Issue No. 149

Happy Holidays! This week’s issue is a short one so that we can hang out with our families. See you in 2022!

The Orbital Index Issue No. 149 | Dec 29, 2021 🚀 🌍 🛰

¶JWST is on its way to orbit L2! On Christmas Day, JWST launched successfully (video) aboard its Ariane 5 from French Guiana. During its flight, the rocket performed a unique sawtooth maneuver, rotating back and forth 30° to protect JSWT’s instruments from overheating due to direct solar illumination (as opposed to Apollo’s ‘BBQ roll’). After release, the spacecraft deployed its solar array—here’s a video, which likely includes the final close proximity image of the craft. Now beyond the orbit of the Moon, it has successfully performed two course corrections and deployed its gimbaled antenna assembly. Jonathan McDowell has a timeline of JWST's ongoing “30 days of terror” deployment schedule on its way to L2. The sunshield has started its multistep deployment and, in about a week, mirrors will begin unfolding. Check-in on its live mission dashboard to see where it is and what it’s doing, follow it on Twitter, or watch NASA’s Deep Space Network real-time dashboard to see active communications underway. Hopefully, the first images from Webb should be available by next summer. 🤞 Update: Santa has been destroyed by the range safety officer. XKCD #2559 The Orbital Index is made possible through generous sponsorship by:   ¶(Short) Papers. An example of the very small shaping the very large: measurements of the thickness of the layer of neutrons surrounding the nucleus of lead atoms suggest that neutron stars are probably about 15% larger than previously thought (paper). The emission spectra of ¼ of Sun-like stars show evidence that they have eaten a planet (paper). We’ve been lucky, but many star systems have turbulent initial conditions that cause a planet or two to eventually plunge into their host stars, altering the stars’ post-meal composition. State-of-the-art climate models suggest that, unlike Earth and Mars, Venus was never cool enough for water to condense and fall as rain—making it unlikely to have ever supported oceans (paper). All cells on Earth are made of phospholipid membranes, but where did these crucial precursors to life come from? While previously seen in meteorites, ethanolamine (C2H7NO), a molecule that forms the hydrophilic (polar) head of phospholipids in cell membranes, has now been spectroscopically detected in Sagittarius B2, a giant molecular cloud about 390 light-years away (paper). Watch stars orbit Sagittarius A*, the Milky Way’s central black hole, reaching 31 million km/hr (​​8,611 km/s, or almost 3% of the speed of light) at periapsis. The detailed observations allowed precise estimation of the black hole’s mass at 4.3 million solar masses (paper).  A possible first: evidence of a circumtrinary planet simultaneously orbiting all three stars in a trinary star system (paper). ¶News in brief. Russia launched their third and final Angara demonstration mission—Angara has now entered operational status, although its upper stage may have failed on this mission ● A Soyuz launched 36 OneWeb satellites ● China launched the ZY-1 02E natural resources remote sensing satellite with 5 m resolution on a Long March-4C to sun-synchronous orbit and two classified Shiyan-12 test satellites ● A Mitsubishi Heavy Industries H-2A rocket launched Inmarsat’s first dual-band telecommunications satellite ● An engine controller on SLS must be replaced, delaying Artemis I to NET March 2022 ● China complained to the UN about the US’s oversight of SpaceX’s Starlink constellation, saying that Tiangong has had to maneuver twice to avoid conjunctions this year.   ¶Etc. JPL recently updated their Near-Earth Asteroid impact probability calculator (paper), replacing Sentry which was developed in 2002, with Sentry-II. In addition to Sentry’s multi-body gravitation model, Sentry-II takes into account non-gravitational forces such as solar heating (the Yarkovsky effect) and has better handling of the effects of keyholes. The system reports the objects of highest risk in the CNEOS Sentry Table. The object with the current highest cumulative impact probability is 2010 RF12, a 7 m wide object with a 4.8% chance of Earth impact over the next 100 years. More concerning, though, would be the famous 500 meter-wide Bennu, which fortunately only has a 0.057% chance of Earth impact during that period. The Planetary Society explores the next six months for JWST and Reuters has an animated article about JWST. An amateur attempt to decode JWST’s telemetry, with a link to a GNU Radio decoder flowgraph (but not successful just yet). A recording of the roundtable conversation we hosted last month with three space startup founders. All SpaceX orbital launches in one picture. RocketCrew.space, a new space-focused jobs site. By measuring the distribution of velocities of neutrons released by the impact of cosmic rays with the Martian surface, ESA’s ExoMars Trace Gas Orbiter has been able to infer a significant amount of water in the upper layers of soil in Mars’ massive Valles Marineris canyon system (paper). While Mars is known to have water, finding it at accessible depths in the warmer mid-latitude regions is exciting for potential human habitation, and Valles Marineris makes a good candidate for settlement due to (slightly) higher atmospheric pressure which is useful for reducing radiation exposure and helping spacecraft aerobrake more effectively. On Duties… in space. And, a quick reminder that there is a cubesat in orbit shouting portal space core quotes. Comet Leonard, photographed the night of December 25th from the Atacama region of Chile. Credit: Daniele Gasparri

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