Saturday, January 2, 2021

When Landing Orbital Class Boosters Gets Too Routine...

You can accuse Elon Musk of a lot of things, but something you can't accuse him of is having no vision for the future.  As recently as 2014, NASA dismissed SpaceX's plans to recover Falcon 9 boosters.  Now, SpaceX has recovered so many boosters that they dropped their production rate; they simply don't need as many boosters, even with their launch cadence that's many times anyone else in the business.  As far as NASA and other agencies are concerned, they've dropped their policy of never flying on a recovered booster - even for manned flights.  While I'm still not tired of watching them do it, landing a booster on a drone ship hundreds of miles from any landmark has become routine.

As reported by Teslarati on Thursday, last Wednesday, Musk revealed that their plans for Super Heavy are changing.  Super Heavy, of course, is the booster for the Starships they've been protoyping.  They're considering not putting landing gear on Super Heavy and landing them as we're used to with Falcon 9 and instead catching them with the launch tower.

It's important not to lose track of what we're talking about here.  Super Heavy will be the largest rocket stage ever built – and by a large margin.  It will lift a ~300,000 lb Starship around 25% of the way to orbit, with a liftoff thrust of ~16.2 Million Pounds.  The booster alone will be 70 meters, around 230 feet, tall.  The Apollo Saturn V booster had a liftoff thrust of ~7.5 million pounds.  I don't have any references for what the Super Heavy should weigh when it's ready to be recovered, but the idea is to modify the launch umbilical tower to allow it to catch Super Heavy by its titanium grid fins. 
Launch mount recovery would require unprecedented precision and accuracy and add a new element of risk or a need for extraordinarily sturdy pad hardware. However, the benefits would be equally significant, entirely eliminating the need for expensive recovery assets, time-consuming transport, and even the time it would take to crane Super Heavy boosters back onto the launch mount from a pad-adjacent landing zone.
In a way, Super Heavy has an advantage over the Falcon 9.  When the Falcon is returning to land, at the very last moments, a single Merlin engine can't be throttled back far enough to allow the booster to hover.  They have to adjust the engine to reach zero velocity at zero height, which requires amazingly accurate knowledge of the booster's position in the real world.  The Super Heavy is so much heavier than a Falcon 9 that it can hover. 

Scott Manley does a great presentation on this.

This idea is wild, and full of risk, but could bring a lot of improvements to the Starship. Not having the landing legs will save weight, which moves into the payload. They are, after all, planning on building hundreds of these.

A few weeks ago, Musk tweeted that we should see Super Heavy fly "in a few months."  I don't see any infrastructure in the Boca Chica area that could catch the booster out of the air; I guess they have a few months to build that, too.

This has the potential of being a lot of fun to watch.  Word is they think they've fixed the issue that caused SN8 to crash, so considering how close to total success that was, Eileen's flight should be fun to watch.  I expect that next week (11th to 15th).  


  1. No matter what you might think of Musk personally, you have to admit that this guy dreams BIG. And his company has a pretty good track record of making the dreams come true.

    Heck, if I was (mumble, mumble) years younger I'd take a shot at working for SpaceX myself, just to say that I did and have it on the resume.

    1. Hi Neon Madman..,
      To say all this is "amazing' is to lose sight of the strides made in "Aero-Space in just a few years!!
      Back in the late 90's .. Kisler Aerospace wanted to become the "Fed Ex of low altitude satellite launching!!!!"
      I was working as a Parachute rigger at the time for Irvin Aerospace which designed and built the 156 foot diameter Chutes ... they needed 6 to bring back the 42,000 lb. booster ... we built and dropped one "6-Pack" successfully! However they "Kisler" went under from money problems!!
      It was a fun project but ya' gotta' say... WOW!! with what these guys are doing today!!!
      I recall being 5 years old in 1950 and at my neighbor's house... "Pumpy" had a TV set and we watched "Tom Corbett, 'Space Cadet'" Take off an land his space ship the "Polaris" just like Muskie's troops are doing!!!!!!
      "*AUDENTES, FORTUNA, IVAT!!!!!!,
      (*) Fortune Favors the BOLD!!!!

      PS Like you, If younger I'd take shot at working for Space X too!!!!

    2. Skybill, there are a bunch of us hanging around here that feel the same about working at SpaceX and some even venturing off Earth with them. I was 7 years old when the first cadre of astronauts was selected. It was ashamed that we throttled back the space program so much in the 1970s. But maybe the times were not right to do what is being done now.

    3. there are a bunch of us hanging around here that feel the same about working at SpaceX and some even venturing off Earth with them.

      Yeah, count me in, too. With them "just up the road" it's tempting. There's a lot of interesting things going on around here.

  2. Arecibo dish just missed a second career.

  3. Yes indeed, have you found out if they are still going to launch? 11th or 15th,would be a great site to see. You would think it would be all over media by now no?

    1. The last time they tested one was live streamed by SpaceX on their website and YouTube. They're big on social media, and tend to have a link to the next launch here:

      The last prototype's test was announced a few days ahead, but these are early tests with prototypes and while they're getting better, they still change the schedules often. I keep an eye on the Lab Padre channel, the Nerdle Cam. There's no date being shown, but they won't know until someone from SpaceX tells them. They're not affiliated with SpaceX in any way

      Road closures this week (M-W) are likely to be Wet Dress Rehearsal, and a static firing. They've never launched until they've done those two things. That's why I'm guessing next week for the test flight.