RCgothic

Quite a nice fireball on splashdown. Nominal insertion for Starship though. Relight test in approx 25mins. Not yet that I've heard.

No-go for catch. Aiming for splashdown.

Liftoff! Max-Q!

Cost of those top 18 launches: potentially $18m for 100t *payload* to lunar surface with basically any cadence once produced. Cost of bottom launch: ~$99m not counting expended spacecraft, for ~10t *total* to lunar surface and probably 1/10th as often bottlenecked by production of the bits that have to be expended. Option 1 gets over 100 times as much usefulness accomplished (20 times as much payload 6 times as often, budget limited) on the same budget as option 2, so option 2 can get in the bin AFAIC. Even if the reusable launch misses it's cost target by a factor of *10*, it's still over ten times better than expendable. Purely considering a bid for an SLS replacement: SpaceX can bid as much for Option 1 as for Option 2 per mission because nobody else can undercut them. Assume a 20% profit margin on Option 2. SpaceX makes $20m. For Option 1 they'd make $100m. SpaceX should not bid Option 2 for anything. And they should not accept a cheque to do Option 2 excepting that it doesn't distract from their pursuit of Option 1.

Cool, if all SpaceX wanted to do is send a flag and footprints mission to the moon or *maybe* Mars. And that might be a sensible way forward (for the getting Orion to the moon portion of Artemis before Starship gets rated for lunar returns) if SLS gets cancelled. But that is *not* what SpaceX wants to do. SpaceX wants a permanent base on the moon. They want a city on Mars. They want the ability to brake hundreds of tonnes of mass into orbit of the outer planets arriving off a fast trajectory. And they want all that to be affordable on their own budget. Starship Superheavy expendable can accomplish some useful missions soon in the short term for a reasonable price. But frankly SpaceX would find that to be a distraction from what they actually want to do. If, as a nation, the US has different priorities, then I'm sure SpaceX wouldn't say no to a big cheque. But humanity would advance faster by investing in the long term goals SpaceX are pursuing rather than distracting them with short term dead-end avenues like flag and footprints (again).

SLS was also really good at shaking sensitive scientific payloads to pieces with those enormous SRBs. Nearly every bit of Artemis except the Landers and the EVA suits could be ditched and nothing of value would be lost. Getting rid of Gateway, Orion and SLS would save a lot of money for more regular flights and actual mission hardware.

The fabrication tolerances won't even hold 0.5cm over the whole booster. Thermal expansion/contraction alone would be much larger than that.

I would personally find 0.5m much more credible.

They have a second launch tower nearly ready. Not a big setback if they break the first. Much useful data to learn.

And even so there's no way impact explosion damage outweighs launch explosion damage. The quantities of propellant involved are just so vastly different.

Also the shipping channel is not exactly free from contaminants either. Of course SpaceX shouldn't be releasing contaminants into the environment. But I struggle to see how the deluge system puts anything into the ecosystem other than would be washed in by the regular storms.

Hypothetically it could come back safe 99 times out of 100 and still not meet human spaceflight safety criterion. Just because it came back safe this time doesn't mean astronauts should have been aboard. Clearly there was division over whether it was "good enough" or not, and we're not particularly well placed on the outside to second guess.

If they could even match Apollo cadence of 2-4/year this wouldn't be a problem. Kick the crew off the next flight to test and delay by 3-6 months. No big deal. Considering the space shuttle SLS is derived from managed significantly better than that in stretches I am genuinely baffled how they've so failed to match what came before.

This

Again, sure, if all we wanted to do was repeat Apollo. But we don't.

Whilst you wouldn't want to stay in the Van Allen belts, this isn't anything humans haven't done before. It'd take just under two months of exposure to the worst bits to accumulate a fatal dose with shielding of 3mm aluminium (25sv/year). Dragons are considerably better shielded than this, the trajectory will avoid the worst areas, and they aren't going to be staying there for months. A few orbits only. Apollo and Gemini both transited the belts with no ill effects to astronauts. Apollo doses were dominated by solar particles outside earth's magnetic field. I think it's awesome people are going beyond LEO for the first time since Apollo.

An RFA rocket just exploded at the UK's Shetland launch site: https://www.bbc.co.uk/news/articles/cy54wqzz0kvo.amp

Hardly anyone else even has a reusable S1. Only electron, to nowhere near the extent of F9 thus far. Reusable vs reusable battle is a long way off IMO. It's cool that Stoke, RL and BO are working on potentially competing approaches. Maybe Stoke's approach might be more easily realisable than starship. But for certain payloads (e.g. propellant) if each approach is fully realised that won't be anywhere close to as rapidly relaunchable as a "land on the launch tower". Additionally, having an enormous mass margin will certainly not hurt. If Starship achieves full and rapid reusability, but it only manages 25t payload to orbit and something like 300 tonnes are required for rapid reuse, that still undercuts Falcon, current market leader in cost efficiency per payload, by a factor of at least 5. If Stoke needs 50t dry mass to LEO for rapid reusability but total mass to orbit ends up being 40t, they'll be stuck. Also the "but it'll be oversized!" case is somewhat rebutted by pointing at the transporter missions that are currently eating smallsat launchers' lunch. If there's a payload capacity of 200t and a customer only needs to send up 2t, it'll be sent up with 50-100 other payloads and the "Cesna" won't compete against the "A320" outside of extremely niche applications.

Probably "Wow, wasn't expecting Sierra Space to be the buyer"

I suspect a folded telescope won't challenge the LEO payload of Starship in reusable mode. And if we want bigger than what will comfortably fold up, we're into multiple missions anyway.

Three times the expendable payload of Saturn V certainly makes an impressive benchmark, but it doesn't make for an impressive moon mission. Replacing SLS with Superheavy fixes a cost issue at least, but it doesn't advance long-term goals. The only use cases I'd find interesting for a single-stick expendable launch are truly enormous monolithic payloads to LEO. But even space stations and telescopes don't need that, just send them up in segments. Currently the only thing I can think of might be a very large nuclear powered tug where the reactor can't be subdivided.

I still don't understand why anyone would just want a repeat of Apollo. It'd land twice and get cancelled. The way EUS is going it might not even manage that. The goal is permanently inhabited lunar bases and crewed beyond earth-moon explorations. Tanker flights get us that. With that within our grasp I don't care at all about pathetically undersized single stick missions.

If US or western european crews don't go up on Starliner before they go up again on Soyuz I'd be shocked.

Also it isn't just a case of "get bombarded by radiation, get activated". Some materials are susceptible to activation by particular forms of radiation, such as cobalt to neutron bombardment by, and if there's a perceived risk of activation by particular forms of radiation then materials containing susceptible elements can be avoided.