RCgothic

Starlink is go for propellant loading at t-35m. Lol, can't beat tater!

15km first flight! In fact, little bit of a tweet storm. 8 bar at top, 9 bar at base: Failed at interface between different stainless steels:

Were mk1's fins actually driven at all? I don't remember any test flexing.

The inside. Hang on, let me dig out the Skylab video (largest diameter hab ever lofted). There's a good video of astronauts lapping the interior, and Starship will be better because it's 50% bigger. At 4m radius you can simulate 1g at a running speed of 6.25m/s!

I'm looking forward to a new video of an astronaut lapping the circumference in zero g!

Formula E is a bit like F1. Accelerations are similar, but the electric cars top out at 170ish mph Vs 230mph for F1, and each driver has two cars and they swap half way through because the batteries can't go full distance.

An expansion ratio of 107:1 (Elon says it could get a little bigger) is not exceptional for a vacuum engine, but it is amazing at sea level. High chamber pressure really helps! RVac knocks the socks off RS-25 (67:1) as a sustainer engine but not a pure vacuum engine like MVac (1:165) or RL10(1:280). There are still trade offs like being able to fire at sea level, fit in the engine bay, and regeneratively cool a nozzle that large. But the number of things this Raptor is great at (if not exceptional) certainly beats every other engine. It seemingly has no weaknesses.

And it wasn't an unsupported test, which helps explain its sea level durability a little, but maybe not entirely:

So the brief is more like: "Design a robot deployable from an HLS lander and we'll pay $55k/kg returned to the lander."?

Yeah I know who you mean.

Am I missing something? $25k per lb is $55k per kg. A reusable falcon nine costs around $50m, so let's be completely optimistic and say a rock-gathering return spacecraft can be done for $50m - $100m total. To turn a profit on that you need to return around 2000kg of rock. F9(r)'s mass to TLI is ~3300kg. That's not returning 2000t of rock. Falcon heavy expendable can send about 20t to TLI, but certainly costs at least $250m inc rock gathering spacecraft. Needs to return over 4.5t of rocks. That's still not happening. Is NASA going to pay for the mission as well as the returned cargo?!?

Aft fins installed!

I'd say SpaceX is likely to continue development whether or not they get NASA funding. Blue might. Dynetics would perhaps struggle.

I take your point, but part of this comes from one of the tweets surrounding the conversation quoted above in which BE-4 was described as "more advanced", ambiguously conflating TRL and sophistication, which is why I went into every metric like I did. Also some of Raptor's design aspirations have legitimately moved, such thrust of up to 3.1MN. The point stands I think, that I can't think of any metric on which BE-4 is better than Raptor.

18 months ago. BE-4 is a year ahead of Raptor. 18 months later BE-4 is definitely not ahead. In fact I can't think of any metric on which it competes. Engine cycle? Raptor's full flow staged combustion is more advanced. Development? Raptor is further along. Prototypes? Raptor has at least 40. Testing? Raptor has flown actual flight articles. ISP? Raptor is ahead. Thrust? Raptor is already topping BE-4's 2.4MN. Cost? Raptor is certainly a lot cheaper. TWR? Raptor is on course for better than Merlin. Size? Raptor fits all the above in a much smaller package. It's a little bit amazing how completely you can squander a twelve month lead in 18 months. Blue needs to pick its game up. This is too Gradatim. More Ferociter is needed!

Hang on, it was JRTI on station for this mission. How much more upgraded can the thrusters get?!

Superheavy pad looking really good!

Going up on Vulcan x3 confirmed.

Briefly thought it would be cool to see them practice the manoeuvre with old F9s, but on further thought falcon's probably not capable of 1) entering the right attitude, 2) relighting engines in that attitude, and 3) surviving hypersonic sideways flight. Also I'm quite attached to the Falcon flight leaders, I don't want to see them lithobrake!

Tim Dodd, The Everyday Astronaut, posted this earlier. One error that's been caught already is that there are parts for 7SRBs, not 35.

SN9 starts to get stacked.

Here's the thing. Even if Starship completely fails to survive EDL and they can't fix it. If they never get refuelling in orbit to work. If Superheavy never sticks a single landing. Then you can still retool the system as a conventional expendable rocket with ~250t payload to LEO and IDK, a 12m payload fairing, and all 34 engines *combined* will cost about half as much as a single RS25. Even if Starship/Superheavy is a complete abject failure, it still renders SLS totally obsolete.

SN9 and 10 are starting to get sleeved. I think some of SN9's sleeved domes may have been mated to some additional rings but I'm not sure. SN 11 is still just bits.