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The Orbital Index

Issue No. 145 | Dec 1, 2021

🚀 🌍 🛰

The TOLIMAN Telescope. A semi-privately funded space telescope is being planned to search the Alpha Centauri system for Earth-like planets. A transliteration of the ancient Arabic name for our Sun’s nearest stellar neighbor (and the official IAU name for Alpha Centauri B), Toliman could launch as soon as 2023 to observe Alpha Centauri A and B for the tell-tale wobbles that would confirm a suspected habitable-zone exoplanet orbiting Alpha Centauri A (paper) and search for more. (As we’ve noted previously, the Alpha Centauri triple star system consists of Alpha Centauri A and B, a pair of co-orbiting Sun-like stars, and Alpha Centauri C, aka Proxima Centauri, a faint red dwarf star that slowly orbits the AB duo 0.21 light-years away and has at least two planets of its own.) The Toliman project is a collaboration between the University of Sydney, Saber Astronautics in Australia, Breakthrough Initiatives, and JPL. It will use a diffractive pupil mirror that spreads captured light into a flower-like pattern to provide high sensitivity to optical wobbles.

A simulated view of the Alpha Centauri system as seen by the TOLIMAN diffractive pupil mirror. Credit: Breakthrough Initiatives

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China Commercial Aerospace Forum. CASIC and partners in the (mostly) commercial Chinese space industry met last week in Wuhan for a commercial space forum. The forum touched on space planes, small launch, and constellations.

  • iSpace shared plans for a commercial space plane that would launch atop their Hyperbola-3 methalox rocket. While scheduled for next year, Hyperbola-3 has not yet conducted hop tests originally planned for this year.
  • CAS Space plans to launch its Lijian-1 solid-fueled rocket in the first quarter of 2022.
  • CASIC announced that it had completed tests of a turbine-based combined cycle engine that looks exceptionally similar to the SABRE engine (this follows several oblique posts about desert engine tests).
  • Jiuquan Satellite Launch Center is being expanded to support additional commercial solid rocket launch providers and possibly new liquid-fueled vehicles slated to debut next year.

Pangea's Aerospike. A small Spanish startup, Pangea Aerospace, successfully hot-fired their demonstration aerospike engine last month. The 20 kN methalox engine is 3D printed using GRCop-42, a new high-performance copper alloy developed by NASA in 2019, and includes regenerative cooling of the engine’s notoriously hard-to-cool center spike by flowing both cryogenic liquid methane and oxygen through the engine walls before combustion. The demonstrator will need to be scaled up to roughly 6x the thrust for use in Pangea’s planned 150 kg payload Meso small launch vehicle. Meso will directly compete with Astra, albeit with reusability built in from the beginning via a novel return-to-launch-site recovery system that uses ducted electric fans to reduce stress on the main engine. Aerospike engines have never been flown successfully, although NASA came close in the 90s and early 00s with the X-33’s linear aerospike engine. Pangea claims their aerospike could be as much as 15% more efficient than traditional bell-nozzled chemical engines, decreasing the rocket’s fuel requirements and increasing its payload abilities.

Papers (about exoplanets).
  • Several large craters in the Arabia Terra region of Mars may be calderas, the remnants of ancient supervolcanoes (paper)—volcanoes with deposit volumes greater than 1,000 cubic kilometers. MRO data correlates ash deposits around this region with topographical maps of the calderas and suggests that thousands of supereruptions occurred there over a 500 million year period ~4 billion years ago. These eruptions would have released massive amounts of ash into the atmosphere, blocking out the sun and altering the planet's climate. We don’t yet know why only this region formed supervolcanoes—on Earth they’re globally dispersed.
  • Meanwhile, although Mars may have once had water on its surface, a new paper suggests that it was never fated to have life. The planet is simply too small—the paper suggests that a threshold exists for the size of a rocky planet under which it cannot retain sufficient water to sustain life. Data on the Earth, Moon, Mars, and the comet 4-Vesta revealed a strong correlation between surface gravity and the ability to retain volatile compounds like water. In the future when we’re studying exoplanet atmospheres for signs of life, in addition to prioritizing planets within their stars’ habitable zones, exoplanets’ masses should be considered as well.
  • Speaking of rocky worlds, a paper suggests that the compositions of nearby rocky exoplanets may be surprisingly different from Earth. Using data from the HIRES spectrograph and the Hubble Space Telescope on the atmospheric abundance of planety elements in white dwarfs (the dense collapsed cores of former stars), the authors were able to reconstruct details about the compositions of planets and asteroids that were consumed by them. Many appear to have had rock types exotic to our solar system, necessitating entirely new rock classification schemes like “quartz pyroxenites” and “periclase dunites".
  • Aurorae on Earth and Jupiter generate powerful radio waves (Jupiter’s are detectable with a homemade radio telescope). Now, the massive distributed LOFAR radio telescope array in Europe (20,000 antennas at 52 sites, spread over 2,000 km) has detected an exoplanet aurorae for the first time. This may become a powerful new way to detect exoplanets around active stars.
A composite of two Hubble observations, with far-UV observations of Jupiter’s auroras in purple on top of an image of the planet taken at a different time by Hubble's Outer Planet Atmospheres Legacy program. Credits: NASA, ESA, and J. Nichols (University of Leicester).
News in brief. Japan is recruiting their first new astronauts in 13 years, to head to the ISS and/or GatewayMeanwhile, Saber Astronautics (the same one that is working on the TOLIMAN Telescope) has signed a deal with Axiom Space to establish an Australian astronaut programRussia’s Prichal 6-port docking adaptor module launched to the ISSChina launched a Gaofen-11 high resolution spy sat which may equal US capabilities, and another classified satelliteTokyo-based Astroscale raised a $109 million Series F to continue developing satellite servicing and active debris removal services (which OneWeb is considering using on a failed satellite)A Soyuz launched a classified payload, probably a Kupol missile warning satelliteJWST fortunately did not sustain damage from being dropped last week 😌Perseverance capped and sealed its fifth sample tube, for eventual return from MarsAstronauts on the ISS had a (bagged) Thanksgiving dinnerNASA postponed a spacewalk to replace a communications antenna due to a debris conjunction warning (it’s unclear if this debris was from the recent Russian ASAT test)Russia, continuing its string of (at best) questionable space actions, may press charges against NASA astronaut Serena Auñón-Chancellor on seemingly fictitious claims that she drilled a small hole in the Soyuz capsule she rode to the ISS in 2018SpaceX may have a production crisis with their Raptor engine according to a Musk email leaked this week—he suggests a potential for bankruptcy if the company can’t achieve a 2-week launch cadence for Starship by the end of next year (although this prognosis of ‘bankruptcy’ seems somewhat overblown and is perhaps intended to push employees more than anything else).
The 13 light-year-long glittery trail at the center of this image reveals the “Cannonball Pulsar”, a pulsar flung at 1,100 km/s away from its supernova remnant after exploding 5,000 years ago. The composite image is made up of VLA data (orange) overlaid on data from the Canadian Galactic Plane Survey. The pulsar was discovered by the Einstein@Home project in 2017.