Saturday, June 12, 2021

A Short Story But A Neat Story

I ran into a short story on Teslarati yesterday, my first stop for SpaceX news.  It's one that isn't important and isn't long, but I thought it was rather cool.   

Regular readers know that SpaceX has a couple of recovery drones that Falcon 9 first stages land on.  These are known as OCISLY and JRTI; more formally as Of Course I Still Love You and Just Read The Instructions. The story broke earlier in the week that after a busy week, with two launches three days apart, OCISLY returned to port first, booster B1067 was removed and work started to prepare her to traverse the Panama Canal and go to Long Beach, California in preparation for some polar orbit launches from Vandenberg Space Force Base. 

The story yesterday said OCISLY was enroute to the Bahamas where the drone barge will be loaded onto a transport ship called Mighty Servant 1 to be carried through the canal and north to Long Beach.  

Mighty Servant 1 (MS1) carrying (I believe they said) an offshore oil platform. 

Formerly stationed in California, drone ship Just Read The Instructions (JRTI) was transported from Port of Los Angeles to Port Canaveral, inspected, and substantially upgraded between August 2019 and May 2020. SpaceX relocated the vessel to give its East Coast fleet a redundant pair of drone ships and enable a launch cadence boost otherwise unachievable. That decision proved smart and SpaceX has made excellent use of both drone ships, completing an incredible 36 orbital Falcon 9 launches, 36 landing attempts, and 35 successful booster recoveries in the 12 months since JRTI entered service alongside OCISLY on the East Coast.

Now, though, SpaceX once again needs a drone ship on the West Coast to support a significant number of polar Starlink launches and missions for US government customers after completing just two launches out of Vandenberg Air/Space Force Base (VAFB) in the last 24 months. Targeting an average cadence of one VAFB launch per month, the first phase of SpaceX’s Starlink constellation – ~4400 satellites – will require approximately two dozen dedicated Falcon 9 launches to fill out three ‘shells’ of polar-orbiting spacecraft.

MS1 is a partially submersible heavy-lift ship.  It will submerge part of the deck, one or the other (or both) MS1 and OCISLY will position the drone barge and MS1 will then float to the carrying position.  

More details in this Twitter thread from Teslarati author Eric Ralph.

Why?  Final words to Eric Ralph.

Why isn’t entirely clear but using a transporter like Mighty Servant 1 – while expensive – could expedite the journey by ~30%, make squeezing a ~53-meter-wide barge through a 55-meter-wide canal less anxiety-provoking, and ultimately allow SpaceX to stick to a schedule that would see it kick off West Coast Starlink launches this July.




  1. That is an excellent example of cost-time analysis.

    Once again, SpaceX is thinking more like a business than Big Aerospace.

    And, on another note, they tested the colored disco lights in the High Bay Bar.

    Also SpaceX is advertising for a Space Medical Officer - must be an MD or a DO with a mechanical engineering degree. Chief Medical Officer... Hmmm.... The SMO will also be in charge of hiring a medical division exclusively dealing with medical issues of passengers, crew, and medical experiments.

    Exciting times.

  2. Makes me wonder how soon they'll start building Version "2.0" drone ships.

    1. Seems like the Mighty Servant would make a good platform for launching and recovering Super Heavy boosters.

    2. The two oil platforms, Deimos and Phobos, they are converting to launch and recovery platforms for Starship?

    3. Supposedly, yes. Launch and recovery. Which means that SpaceX will be getting into the watertaxi business. Wonder what that's going to look like.

  3. Exciting times - and cool names.

  4. That looks like a production spar or tension leg platform on the back of the MS1 - the angled sides would be for vortex shedding in areas of high current.

    I've used the vessel to move floating drilling rigs. It's a fascinating process, preparing, loading, offloading. The chief reason it's used is because it's so fast. Wet-towing a rig with ocean-going tugs will proceed at around 5 knots or less. Can't outrun the big storms that way, as you well know - hurricanes can make speed sometimes.

    But a dry-tow on something like this will make close to 15 knots. They can outrun the weather. If the rig is on day rate, the expense of daily rent and fuel for the tugs make a dry tow a good option. The time element is probably what is driving a dry-tow option for Space X.

    1. Thanks for the input. The guy who writes at Teslarati had some numbers today that are like yours for the ship, but faster for the tugs. His numbers show the big ship like MS1 doing the run in half the time of a tug. Yours are better than that, maybe a third the time of a tug.

      I think that SpaceX is more comfortable letting an experienced crew carry their drone ship through the Canal with the roughly 3 feet of clearance they say the drone ship would have.

    2. I'm not terribly familiar with the subject vessel. Semisub rigs are a bit slower than a barge, because they are much bigger (tonnage) have more wetted surface area, hence a lot more drag in a wet tow. Rigs inevitably gain weight with age too, modifications, and improvements, so they ride lower in the water even when ballasted up, making the situation worse. They won't have much trouble getting through the canal - they're used to tight squeaks and the transit is controlled by tractors pulling the ship through, where it's critical.

  5. Forgot to mention that when S7 moved the former Sea Launch Odyssey Launch Platform, they used a heavy lift ship. Between the reduced time, and the savings in fuel cost for the Launch Platform, it cost them significantly less than to just sail the Launch Platform from Long Beach to Russia.