Monday, September 20, 2021

Looks Like a Week to Keep an Eye on Boca Chica

SpaceX has scheduled road closures all week, with one closure in place as I type (it's just about 7PM CDT).  The county website says the only exception to "all week" is Tuesday, a secondary day to today's closure.

As you can see, most of the closures are for 5:00 to 11:00 PM, when traffic going the beach is lowest and extending the closure for a test that doesn't go as quickly as planned is less likely to interfere with someone going to the beach.

Teslarati is suggesting this could be a full week of testing.  

First rolled to SpaceX’s Starbase orbital launch site more than six weeks ago and stacked together for the first time on August 6th, the company has spent the last month putting the finishing touches on Starship 20 (S20) and Super Heavy Booster 4 (B4) – ranging from heat shield installation to plumbing and wiring. Perhaps most importantly, SpaceX has also installed some or all of the Raptor engines that are expected to support the ship and boosters’ first static fire qualification tests.

As a quick reminder, Booster 4 (B4) and Starship 20 (S20) first went to the test area around the start of last month, went through a trial stacking, then were de-stacked and both went back to the Shipyard area.  Both had their Raptor engines pulled with some sent to McGregor (Texas) to be tested on their static test stand.  S20 went back to the test area, had its engines replaced (three Raptor Boost engines and three Raptor Vac engines for use in space).  B4 followed on September 7th and similarly had its engines replaced.   Raptor 67 (left) was replaced by #64 (right) at some point recently.

Photo credit shown on the photo, to @bocachicagal, via 

Super Heavy boosters have only the Raptor Boost engines, like #67 and 64 above, which have been static tested many times.  We have never seen a vehicle static tested with the Raptor Vac engines so that will be big milestone for them, but much of what lies ahead are major milestones.  There was one static fire of three engines on B4.  I expect them to recreate the cryogenic tests to S20, perhaps just plunging ahead to the static firing on the first try.  I think that once S20 is tested with all six engines, it's ready for flight.  

B4 will need to be tested with all 29 of her Raptors and that will be epic to watch.  If those engines are set to maximum thrust, Super Heavy will likely become the most powerful rocket ever tested and – like with S20 – will be more or less qualified for its first flight if the test goes according to plan.

EDIT 9/21/21 1140 EDT:  Thanks to comment by Malatrope, who pointed out that I posted an obvious error.  My apologies.


  1. Stunning progress! When I was a kid back in the 1960's, I was glued to the TV for stuff like this.

  2. Heh. I remember that, too. Good times. Exciting stuff for a young boy.

    Here's a nice story. It would have been the early 70's and I was may 11 or 12 years old. I got the idea of writing to NASA and asking for any printed material they had. So I hand printed up a letter with my mother's help in my child's handwriting and put it into the envelope.

    The problem was there was no internet back then. We were on a farm in rural Ontario outside of a very small town. No way to know what a proper address would be. So I just addressed it to NASA, Florida, United States of America along with my return address. All hand printed.

    I sent it off and forgot about it after a few weeks. A few months later my mother comes to my small rural elemtary school with this huge envelope. From NASA. And full of pamphlets and pictures and other material.

    I always thought how nice it was of them to pay attention to some little letter from a little boy from so far away.

    Those were special times.

    1. In the mid-60s, NASA brought the Space Mobile to my elementary school. I must have been 11 or 12. They had some handouts and one had an address for kids to write, so I did.

      Like you, I got a large manila envelope full of NASA Facts, magazines and reports. I collected them for years and I think they're still around the house somewhere.

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  5. I wish I could go camp down there as all this unfolds. watching B4 light off that many raptors would be amazing. video is not the same. you can't feel it

  6. "Super Heavy boosters have a mix of both kinds of engines as well."

    To clarify, Super Heavy doesn't have any vacuum engines. It has fixed engines (outer ring), and gimbaled engines (inner cluster). It never goes high enough to need the low-pressure version.

    1. I actually said, that, didn't I? Thanks for pointing that out. I'll do an edit to correct it.

      Every so often, I write something that's so obviously wrong it surprises me. Usually, it's that I'm intending to say something else and the wrong words come out, making the wording so confusing that I can't make sense of it a minute later.

    2. No worries! Everybody does that.