RCgothic

I believe Polaris 1 will be a record for number of astronauts simultaneously in depressurised conditions? IIRC ISS and shuttle never had more than two at once. Apollo occasionally had 3 during depressurisations of the command module for stand up EVAs. Polaris will be 4. Unless different national missions randomly had spacewalks occur at once.

Aha! Fixed! It was importing cropped for some reason.

Image won't link properly. Oh well.

There's no such thing as a minimum viable commercial off the shelf lunar lander made from existing parts. And even if there were, SLS couldn't send it. And even if it could, starting from now would only incur huge delays. And even then it'd only get a very very poor excuse for a lunar mission. If value for money is the concern, then the Landers should be at the very bottom of the list of things to change, right behind *gestures at literally every other thing in the Artemis program and very specifically at SLS/Orion*. Any criticism of Artemis on cost grounds that doesn't want HLS but does want SLS is completely devoid of credibility IMO.

Maybe a waterproof robot could take a normal shower after dirty tasks.

I also suspect one of the reasons Delta Cryogenic Second Stage was chosen over Centaur for the basis for ICPS and EUS was the separate tanks make an explosion due to propellant mixing less likely. A lander based on Centaur would go against this philosophy. (So does Starliner on Atlas/Vulcan, but that's not a NASA designed vehicle).

True. But say (impossibly) they were. Then what? What does that SLS-Orion-Apollo do next? What are its stretch goals, what can it achieve? Maybe 12t of down mass every other year, disregarding crew missions? Can't achieve anything lasting that way. It'll get rapidly cancelled after its flag and footprints. The HLS landers are the genuinely useful bits of Artemis. Suddenly the downmass is hundreds of tonnes, multiple times a year. Habs. Labs. Construction equipment. Solar collectors. ISRU. Refuelling stations. Giant surface telescopes. Permanent off-world inhabitation for dozens to hundreds of individuals. Enabling technologies for Beyond Earth/Moon exploration! And the development costs to enable those sorts of plans are essentially peanuts in spaceflight terms. "It's too hard!" Not as hard as closing SLS's 20 tonne mass budget deficit I'd wager. "It'll be delayed!" Not as delayed as any alternative program would be. "It's a waste of money!" This can't possibly be serious.

I'm never going to get on board with paring back Artemis. I want permanent off-world habitation. Single-stack SLS missions are never going to achieve that.

The secret about starship being oversized for Artemis is that Artemis is a customer but Starship has grander ambitions.

Nuclear (and other thermal plants) don't strictly need water for ultimate heat sink. I've seen several proposals for arid areas.

What's the worst thing someone could do with a loose fully charged battery? That's basically the problem with hot swappable battery packs.

I'm completely unconvinced that hybrids are the way to go for most domestic vehicles. The round-cycle efficiency for synfuels is way less than direct electric, and if the plan is to keep burning fossils then that's bonkers. The only relevant use cases IMO are vehicles that need the increased energy density for routine long hauls like trucks, and/or have necessarily tight margins like aircraft. As much as I love my current petrol Mondeo, when it expires my next vehicle will absolutely be full electric (although not a Tesla).

There are a number of things in comics universes that are effectively magic. Like punching or throwing things without equal and opposite reaction. In reality he would leave a brightly glowing fireball, but if he doesn't then just chalk it up as one of his necessary secondary powers

There's no surprise that with how late they started HLS it's not ready, and there's no reason to think anyone else would have done better. That said, HLS isn't the only source of the delays, because even if that was ready to go the space suits aren't. Both programmes started (and restarted) far too late.

Apollo 9 was entirely in earth orbit, as would be this.

That's certainly the direction I'd go. Or maybe Starliner to throw someone other than SpaceX a bone.

Orion to starship in LEO would be a total waste of an SLS.

Factually nothing to do with IFT-3. The dismantling was noted on March 12th and IFT-3 was the 14th. https://x.com/_mgde_/status/1767547040089657675?s=20

Or these are just teething troubles as they discover what's vulnerable and better protect those bits; pad turnaround is getting faster between each flight; and they're going to have three or more pads to launch from.

There's not a shred of evidence IFT-3 was anything other than a completely nominal flight until SECO or that raptors operated anything other than exactly as intended to achieve the final trajectory.

Ablation and corrosion are types of wear - material thickness or effective thickness reducing by physical or chemical action. I've also always found it weird that "no endurance limit" is not actually a good thing.

Isn't this basically a substantial part of the reason DIVH is getting retired? The pad infrastructure is old, complicated and creaking, and DIVH doesn't fly often enough to make it worthwhile to keep everything fully tested and operational between flights. Then when they do come to launch, something has inevitably failed and needs fixing.

It's certainly theoretically possible to protect bridge piers from collisions. But in the specifics of cost/obstruction of navigation channel/river bed conditions it may not be practically possible to adequately defend every existing bridge. If I were a security agency I'd be pretty nervous about deliberate follow up attacks right about now.

It took over 3 years for Falcon 9 to get flight cadence to under 3 months from the first flight. Starship not doing badly.

IFT-1 pad destruction was likely as a result of a steam explosion from vaporised groundwater boiled by exhaust gas penetrating the cracked slab, argues a new paper: https://arxiv.org/abs/2403.10788