Quick question - what kind of benefit would a MARSIS style ground penetrating radar examination of the Jovian system give us? I’d imagine induced currents, and power requirements, might not make it feasible though.
A MARSIS type ground penetrating radar will probably just reflect off of the ice-ocean interface. It would be useful in looking at the thickness and density (and possibly composition) of the ice, but it probably won’t offer much insight about the ocean bed or composition.
Stranger
No argument there. The question, I guess, is “what’s the pain threshold?” As you say, the Voyager missions were fantastically successful despite the crudity of their instruments–that argues for the “anything is better than nothing case” (I don’t think that had to be true–sometimes bad data is bad data–but scientists have proven to be clever, which I suppose is what happens with a glut of grad students and a dearth of data). The infrequency of missions argues for more complexity–but only just short of the point where the budget becomes painful (including, of course, the inevitable cost and time overruns).
A Stirling system would be a help, though it’s not quite the order-of-magnitude improvement that one wants. Still, it’s a little more straightforward than an actual reactor (and besides, a reactor still needs to convert heat into electricity, so you need a Stirling engine or similar anyway).
Definitely. I’ll suggest that such a reactor–staying on the surface–would pair quite well with the probe design I sketched. The optical fiber allows a very high data rate at low power. Megabits/s would be completely trivial even for a simplistic system, and I can imagine the lander storing many gigabytes of data–much of it in a burst when the probe reaches water.
The problem, of course, is getting that information back to Earth. The Huygens probe relayed through Cassini, and even then only achieved 8 kb/s for its 90 minute lifetime. That’s only 5 megabytes!
If there’s any hope of getting that data back, let alone any the lander generates, you need a bit more oomph. An actual nuclear reactor would do nicely.
Interesting. Do you know of any NASA studies on the subject?
So: you’re suggesting that NASA take on a big, imagination-inducing goal that requires solving big, complex problems. Something like Apollo, but nothing like on the scale of the Apollo program.
Okay, then.
Once NASA had video of alien creatures swimming around, they would be able to write their own budget for return missions.
:rolleyes:
Try reading for comprehension instead of reading for sound-bites you can snark at. I said that the success of Apollo was in part due to the mission being extremely well defined. The requirements were defined very early in the process, and the constraints on the solution were also known. This tends to focus engineering efforts and prevent the kind of bloated, aimless projects NASA has engaged in over the years.
Therefore, it would be beneficial to NASA and to the taxpayers for it to be given a tightly defined objective - one big enough to focus the agency and keep it from drifting back and forth between designs-by-committee and make-work projects designed to justify jobs programs like the SLS.
I’ve already explained that in this thread, and you’re the only one who seems to not uinderstand what I was saying.
[quote=“Dr.Strangelove, post:63, topic:683338”]
Well, yes. NASA thrived when faced with the well-defined challenge of the Apollo program. But most of the cost of the program went not into exploring the Moon done by the Surveyor program for less than US$470M for five successful landings and two failures, which was a pittance compared to the Apollo program at >US$20B (around US$110B in 2010 dollars) for six landings and one recoverable failure; that is almost US$18B per successful lunar mission, which is about seven times the cost of the most expensive Mars rover or more than five times the cost of the most ambitious outer planets mission to day (Cassini-Huygens), both of which have operated for much longer, provided much more scientific data, and have survived environments which would have killed an equivalent human crew in short order.
“Oh, but we need a human crew to do ____!” cries the space enthusiast contingent. Well, it is true that circa 1960 the best flight controller was a human pilot and robots were wind-up toys which waddled across the screen with flashing lights in their chests, but given the vast improvements in automated systems and remote mission management (which have not been matched by advances in propulsion systems or radiation and environment protection to get crew to a destination quickly or protect them against the harsh conditions they’ll face in interplanetary space) it scarcely worth the the 50:1 or more cost ratio of a crewed mission over a remote one, notwithstanding eliminating the need to bring a remote probe or rover back to Earth at end of mission. Another, more extensive “Grand Tour” of the Solar System, exploring in more detail the outer planets, the Oort cloud and Kuiper objects, the the asteroid belt (almost completley unexplored at this point) and the near-solar environment would be a fantastic overall mission which could all be supported within the current NASA funding…provided they are not longer forced to spend money on the absurd monstrosity of the Space Launch System which isn’t really designed to go any place in particular and has no well-defined mission to support.
Of course, people do bring capabiltiies to the milieu that automated systems are unlikely to match in the foreseeable future, e.g. their ability to interpret and adapt, and it may be that the most effective mode for some exploratory mission is some combination of remote probes controlled and supported by a local crew. But if you really want a sustained human presence in space, the way to do so isn’t to make desperate, grasping, multi-hundred dollar missions to plant flags on other worlds. It is to advance the technology and techniques for space travel and habitation, develop remote in situ resource utilization, and reduce the costs to orbit to something that is within the reach of a plausible budget. Once those capabilities and the infrastructure to support them are in place, crewed exploration and human habitation become foregone conclusions rather than extraordinary measures afforted only by the most wealthy nations for a tiny handful of privlidged individuals.
Tell me you are just yanking peoples’ chains with this. By what rationalie would you expect to find a) complex mobile life, b) within the murky view of your dangling camera, and c) enough information from said images alone to do any useful amount of actual science? Actual scientific exploration isn’t about “Eureka!” moments; it’s about the careful collection and interpretation of data to develop an understanding of a phenomenon or event and how it fits into an overall system. And even finding complex life would not guarantee that “they would be able to write their own budget”; the response of the general public would be a slightly bored yawn to such news, followed by more arguments over whether Obamacare is a disaster or a nightmare.
However, if they found some exo-terrorists with yellowcake, you better believe we’d put some War on Terror action on those squid, regardless of the cost.
Stranger
Looks like your post has a quote bug.
I was reading a bit on subcritical reactors, and it seems to me like they would make a good match with plasma wakefield accelerators. The thorium energy amplifier needs a proton beam on the order of 1 GeV. That’s a pretty big cyclotron or linac. However, plasma wakefield accelerators appear to be a promising route for a vastly more compact accelerator.
They aren’t yet at a development level where they can replace multi-TeV beams like the LHC, but they have reached the 1 GeV level in the lab. I’m not sure what it would take to adapt one to a long running reactor, but it seems like a good start.
I was ready to start a new thread with a joke about us specifically being told to NOT go there, but Discourse brought this thread to my attention instead.
Anyway, thread bumped after a decade with an update. The mission is scheduled to blast off from Kennedy Space Center on a SpaceX rocket as early as October 10, 2024.
I posted this in the ongoing space exploration thread earlier: