Monday, May 11, 2020

Starship Getting Ready to Hop

In the two weeks since I last posted about Starship SN4, SpaceX has continued to make progress, steadily checking off one test after another until now they're one set of tests short of waiting for the formality of approval to make the 150 m (~500 foot) hop flight. 

In the two weeks since then, they've done a "wet dress rehearsal" and two short (~3 second) static test firings of the Raptor engine (first and second).  Then they pulled that Raptor engine off SN4 and did another cryo pressure-proof test that was done to higher pressures than the previous test: 7.5 bar (110 psi) versus the 4.9 bar test from two weeks ago. 

Today we learn that they replaced the engine today, with a second Raptor engine, serial number 20, seen here.  Because that's a new Raptor, there will be a first static test of that engine, currently looking like it will be May 13th, with a test window open from 9am to 9pm CDT (UTC-5).  Backup days for road closures and such are the next two days.

What's that up there?  The world's highest thrust per buck rocket engine, being driven down a beach road by a fork lift?  Must be Boca Chica and SpaceX.  That was yesterday morning.  Taking a look at the live video feed just now it seems like the engine has been mounted. 

Final words to Teslarati, with one modification.
If that static fire and included wet dress rehearsal (WDR) is successful, Starship will technically be cleared for flight. The only obvious missing piece is an attitude control system (ACS). Starhopper, for example, used cold nitrogen gas thrusters quite literally taken off of flight-proven Falcon boosters. It remains to be seen if SpaceX will take the same approach with Starship SN4 or if a different kind of ACS thruster is already installed on the rocket and hidden in plain sight. For now, it looks like we won’t have to wait long at all to find out.
Instead of "If that static fire and ..." is successful, I'll say "When that static fire..." is successful.  After watching them for these last several months, they are nothing if not relentless.  If the tests don't go well, they'll keep working until the tests pass.  Starship SN5 is almost ready to roll to a test stand now.  Construction on SN6 has started as well.


  1. It's remarkable how well the private starship program has done, as opposed to the moribund competition.

  2. Once again, SpaceX passes all the other 'space' companies. Every other one. Foreign, domestic, public, private, governmental.

    I hope they do well in the next round of tests.

    And, Bezos? Suck it!

  3. I have to admit I've gone from a skeptic to an admirer of SpaceX. Yes, Mr. Musk has possession of a Steve Jobs Reality Distortion Field Generator, but I'm not sure he knows how to fully use it yet.

    But his company? Holy smokes they get stuff done! And they most definitely understand the relationship between "good on paper" and "good in the real world". In short, they break shit, fix, test it again, and fix it again if it breaks again. Lather, rinse, repeat until you can fly the same booster 5 or more times, and recover expensive items that were always considered expendable.

    Well done, SpaceX!

    1. We're on the same page. I've gone from having low tolerance for the guy to admirer. Not quite Fanboi/starry-eyed, but I don't get there. I think maybe I've gotten there once in my life.

      I don't really know how his fleet of companies operate; they all seem to have a president/CEO with Musk bouncing back and forth between Tesla, SpaceX, The Boring Company and others, but he's apparently there in Boca Chica almost all the time.

      Meanwhile, the European Space Agency, Russia's agency, and now China's are all rushing to copy SpaceX's designs. "Routinely doing what everyone thought was impossible."

    2. I know several people who work for SpaceX, several more who have worked for SpaceX, and several more that interviewed with Mr. Musk and turned down job offers. The ones who left told me he can be very difficult to work for, a couple were let go due to "overhiring", and the ones who turned down the offers said they just didn't like him, and didn't want to work there.

      There's a great many HUGE egos in the space biz, and some of the people who interviewed there were also well-stocked in the ego department, and I think they didn't want to work at a place where there could be constant clashes between high-level people.

  4. If you will note, the engine is Raptor S/N 20. Combine that with Starship prototype SN 4 you get 4-20 which has some mystical meaning to Elon.

    LL - Yep!

    Beans - Agreed

    Drjim - My wife was wondering about Elon Musk's background because of his name. While I don't fully trust Wikipedia, after reading Elon's biography there, I have to say that he is a polymath eccentric. He lives and breaths SpaceX. I wish I was thirty years younger and could be part of the SpaceX Starship effort.

    1. I saw some exchanges about serial number 4-20 on the Lab Padre video feed comments or maybe Teslrati. Back on April 20th, people were calling it Elon Musk Day, so I thought it was his birthday, but Wiki says that's in June. I have no idea what's up with that.

    2. April 20th is International Weed Day. This is when everybody goes out and smokes pot in countries where it is illegal. It is also the price point ($420) when Musk was going to take Tesla private (never happened, it's sitting at $839 now).

  5. Dunno , but some of my best ideas came while smoking the magic weed. Tho I like Elon, would never condone using herb while on the job of course.
    Much better than killing off brain matter with alcohol say I .
    All things in moderation quoted Christ...