That was a great article.

Adding to it - Apollo 13 was a mission where 3 men should have died, but somehow didn't. If it had happened while the LM was on the moon, you would have had the CSM lose power, and then two men on the moon would have had no way to return home.

(And for the shuttle design mission - my understanding is it was likely the ability to do a HEXAGON-style film return mission in a single orbit, before the Soviets knew what was happeneing.)

Nice article, although I'm not so sure about this part:

> There’s a reason why there wasn’t an Apollo 18, or 19 and 20. Even though funding had been secured, an executive decision was made to kill the program early, because LoC was inevitable.

Was funding really secure? I believe that was the main sticking point; a quick search [0] seems to confirm this, and the John Young quote below backs it up: "Even if they’d had the money..." Not to say the risk wasn't a factor too of course, but it doesn't look like funding was otherwise guaranteed.

Anyway, I think what sets the risk of the Shuttle apart from Apollo is summed up nicely in one of the quotes (in reference to the Apollo program): "The awareness of risk led to intense focus on reducing risk." In the Apollo program, there was a pattern of rigorously hunting down and eliminating any possible known risks, leaving unknowns as the primary source of risk; on the other hand, the Shuttle program let known risks accumulate continuously until crews paid the price for a bad draw.

When debris hit Atlantis on STS-27 [1] and the shuttle only survived on a one in a million stroke of luck -- the completely broken tile happened to be over an aluminum mounting plate -- it should have been taken as a free lesson on one more known source of risk to eliminate. Instead, it led to seven people dying completely preventable and unnecessary deaths a few years later.

Spaceflight is inherently risky, it's true. That's why things like the Orion heat shield are so worrisome; because it is physically possible at our current level of technology to make it safer, and yet for political / funding / etc. reasons we're not doing the best we can.

[0] https://airandspace.si.edu/stories/editorial/why-did-we-stop...

[1] https://en.wikipedia.org/wiki/STS-27

Im not really convinced SLS and Artemis are best effort projects; we improve through refinement, and the only way to get there is cadence. More launches with the same general mission requirements.

One launch a year is not even close to what we can manage with our current technology, to the point where the scope is too small to be legitimately worth doing.

Its not solely a matter of energy; its about opportunity for learning. The current scale is too small to be worth doing at all.

If it was a program of something like >50 payloads over a decade, that gives enough opportunity for refinement, in cost, safety, and scale manufacture methods to actually see something new.

Artemis certainly seems safer at least in launch. It has an escape system that could be triggered throughout launch. In comparison shuttle could not abort at all until srb separation and after that could have needed risk aerodynamic manoeuvres.

Thanks for sharing your article - very well written.

I am stunned to see that LoC risk assessment.

I kept wondering to myself over the past week, “will this be the last USA-supported human space travel if these astronauts don’t survive?”

I’d have a hard time imagining the general public would support any future missions if they hadn’t survived.

These astronauts are some elite humans. My respect for them is even greater now that I’ve seen the risk quantified.

Wouldn’t the soviets or any other adversary prepare against letting NASA capture their satellites? You need a very small amount of C4 in the satellite to destroy the shuttle in the event of capture. Tampering with other entity‘s satellites can best be done with satellites. That also frees resources needed for bringing life support systems to orbit.

If I may be allowed one nitpick. Without fully understanding the FAA doc you link to in the article, I think it would be better to say something like loss of a plane is a 1 in a billion event for commercial airplanes. Many types of parts used in airplanes and jet engines break at much higher rates though, they just don't necessarily cause a plane loss when they do.

> It's physically not possible at our current level of technology to make this "safer" due to the distances and energies involved.

That's not true at all.

It is entirely within current technical and fiscal means to launch a much more robust and powerful craft that is capable of goign to the moon and returning with lower velocity by sending it up in pieces with Falcon 9 (Heavy) and assembling it in LEO before launching to the moon.

This mission architecture is intrinsically compromised by social constraints in the form of pork barrel spending dsfunctional decision making process.

The Smithsonian article on John Young that you linked to is a good one. The only John Young quote they didn't include that I wish they had was his response to the proposal to make STS-1 an on purpose RTLS abort: "Let's not practice Russian roulette."

Well said.

> We're a very primitive species, and the forces involved here are genuinely new.

It's absolutely wild to me that we went from inventing flying machines to putting people on the freaking moon in the span of a human lifetime. What we've accomplished with technology in the last 500 years, let alone in the last century, is nothing short of remarkable.

But, yes, in the grand scheme of things, we're still highly primitive. What's holding us back isn't our ingenuity, but our primitive instincts and propensity towards tribalism and violence. In many ways, we're not ready for the technology we invent, which should really concern us all. At the very least our leaders should have the insight to understand this, and guide humanity on a more conservative and safe path of interacting with technology. And yet we're not collectively smart enough to put those people in charge. Bonkers.

> We're a very primitive species,

compared to what? We're the most advanced species we know of.

It might even hold true over the entire universe. All species might top out at where we are. We don't know.

>It's physically not possible at our current level of technology to make this "safer"

Absolutely it is, if NASA was not constrained by congress to use shuttle components to build the spacecraft, they could have had double the payload mass capability at least (the Saturn V was almost twice as capable, we should be able to do a little better now). This would provide tons of extra margin for safety, and allow a shorter and thus safer route to the moon as well.

NASA certainly took many risks back then. People remember Apollo 11 for the landing, but for example on Apollo 8, with a fire roughly 2 years earlier that killed 3 astronauts, they had one manned mission (Apollo 7) and then immediately sent Apollo 8 around the moon with ONE rocket nozzle that had to work (and no LM to escape into, as the Apollo 13 astronauts had to do), basing their faith in trajectory mechanics which hadn't been tested that far out

The ejection seats on Gemini were a joke, and there's an anecdote Gene Kranz tells in his book about Gemini 9 where he thought it was too risky for them to cut away the shroud on the thing they were going to dock with (the Agena having blown up on launch) but NASA was this close to overriding him and doing it anyway (they were saved by the astronauts vetoing it, which was good because the EVA, separately, that Gene Cernan did was incredibly harrowing. he was sweating, way overworked, could barely see)

Shuttle was awesome and the people who love to hate it can personally fight me.

I often think about the shuttle program in relation to all these crazy complicated, wildly expensive, and incredibly fragile space telescopes we're sending to LEO or the Earth-Sun L2. Would be damn useful to be able to repair/upgrade these things like with Hubble.

Obviously I realise the shuttle program was pretty far away from being able to head out to the Earth-Sun L2(AB, and wasn't even working towards it. But man, it would be nice to have that ability.

2.4% is not bad given how new this still is and how extreme the speeds and energies are.

Note that all the fatalities have been launch or landing related, not in space itself. Clawing out of this gravity well is tough. Make Earth a bit larger and you’d never get off it without something like NERVA or nuclear pulse Orion.

I wonder sometimes if that’s another thing to toss in the Fermi paradox bucket. Many rocky planets might be much more massive than Earth. On one with 3X our gravity a space program might never get going.

Is 12 enough of a sample size to make a statistical judgement? What if there were 20 more which didn’t have a loss of life? Is it then 1/30? What if there were 20 more?

The risk factor is calculated _per mission_ from what I understand. You can have three accidents in a row and nothing for decades but the risk itself can still be 1 in 30.

Or the extreme casualty rates experienced by the (mostly very young) East India Company clerks in Calcutta. From Dalrymple's The Anarchy:

"Death, from disease or excess, was a commonplace, and two-thirds of the Company servants who came out never made it back – fewer still in the Company’s army, where 25 per cent of European soldiers died each year."

It's worth noting that Magellan lived in a time of extremely high infant and childhood mortality. Approximately 30% of newborns would die in infancy, and the odds of reaching 16 were only about 50%. This wasn't just skewed by people in poor circumstances, even the wealthy elite in society with the best access to resources and medicine of the time faced grim odds. Everyone went through their formative years with the understanding that their survival was unlikely, they watched their siblings and friends of the same age die, they were raised by parents who knew damn well that half their children likely wouldn't make it,and their society was structured around the assumption of an heir and a spare. Under such circumstances, the value of human life, and thus the reward necessary to justify risk, would logically have been much lower.

Indeed, it's rather amazing to think about just how recently things changed. The generation that first went to the moon had a much lower infant mortality rate than in the 1500s, but it was still about 20 times higher than today, and critically they were all raised by parents and lead by people who had grown up around normalized high infant mortality rates. Boomers are the first generation where infant mortality was continually below 5%, and millennials are the first generation to be raised by parents who considered their children's survival to adulthood a given. And of course that's for the developed world; global infant mortality only fell below 5% in 2010. Right now is the first time in human history that you can say with 95% confidence that a random human newborn will survive to adulthood. We should be much more risk averse than our ancestors, we are on average anteing up many more happy, healthy years than they were.

Agreed, but people were often forced into those conditions. Or were forced to make an impossible survival decision.

Were Magellan’s men volunteers? For example, in the incident with The Wager, 1,980 men left on 6 ships, and only 188 survived. Men of the original men were press-ganged (kidnapped to crew these ships), and a lot of them were even taken from an infirmary and not in great health. And, of course, conditions were pretty terrible.

So yeah, we’re more risk adverse… and also a lot better at keeping people alive. I think most people would not have signed up for some of these really risky endeavors if they knew the true risk.

https://en.wikipedia.org/wiki/Wager_Mutiny

https://en.wikipedia.org/wiki/Shanghaiing

Crazy indeed, glad that someone else has already mentioned Magellan, because that’s whom I also had in mind. Not sure there’s a solution for this because at this point the risk scare has been institutionalized among most if Western (and not only) society.

You're acting like if it fails they can just say "Well we said it was 1/3!" and then just get on with it. "Oops we lost a zillion taxpayer dollars and no one will mind and maybe they'll give us more money this time around!" That's just not how the world works.

Hopefully this time we can keep going for what we can do for engineering instead of what we can do for science.

First couple of crews to orbit the earth at 0’ AGL had mortality rate of 9 in 10.

I’d say we’re doing better!

A lot of advancement is multipurpose. CNCs are more accurate than machinists, computers are faster. And we have a lot of the technical knowledge written down.

Landing on the moon is enormously riskier than simply going further out.

They could go twice the same distance, the risk would be roughly the same at that point. It's mostly the complexity and changes that make it more risky once the initial trajectory is in place.

One way to see it:

  1) Eventually you will die, no matter what. It can be the most mundane thing. Slipping on a ketchup splatter can cause great damage for example.

  2) It's a profession where you intentionally kill people, so, that changes the calculation for your own risk.

  3) It's a unique opportunity.

(and potentially)

  4) Gives a sense of living / be in history books for his family.

So you have a possibility of a guaranteed exciting life for a death that you anyway will have, but doing something you love, it's not too bad.

Your father is a better man than I am.

The movie was good too. I haven't seen it in years, but from memory:

Gordo! Who's the best pilot you ever saw? -- You're lookin' at him!

Loan me a stick of Beemans.

Light this candle!

It just blew!

No bucks, no Buck Rogers.

That’s precisely my point. The question is what a crew mortality rate of 1 in 30 means.

If it means that, on average, a team member dies every 30 flights, with a crew of four, it’s likely there are fatalities in ‘only’ one in every 120 flights.

For space shuttle, that number was about one in every 60 flights. So, with that interpretation, Artemis would be about twice as safe as the Space Shuttle.

If, on the other hand, it means that, if you step aboard Artemis, your chance of dying during the flight is about one in 30, the Space Shuttle would be about twice as safe as Artemis.

The craft has aerodynamics and speed. It might be figuratively true "unrecoverable" but if it takes e.g. 2 weeks to complete a return, their oxygen and food and batteries ran out. Alternatively if it enters too fast they return ... in pieces.

I think you're being a pedant, if your point is a grazing entry causing rebound skip ultimately returns to some orbital path downward.

Anyone who has had hit period key once too many during Munar free-return in KSP knows it's exactly how orbits work...

Hilarious the the intellectual forum downvoted you for being absolutely right.

Artemis II never escaped Earth’s pull.

That video that NASA put out where the craft did a sling shop around the moon is extremely deceptive. The pull of the moon had very little effect.

If they had missed, they would have eventually crashed back to earth in the worst case, and best case just re-adjusted and returned a little bummed.

I think we are a long way along from digging out Dr Feynman to look into why a shuttle exploded.

Unless you happen to have some deep links into NASA, in which case please elucidate us all, then why not celebrate a happy and safe return from a sodding dangerous mission that involved things like >25,000 mph relative velocity and some remarkable navigation.

When you depart earth (close quarters gravity, air resistance, things in the way), everything moves really fast, really fast and any acceleration becomes an issue really ... fast!

The moon moves, the earth moves: both famously in some sort of weird dance around each other and both orbit around the sun. Obviously the moon affects the earth way less than vice versa but it still complicates things.

I think that NASA did a remarkable job of making Artemis II look almost routine and I don't think that was down to behaving as they did in the past.

Yes, and the four RS-25 main engines on the SLS rocket (Space Launch System) are literally SSME's harvested from the shuttles (Space Shuttle Main Engine). Of course that means they are re-usable. So sad to see them plummet to the ocean floor. Perversely Rocketdyne is building cheaper non-reusable versions of the RS-25 for future missions.

It has a launch escape system, unlike the shuttle.

Was any shuttle lost to the SRBs?

The Artemis SRBs incorporate design changes to address the causes of the Challenger failure. Specifically they changed the joint design, added another o-ring, and they have electric joint heaters to keep the seals warm.

It is about trends and perceptions - 70s were very hopeful, now with global problems - wars, climate, AI, uncertainty, what is growing is desperation.

I definitely don’t envy kids that are born nowadays.

A global view is probably not the right way to look at things, encouraging as it may be. Of course globally hunger rates fell and so did child mortality. If nothing else, by the inexorable progress of science and technology.

But what about comparing the same country/region? After all that's a better sense of how things are progressing locally to you, and when people are asked "are things better or worse" they probably compare the way they live with the way their parents lived.

Would you rather be born in 1980 or 2020 in China? In Poland? No question. Same question but in the USA? In the UK? The West in general? I'm really not so sure.

Nope. Not from usa. I was born in 80s and would like to stay before 2000.

There’s a big difference (not really as much as you might think because fuel is limited) between a single shot with no thrusters and a rocket that has all sorts of adjustments possible.

It’s all in fun, really, like the old analogies involving hard drive heads and jet planes.

The first-order approximations are easy. When you start adding up all the other factors, it gets complicated fast. The solar wind, which isn't constant, affects trajectories. Earth's atmosphere is neither homogenous nor perfectly predictable along many dimensions: upper-level wind speeds and directions, air density, and temperatures, to name a few. The Moon's gravitational field is very lumpy. Earth's gravitational field, while relatively smooth compared to the Moon, also isn't perfectly uniform. Propulsion systems have tolerances. Same with parachutes. The location of the vehicle's center of gravity affects everything.

All of these factors and more have to be taken into account if you want your predictions to be accurate. Aside from telemetry processing, most of the computing power on the ground during a space mission is used for churning out navigation solutions.

Agreed.

Fun info: The NASA orbital codes include things like photon pressure... from sunlight reflected off of other planets in the solar system. At some point, I think they are just showing off :)

Not a great analogy because there actually is interference and golf balls aren't typically monitored and course corrected during flight

If that were the case then the mach-10 Kinzhal would be harder to hit than the mach-5 Kh-32.

But the interception rate for the Kh-32 is basically nonexistence (<1%).

The Kh-22/32 is why mach-5 + maneuverability is the current goal of offensive missile systems.

The plasma has complex interaction with radar, it's not stealth as in entirely invisible just chaotic scattering and reflections. The result is a jamming effect preventing a definite intercept solution.

On the other hand the plasma shows up on satilite based IR tracking systems.

That's an absurd statement. By your logic, you can't just say that we have the smallpox vaccine "because of Edward Jenner". Because you would also "have to prove we could not do it without Edward Jenner". What does that even mean??

Siri turn on main screen

I wondered about that. Winching someone who can barely walk and is wearing a spacesuit into a helicopter over choppy water is safer and quicker than parking them on a motor boat and sailing back to the mothership?

What was the real reason? Tradition? Lack of imagination? Photo opportunities?

The rest was great tho.

“Stepping” from one vessel to another in the middle of the ocean is not like getting on your buddy’s sailboat at the marina even if you have your sea legs. Astronauts don’t even have their earth legs when they splash down; when they return from ISS they can’t even walk right away, though Artemis was a shorter duration mission than that.

Agreed in principle. Let’s make things norminal, not superlative.

Everything. No radio signals make it in or out of the capsule due to ionization from the heat and plasma of reentry.

It seems like they had limited telemetry for a short period before they did any audio

No doubt there are people looking at the heat shield right now and saying "Hmmm."

I am very curious about what they're seeing, and how well the get-it-over-with solution worked.

It was a bold move and the results will be fascinating.

In my understanding of the Manley video, the materials change will only occur for Artemis 3, for which it will be irrelevant as that will not be leaving LEO.

Helicopter -> large boat is much easier, and much faster, than small boat -> large boat. And it's not riskier. I know the inherent risk in flight is greater, but it's also much more managed, so the actual risk is less.

>Why not just use the speedboats to take them back?

They actually covered this in the broadcast: Helicopters are faster to get the astronauts to medical, smoother in rough seas, and there's less risk of being swamped by a rogue wave. Plus, since the astronauts might have fatigue/muscle atrophy/whatever, it complicates potential boat transfers.

> subsonic lift is well understood and has been for decades

I said easy. Not well understood. I can fly planes. It’s hard, and has limited room for fucking up. (It’s also hyperbole to suggest we understand lift. We don’t.)

Piloting a boat is easier and more forgiving. Hence, splashdown. You don’t need direction. You don’t need lift. Parachute physics is a backbreaker, but it’s symmetrical. Same for splash.

On the press conference they mentioned the RCS was used to orient the craft with the most sturdy part facing down for the ocean impact.

Otherwise I would also just bet on RCS venting like in Apollo.

There should be an opposite thruster for each axis. I wonder if the short bursts were due to heating limits.

Collaboration like that is all a (positive!) part of projecting influence - in both directions.

All those countries are essentially American vassals. No shade to them, just stating the reality, and not really sure why we need to keep pretending. There's no shame in that. It's often the smartest move to join forces with the big guy in the block!

I blame the "space race" narrative - it made everything unsustainably expensive just to beat the goal of landing on the Moon by the end of the decade and before the Soviets. That also made the program even more dependant on political whims and easy target for budget cuts in the Vietnam era.

I recommend looking into the space flight plans from the pre Apollo - while tere were bonkers ideas like Project Horizon, most of the plans sounded quite sensible, with incremental building of space infrastructure and emphasis on cost and reusability (in the 1960s).

Of course when it became a race all the sustainability and infrastructure went out of the window and got sacrificed in the name of speed. :P

Suarez is, IMO, very good at researching current/near tech and mixing it into a good story about what is possible with what we have right now. Nothing in the books is really out of our reach except the will and perhaps strategic discipline to make and execute the plan.

Only the internet is grim. The actual world is better than its ever been.

It's fully scripted. The hokum is pre-planned.