Issue No. 100

It’s hard to believe that it has been 100 issues and 100 weeks since we started writing The Orbital Index. It’s been an incredibly educational and rewarding experience. Here’s looking forward to the next 100 issues. — Andrew & Ben


The Orbital Index

Issue No. 100 | Jan 20, 2021

🚀 🌍 🛰

Virgin Orbit rings in 2021 with an orbital launch. Virgin Orbit’s second orbital attempt for LauncherOne went off without a hitch (their first attempt failed shortly after ignition due to a problem with the LOX lines to the engine). The 21-meter, two-stage vehicle (which can deliver 500 kg to orbit) was released from Cosmic Girl (a modified Boeing 747-400) at 10,700 m over the Pacific Ocean. The primary benefit of launching from an aircraft at this altitude isn't lower fuel requirements, but the clear skies and many inclinations that you can launch into due to a plane’s mobility. This launch carried 10 cubesats (via NASA’s Educational Launch of Nanosatellites program) and was dedicated ‘For Eve’ after Richard Brandon’s mother who passed away from COVID-19 earlier this month. Virgin Orbit joins SpaceX and Rocket Lab in the elite club of NewSpace startups that have successfully made it to orbit. Also in this club—albeit employing either hydrazine or solid fuels and likely significant Chinese military tech transfer—are iSpace and Galactic Energy. We’re thrilled for Virgin Orbit and look forward to seeing many more launches, including to deep space.


LauncherOne ignites its NewtonThree engine (here’s an up-close-and-personal test fire video) seconds after being released from Cosmic Girl (another good review of the launch with videos from multiple sources).


SLS finally finishes something ahead of schedule 🙄. NASA & Boeing’s SLS Green Run hot-fire test at the Stennis Space Center was automatically aborted 67 seconds into the intended 8-minute test due to engine gimbal hydraulics reporting over-limit readings on one of the four RS-25 engines. (each previously-reusable Space Shuttle Main Engine costs over $100 million, but is now destined only to burn up upon reentry). In an actual launch scenario the booster would have continued flight, and likely experienced no side-effects since testing limits are conservative, but this makes us glad they decided not to skip this test. NASA now has the unpleasant choice of foregoing a full hot-fire test (it required >250 seconds of data to be considered successful) or to re-test the engines and allow the uncrewed Artemis I launch to slip yet again, this time to 2022. The Orion capsule for the mission recently completed testing and is awaiting final integration and fueling.


Survivorship Earth. There are numerous ways that Earth could have become uninhabitable over the last 4 billion years. The Sun’s luminosity increased 30% over that time, requiring balancing forces to prevent the planet from overheating. Meanwhile, volcanoes, meteors, or both too much or too little CO2 all also could have easily rendered life extinct. Conventionally, it is assumed that feedback loops tend to stabilize these forces, but a recent paper suggests that luck also plays an enormous role. In simulations of 100,000 initially-habitable planets, only ~9% remained habitable in at least one simulation over a 3 billion year window, and only 1 out of the 100,000 remained habitable through 100 simulations. Survivorship bias likely plays a large role in how we view the Universe.


Magnetospheres. Another thing that makes a planet less habitable is being bombarded by flares and coronal mass ejections from its host star—and, about 4 billion years ago, our Sun was treating Earth to these types of events. But, according to a recent NASA-led study, we were fortunately protected by our young Moon, whose still hot, convecting iron core generated its own protective magnetosphere that merged with Earth’s at the poles. Life on Earth should be grateful that “the high-energy solar wind particles could not completely penetrate the coupled magnetic field and strip away the atmosphere.” Evidence comes from residual magnetism and traces of nitrogen (likely from Earth’s atmosphere) found through modern studies of Apollo-era lunar surfaces. Related: a tour of the solar system’s best magnetospheres.


An illustration of the Earth and its young Moon with coupled magnetic fields.

News in brief. Russia may fine citizens for use of non-Russian satellite Internet services (e.g. OneWeb, Starlink, and Europe’s new proposed mega-constellation); meanwhile, SpaceX launched another Starlink mission this morning, setting yet another reusability record with an eighth successful launch and landing of a Falcon 9 booster; RocketLab also got off to a good start, launching their Another One Leaves the Crust mission successful; NASA and JAXA finalized an agreement to provide batteries and life support systems for Gateway; Blue Origin’s New Shepard performed a test flight of a new capsule ahead of future crewed suborbital flights (webcast) and carried ‘Mannequin Skywalker’, a life-sized test dummy flight recorder; SpaceX’s next-gen CRS-21 Dragon capsule splashed down successfully and, among other things, brought back 12 bottles of red wine that had been launched in 2019—somehow we doubt they taste any different; and, NASA has given up on getting InSight’s ‘mole’ to bury itself after trying numerous approaches since March 2019—the regolith at the landing site is simply too clumpy for the self-hammering nail to function. 😭

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