# The Great Ongoing Space Exploration Thread **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Tags:** science-math\ **Created:** [November 16, 2020, 12:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703 "2020-11-16T12:18:17Z")\ **Posts on this page:** 20\ **Page:** 50
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 3, 2023, 1:47pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/982 "2023-11-03T13:47:35Z")
In the relatively dense cloud of space junk that is the asteroid belt, I’d imagine there are lots of temporary pairings like this. “Temporary” might be 10K or 100K years, but it isn’t forever. The whole place is a veeerrrrrrryyyyy slowly simmering mass of meetups and breakups. We just got lucky finding one of the many one-night stands in progress. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [November 4, 2023, 2:22am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/983 "2023-11-04T02:22:45Z")
Astra soon to be gone? > **[Astra defaults on debt agreement, warns it may not be able to raise needed cash](https://www.cnbc.com/2023/11/03/astra-defaults-on-debt-agreement-may-not-be-able-to-raise-needed-cash.html)** > > Struggling space company Astra warned in a securities filing on Friday that it may not be able to raise needed cash as funds dwindle. > **[Astra (American spaceflight company)](https://en.wikipedia.org/wiki/Astra_(American_spaceflight_company))** > > Astra is an American launch vehicle company based in Alameda, California. Astra was incorporated in October 2016 by Chris Kemp and Adam London. Formerly known in media as "Stealth Space Company", the company formally came out as Astra Space, Inc. in a Bloomberg L.P. article by Ashlee Vance. Investors include BlackRock, Advance, ACME, Airbus Ventures, Innovation Endeavors, Salesforce co-founder Marc Benioff, former Disney CEO Michael Eisner, and more. > Astra was founded in October 2016 by Chris... ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 4, 2023, 2:59am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/984 "2023-11-04T02:59:04Z")
Not the first victim of the Great Culling, and won’t be the last. High interest rates means less venture capital bucks, not to mention expensive loans. Anyone with a business model that still involves burning a ton of cash and doesn’t already have a big warchest is in for a rough time. Most of these startups won’t survive. I’m not even sure about Rocket Lab, and they’re in a better position than anyone (except SpaceX, obviously). While I like to see space investment, ultimately I’m not too concerned with a belt-tightening here. I’m a little more concerned with the impact on green energy startups–it’s not a great time to be killing these off. I hope they can get a bit of a boost via other means. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 4, 2023, 8:59am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/985 "2023-11-04T08:59:27Z")
Was browsing the thread for old Astra posts, when I came across this from ~2 years ago: > [@Dr.Strangelove](#): > > Their Raptor issue won’t sink the company on its own. But Musk has experience with capital liquidity drying up at just the wrong moment, and is understandably concerned that SpaceX could see the same fate. Starship and Starlink are both expensive. And here we are. We may or may not be on the verge of a recession, but VC money has dropped significantly over the past year, and there are no cheap loans. People are looking for safer bets, and small launch startups are not that. I vaguely wonder if the SBF/FTX debacle will cause some to reallocate their limited capital from dubious crypto startups to… pretty much anything else. Maybe there will be a teeny bump from that, but I’m not holding my breath. We’ve seen a couple recent comments from Gwynne Shotwell and Musk that both SpaceX and Starlink are cash flow positive, or at least have had individual quarters where they were. They’ve managed to keep their consts under control, despite the large investment in Starlink and Starship. They should weather the storm easily, but we’ll see about the others. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 4, 2023, 12:46pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/986 "2023-11-04T12:46:59Z")
The great cull in the e-VTOL / Urban Air Mobility space I follow closely will be similar. 2024 and into 2025 will be a very bloody show. For similar reasons. Far too many me-toos with no realistic appraisal of what it really takes (in effort and in time which equates to dolllars^4) to get a flying machine past the regulators and into service. The optimism about market size is the other big factor. Getting to low-priced machines imply massive production volumes to get economies of scale and good amortization of non-recurring costs. Which is also what enables low cost of the actual service delivery. But which requires both huge customer demand and correspondingly huge ground infrastructure in place first. The real world is not like the web (or cyrptocurrency), which are conveniently elastic and can quadruple in scale in a few weeks at low cost with minimal pushback from anyone. IMO when times get tough, the volatile money will not move into financing real stuff with real but boring returns. Their desire for outsized returns pretty well guarantees it’ll have to be something in the comparatively “frictionless & regulationless” = virtual / IT arena. More crypto, not less. Or maybe more VR / Meta stuff. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 4, 2023, 11:08pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/987 "2023-11-04T23:08:16Z")
> [@LSLGuy](#): > > Their desire for outsized returns pretty well guarantees it’ll have to be something in the comparatively “frictionless & regulationless” = virtual / IT arena. More crypto, not less. Interesting take. Real-world stuff is definitely capital heavy when it comes to scaling. Even the best-run companies that make physical products took immense capital to get there. So, perhaps you’re right that in lean times, VC money will go to those that can scale better with low resources. AI may or may not fit in there. On one hand, it is pretty frictionless compared to manufacturing. But it does still depend on huge quantities of GPUs. It’s not quite like a factory, but there’s definitely some capital involved. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [November 4, 2023, 11:22pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/988 "2023-11-04T23:22:11Z")
> [@LSLGuy](#): > > The great cull in the e-VTOL / Urban Air Mobility space I follow closely will be similar. > > 2024 and into 2025 will be a very bloody show. For similar reasons. Far too many me-toos with no realistic appraisal of what it really takes (in effort and in time which equates to dolllars^4) to get a flying machine past the regulators and into service. That’s a good thing. Most of those were sucker traps for ZIRP (zero interest rate) money. The world has been awash in fanciful product ideas designed to separate investors from their money and little else. Notice all the Hyperloop companies seem to have vanished? I’m sure there are still a couple around, but they’ll find their investment capital drying up. > [@LSLGuy](#): > > IMO when times get tough, the volatile money will not move into financing real stuff with real but boring returns. Their desire for outsized returns pretty well guarantees it’ll have to be something in the comparatively “frictionless & regulationless” = virtual / IT arena. More crypto, not less. Or maybe more VR / Meta stuff. Software is about to get a lot less permissionless. Biden’s new AI executive order touches a LOT of software makers, and a lot of the regs in there will be pretty onerous. Couple that with coming cryptocurrency regulation, and we might see the rapid gworth in software capability comes to a screeching halt. Or at least a slowdown. In the online service space, we are going to run into increasing conflicts with EU-style regulation of speech, which is not compatible with the first amendment in the US. That will probably result in even more regulation. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [November 5, 2023, 12:01am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/989 "2023-11-05T00:01:31Z")
> [@Dr.Strangelove](#): > > So, perhaps you’re right that in lean times, VC money will go to those that can scale better with low resources. > > AI may or may not fit in there. On one hand, it is pretty frictionless compared to manufacturing. But it does still depend on huge quantities of GPUs. It’s not quite like a factory, but there’s definitely some capital involved. My understanding is that any AI available ot the general public is losing money hand-over-fist. The companies that own them are buying mind-share by giving the product away for free. Eventually those AIs will stop being free and anyone depending on them to write advertising copy, training manuals, or whatever will either have to pony up or rehire the writers they layed off. Since venture capital is drying up, that day of reckoning will come sooner rather than later. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 5, 2023, 12:19am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/990 "2023-11-05T00:19:05Z")
That model has been expensive for early investors but ultimately successful in many other IT-heavy endeavors. Might well work here too. The real problem is once the public gets used to getting the product for free, it’s real hard to graft non-trivial pricing onto it. Witness the screaming about Google finally cracking down on ad-blockers on YouTube. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 5, 2023, 12:24am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/991 "2023-11-05T00:24:50Z")
> [@dtilque](#): > > Since venture capital is drying up, that day of reckoning will come sooner rather than later. And, possibly, increased regulation (see Biden’s EO). Always hurts the little guys more than the big ones. I dunno, though. Open models are already pretty good. They’ll only get better over time. Maybe the closed models will be _so much_ better that no one will use the open ones, but that really depends on the price, and how much they dick people around. I see a lot of people being really frustrated with GPT-4 because it seems to degrade in weird ways, and it seems like OpenAI is trying to save money by shortening the context window or use weaker models or something else. Not to mention all the “safety” stuff that may make it so it’s less likely to say racist stuff, but also refuses to say things that are controversial or maybe just seem controversial. Those things may drive people to open models where at least they know what’s going on. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 5, 2023, 12:26am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/992 "2023-11-05T00:26:34Z")
> [@LSLGuy](#): > > In the relatively dense cloud of space junk that is the asteroid belt, I’d imagine there are lots of temporary pairings like this. There are lots of pairings, but no reason to assume that they are especially short-lived. > **[Minor-planet moon | List](https://en.wikipedia.org/wiki/Minor-planet_moon#List)** > > As of January 2022\[update\], there are 457 minor planets (systems) with 477 known companions. The following table is a listing of the total number of these systems by orbital class: ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 5, 2023, 12:37am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/993 "2023-11-05T00:37:37Z")
IANA orbital mechanics guru. Unlike perhaps yourself or others here. I suck mightily at Kerbal. ISTM that stability comes from large primaries, small secondaries, and both with uniform nearly spherically symmetrical gravity fields. With few other nearby or passing objects of sufficient scale to generate significant perturbations. My back of the envelope WAG is that all 4 of those desiderata are in (relatively) short supply in the Belt. The wiki cite certainly discusses what’s out there in 2023. It did not, that I could see, really discuss how long-lived any given pairing might be. Not trying to argue a foregone conclusion here; just hoping to learn. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 5, 2023, 1:24am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/994 "2023-11-05T01:24:11Z")
My extremely crude intuition comes from the phenomenon of lunar “mascons”, which makes the gravitational field of the Moon lumpy. With few exceptions, it means low orbits around the Moon are unstable and the object will crash into the surface in a few months or years. But it seems that these binary asteroid systems aren’t nearly that unstable. I found this paper: > **[Non-destructive collisions and the evolution of the orbits of binary asteroid...](https://academic.oup.com/mnras/article/425/2/1492/1196819)** > > Abstract. The effect of collisions on the stability of binary asteroids is discussed. The following mechanisms are taken into account: (1) complete disruption o It has a table showing a bunch of binary Main Belt systems (like [22 Kalliope](https://en.wikipedia.org/wiki/22_Kalliope)) under a few perturbation scenarios (a distribution of possible impactors). There’s a wide variation, but note the scale: all the numbers are in _megayears_. Collisions are certainly not the only perturbative effect, but if the systems are that resistant to actual collisions, they can’t be _too_ unstable overall. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 5, 2023, 1:40am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/995 "2023-11-05T01:40:47Z")
Very interesting. Thank you! As they say, they’re just considering what they call “smashing” or “evaporation”, both of which are strictly collisional phenomena. So their conclusions should be taken as an upper limit on actual binary survival since there are other disruptive influences in play that are not in-scope for their research paper. But nevertheless, I agree their findings are suggestive that binary lifespans are a _lot_ longer than I had naively thought. As in multiple orders of magnitude. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [November 5, 2023, 3:45pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/996 "2023-11-05T15:45:13Z")
> [@Dr.Strangelove](#): > > AI may or may not fit in there. On one hand, it is pretty frictionless compared to manufacturing. But it does still depend on huge quantities of GPUs. It’s not quite like a factory, but there’s definitely some capital involved. I think AI is really the dark horse here … at this stage nobody can with any reasonably degree of certainty predict future revenues/profits from AI … but I think we can all agree that this market has the potential to become HUGE. … and by huge I mean “like the internet / www business in the 90ies - huge” so, ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [November 5, 2023, 6:15pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/997 "2023-11-05T18:15:42Z")
> [@Dr.Strangelove](#): > > My extremely crude intuition comes from the phenomenon of lunar “mascons”, which makes the gravitational field of the Moon lumpy. With few exceptions, it means low orbits around the Moon are unstable and the object will crash into the surface in a few months or years. I am not an expert, but just how ‘lumpy’ is the gravitational field of the moon? Are the mascons sufficient to perturb it that much? Compared with Newton’s concept that the gravitational field of a uniform sphere can be modeled as a point? Or to put it another way: are there possible lunar orbits which are actually fairly stable? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [November 5, 2023, 6:47pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/998 "2023-11-05T18:47:40Z")
There are stable orbits, known as 'frozen ’ orbits: > **[Lunar frozen orbits revisited](https://ui.adsabs.harvard.edu/abs/2018CeMDA.130...61N/abstract)** > > Lunar frozen orbits, characterized by constant orbital elements on average, have been previously found using various dynamical models, incorporating the gravitational field of the Moon and the third-body perturbation exerted by the Earth. The... ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [November 5, 2023, 9:04pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/999 "2023-11-05T21:04:52Z")
Then there’s TMA-1…. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [November 5, 2023, 9:13pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1000 "2023-11-05T21:13:59Z")
> [@xtenkfarpl](#): > > Compared with Newton’s concept that the gravitational field of a uniform sphere can be modeled as a point? Yes, it’s very lumpy compared to that. I did mention a “few exceptions”, which are the frozen orbits that **Sam\_Stone** brought up. They’re the cases where the perturbations cancel out in some way. But they’re relatively rare. I’d liken them to how, if you have a 4-legged table on a lumpy surface, you can always find a stable position if you rotate it enough. There are positions where one lump is decreasing while another is increasing, and when they intersect you have a stable position. But there are only a few rotations where that happens. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 5, 2023, 10:10pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1001 "2023-11-05T22:10:29Z")
And those positions of the table / lunar orbits may really suck versus whatever mission you’re trying to get your orbiter to accomplish. Orbiting the Moon is a real PITA if you’re trying to do it for very long. [Previous page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=49) [Next page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=51)