The Orbital Index is a curated newsletter about space and the space industry.

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The Orbital Index

Issue No. 121 | Jun 16, 2021

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Supernovae and the SNEWS. The SuperNova Early Warning System (SNEWS) uses neutrino detectors to watch for rising emissions hours or days before a (relatively) nearby star goes supernovae—so we have time to point our telescopes, grab a beer, and catch the drama unfold. SNEWS is currently getting an upgrade for improved sensitivity (paper). Our last chance to see a nearby supernova was in 1987 when SN 1987A exploded 168,000 light-years away in the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. SN 1987A was the closest observed supernova since 1604 when Kepler (the human, not the spacecraft) observed a Type Ia supernova that went off a mere 20,000 light-years from Earth. Astronomers do not want to miss the next one in our galaxy since they’re expected to occur at a rate of just a few per century. Anything closer than 50-100 light-years away would put Earth’s biosphere at risk… but, we don’t currently know of any supernova progenitor candidate stars that close to us. The closest known candidate is IK Pegasi B at 154 light-years—but we should keep looking for faint white dwarf stars with accreting twins, just in case. If you’d like to sign up for SNEWS alerts, you can do so here. Related: We may have finally found the neutron star left over after SN 1987A.


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The race to crewed suborbital space is on. Blue Origin just auctioned off its first commercial seat on New Shepard for a whopping $28 million ($29.68 million after fees and commissions). The New Shepard flight will launch sometime next month carrying the unrevealed auction winner, Jeff Bezos, Mark Bezos, and a still-unnamed fourth passenger. Standard pricing for future flights is still yet to be announced. Meanwhile, it is rumored that Virgin Galactic may be racing to send Richard Branson to suborbital space before Bezos can get there. Related: Ignoring this current flurry of suborbital activity, earlier this month Axiom space confirmed three more orbital missions Ax-2, Ax-3, and Ax-4, all launching with SpaceX to the ISS through 2023.


And ESA makes it three. The European Space Agency selected their own Venus mission last week. Its EnVision orbiter, scheduled to launch in the early 2030s, will study the planet’s atmosphere, surface, and subsurface to understand how it ended up so starkly different from Earth. EnVision will employ SAR, much like Veritas (good explainer video of that mission, if you missed it last week), to look through the planet’s thick atmosphere—in traditional ESA/NASA cooperative fashion, the craft’s VenSAR instrument will be provided by JPL. In addition to SAR mapping, the mission will use polarimetry to characterize surface materials, subsurface radar to examine the planet’s outer layering (up to 600 m below the surface), spectroscopy to study its composition and search for volcanism, and Doppler measurements to create a full-planet high-spatial-resolution (200km or less) gravity map from its polar orbit.

News in brief. Relativity Space raised $650 million, bringing their total investment to $1.3 billion since 2015—they are using the money to develop Terran R, their 3D-printed Falcon 9 challenger, designed to recover both the first and second stage, with affixed fairings, a bit like a mini-Starship—they are hoping to launch their smaller Terran 1 by year’s end; a Long March 2D launched four small spacecraft: Origin Space’s asteroid-spotting Yangwang-1 optical telescope (more coming about Origin Space soon!), the remote-sensing Beijing-3, the optical marine-ecological-monitoring Hisea-2, and the likely-military TKSY01-TJ for “teaching and training on in-orbit services”; Space Force launched a space domain awareness satellite that was mostly an experiment in rapid development on the second-to-last extant Northrop Grumman Pegasus-XL air-launched rocket; a crewed mission to China’s Tiangong station is expected to launch this week; both the AWS/Seraphim Space Accelerator and Techstars’ Space Accelerator announced their latest classes (the first for AWS’ accelerator); back in action, Ingenuity flew for a 7th time; and, the Zhurong rover deployed a wireless camera, backed up, and took an excellent selfie on Mars (announcement in Chinese)—it was also caught from orbit by HiRISE.

Juno flew by Ganymede last week, just 1,000 km above its cratered surface, capturing this image at 1 km per pixel resolution. Ganymede is the only moon in the solar system with its own magnetic field. Raw JunoCam data is available for your re-processing pleasure.