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I believe that currently, SpaceX only has two landing barges - one in the Atlantic (Of Course I Still Love You (OCISLY)), and one barge in the Pacific (Just Read The Instructions (JRTI)). How long would it realistically take to cycle a barge from having a rocket landing on it, returning to port, offloading the rocket, and deploying it back to the landing zone ready for another ocean landing?

Obviously part of the cycle time is how far downrange the landing zones are, but although a return to land scenario is going to provide a faster cycle time, I am guessing that there will still be launches that require an ocean landing for various reasons. Just wondering if there are announced plans for multiple landing barges to provide redundancy or additional landing ocean landing capacity?

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Let's look at some of the past missions to get an idea. In particular, let's look at the Echostar 105 mission. The mission launched on October 11. It arrived in port on October 15th. Unloading the booster takes less than a day. There is some amount of time to refurbish, and then the ship goes back out for the next mission. It then could take about the same amount of time to leave. So the lower limit is a week.

The upper limit can be done by seeing how long between missions. The closest pair I believe was the Oct 11/ Oct 30 2017 landings, with only 19 days apart.

I suspect it could be done faster if required, but 1 to 3 weeks seems to be the fastest turnaround, if there aren't any issues with the landing.

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  • $\begingroup$ I wonder how much thought SpaceX has given to partially refuelling the booster and flying it home. As they step up their launch pace eventually the turnaround time will be a problem. When that happens will they be better off adding another landing barge or adding a fueling operation to the existing one? All things considered it's probably better to add a second barge than to add fuel storage, delivery, and launch operations to their ocean operations for the Falcon 9. BFR might be another story. $\endgroup$ – Kengineer Jan 17 '18 at 23:32
  • $\begingroup$ @Kengineer space.stackexchange.com/q/13555/25 $\endgroup$ – PearsonArtPhoto Jan 17 '18 at 23:36
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Towing speed is usually around 5-8 knots. The ASDS Barges do not have engines for travelling, rather the Thrustmasters at each corner are used almost exclusively for station keeping as the booster is coming in for a landing.

The towing ships are different on each coast, and have different capabilities.

The folk on NasaSpaceflight.com forums usually track (Via the AIS system, land based is free, satellite data you have to pay for) and predict when the returning barge should come in sight of the various web cams.

Usually it is a day or two to return.

The real interesting question is how much work is required to get the barge ready to head back out.

They need to remove the stage from the barge, which has happened within the first day most of the time now that it has become more regular. Once the stage is off the barge, they need to refuel the Thrustmasters, unweld and clean up the brackets they used to hold the stage down.

No clear answer has emerged, since there have been no really close landings to see how fast they can do the work.

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