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> Artemis acceptable crew mortality rate is 1 in 30.

This seems insane to me. That X decades later we accept, with all our advancements in tech, a weaker system than ever before. That if we send 30 people we _accept_ that one is possible to die.

That's the starting point? That's what we document as acceptable?

Astronauts are, as a group, extremely risk loving. Every single person who signs up to go into space knows what they’re signing up for - they’ve spent their entire life working for the opportunity to be put in a tin can and shot into orbit atop a million pounds of explosives. There’s a very valid critique that NASA has become far too risk averse - we owe it to the astronauts to give them the best possible chance to complete the mission and make it back safely, but every single person who signs up for a space mission wants to take that risk, and we don’t do anyone any favors by pretending that space can be safe, that accidents are avoidable, or that the astronauts themselves don’t know what they’re signing up for. A mission that fails should not be considered a failure unless it fails because we didn’t try hard enough.

> Artemis acceptable crew mortality rate is 1 in 30. Roughly 3x riskier than the shuttle

Do you have a link? I’m asking because it is very easy to make mistakes when comparing risks. For example https://news.ycombinator.com/item?id=47725961 translates that into “That if we send 30 people we _accept_ that one is possible to die.” If that interpretation is correct, given Artemis has a crew of four, that looks more like a 1:120 chance of a mortality of 4. I think that would make it an improvement over the space shuttle.

> Artemis acceptable crew mortality rate is 1 in 30.

How did they arrive at that number?

(Eg. Did they arbitrily establish the target at the outset? Or did it evolve by gauging the projected failure rate of their core mechanical etc. systems as those began to take shape, then establishing a universal minimum in line with that, to achieve some level of uniformity and avoid drastically under/over-engineering subsequent systems?)

For context, Jared is NASA Administrator Jared Isaacman. I didn't know, so I think it could be useful for others.

> but it wasn't thought of or acknowledged by NASA as being risky until very late in its lifecycle.

They understood it to be extremely risky immediately. They understood the ice issue early on as evidenced by the fact that they completely changed the coating on the external fuel tank to try to compensate for it. They also added ice bridges and other features to the launch pad to try to diminish the risk. They also planned for in orbit heat shield tile repair. They specifically chose the glue to be compatible with total vacuum conditions so they could actually detach and rebond a whole tile if necessary. They developed a complicated and, unfortunately wrong, computer model to estimate the damage potential of ice strikes to the heat shield tiles. What they _finally_ came to understand was that you just have to swing the arm out on orbit and take high resolution pictures of the vehicle to properly assess it's condition.

NASA was and always is very bad at calculating systemic risk. They have the right people developing risk profiles for individual components but they've never had the understanding at the management level of how to assess them as a complete vehicle in the context of any given mission.

> Roughly 3x riskier than the shuttle.

The huge advantage they now have is a capable launch escape system which can possibly jettison them away from the rocket should any issues arise during ascent. That was the one thing the shuttle could not possibly integrate.

On the other hand they could take a far larger crew to orbit and maintain them comfortably for several weeks during the mission. The "space bus" generated a healthy 21kW from it's fuel cells and created so much water that you had to periodically dump it overboard. This was a blessing for the ISS because you could bag up all that excess water and transfer it for long term use.

Anyways.. as you can tell.. I just really loved the shuttle. It was a great vehicle that was ultimately too exceedingly tricky to manage safely.

An error in any of the orbital math may have seen them flung out into space with no chance of recovery.

Glad that you are glad that they are safe and sound

>The Shuttle was risky, but it wasn't thought of or acknowledged by NASA as being risky until very late in its lifecycle.

The whole idea of the shuttle program was to make space travel routine and less-risky. Like air travel.

It obviously failed at that goal.

> Artemis acceptable crew mortality rate is 1 in 30.

So with 4 crew members, chance of one dying was 13%! Very lucky they all survived.

> The Shuttle was risky, but it wasn't thought of or acknowledged by NASA as being risky until very late in its lifecycle.

I think they did think of it as risky and acknowledge that it was risky, they just had a different tolerance for risk.

The Artemis mission is "more difficult" - you're firing folk way out into space and hoping you hit a fairly narrow channel where they swing around the Moon back towards you, and not just keep going straight on out beyond any hope of rescue, or biff it in hard becoming a new lunar crater. You've got to carry a lot more fuel, and a lot more technology. You're going to have them up there in a much smaller space than the Shuttle for a lot longer.

The Shuttle by contrast was kind of "proven technology" by the end of its life, and we really should have developed some new stuff off it. Columbia first flew in 1981 but "the keel was laid" as it were in 1975! Think about the massive shifts in technology between 1975 and 1981, and then maybe 1981 and 1987.

I remember someone saying in 1981 that their new car had more computer power controlling the engine than took man to the Moon (the first time round!), and my late 90s car has more computer power than took man to the Moon in the instrument cluster. Your car is probably a lot newer, and has about as much computer power as NASA had on the ground for the Apollo missions just to operate the buttons on the steering wheel that turn the radio up and down, in a chip the size of your fingernail, that costs the price of a not very good coffee.

The main failure modes of space travel have always been "we can't get the astronauts back down", "we can't get the astronauts back down at less than several times the speed of sound", or "the astronauts are now a rapidly expanding cloud of hot fried mince". What's changed is the extent to which we accept that, I guess.

I’d bet a million dollars that Orion will win every safety metric compared to the shuttle once it is retired. NASA deluded itself in thinking the Shuttle was safe. The reality is that the Shuttle was the most dangerous spaceship anyone ever built.

Jared? Sounds familiar, is it a friend of yours? If yes should you not disclose it? The casual first name use basis is a tell. You wouldn't say "glad Bill is cooking something up" about Gates. This kind of parasocial familiarity with billionaires is how PR becomes indistinguishable from fan fiction.

Isaacman is a space tourist, not an astronaut. He is the CEO of Shift4 Payments, which processes payments for SpaceX. Musk, who spent hundreds of millions on Trump's campaign, got him installed as NASA administrator. That's not meritocracy, it's transactional politics. If you or I had billions, we could also buy seats on rockets.

"His own version of Gemini" is wild spin. Polaris was Isaacman paying SpaceX to fly him on SpaceX hardware. He had no engineering role, no mission design input. Calling it "his Gemini program" is like calling a chartered yacht trip "your naval program." Naming something after a historic NASA program doesn't make it one.

The risk decision process was theater. Isaacman reportedly had already decided Artemis II would proceed, then invited Dr. Charlie Camarda and others to a "transparent review" that was anything but.

When the conclusion is predetermined and dissenting experts are brought in for optics, that's not risk management, it's liability laundering.

On the 1-in-30 mortality figure, framing astronauts making it home as something to be "grateful" for, rather than questioning why we're accepting odds 3x worse than the Shuttle (which killed 14 people), is a strange way to celebrate progress...

We should be glad the crew is safe. We should also be honest that the person running NASA got there through financial entanglements with SpaceX, not aerospace credentials

I mean it's the first space crew on an anti-science mission, right?

The point of them being there isn't discovery, it's to try to discourage anyone who wants try to understand and protect the planet that we all rely on for life

I think especially online there's a lot of emphasis on "everything is wrong". A mission like this is hard to ignore and highlights the bias. On the whole, despite setbacks, we continue.

Many of those who saw the first moon landing as a child are still alive and remember what it felt like.

The nice thing about a public space program is everyone can share in its success!

From one of the ground staff for Artemis: https://bsky.app/profile/captnamy.bsky.social/post/3mi36brfw...

"1968 and the country was on fire. Vietnam. Assassinations. Civil unrest. Protests.

Apollo 8 was the one bright event of a terrible year.

2026 and the country is on fire. Iran. Corruption. Fascists. Civil unrest. No Kings.

I hope Artemis II will stand out as a bright spot for our country."

Some more background on her: https://chicago.suntimes.com/news/2026/04/01/chicagoan-amy-l...

The analogies for these things like "hitting a golf ball into a hole in one 5,000 miles away" are always fun.

I like starting from the fact that Ptolemy was able to get the accuracy of the "motions of the heavens" down so well that it took more than a thousand years to get observations that showed discrepancies. The math, it maths.

I'd add a caveat to this.

We can do this because of war.

We know where it will land accurately because that maths and physics has been sharpened with butt loads of data. Even the reentry blackout has links to war in Plasma Stealth[0].

That data was mostly obtained because we want to know where our ICBM warheads will land. And where the enemies ICBM warheads will land so we can work on the problem of shooting them down.

The Russian Kinzhal missile can hit targets at mach-10, with a plasma aura making it's terminal phase hard to track on Radar. But after some data was collected Patriot missile systems were able to intercept about 1 in 3 air launched Kinzhal missiles. Then minor terminal adjustments were introduced and interception fell to about 1 in 20. Now there's a constant cat and mouse game going on in Ukraine.

On the one hand that's a good thing, our combative efforts being sublimated into curiosity of the world.

On the other hand, we still put far more effort into furthering our ability to destroy the world.

[0] https://en.wikipedia.org/wiki/Plasma_stealth

Judging by the fact that almost nobody in the mainstream talked about this until a week leading up to the mission, and that it’s been 10+ years in the making, I doubt it’s some vanity thing.

I don’t see how anything as substantive like this can be seen as “vanity” (unless you mean to count that as a bonus).

It’s amazing to see NASA doing newer great things (Webb, Mars probes, all have been incredibly cool too, but manned stuff always hits a different note). Yes they’re way more expensive than SpaceX, I get all that. But it’s nice to see something so overwhelmingly positive and a true example of human ingenuity, collaboration, and bravery, that we need a lot more of that to remind us these days of the positive times we live in.

And the fact that we did this 50 years ago, at least to me, means I appreciate even more how we got it done with that age’s technology and knowledge the first time.

My friends and I have been deriving much amusement from the comms issues. We can fly people around the moon, talk with them, send back high res video, but talk to the boat that’s close enough to swim to? Forget about it!

Note: next time, pack a walkie talkie. ;-)

Just like in the year 3000, we will still ask "Can you hear me?" in video meetings.

i was thinking maybe astronauts can be disoriented when splashing down and that's why they figured they should ask if the right buttons were being pushed?

Cellphone coverage notoriously flaky in the Pacific.

This is the same mission where the commander radioed to Houston, “I have two Microsoft Outlooks, and neither one of those are working”.

...and informing them which button was the PTT button. She had to say it, but it'd be hard not to react to that.

I give you Apollo 16:

https://www.youtube.com/watch?v=Uuv6TVv0r44

Good thing they have redundant systems.

1 hour 29 minutes seems excessive to extract the astronauts; if any of them _did_ have a medical issue they'd be in for a long wait.

The commentary said that the initial problems with the boats approaching Integrity was due to an unexpected swell. Unexpected, in the Pacific?

Edit: all of the Apollo missions, except 8, had their stabilization collars inflated in under 20 minutes. With Integrity today it took nearly an hour more.

Still waiting to see comparison to A1’s used heat shield. Obviously it worked at least just well enough. They have a new formulation apparently for use with subsequent missions. New might be better but obviously it has not been tested in a real re-entry scenario so also kinda concerning for the next flight.

also astronauts: "the moon is quite a bit smaller than it was yesterday"

control: "i guess we'll have to go back".

(paraphrased from memory)

The humor was what really made my day today. Or in my case my night here in Germany.

I guess they're not Kerbals :)

That speaker voice was a bit odd. Everything was perfect! At least one superlative every 5 seconds or so.

I think that audio stream was designed to be POTUS safe.

I've noticed there's a pretty big difference between the people who remember how routine shuttle flights became and the younger crowd at work. I do think Artimis is cool, but I will admit to being a bit jaded about it as a GenX who watched Challenger live in 2nd grade. The GenZ at work seem genuinely delighted. And that's pretty cool.

I think it you ask the average person they're more surprised that people haven't been going to the moon for the past 50 years. In people's minds it's a solved problem and it's been boring for decades now. If supersonic air travel came back it would only interest people because of reduced journey times. But this doesn't even have anything that directly benefits people so they don't care.

A diverse and inclusive crew, a publically-funded mission, an emphasis on science and discovery, and government investment in a long-term strategy, not a quick politcal win.

This current administration has made sure these things never happen again, Artemis is very much the swan song of an America that has died. I am not interested in watching our corpse twitch and calling it life.

Yes it was worrisome, but how could it not be even with the best tech we'll ever have - I feel relief still on every plane touchdown.

Bravo, Artemis team for an exceptional return to extra-orbital space travel.

The LOS was also more than 6 minutes as predicted (I measured a bit over 7 minutes). What a tension.

I was wondering about that, so I looked up the heat shield issues. It seems like their solution was very defensible and there was every reason to believe it would work out just fine. The plan that did not work as they wanted had a new idea, a double re-entry, and when the results were concerning they backed off to using a traditional single re-entry. That seems like a legitimate fix?

Same! Glad everyone made it safe.

A big part of the reason is that Orion (and Apollo) reentry speeds are way higher due to the orbital mechanics involved in going to the moon and back. Today's was actually the fastest manned reentry ever attempted.

For reference the shuttle generally reentered at ~17.5K mph, and today's was 24K-25K mph.

It's not clear that we could build a craft with wings that could survive that. So then you're looking at adding fuel just to slow down, plus fuel for the weight of the wings themselves, plus fuel to carry all this extra fuel to the right place, etc.

The space shuttle landed like something resembling a plane, but it is more accurate to say it landed like a concrete brick traveling faster than the speed of sound.

Splashdown-style landings are the simplest and safest, parachutes are always good but adding water makes for another layer of safety (and of risk, to be fair, it could sink).

Wings and rudders and landing gear are very heavy. Then there's the flight control system in all its complexity, along with redundant hydraulic systems and so on.

Lot of the world is ocean & they basically decided the landing point the moment they entered the free return trajectory, 9 days prior - easier to shift the landing point a little to a different place in the ocean place with better weather tha. to switch to a backup airport.

With lunar landing flights they would still have to choose 4 days before, as long as they do direct return.

Eventually you want to break to Earth orbit (propulsively or aerodynamically) and board a dedidacted craft for landing. But till then water landing capsules work.

A Space Planes is needed to land at a runway like a plane.

Space Planes are not only much more dangerous, but are not ideal for this type of mission. They carry a lot of extra weight (wings) that would affect how much fuel is needed to launch them to the Moon.

Capsules are safer and more lean in terms of weight.

The Shuttle was not ideal in many ways. It was used so long not because it was the best option, but because Congress wanted it to keep it going for jobs.

Buoyancy is an easier equation to solve than lift.

Aerospace engineer here: The simple answer is that the Shuttle form factor is unnecessarily complex for this mission.

A small Apollo-style capsule that parachutes into the ocean has a simpler mission profile, which allows for simpler technical and operational requirements, which in turn reduces program cost.

Too fast. The space shuttle used to reenter sometimes over us in California. I remember in elementary school the entire building shook, and that was just one building! The amount of energy being dissipated is literally astronomical! If you've never experienced the sonic boom of reentry it is something to marvel at. It literally feels like an earthquake!

Not for the same reason as you, the whole time I was thinking "I'm pretty sure NASA can assess the risk of their mission better than an Internet famous blogger", despite the sentiment on HN at the time being very negative after reading these words [1].

These days the only qualification required for people believing anything you say is to have a blog and strong critical opinions about $AUTHORITY. Software engineers somehow believe they are knowledgeable in any topic just because they spend a lot of time reading on the Internet.

1: https://news.ycombinator.com/item?id=47582043

It's hard to know who was right. All of these things can be true: it made it back ok; it had a high chance of making it back ok; it should've had a much higher chance of making it back ok. Most of the concerned people were stressing this last point, that it should've been safer than it was. They still thought it had a quite high chance of making it back ok. It took a lot of shuttle missions before Columbia failed.

We'll need a post mortem to know what the margin of failure was. This said they had made changes since the first flight so we'd expect less to no damage this time.

The Moon.

Interesting.

I get that there are people who think the moon landing was staged, but are there really people who think rocket launches are staged? Because it's pretty easy to go witness one yourself.

The fools who would believe that wouldn't believe Apollo happened either. No need to dignify their existence.

Dammit. I hoped Jeb was on board for a second.

It was essentially a dress rehearsal for next year's mission, which will result in an actual moonwalk. And then in 2028 we will go back for a second moonwalk and foundation delivery to start building an actual moon base. Artemis is a really cool and systematic set of missions that ultimately will result in a permanent human presence on the moon.

My suspicion was they were burning excess propellant, rather than attitude adjustment while under the parachutes. Though who knows how much propellant remained. It could be quite a bit more than it appears was used.

RCS (Reaction Control System) which you can see on Artemis I internal video as it falls down https://www.youtube.com/watch?v=-QbYrs5SZ5M

I was wondering about that too, I assume maybe there was some additional adjustments needed to land in the right spot, but they didn't mention it on the stream.

…and this is how the America I thought I knew growing up projected its influence upon the world.

How? I struggle with this. It all seems like a fearful waste of money and resources. We can't live on the moon. We can't live on Mars. It is a fantasy. We have so many problems here on Earth that are more important to solve than sending a handful of men to the moon (again).

In 2028, so only 2 years from now. They will be able to bring 4K pictures and videos of the walk on the moon and they promised not to delete them this time.

They will have Nikon cameras, GoPros, and iPhones with them.

Very different from the videos taken with the Gameboy Camera.

Do you think the billions spent disappear into space? It pays the salaries of everyone involved so they can eat.

Let's feed millions for free so they can breed billions who must be fed.

The guidelines ask us to avoid being curmudgeonly. I'm sure you didn't mean to come across that way, but could you try not to make Hacker News the kind of place that responds with “meh” to a successful space mission?

We can't build a TV from 50 years ago, much less a space rocket.

Because we stopped, we get to do everything over again with hardware from this century.

Huh? The research done to develop the flight control computer for Apollo (and IBCMs of the time) lead directly to modern microcomputers. It’s hard to name something more impactful than that.

It could easily have taken another decade or two to develop the modern computer if not for the resources spent in the space program at that time. It still would have happened, but Apollo and the space program was soaking up something like 90% of computer demand for a full decade. Computers went from room sized behemoths to the size of a file cabinet in that time.

They can't just build Apollo 18 and resume the program as if there weren't a 50 year hiatus.

Imagine if your employer wanted to start using a software system it retired in 1972. What would you do?

What is delta v/critical mass?

I think we've all become to numb and jaded. This is the first moon mission in 50 years and the furthest any human has ever been from Earth.

Hard disagree. Yes it is corny for us oldies but channel your 12yo self watching Cosmos.

I read "Shakspear" as a combination of Shaquille O'Neal and William Shakespeare.

Someone hasn't stayed awake all night listening to YouTube ATC. I recommend Kennedy Steve.

What a curmudgeon. You must be great dinner company.

Because we haven’t had translunar manned flight in fifty years, and this is the precursor to start it up again