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Impressive that all this happened after many uneventful flights of this vehicle.

Makes STS-1 even more impressive. Huge respect for John Young and Bob Crippen.

The achievements of John Young and Bob Crippen during STS-1 are indeed remarkable
John Young was (and remains ?) the only astronaut to fly every class of US manned space vehicle.
John Young was not one of the Mercury seven - so "almost" every one.
Oops! I misremember something I heard during the Shuttle's debut flight.
In no way diminishes his accomplishments!
Young was only active as an astronaut from 1965 to 1983, so "every one available at the time" might be a better description.
Even more pedantic but I think it has to be “every one ever available up to that time”. Otherwise, everyone flying in dragon would have had the same claim until SLS launched, because for some time, dragon was the only active US crew launcher. Young’s achievement was having flown every crew launcher that the US ever made, right?
There's a good book on that flight - Into the black by Rowland White. Especially on how the National Reconnaisance Office - NRO used a spy-satellite to image the orbiter for damage to its heat tiles. The paperback has more details. Apparently this was set up in advance.

Here's an article about it by the same author:

https://www.smithsonianmag.com/air-space-magazine/spysat-and...

Expecting the unexpected is a necessity in space exploration. Murphy’s Law: "Anything that can go wrong will go wrong"!
On the other hand, isn’t there a lot less things that could happen in space compared to Earth?

The atmosphere is unpredictable. The ecosystem is teeming with life and a lot of it is animals with their own agency.

Then there’s the whole human factor. If you’re making a vehicle that operates on Earth, you have to be prepared for drunk people and terrorists and all sorts of human contingencies. They’re not causing havoc in deep space.

For better and worse, space is dead.

On the other hand, you don't usually get hit by random pieces of debris traveling at mach 25 [1] on Earth.

And on the other-other hand, the things that go wrong in spaceflight usually go wrong on launch or reentry - the parts where you combine the extreme conditions of space with the unpredictable extra nonsense of Earth. Like, say, a cold morning making an O-ring brittle or aerodynamic stresses ripping you apart on reentry. Only three deaths - the crew of Soyuz 11 [2] - have actually occurred in space proper; all other deaths have occurred within the Earth's atmosphere. (Although Apollo 13 came close to adding to that list.)

[1] LEO orbital velocity is ~8 km/s, mach 1 is ~300 m/s, although meteoroids necessarily strike at much higher velocities than that because they're accelerated to at least Earth's escape velocity on descent.

[2] https://en.wikipedia.org/wiki/Soyuz_11

I suspect that it isn't the unpredictability, rather it is the acceptable margin of error.

Say you have a 1500 kg car with a 100 hp engine, which starts from a standstill and runs for 5 seconds. How fast will the car be moving at the end of this run? This depends on how much friction the vehicle experiences, and is difficult to accurately predict. Try a similar calculation with a rocket in space, and you can calculate its final speed with a very high degree of certainty.

But now consider the potential impact of a malfunction: if the car engine fails to start, you might be inconvenienced, but you will be fine. On the other hand, if the rocket engine fails to ignite in space, you can't perform necessary orbital maneuvers and you might be in deep trouble.

It's something about environment on Earth being fundamentally hospitable to human life, and environment in space being similarly inhospitable. Because of this, malfunctions and unpredictable system dynamics on Earth are most often just minor inconveniences, while malfunctions in space / underwater / deep underground are disastrous events.

> But now consider the potential impact of a malfunction: if the car engine fails to start, you might be inconvenienced, but you will be fine. On the other hand, if the rocket engine fails to ignite in space, you can't perform necessary orbital maneuvers and you might be in deep trouble.

On a smaller but more relatable scale: it's like the difference between a car or a train, and an airplane. When you have a malfunction on a car or a train, an appropriate response is just to stop; when you have a malfunction on an airplane, you can't just stop, you have to keep things working long enough to get to land before you can stop.

Think about it this way: what happens if your car won’t start in the grocery store parking lot? What happens if your lunar ascent module’s main engine doesn’t ignite on the moon’s surface?

One is mildly inconvenient, the other is deathly inconvenient. Yes, many aspects of the extraterrestrial environment are predictable, but the consequences for being wrong are far greater.

And as another has noted, most deaths during space flight actually occurred in the atmosphere anyway.

> Think about it this way: what happens if your car won’t start in the grocery store parking lot? What happens if your lunar ascent module’s main engine doesn’t ignite on the moon’s surface?

Is this a pitch for a near-Earth Uber service?

Yeah, just open up the Lünr app and get an available seat on the next manned mission.
The toilet on the shuttle dumps urine overboard but keeps feces in a tank. They just float around in there. There is a mechanism that gets actuated once or twice during flight which spins a net attached to an arm through the tank, to catch all the feces, and then smashes them up against a wall of the tank.

The mechanism to run the net can break. It has broken during flight before. At that point you have to put on an arm-length glove, stick your hand in the tank, then smash all the feces up against the wall of the tank manually.

You need to do this because at a certain point if you open the toilet to use it there's a very good chance you'll get something floating _out_ of the toilet.

Free floating zero-g human waste is an absolute nightmare.

> "Anything that can go wrong will go wrong"

The proper version of Murphy Law, which seems missing on Wikipedia is ~ "If a part can be installed in more than one position, it will be incorrectly installed in the field given enough time"

It is almost last on the mitigating risk pyramid, training people to do things properly. PPE is the only one lower.

To apply it here, would be "inadvertently stepping on it". They chose to train staff not to step on it.

You can't mitigate all risk, maybe it was the best choice.

If that was true then spaceflight would be impossible. In reality risk is managed, not eliminated.
A picture would be worth a thousand words here. Where exactly is the LOX pin and what nozzle are they talking about?
The article introduces LOX - it's Liquid OXygen, the oxidizer for the Shuttle's main engine (with hydrogen as the fuel). The nozzle is the portion of the engine where the hot exhaust gas is allowed to explosively expand to provide thrust (what you probably think of as the "exit" of the engine).

The pin caused two problems. First, the LOX itself was dangerous because if it had been released incorrectly, it could have caused an explosion. That, fortunately, did not happen. And second, the ejected pin severed several hydrogen pipes being used to cool the nozzle. I assume the cooling is to keep it from melting under the extreme temperatures of the launch - the article mentions "burn through", which I'm guessing is "the nozzle material melts and your rocket exhaust goes off in a random direction so you Will Not Go To Space Today". It severed three pipes; fortunately the shuttle was designed such that it could tolerate the failure of up to four, and the nozzle held.

Wiki has a picture at [1] - the hydrogen leak from the severed pipes is in the engine on the right of the image, creating a white streak on the side of the nozzle and distorting the shape of the exhaust.

[1] https://commons.wikimedia.org/wiki/File:STS-93_SSME_Hydrogen...

Ok, assume that I've also read the article. What does the "pin" part of "LOX pin" refer to?
It's a plug that was inserted to block a damaged passageway. It fell out and hit the (fragile) wall of the nozzle which is hollow and itself full of tubes.

Ironic really, that a leak prevention patch job ended up causing a different leak.

Conclusion: never trust a vehicle that was patched in any way.
That leaves you with single use vehicles. You have never been on an airliner without a patch. SpaceX is famously making a business of operating rockets the same way.
Well, I hereby introduce "patch-only manufacturing", where every vehicle is patched, even new ones. That way, you reduce variations between vehicles, hopefully making them more reliable.

If every vehicle is patched and it is part of normal manufacturing, then you could say that none of them are patched.

> If every vehicle is patched and it is part of normal manufacturing, then you could say that none of them are patched.

This is only true if they are all patched in exactly the same way and if you patch existing examples in the field.

In the real world patches are applied as repairs to incidents that are unique to each example. Airliners are too expensive to throw away because of minor flaws and damage.

> I assume the cooling is to keep it from melting under the extreme temperatures of the launch

Yep, rocket nozzles and combustion chambers must be cooled down while they work. This is usually done by passing the fuel through their outer walls before it burns.

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So I suposse building an aircraft involves standard bolts, procedures, testing and much more standarized ways.

In contrast a spacecraft like the shuttle, faces much harsher conditions and, as not many of these were built, I expect more manual procedures and tinkering while building the thing.

In the end, it's incredible these things didn't crash more often.

Also, the smaller number, and the smaller number of flights, means much less experience to wring out the low probability gotchas.

Today's extremely reliable airliners got that way on a long, long string of accidents and near accidents.

The risk of spaceflight is still very high. Wiki [1] lists 676 people as having traveled to space, of whom 19 have died in accidents as a result of that travel, meaning that going to space has about a 3% chance of killing you.

The average age of an astronaut is 34 [2], and most are male, so a look at an actuarial table [3] tells us that going to space is approximately as likely to kill you as literally every risk an ordinary person would take in their life up to that point (at 34 years of age, about 4.3% of men have died, and a large proportion of those deaths are due [4] to accidental injury).

[1] https://en.wikipedia.org/wiki/List_of_spaceflight-related_ac...

[2] https://en.wikipedia.org/wiki/NASA_Astronaut_Corps#Qualifica...

[3] https://www.ssa.gov/oact/STATS/table4c6.html

[4] https://www.ncbi.nlm.nih.gov/books/NBK600454/table/ch2.tab4/

> at 34 years of age, about 4.3% of men have died

I think what you are saying is that 34 years after being born 4.3% of male individuals are dead.

In my understanding if someone dies when they are 10 years old they will never be "34 years of age". This probably feels nitpicky but it has thrown me into a loop of trying to understand what you are saying.

(Not even mentioning that I read the table you linked as 4.2% not 4.3%)

Saying 95.7% of men live to at least 34 would be more clear. (i have no idea if that stat is legit or not, i'm just writing it differently)
That sounds even better! Thank you for that rephrasing.
This seems needlessly pedantic as the meaning is still very clear.

And you did mention it, by saying you weren't mentioning it.

> This seems needlessly pedantic as the meaning is still very clear.

As I said it wasn’t clear to me. The two meaning which was fighting in my mind were the one i wrote and that the percentage is the probability of a male dying in their 34th year of life. Had to consult with the table to figure out which one they mean.

> And you did mention it, by saying you weren't mentioning it.

Well spotted. Exactly because the discrepancy troubles me. It either means that I don’t understand how to read or what to read in the table (in which case I would love to be corrected) or that the commenter made a typo (which doesn’t matter at all). If i were certain it is a typo I wouldn’t mention it. But since I can’t be certain that the error is not “in my equipment” i shared the observation hoping to get clarification.

> The risk of spaceflight is still very high. Wiki [1] lists 676 people as having traveled to space, of whom 19 have died in accidents as a result of that travel, meaning that going to space has about a 3% chance of killing you.

But 14 of those were caused by the shuttle alone. All the others were over 50 years ago. So far, all the spacecrafts still in use today have had a pretty good track record.

That 19 is a rather narrow list. It excludes the Apollo 1 mission where astronauts died in the spaceship during a rehearsal etc. In total 11 died during training including a cosmonaut in 1993 and a Spaceship 2 test pilot in 2014. “As of 2024, there have been over 188 fatalities in incidents regarding spaceflight.”

The shuttle also carried over half of all astronauts (355) on orbital missions, so if you’re excluding the shuttle it’s not that much safer.

Soyuz MS is a refined design, but Soyusz 11 killed 3 people and Soyuz 1 killed 1. Calling it a different design isn’t unreasonable but by that token it would be limited to 22 successful crewed missions and 1 in progress.

We're there more Soviet accidents that we don't know about?
Probably on the ground, but we likely know or highly suspect most of the ones in the air or in space.
Out of 355 astronauts that have ever used the shuttle, which comes out to about 4%. Not that much worse.

The shuttle's lack of a launch abort mechanism is something NASA wouldn't accept in any modern human-rated spacecraft. But arguably the deadliest feature of the shuttle was that it was pushed as the single launch platform for all launches, even those that didn't require any crew. Putting crew on every single flight made many missions more risky than they had to be

And also made missions at least 3X more expensive..... It wasn't just the on-paper launch costs. Everything had to be man-rated, meaning, among many other things, everything that operated during the launch had to be triple redundant, all the pyros had to be unpowered while onboard the shuttle (meaning you had to design another system to then power up the pyros and make it reliable), you needed three full launch crews (Cape, Johnson, plus wherever you actually ran your own ops) and all three launch crews had to support an endless set of rehearsals and launch delays.... The costs kept mounting. (source - was in program office of expendable launch comm sat, each satellite was ~$150M, launch was ~$80M. Roughly comparable mission down the hall cost ~$300M / satellite, ~$500M / launch.)
Or taking a guided climb of Mt Everest, roughly same numbers (compared to Aconcagua which sits around 30%)
Aconcagua is not notoriously difficult, and around 1k people per year summit. I can't find anything that says that hundreds of people per year are dying.

Do you mean Annapurna? It, at one point had a death rate above 30%, but is now below 20%. K2 has taken over the crown for deadliest mountain with a death rate of 24%

>compared to Aconcagua which sits around 30%

??? Aconcagua doesn't have an especially high fatality rate.

Small populations make for terrible statistics.
An estimate is better than no clue at all
To what extent is that true when the cause of the fatalities is the technical design of completely unrelated systems?

If one space agency built a rocket which always immediately exploded after launch, and another space agency built one which always worked, you could say the odds of failure for the next astronaut was 50%. But of course the two rockets are essentially unrelated. The chance of success of each rocket is a function of design, engineering process, organisational culture of that organisation.

Telling the astronaut strapped to the top of the explody rocket that there's a 50% chance of exploding is actually less help than no estimate. Because actually there's a 100% chance of them exploding. An estimate is only as valuable as the assumptions that drive it.

Often true.

But when that many people die, in that many separate incidents, across a variety of nations & launch vehicles - then the "The risk of spaceflight is still very high" thesis is statistically solid.

> ... of whom 19 have died in accidents ...

Skimming your reference [1], I see 11 more who died in accidents during testing & training. Including the https://en.wikipedia.org/wiki/Apollo_1 fire on the launch pad (during a launch rehearsal test).

Until spaceflight is "buy your ticket, show up, get in your seat, wait, exit at your destination", I'd argue that we should include the testing & training risks in the risk of human spaceflight.

That was part of the rationale behind the space shuttle in the first place. It was to create a space plane with aircraft-like operations in order to fine tune processes and technology to bring down the cost of space flight. Unfortunately, NASA never managed the operational cadence required, in part, because of the per-flight cost (which was, in turn, high, in part, because of the low flight cadence). It was a fine idea, but it didn't work out so well in practice.
Turns out, making something look like an airplane doesn't mean you can treat it like an airplane.
The space shuttle's appearance has little to do with its flight cadence - the airplane-like flight cadence (and thus, airplane-like reliability and cost) just never manifested. Especially after January 1986.
It also didn't help that the design was compromised.

In order to get funding from the miltary, the shuttle had to be able to switch to a polar orbit which is why it had those stupidly large engines that serve no purpose otherwise.

If you get rid of that, you actually can design a reusable space plane.

NASA has incredibly detailed records about every piece of their spacecraft down to things like:

- material used to make a bolt

- what the torque used to tighten the bolt was

- who tightened the blot

- when it was tightened

- etc

This allows them trace back through the history of each vehicle for debugging purposes.

They also applied this to the Space Shuttle software. This article from 1996 does an amazing job of describing the process: https://www.fastcompany.com/28121/they-write-right-stuff

It's interesting how modern some of the practices described are. Plus, some of the practices (E.g. the bug rate model), from my experience, only existed there.

  > It's interesting how modern some of the practices described are.
It should be noted that among famous NASA inventions, modern Project Management is listed among them.
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A reusable aircraft that faces that sort of intense vibration, I'm not at all surprised that we need to track when the last time each bolt was checked and by whom.

(One of the things you have to watch out for is that if the torque on a nut drops for no reason, it may be a hairline crack in the bolt it's attached to)

> In the end, it's incredible these things didn't crash more often.

I think two catastrophic space shuttle failures is more than enough :-/

Though a large batch and large amount of flights by space standards, Shuttle was basically all prototypes by normal manufacturing standards. The 135 STS flights wouldn't even make a dent in an airliner certification and test campaign. It's not surprising they kept encountering problems.
Even in commercial aerospace, every part is tracked like a library book. There's rarely a question about whether a particular part is the right part or more importantly a used part. Because there's a chain of custody for each one.

You also have some parts that are destined for QA purposes, and those have a tagging system that is meant to prevent them from being recycled onto a real aircraft once they've been used for stress testing.

Wayne Hale is always my favorite source for these: https://waynehale.wordpress.com/2014/10/26/sts-93-we-dont-ne...
That was a great read, thank you! It has this tidbit:

  > STS-93 carried the heaviest payload the shuttle ever launched; the Chandra X-ray observatory (formerly known as the Advanced X-ray Astronomy Facility or AXAF) and it IUS booster.
Why would such a heavy payload have been launched on Columbia, which famously was the heaviest orbiter and thus never visited the ISS?
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Columbia had slightly more space in the payload bay due to her airlock being internal and not taking up cargo bay space. Other shuttles had to have an external airlock fitted in the payload bay as needed which made them unable to fit AXAF. IIRC the airlock requirement was as a back-up in case there were deployment issues.

Again, if my memory serves, Columbia's internal airlock however is what made it unable to dock with the ISS. It was the only shuttle that retained that configuration. It's also part of the reason it was heavier, along with it being the initial airframe and built heavier than the subsequent ones.

I am so glad that I asked. Thank you!
>it being the initial airframe

Very minor nitpick, but the first airframe (spaceframe?) is OV-101 Enterprise. OV-102 Columbia is the second.

True! Enterprise was intended to be retrofitted into a flight capable airframe but changes in the design made it unfeasable. Thanks for the catch!
Why not OV-99, then? It was a test article, later retrofitted to spaceflight (Challenger), but laid before OV-101.
If we really want to get particular there was OV-098, Pathfinder, though being made of wood it obviously was never meant for more than fitment testing. Oddly though it did get the OV designation, not the STA designation.
OV-099 Challenger was renumbered from STA-099 (Structural Test Article), it was not originally built to be flown.

OV-099 as a number actually doesn't make sense, because the numbering scheme (OV-XYY) in full reads: Orbiter Vehicle, Series X, Vehicle YY.

Series 1 is the original (and only) line of flightworthy Space Shuttle Orbiters including Enterprise, Vehicle number is given in sequence within a series starting from 01.

So OV-101 (Enterprise's) reads Orbiter Vehicle, Series 1, Vehicle 01. OV-102 (Columbia's) reads likewise Vehicle 02, and so on.

OV-099 (Challenger's) reads Orbiter Vehicle, Series 0, Vehicle 99 which makes absolutely no sense.

But in the context of this thread we're discussing how heavy the airframe is. Wouldn't OV-99 be lacking the airframe lightening enhancements that OV-103 and later enjoyed?
Oh the fear, that you are in space and you can only convert/adapt/manipulate matter to only a certain degree, so if you are missing a critical spare part... then what??

Which got my thinking and Ducking, and yes, in 2014 ISS got a 3D printer.

https://www.nasa.gov/missions/station/3-d-printer-powered-up...

Regarding some comments on "average", "male", "34", well they ain't the average dude, they are models T101 in the flesh (to begin with, and then they get extra training).

But man.. I misplace a screwdriver and I stress..

> "How lucky we were," Hale said. "Instead of being 200 or more fps short at MECO, possibly leading to an abort landing or requiring two tons of OMS propellant to make up, we wound up being only 15 fps short, well within the capability of the OMS budget."

Is that feet per second?

Yeah, it's delta-V, which in this case represents the remaining potential energy in the spacecraft's dwindling fuel supplies: in terms of how much it can change its velocity by burning it.

https://en.wikipedia.org/wiki/Delta-v

Yes, the confusing part was that it wasn't in meters. I've never seen anyone use feet per second as a unit before.
Feet per second is used when describing rate of climb/descent in aviation, though it's usually converted to feet per minute for better handling.

eg: Climbing 1500 feet per minute.

Attempted TLDR: "The shuttle wasn't going fast enough when the big rocket ran out of fuel, but luckily it was close enough that we could fix it by running some of the rockets for moving in space, which use their own small fuel supply."

________

> "How lucky we were," Hale said. "Instead of being 200 or more [ft/s] short at [the time of Main Engine Cut-Off], possibly leading to an abort landing or requiring two tons of [Orbital Maneuvering System] propellant to make up, we wound up being only 15 [ft/s] short, well within the capability of the [Orbital Maneuvering System] budget."

Right, the only part that confused me was "fps."
If you've not already listened to the podcast, I'd really recommend The Space Above Us episode on this particular rabbit's foot/four leaf clover of a near miss...

https://thespaceabove.us/

To have several "balancing" failures occur at the same time would be so unlikely as to be ascribed to some synchronicity rather than real life.

STS-93 carried the Chandra X-ray observatory, one of NASA's Great Observatories alongside Hubble, and which has been operating continually for the past 25 years. It can likely continue for up to another decade before it runs out of fuel, except that budgetary pressures mean that it might be cancelled this year: https://www.savechandra.org/
> It was just a couple of minutes later that one of the projectors hanging from the ceiling in Mission Control – the projectors that put up the displays on the front screens – overheated and started smoking. Quick action by the Ground Control officer to shut it off probably prevented a fire in the MCC, which would have lead to an evacuation.

Everyone prepares for complete engine failure, but no one expects and electrical fire in the office