Wednesday, May 26, 2021

SpaceX Changes Their Mind - SN15 Has Been Retired

Since the start of May, after SN15's successful test flight, we've been under the impression that SpaceX was going to re-fly SN15 "soon."   All of that apparently changed in the last several days.  First we heard that one Raptor engine had been removed, then we heard that all three Raptors had been removed.  Last night, I noticed that one of the two, new, very large cranes (the yellow Liebherr crane in the center here) had hooked up to the nose cone of SN15.  Today around midday, the crane lifted her off of the test stand and onto a multi-axle transport.  That was puzzling.  Then in the evening East Coast time, SN15 was gone. 

You can read in that blue bar on the left of the image that it says "SN15 retires to the RV Park Display Stand."  I didn't even know there was an RV Park.  But that's apparently SN15's new place; as a memorial to the fact she was the first one that "sticks the landing and keeps on standing" (to channel my inner John Cameron Swayze, Timex Salesman).

So now what?  I've seen nothing in particular that's official.  As I said a few days ago, the emphasis seems to have switched to preparing support for the first orbital flight of a Starship and Super Heavy in the third quarter.  In that picture of the launch complex, you can see two large fuel/oxidizer tanks; Ground Support Equipment (GSE) for Starship and Super Heavy missions.  Near the right edge, you can see the Orbital Launch Integration Tower (OLIT), and if you look about halfway up the metal portion, you can see some rails and hardware where base section 1 joined section 2.   Sections 3 through 5 are being assembled now in the Shipyard area, near the High Bay.  The crane on the left is the most experienced crane in the launch complex, the one we've called Bluto.  The tall, yellowish one is the Liebherr crane and the one on the right, is the most recent addition, named Kong by the people who hang out on the Lab Padre camera chats (called nerdles). 

The High Bay itself currently is housing both Starship prototype SN16 and the beginnings of stacking Booster Number 3.  BN3 is expected to be the first Super Heavy to fly, although no one knows exactly what that means (officially); will they try to land it on some sort of legs or will they try to catch it by the grid fins as Musk has proposed?  The first Starship prototype to fly to orbit is expected to be SN20, which is also currently under construction. 

If I had to guess, I think they'll fly SN16 if any improvements were made after the data from SN15 was analyzed.  Based on how long prior vehicles took, SN16 could fly by the end of June.  If SN16 isn't necessary, we may not see anything flying for a while.


  1. Sad to not see SN15 try again, but I suspected it might happen after looking at the methane fires and flaming insulation from it's launch and landing. But not sad that she's getting a nice retirement.

    As to the RV park, if you look at an aerial photo of the production site, the RV park looks to be populated by Airstreams and is near the offices and other non-assembly buildings. (Which reminds me of Silver City, the north end of Kwajalein during the late 60's and early 70's that was basically a big mobile home park full of Airstream trailers...)

    So it's up to SN16 to fly farther, higher (up to 20km or more, from what they report) and hopefully more than once.

    SpaceX has more cranes of all sizes than any other location short of a shipyard (which, come to think of it, it is...) or a skyscraper.

    And they're putting windows into the SkyBar on the High Bay. They've put the internal elevator cage into the base of the OLIT and have stacked two of the tower segments together and probably stacking the third by the end of the week.

    All of the ground support tanks are well on the way to being built, along with manifolds and pipes and hoses and connectors and all sorts of stuff.

    It's amazing. Every update from the watchers is showing a 20-ring circus of spacey goodness. And it's like watching a multi-ring circus, you can't focus on one place and not miss things happening elsewhere.

    The camera watchers and RGV aerial photos are doing a truly historic job of keeping visual records of what is going on. From building to unbuilding to making messes to unmaking messes. Damn good job, boys and girls!

  2. SN15 represented a great leap forward. It deserves a place of honor and remembrance.

  3. The reason for the move is that all of the cranes, including the new one that would have to be disassembled again, would have to have been removed from the site for any launch (they are rented). In the case of the one building the orbital launch tower, that would have put two weeks into the schedule unnecessarily.

    Elon really wants to get to orbit. Any information from a relaunch of SN15 is minimal compared to information from launching BN3 and putting SN20 through the atmosphere entry interface.

    As I understand it, the height of the stacked system requires using the tower for stability.

    1. Thanks for that insight. If that's right, and it sounds reasonable, there will be no launches from Boca Chica for a while.

    2. Do you watch the telemetry when the Falcon 1st stages come down? It's fascinating.

      The acceleration hovers around zero for awhile, then it comes out of the ballistic trajectory and starts speeding up as gravity takes hold. At a specific instant, they do the entry burn, which brings the velocity down a few thousand kph. But then, flame gone, the drag kicks in and acceleration builds up in the negative direction.

      The interface between air and space is much more defined than my gut tells me it should be. And no, I don't have any friends who stare at telemetry readouts for fun...and my wife is certain that I'm crazy.

  4. This comment has been removed by a blog administrator.