¶Astra Powerslides. In one of the most unique launch failures we’ve seen, Astra’s Rocket 3.3 performed a powerslide off the pad, moving sideways and scorching the grass due to the loss of an engine immediately after ignition. It then recovered and slowly climbed for 2.5 minutes, passing through Max Q, before the flight was terminated and tumbled into the Pacific. The fact that the rocket maintained control and hovered, instead of immediately turning into a fireball, is an impressive testament to the quality of their GNC team. This version of the rocket had been improved with a stretched first stage fuel tank (since the last one just barely missed the delta-v necessary for orbit) and started out with a thrust-to-weight ratio of ~1.25. But, after losing one of its five engines that ratio dropped to roughly 1, creating the hover effect until enough fuel was burnt off to allow vertical acceleration. Space is hard, and we wish them the best for their next attempt (that rocket is already mostly finished). |
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¶The active solar wind. Beyond stripping planetary atmospheres, creating auroras, and allowing reactionless interplanetary transport, the solar wind also has a larger effect on unshielded planetary bodies like the Moon than previously thought. New evidence suggests that the solar wind’s constant flux of electrons, protons, and alpha particles creates abundant iron nanoparticles found on the Moon (paper). It also may spark, melt and vaporize the lunar soil at a rate comparable to micrometeorites (paper), explaining the coloration of the dark mares of the Moon, and why protective localized magnetic fields result in striking lunar swirls where regolith is less altered. Meanwhile, a JAXA research team demonstrated that solar protons can react with silicate materials on the Moon or small solar system bodies to form water directly (paper). |
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 | A lunar swirl, the result of a localized magnetic field diverting incoming solar wind and protecting the lighter-colored region. |
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¶Starlink Gen2. SpaceX recently applied to the FCC to deploy Starlink Gen2, its second wave of Starlink satellites which the company intends to launch primarily on Starship (although could use Falcon 9 until it is ready). The 29,988 satellites will be slightly larger, generate more power, and have the capacity to host 3rd party payloads (such as Swarm, perchance?)—here’s a video overview. Using Starship to deploy Gen2 sats would significantly decrease the time from launch to operational station arrival. “The revised orbital planes would enable single plane launch campaigns that capitalize on the ability of Starship to deliver satellites at a faster pace by not necessarily requiring a waiting period for orbital precession in a parking orbit. SpaceX could deploy satellites into their operational orbits within a matter of weeks after launch, rather than months.” (Scott Manley recently did an excellent video about how the current crop of Starlink launches use precession from Earth’s equatorial bulge to spread satellites across their final orbital planes with a low delta-v budget.) Gen2 satellites will also feature redundant control and power systems to facilitate a higher likelihood of powered deorbit in the case of a collision. Most of the Gen2 satellites would also be deployed at a lower altitude than the current shell (at 550 km), reducing the time between any potential complete failure and unpowered reentry, as well as somewhat decreasing the constellation’s impact on astronomy. (Related: Starlink recently had its first global outage for about 15 min. Also related: the recent lull in Starlink launches has been partly due to the addition of laser crosslinks on all future satellites, and partly to a LOX shortage as hospitals require O2 supplies for large numbers of Covid patients.) |
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| ¶News in brief. The first SLS launch (Artemis 1) is probably slipping to early 2022 ● SpaceX launched their 23rd Cargo Dragon ISS resupply mission (video), which included 2,170 kg of supplies and studies on preventing bone density loss, crew eye health monitoring, and mitigating space-related stress in plants, and a robotic arm demonstration from Japanese company GITAI—the returning booster used the new ‘A Shortfall of Gravitas’ autonomous drone ship for the first time ● Astroscale’s ELSA-d completed the first test of their satellite capture technology by releasing and then recapturing a test target (cf. Issue 108) ● ULA announced that all 29 existing Atlas Vs have been sold to customers and no more will be made ● Firefly Aerospace is hopefully attempting the first launch of their Firefly Alpha vehicle on Thursday from Vandenberg after a successful static fire last week Blue Origin’s suborbital New Shepard made its 17th launch, this time uncrewed with 18 commercial payloads and a test of autonomous landing systems for NASA ● In China’s 29th orbital launch of the year, a Long March 4B lofted a pair of Tianhui-2 radar satellites that will fly in formation to perform stereoscopic 3D mapping at a resolution of ~3 m ● Carolyn Shoemaker has passed away, aged 92—she is best known as the co-discoverer of comet Shoemaker–Levy 9, whose dramatic collision with Jupiter in 1994 (the first collision of two solar system bodies ever observed) is very memorable to Andrew—Shoemaker was trained in the humanities, but for many years held the record as the discoverer of the most comets (between 1980 and 1994, she spotted 32 comets and 400+ asteroids) ● Testing is now complete on the JWST—it’s about to be shipped through the Panama Canal to Kourou, French Guiana, for launch, but the shipping details are secret to avoid pirates (or the CIA). |
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 | JWST fully assembled and tested. |
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¶Etc.- From 2016, here’s an optical video taken over 7 years of four giant planets orbiting star HR 8799, 130 light-years away. Watching the orbital dynamics has also allowed the weighing of the innermost planet.
- A rumor that the iPhone 13 could support LEO satellite connectivity. We’re skeptical given the size of some other LEO-connected cell phones, although companies like Lynk and AST SpaceMobile are making large amounts of progress in enabling this sort of service with standard consumer phones.
- As mentioned previously, China is very seriously exploring building massive, kilometer-sized spacecraft in orbit, initially for space-based solar power arrays. The first step is the National Natural Science Foundation of China’s five-year project to study ultra-large spacecraft, including developing lightweight structures and on-orbit assembly. While not heavily funded right now, China may be one of the few countries with the ability, given both its long-term ambition and lack of political whiplash every election cycle, to make this kind of program a reality.
- ‘How To Save The Night Sky From Satellite Megaconstellations’ by Ethan Siegel.
- A recent paper found that filaments of the cosmic web of galaxy clusters - the largest-scale structures of the Universe - appear to be rotating along their axes (like rolling noodles), making them the largest spinning structures ever found. “When most of the galaxies on one side of a filament were moving away from us and most on the other were coming towards us, that indicated that the whole filament was rotating. Some of these gigantic strands of galaxies were spinning at nearly 100 kilometres per second.” We wonder if these net motions may help explain where the angular momentum—which must be conserved as a whole—of smaller systems, like solar systems and galaxies, comes from.
- Last Month, the Perseids meteor shower had an unexpected burst of activity the day after its peak. This burst may have been from the same filament of material left by Comet Swift-Tuttle that caused a collision with the Olympus-1 satellite in 1993, disabling it. Ben happened to see the show while in upstate New York. 🤩
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