Thoughts on Starship

Of the three big American rockets – SLS, Starship, and New Glenn – New Glenn is probably my favorite.  Yes, it’s behind schedule and probably over budget, but that can be said about all of them.  But that’s about the end of the bad stuff about New Glenn.  I’m sure if we knew all the details about it, there would be other bad stuff, but so far so good.  As to the SLS, I do want humans to return to the moon, but I want to do it sustainably.  A multi-billion dollar rocket that launches every two years (maybe) isn’t how you do that.

And then there’s Starship.  The basic idea of Starship – big rocket, go space – isn’t that bad.  But there’s so much bad or weird stuff around it.  Like, all the talk of using Starship to transport people or goods to any point on the globe in under an hour.  Which is stupid for a multitude of reasons.  For example, you’re going to take off from some place in the middle of nowhere an hour from some big city, fly for an hour, then land in the middle of nowhere an hour from some other big city on the other side of the planet.  Okay, but people wouldn’t just fly into a spaceport and walk onto a rocket.  There would need to be technicians loading and securing all the baggage, as well as a flight crew securing all the passengers.  (You don’t just have a seat belt on a rocket.)  And then all the extra personnel have to get clear of the rocket, and assuming there’s no delay in fueling, or weather, or an aircraft/boat in the launch/landing area, this “anywhere in an hour” is more like five or six.  Which would be cool, but is the demand for that enough to warrant a massive rocket? 

Anyway, what about the Starship taking stuff to orbit.  How do I feel about that?  It seems with each launch I’m becoming more … dubious?  Like, I’m starting to wonder how many more test flights will be needed for Starship to do what it is supposed to do.  Five?  Ten?  Fifty?  So in this post I’m going to give my concerns for the Booster, and the Starship, as well as a section on what I would have done if I had been in charge of Starship development.

Booster concerns.

The Booster I’m mostly fine with.  It goes up, then comes back down, like the first stage of Falcon 9.  Great.  My issue is the landing, or lack thereof.  I understand the idea of catching a rocket means you save mass on landing equipment, so you can have more fuel to get more into space.  I understand that.  But a rocket landing on a concrete pad with landing legs is far simpler than what they’re doing.  Being simpler, it’s probably also a lot safer.  First off, I heard the reason they didn’t catch the Booster on Flight 6, is because there was a communication error with the tower.  So basically, any software glitch at the tower turns this reusable rocket booster into an expendable rocket booster.  There’s no other chance of recovery.  Well, that’s why they want to build a second tower.  Okay.  But if there’s an accident on a concrete pad, it can probably be cleaned up and repaired pretty quickly so you can get back to landing rockets.  But an accident at a tower could mean months of disassembly and rebuilding before you get back to landing rockets, not to mention launching them.  If they can make the catch work, great, but it almost feels like they’re skipping some intermediate versions where they would have learned how to precisely land this huge rocket on legs before moving over to catching it.

Starship concerns.

Was it Flight 4 that had the one flap nearly burn off?  While all the Musk-Bros were cheering about how tough Starship was, I was wondering how do you make this a quickly reusable craft if you have to do major repairs after every mission?  And while there has been less damage with each test flight, there’s still been damage.  This next flight is with an updated Starship, and if there is obvious damage to it during reentry, then I will officially become concerned that this Starship – as pitched – doesn’t work.  The whole point of Starship was that it could launch, land, and then be reloaded and launched again very quickly.  But if it needs to be refurbished after every flight, then you can’t do that.  I’m not saying that Starship should then be scrapped, but if it can’t be quickly reuseable, then all of its supporters need to adjust how they present it and how it is to be used.

And then there’s the … not landing.  Again, I understand that without the weight of landing legs/gear you can get more stuff into space.  But for any eventual cargo that complains, you better enjoy roller coasters for that last second pitch up for the landing.  That’s why any cargo – living and non-living – would need to be very secure in any passenger version.

If I were designing this

If I were designing the booster, it would have landing legs.  At first that’s how we’d land it.  But once we were sure we could hit a target precise enough to try catching it, there’d still be landing legs.  These could be less massive emergency ones that could only survive one use.  The point would be if there was a last-minute issue with the tower, we could divert to a landing pad and save the booster instead of just ditching it in the ocean.  Then maybe once we have a 95% success rate in catching, we can scrap the legs altogether.

The first big change for the Starship, is I’d start with an expendable second stage.  This way you could start carrying space stations or other big satellites to orbit while still working out the whole reentry thing.  Once the satellites were deployed, these second stages could then basically do the reentry tests that have been done, just without the flip at the end.

As to the flip to land vertically, I understand that that will be needed for a Starship to land on Mars.  But to land back on Earth, we have countless runways already built.  Why not land on one of them?  But the weight of landing gear would mean less stuff to put into orbit.  Maybe.  But if Starship only needed rocket engines in space, then you’d only need the vacuum engines.  If you followed the Space Shuttle route and made it an unpowered glider, you also wouldn’t need any extra fuel.  But it’s likely you want to save some fuel and have a small engine to have some landing range.

But the whole point of Starship is to land on Mars, and there aren’t runways there.  Yeah, but they’re not going to build a Starship, then flip a coin to see if it will land on the moon, or go to Mars, or stay here on Earth.  Each version of Starship will be different, so why not build the Earth version to take advantage of all the runways we already have built?  The whole flip and catch for the Starship seems needlessly complicated.  But the point of catching it is so it can just be stacked on top of another booster and launched quickly.  Assuming there isn’t massive damage to the heat tiles during reentry.  If – as seems increasingly likely unless they’ve somehow managed to fix all the problems – a Starship needs to be refurbished before it can be launched again, then what difference does it make to how quickly it can be turned around if it lands on a runway or is caught?   

The Starship program is a bold new approach to rockets that faces numerous challenges.  My concern is that while I feel it is likely these challenges can be overcome, they can’t be overcome as quickly or easily as is being hyped.  Basically, we were promised a wunderrocket today that I don’t think we’ll see for a couple of years.  I know it is rocket science and it’s not like a new phone that comes out every year, but this rocket is supposed to be part of our return to the moon.  And I’m starting to be concerned that even with all the delays and issues with the SLS and Orion, Artemis III will be delayed – or even cancelled – because Starship won’t be able to deliver.  So maybe, they should have tried a less bold approach like what I outlined to get a Starship delivering stuff to orbit and then worked out how to make the bolder step instead of trying to do it all at once.