on the 'thing' would be fine.

Waves hits? Big magnet sucks the 'thing' down to the deck if the system detects a harsh unexpected movement.

Online Alastor

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1823 on: 03/01/2017 12:20 PM »
No... the ASDS is out on the open ocean - not some factory floor. There's still a risk of the robot(s) driving out of the garage straight into one of the legs after a mistimed wave (wave impacts can be quite random) sends it off course. Problem (c) above. The bigger the robot, the bigger the impact on a fragile carbon-fibre leg.  As we've seen already, loss of one leg generally means loss of the rocket.

I commend the Roomba idea, but as I posted, I just can't see the risk/return indicating money well spent and I do think that in my experience, until you can teach a robot situational awareness on the high seas, for reasons of safety of both crew and rocket the decision to move anything out of the garage and around the deck would be better taken by a human on-board, making the entire exercise rather pointless.

You make some realy good points.
We'll have to see how it pans out. 

I'd just like to point out a few elements: 
 - In my mind, said robots were never autonomous. It's like remote submarine operations or mars rover operations. The robot doesn't take cratical decisions (and in a lot of cases any decision) on its own. There is an operator, who just isn't on site.
 - With a crawler, you sould be able to arbitrarily increase friction. You could even imagine safety tethering to specific fixtures on deck, even if we have seen no evidence of such a thing. For me, the loose cannon robot scenario is something that has to be solved, but not something that can't be solved.
 - Worst case scenario, if there remains cases like you point out, where a crewman would be just fine and not a robot, it should remain an edge case, where you send someone with a nice risk bonus to perform unsafe operations. Not a part of routine operations.
« Last Edit: 03/01/2017 12:21 PM by Alastor »

Online matthewkantar

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1824 on: 03/01/2017 01:42 PM »
If there is a some sort of automated hold down coming, I would guess it would be about the diameter of the rocket and crawl underneath to engage the holddowns. Battery powered clamps like those on a magdrill don't use a lot of juice. When the gizmo is in position it could lock itself in place with the magnets, and then secure itself with powder actuated fasteners, self drilling/tapping bolts, or stud welding.

I don't think grabbing the feet is the gentlest way to handle or secure the stage.

The garage seems big enough to accommodate such a device which would be roughly 12 feet in diameter and three feet tall.

Matthew


Online John Alan

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1825 on: 03/01/2017 02:12 PM »
Opinion...  ;)
It will be powered by the gensets on the barge and will trail a power cord to power itself...
It will have rubber tracks to move around and magnetic feet to stop and lock itself down to the deck...
Wifi control linkage to the barge systems and a remote operator elsewhere... Video linkage, same system...

Operation...
Rocket lands... fires put out... situation on deck assessed..
Door opens... Rocket "Roomba" driven out and maneuvered remotely under the stage on deck...
The magnetic feet lower... energize...  and pick the robot up to latch onto the rocket...

Something along that lines... what I'm thinking... my opinion on topic...  ???

Offline rsdavis9

That sounds about right from the pics we have seen.

Now is there any process flow improvement we can get?
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Online John Alan

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1827 on: 03/01/2017 08:29 PM »
Now is there any process flow improvement we can get?

I think the goal for now... is safety for the workers...  ;)
Moving those heavy jacks into place... welding angles down... chaining it down... is so 'old school'...  :P

It will be interesting to see what exactly comes out of that tent and onto the barge...  8)

I think later and if the need for speed is real... they will look at further things to improve the process...  ;)
The number one slow down IMHO is transit time port to sea and back... not much they can do there at this time...  :P

Offline rsdavis9

well once you got something clamped on to the bottom of the rocket it could stretch up just a little more and allow you to remove the legs as soon as you got into port. from their just tilt horizontal on the barge and pickup with crane and put on truck. Seems like a lot of steps could be eliminated by the correct design of this roomba.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Offline Zardar

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1829 on: 03/01/2017 10:44 PM »
There are several process improvements the robot could do.

Anything that reduces the time that crew have to be on the deck and interacting with the rocket will improve the safety of that crew.

Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?

Perhaps it could also supply 'keep alive' power to the falcon avionics, to ensure telemetry can be received and valves etc. can be commanded?

Perhaps it could keep the tanks pressurised with clean air/N2, protecting the tanks from sea-air ingress?

Perhaps it could do a photo-survey of the base of the rocket?



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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1830 on: 03/01/2017 10:50 PM »
There are several process improvements the robot could do.

Anything that reduces the time that crew have to be on the deck and interacting with the rocket will improve the safety of that crew.

Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?

Perhaps it could also supply 'keep alive' power to the falcon avionics, to ensure telemetry can be received and valves etc. can be commanded?

Perhaps it could keep the tanks pressurised with clean air/N2, protecting the tanks from sea-air ingress?

Perhaps it could do a photo-survey of the base of the rocket?

Perhaps it could brew up hot coffee for the crew when they arrive?  :P
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 meekGee

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1831 on: 03/01/2017 10:51 PM »
There are several process improvements the robot could do.

Anything that reduces the time that crew have to be on the deck and interacting with the rocket will improve the safety of that crew.

Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?

Perhaps it could also supply 'keep alive' power to the falcon avionics, to ensure telemetry can be received and valves etc. can be commanded?

Perhaps it could keep the tanks pressurised with clean air/N2, protecting the tanks from sea-air ingress?

Perhaps it could do a photo-survey of the base of the rocket?

Perhaps it could brew up hot coffee for the crew when they arrive? 
I so saw that coming...
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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1832 on: 03/01/2017 10:55 PM »
Perhaps it could brew up hot coffee for the crew when they arrive? 
I so saw that coming...

LOL.  ;D
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 Jim

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1833 on: 03/02/2017 12:39 AM »

1.  Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?

2.  Perhaps it could also supply 'keep alive' power to the falcon avionics, to ensure telemetry can be received and valves etc. can be commanded?

3.  Perhaps it could keep the tanks pressurised with clean air/N2, protecting the tanks from sea-air ingress?


1.  No, it would require tanks.  Plus it is not needed.  The only fluid is RP-1

2.  Not needed.  it has sufficient batteries.

3. Not needed.  They already are. 

Offline Zardar

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1834 on: 03/02/2017 09:03 AM »

1.  Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?


1.  No, it would require tanks.  Plus it is not needed.  The only fluid is RP-1


What about the Triethylaluminum/Triethylborane? Or is that all burned off during the landing burn?


Online Alastor

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1835 on: 03/02/2017 09:22 AM »

1.  Perhaps once the robot has secured the base of the rocket, it could connect up to the base fluids connector and drain and make safe any residual propellant or other hazardous fluid?


1.  No, it would require tanks.  Plus it is not needed.  The only fluid is RP-1


What about the Triethylaluminum/Triethylborane? Or is that all burned off during the landing burn?

If I remember correctly, one of the first things the stage does (or did) upon landing is burn them off, as part of the safing the stage procedure.

Offline meekGee

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1836 on: 03/02/2017 03:41 PM »
So out of curiosity..  assuming the robot weighs enough so that welding is not necessary - what will the crew be doing after the stage is latched and secured?
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Offline rsdavis9

So out of curiosity..  assuming the robot weighs enough so that welding is not necessary - what will the crew be doing after the stage is latched and secured?

Hopefully not even getting on board.
They could even hook up to the towline without getting on board.
Boarding ships at sea in waves is something that should be avoided if possible.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Offline JasonAW3

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1838 on: 03/02/2017 06:38 PM »
So out of curiosity..  assuming the robot weighs enough so that welding is not necessary - what will the crew be doing after the stage is latched and secured?

Hopefully not even getting on board.
They could even hook up to the towline without getting on board.
Boarding ships at sea in waves is something that should be avoided if possible.

Might be able to rig up a bosen chair between the ship and ASDS, but it'd still be dangerous as all heck!
My God!  It's full of universes!

Offline Nomadd

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Re: SpaceX's Autonomous Spaceport Drone Ship Discussion Thread 3
« Reply #1839 on: 03/02/2017 07:34 PM »
So out of curiosity..  assuming the robot weighs enough so that welding is not necessary - what will the crew be doing after the stage is latched and secured?

Hopefully not even getting on board.
They could even hook up to the towline without getting on board.
Boarding ships at sea in waves is something that should be avoided if possible.

Might be able to rig up a bosen chair between the ship and ASDS, but it'd still be dangerous as all heck!
From ships to  platforms we'd use cranes. The crane operator would get to Tarzan over on a rope. Managers in dry offices on land came up with lots of brilliant schemes for ship to ship in seas, but it always went back to jumping when the odds looked good.
 Most of us put Bosun's chairs up there with Bangalore torpedoes as the worst inventions in history.

 If you were going to secure the legs in seas with Roombas, electromagnets would be a lot simpler and faster than automated welding. I doubt if the barge would ever be allowed in any port before a crew boarded and took care of a few things.
« Last Edit: 03/02/2017 07:43 PM by Nomadd »

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