The barge, the ASDS (Autonomous Spaceport Drone Ship) that SpaceX plans to demonstrate landing with is based out of the east coast of the US. But the landing site will be well downrange off the coast.

How will it get to the proper location?

Will it be towed, or will it use the positioning thrusters to travel?


Update: This article mentions a tug.

I'm not certain. IANAS(ailor) but I believe it could technically do either. This brief Reddit discussion backs that up a little, but it's never been officially answered to my knowledge.

This SFI article goes into some detail about the ASDS, including some information about the company supplying the dynamic positioning system: Thrustmaster's Portable Dynamic Positioning System. All of the press releases, Twitter mentions, and publicly-available info on the ASDS have discussed the fact that it can maintain position autonomously, but not how it gets to that position exactly. Of the two problems, maintaining a position is by far harder than moving to one.

An additional consideration is the question of what they are planning to do once the stage is secured. If they are keeping the stage on the barge and then moving everything back to shore, a tugboat may make more sense because there is additional weight involved. But again, my knowledge of boats > my knowledge of spacecraft.

Tl;dr - I think it will probably be towed by a tugboat because that's usually how barges move, but I'm not certain.

  • $\begingroup$ Maintaining position is technologically harder than moving to a position but moving from place to place in reasonable time requires much more powerful engines. So it would be plausible to have a barge that could maintain its position and slowly move itself short distances, but which was towed from place to place by tugboats. $\endgroup$ – David Richerby Dec 27 '14 at 11:14
  • $\begingroup$ @DavidRicherby That's what I was thinking -- I'm sure it's plenty capable of moving itself short distances. Moving from shore into position, though, probably is with the assistance of a tug. The photo Elon posted does look like it's moving on its own power, so I'm not 100% sure. I asked Elon to clarify, but he didn't respond. (I'm sure he's a little busy...) $\endgroup$ – Nate Barbettini Jan 11 '15 at 18:01
  • 1
    $\begingroup$ @NateBarbettini The barge is towed by the tug "Go Quest" and has "Elsbith III" as a support vehicle. $\endgroup$ – ReactingToAngularVues Jan 11 '15 at 20:51

For the first set of missions, the ASDS JRTI was towed by two barges, Elsbeth III (you can see where Elsbeth III is on VesselFinder) and Go Quest.

The tug Rhea towed the Marmac 303 based ASDS (OCISLY probably) through the Panama Canal to the West Coast.

The Thrustmaster units on board (one on each corner) are designed for position keeping only. They would not be efficient to travel any kind of distance, and there is not enough fuel for them for any appreciable distance of travel.

The Thrustmaster units are powered from the deck, with hydraulic fluid running down to turn the propellers which can rotate in plane, and the arm of the Thrustmaster can be lifted up as the water gets shallower.


It appears to be motoring under its own power in the photo posted by SpaceX saying it has left the port on Jan 5. There was a statement posted that it would be approximately 200 miles east of Jacksonville. (did not record where I got this). I believe that this is true and that the booster will never backtrack because of the extra fuel to turn it back. My conjecture is that until landings back at the cape are approved,this will be the operating mode to simply secure it to barge and motor back to shore. Probably less than a 48 hour trip. If barge landings turn out to be successful, why would you ever fly back to shore , taking a chance of loosing the booster plus using precious engine life??

Just saw the pic of barge in port at cape with tools to rotate booster from vertical to horizontal and a trailer to haul it to where it will be checked out. I would drive to port to get a pic, but based on discussion 5, it will be well covered :>)

  • $\begingroup$ I think this is incorrect. It does not get onsite by its own power, it gets towed by two tugs. $\endgroup$ – geoffc Jun 10 '15 at 19:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.