lobsters score: 83 · tags: science
She’s not dead, she’s just senile… and soon we’re just going to stop listening to her rambling, rather than watch her go off into the dying of the light.
The should at least let her keep muttering bravely away but still check in every once and awhile.
score 2 · canonical
The problem was, the gibberish was coming from the flight direction software — something like an operating system. And no copy of that operating system remained in existence on Earth.
(This is a problem NASA long since solved. These days, every space probe that launches, leaves a perfect duplicate back on Earth. Remember in “The Martian”, how they had another copy of Pathfinder sitting under a tarp in a warehouse? That’s accurate. It’s been standard practice for 30 years. But back in 1977, nobody had thought of that yet.)
I only take issue with the pop culture history, here. It’s incorrect to say that in 1977 nobody had thought to do that. This is literally a major plot point in 2001: A Space Odyssey, which was written in 1968, and definitely should’ve been the cultural reference instead of The Martian.
score 10 · canonical
This is literally a major plot point in 2001: A Space Odyssey, which was written in 1968, and definitely should’ve been the cultural reference instead of The Martian.
I had to think about that a bit. I presume you’re referring to the fact that Hal went on the mission but Sal didn’t? I don’t think that was portrayed as mission policy, nothing else was duplicated at home except mass-market things.
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I had to think about that a bit. I presume you’re referring to the fact that Hal went on the mission but Sal didn’t?
Yes. Though I believe “SAL” wasn’t actually named in 2001 (“she” was referred to as SAL in the beginning of 2010, IIRC).
As for it being a major plot point; when HAL begins to malfunction (“mistakenly” predicts that some antenna was about to fail), the crew as well as mission control were baffled as to how HAL could’ve been wrong, and they explicitly explain that the identical unit they have back on Earth (SAL) did not make the same prediction when fed the same input.
This is important to the story, because one of the key revelations about HAL’s behavior is that he was secretly given extra instructions about the mission that were not given to SAL. So, they turned out to not be identical conditions after all.
Whether or not it’s described as “mission policy” in the story–I would argue–is not relevant to my point, because the author(s) of the story clearly did consider the value of having a clone of the mission-critical space tech stay on Earth for debugging purposes. Which refutes the claim of the article that “nobody” thought of such a thing before 1977.
score 5 · canonical
I had to look up SAL 9000, according to the 2001 fandom wiki that computer is introduced in 2010: Odyssey Two.
score 2 · canonical
The fact that there is an identical HAL9000 computer back on Earth is discussed in 2001. It just got the name, SAL, in 2010.
score 3 · canonical
OK, it’s been a long time since I read the novel so I don’t remember that part.
It’s still plausible that NASA in the mid 70s might have known about this fictional premise, but decided it wasn’t worth the money to make an exact replica of a probe that wasn’t designed for the service life it ultimately achieved.
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It’s in the movie too iirc, they talk about a disagreement with a different hal-9000 on earth.
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I can’t decide which is more impressive, the fact that it survived this long, or the things that the ground team did to make it last so long. The power supply comes from radiothermal generators, which rely on heat output from radioactive decay to provide power. These suffer from generated dropping off in proportion to the half life of the element powering them (modulo the fact that the next thing in the decay chain may also emit heat as it decays) and then further from the fact that heat engines are less efficient with smaller temperature differentials . These are Plutonium-238, which has a half life of 88 years and was plenty for the original mission. The power has been gradually dropping off since then and it’s taken heroic efforts to keep some bits working.
It’s sad that it’s failing now, but it only had another year to go before the available power was expected to drop below a usable threshold, decades after it was originally expected to last.
While it’s somewhat sad that nothing is likely to overtake it in the readers’ lifetime, there isn’t much point without a much better drive. A solar sail and ion drive could probably overtake it but it’s not clear that there’s much scientific benefit in going a little bit further into interstellar space. Reaching another star remains out of reach, especially with something that’s able to send a signal back that’s strong enough to be detected.
score 17 · canonical
A solar sail and ion drive could probably overtake it but it’s not clear that there’s much scientific benefit in going a little bit further into interstellar space.
There is a specific destination that is desirable and feasible to reach with a solar sail beyond distance of 150 AU Voyager 1 reached. It is a focus of solar gravitational lens at 542 AU. I hope we get a mission to reach it within our lifetime.
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I’ve never heard of a gravitational focal point before, thanks! I guess it’s a natural consequence of lensing. What a cool concept.
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I can’t decide which is more impressive, the fact that it survived this long, or the things that the ground team did to make it last so long.
Come to think of it, a lot of NASA probes last well beyond their lifetime. Spirit and Opportunity were supposed to be 90 day missions but were active for 6 and 18 years, and Curiosity is still going strong. I’d speculate it’s because they’re all engineered to last their full lifetimes in the absolute worst case, which for space problems is much, much worse than the average case.
score 7 · canonical
My guess is that this is right, except that the “absolute worst case” is either
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green Martians shooting it with kryptonite-unobtanium hyperlasers, or
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more interestingly, arguably an incoherent concept.
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I do wish NASA would/could take a more mass-production approach to science. We could build like 8 little probes with ion drives and interesting magnetic/particle sensors, and just shotgun them out into interstellar space in every direction to find out how the Sun’s magnetic field is actually shaped. Perseverance is great, but for the same price we could have built 10 more Spirit/Opportunity rovers and scattered them across Mars. Then updated the thermal/power systems for vacuum and different solar conditions and sent a bunch more of them to the Moon, Mercury or maybe some large asteroids/dwarf planets. JWST is great, but for the same price we could have probably 20 more Hubble telescopes instead.
But no, NASA gets paid for doing ambitious one-off Big Science projects, not for actually exploring space.
score 6 · canonical
We’re at the point that major investment is needed for the Deep Space Network (large radio transceivers spread around the world) to support more missions. They are already rationing bandwidth for the various active missions.
score 2 · canonical
True, but we’ve also been at that point for at least 20 years. …Hmmm, there’s a business idea, I know that Russia and China space agencies some communication ships out in the Pacific and just suck up the blind spots when they can’t get global coverage. Maybe there’s opportunities for a company that sells time on big honkin’ radio dishes across the world?
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Not that I disagree with the overall point – we need more, and better, and faster, and more comprehensive space exploration, even without Big Science – but 8 little probes is orders of magnitude away from mass production. The price, and for sufficiently novel technology the risk of shotgunning eight little probes with advanced equipment that can conclusively measure things we can only measure in situ is… roughly eight times the price of sending just one. A program that’s (let’s conservatively call it) four times as expensive as the original had better offer results that are at least (let’s be conservative, again) twice as good, or as useful, as the alternative. Eight probes with less advanced capabilities are generally unlikely to offer that.
Maybe a policy that encourages the private sector to work on more dual (space/non-space) use technology might help offset some of the costs, but not in every application. E.g. stellar magnetic fields are technically “just” magnetic fields but there aren’t too many industrial applications that both require exactly the same kind of sensing and aren’t already being generally adequately served by existing solutions. There aren’t too many people down here who lose sleep over the disappointingly slow step response of most commercially-available spectropolarimeters.
Also, additiveness matters only for some capabilities. Hubble has been in orbit for more than thirty years. Nineteen other Hubbles can’t realistically give you anything this one can’t already provide except maybe some faster observations. JWST has already produced a lot of novel observations and informed a lot of new model that were out of Hubble’s reach not because we had just one Hubble, but because we had just the Hubble.
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It’s easy to say we’ll shotgun out 8 small probes, but the only reason it’s “easy” to do that now is because of the “Big Science projects” NASA did earlier proving it out. I think having a lot of small, publicized failures early on would have derailed everything. It’s hard enough for them to get funding with big successes.
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Oh, of course. I’m not saying don’t do Big Science Projects, I’m saying don’t do only Big Science Projects. But those are Exciting and so that’s what NASA gets paid to do.
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