Happy Thanksgiving to fellow USAns. And for all of you around the globe, may autumn and winter bring gifts of hope and resilience and joy - and fresh horizons of adventure - for us all.
Here in this posting are just a few high-horizon bits to help you digest that overstuffed meal.
I'll be posting soon about the new white paper issued by the White House re: colonizing the Moon. I understand their reasons. Consider me the Loyal Opposition on this particular matter, as I explained here... and I will post more about it soon.
== Out where we really should be active! ==
DART hit on target! See the way-cool flash as seen from ATLAS! And this zoom in closeup from DART itself. Amazing they used the same 'transmit video until smash' approach that I remember from summer 1964's Ranger probes to impact the moon. Took 7 tries to get it right.
And a month later? The Double Asteroid Redirection Test (DART) slammed a spacecraft into one asteroid to see if it could change its orbit around another asteroid. It did. After impact, the orbit of Dimorphos around Didymos was shortened to 11 hours, 23 minutes: a 32-minute change.
Speaking of hits… The largest space rock to strike Mars since spaceflight began ‘rocked’ the Insight Lander’s seismometer 2500 miles away… and also revealed boulder-size ice chunks when it slammed into Mars. They were found buried closer to the warm Martian equator than any ice that has ever been detected on the planet. “Since landing on 2018, the mission has revealed new details about Mars’ crust, mantle and core and detected 1,318 marsquakes. Sadly, InSight’s mission is running out of time. Increasing amounts of dust have settled on the lander’s solar panels, only exacerbated by a continent-size dust storm detected on Mars in September, and its power levels keep dropping.”
We're a lot better at it, now... we need to be! And yes, THIS stuff... planetary protection and asteroid mining... is what we should be doing with Japan and EU, instead of going back to that useless sandbox of worthless poison dust.
== Deep space ==
The James Webb Telescope captures the Tarantula Nebula in stunning detail. 160,000 light years away, it is the largest star-forming region in the Local Group of galaxies.
And other NASA scopes captured this color snapshot of a magnificent supernova remnant.
A black hole has been "burping" out energy from a small star it was observed shredding in 2018, after two years in which it didn't eject any such material.
Another black hole that is about 10 times more massive than the Sun and is located only about 1600 light-years away is Gaia BH1, a dormant singularity in the constellation Ophiuchus. This means it is three times closer to Earth than the previous record holder.
== Life, who needs it? ==
Speculation: “it's possible that life appears regularly in the universe. But the inability of life to maintain habitable conditions on the surface of the planet makes it go extinct very fast.” At least that’s a theory re early life on Mars.
Following on that… Well dang. The hunt for habitable planets may have just gotten far more narrow: “The pressure from a class M red dwarf star’s radiation is immense, enough to blow a planet’s atmosphere away,” boding poorly for the “Goldilocks Zone” around such stars (the most common type.) This does not affect the kind of planets where most of the life in the universe likely resides - Europa style ice worlds, which might orbit almost every star out there. Alas, very unlikely to build civilizations with starships or radio.
== The best place for humans off-Earth? ==
Veteran space engineers Joe Carroll and Al Globus point out that that the best place for the earliest human space settlements is in equatorial low earth orbit or "ELEO". Going to the moon, Mars, or beyond takes roughly an order of magnitude more launch mass. So, until you can reliably harvest >90% of your mass from non-earthly material, it is cheaper to expand in ELEO than anywhere else. Also, you don't need heavy radiation shielding in ELEO.
The earliest tests will involve large slow-spinning dumbbell shapes, because they provide any desired range of artificial gravity with lower annoying artifacts than feasible with any other shape or facility mass. But I think the argument is likely to remains true for other design approaches as well.
There is another key factor. Expanding settlements with Moon, Mars, asteroid, or comet materials involves distinctly different mining and refining technologies, and unique other constraints like long lunar nights, launch windows to each NEO, etc. Mastering each site will require mastering and reliably maintaining site-specific capabilities. But every site will require one common capability: reliably delivering usable air, water, food, and other supplies to support the settlers. This is almost certainly best done mostly by recycling onboard waste flows. And that (plus occasional launches) are the ONLY key capabilities required for settling ELEO. If you start there, you can "close the life-support loop" at whatever rate you want, because you can get supplies from earth >90% cheaper than anywhere else, and without launch constraints or latencies.
I strongly suspect that any serious plan to settle the moon, Mars, or beyond will end up redirecting the plans to start in ELEO first, because it lets you crawl and walk before needing to run or fly. And it is likely to kill far fewer people unnecessarily, even though it adds "unnecessary" steps in a long-term plan for serious human expansion beyond earth.
There is yet another factor that may become dominant in any commercial scenario: large-scale orbital tourism and even retirement-in-space should be >90% cheaper in ELEO than further out, That may drive viable early investments. ELEO is clearly the "minimum viable product."
… and along those lines… Orbital Assembly inc. is planning the first free-flying, habitable, privately operated facility in orbit for both work and play. With artificial gravity, OA is leading the space tourism market with a safe and comfortable destination in orbit. Several of the required technologies were first developed at NASA’s Innovative & Advanced Concepts program – (NIAC)
Finally… Here is a discussion with Seti Institute legend Jill Tarter – after a screening of "Contact" – interviewed by author David Brin and physicist Brian Keating.
And yes, I will post about Greg Bear, soon. It's just too painful a bummer for Thanksgivingtime.
Peace & joy to all.