There's a difference between quantifiable but unmanageable situational risk and predictable, manageable technical risk.
The heatshield issue is the latter.
$100 billion has been spent on this project. Ablative heatshield coatings have been used since the Atlas ICBM in 1957. Yet they still flew Artemis with significant technical risk on a political grandstanding mission that delivered no significant science.
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.
I imagine if there was a medical emergency they'd worry less about capsule recovery and safe shutdown. IIRC because the sat phone wasn't working, they had to wait an extra 15 mins to power down the capsule (I guess so they could use its radios?). In an emergency I imagine they'd just leave it as-is
I also like how they waffled on about how winching them up to a helicopter was the fastest option, when they obviously could have shaved an hour off the recovery time by simply having them step out onto the waiting boats!
Having worked for various government agencies for a while I've learned to recognise the signs of the "We're following the procedure whether it makes sense or not, dammit!" attitude you get with large bureaucracies.
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?
To play devil's advocate against my own argument: The nearest ship was about 5 km away, which is a decently long boat ride. In choppy waters with a small boat that could be less than ideal for someone who may be injured, weak from an extended stay in microgravity, etc. I assume the plan -- written months or years before the landing -- also had to factor in the possibility that the ships wouldn't have been so close. They did mention several times that the landing was unusually accurate, so it is entirely possible that their pre-planned helicopter ride would have made a lot more sense if they were, say, 20+ km away instead. You don't want dozens of people improvising the procedure in the middle of choppy waters with bad comms, so the best thing to do is to just follow the plan, even if it looks a bit absurd on camera.
100%. Easy to criticize this but you have to remember these are the people that planned and executed a successful moon mission. Pretty sure they know what they are doing and have thought about things in more that just a passing way.
“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.
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.
Yes, Challenger - although program management knew they were violating a launch constraint (temperature), and it was the low temperature that produced the conditions necessary for SRB failure.
As with any aerospace mishap, it's a chain of events, not just one cause.
I believe what it destroyed was the strut holding the booster to the tank. When the strut burned through the assembly came apart and aerodynamic forces did the remainder of the destruction.
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.
I've raised concerns about the Signal project whitewashing risks such as keyboard apps or the OS itself, and the usual response is that it's my fault for using an untrustworthy OS and outside Signal's scope.
At some point there need to be a frank admission that ETE encrypted messaging apps are just the top layer of an opaque stack that could easily be operating against you.
They've made encryption so slick and routine that they've opened a whole new vector of attack through excessive user trust and laziness.
Encrypting a message used to be slow, laborious and cumbersome; which meant that there was a reticence to send messages that didn't need to be sent, and therefore to minimise disclosure. Nowadays everything is sent, under an umbrella of misplaced trust.
In the US, libraries are often part of a network, and we have access to all the materials in the network. So if my local library doesn't have it, I simply request it from another library. They ship it to mine and I pick it up (and return to mine).
Then we also have a larger inter-library loan, where I can request things from libraries far, far away (even in another state). It takes much longer, though, and if it is deemed a popular/useful item, my local library may decide to purchase it and give that one to me rather than use ILL.
You may want to check if your local library has something similar.
It's difficult to decoy because the missile's processor is programmed to know what typical aircraft profiles look like; for example a transport aircraft has two or four propellors with hot leading edges, numerous turbine exhausts and warm leading edges. A flare is a seen as a hot ball, in contrast.
To decoy that, the decoy needs to basically _be_ the aircraft.
Vast amounts of hardware and many American lives were lost trying to recover downed pilots, even when it was known it was a body retrieval operation.
For one famous example, the rescue of BAT21 Bravo resulted in the loss of five aircraft, the deaths of eleven and two taken as POWs.
It is a point of principle that the USAF does not apply a 'cost effectiveness' test to aircrew recovery.
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