Issue No. 252

The Orbital Index

Issue No. 252 | Jan 17, 2024

🚀 🌍 🛰

SLIM targets a lunar landing. After a leisurely, fuel-efficient trip to the Moon, JAXA’s SLIM lander (aka Moon Sniper) is scheduled to attempt a pinpoint landing in a couple of days, at 10AM EST on Jan 19th (live stream). Pinpoint in this context means shooting for a landing area ellipse of 100 x 100 meters after a 20-minute autonomous descent process. Our friend Jatan did a rundown of planetary landing accuracies, with Chang’e 3 holding the current record with a landing 89 m away from its target point—but, this was within a 6 x 6 kilometer target ellipse, where SLIM’s is 100 meters. Chandrayaan 3’s accuracy was ~350 m in a 4 x 2.5 km area and Apollo 17 was ~400 m in a 15 x 5 km area. (With an atmosphere and greater mass, Mars landers trend toward much larger landing area ellipses, with Perseverance targeting a 7.7 by 6.6 km ellipse and landing 1.7 km from its center.) SLIM’s target lies within the ejecta field of the 300-meter-wide Shioli crater, an ambitious and rocky target, but also one interesting for analysis of the Moon’s geologic history via exposed material naturally excavated from many meters below the surface by the impact that created the crater. In true JAXA style (and exceptionally true to its name), SLIM is also attempting to do this landing with a mass of only 730 kg, requiring mass reduction techniques like an integrated structural fuel and oxidizer tank and thin-film solar cells. SLIM also carries two tiny rovers: Lunar Excursion Vehicle 1 (LEV-1) is a small hopping vehicle with cameras and a few sensors, and LEV-2 is a 250-gram, ball-split-in-two vehicle that can wiggle and roll on the surface. SLIM lacks radioisotope heaters so it is only expected to survive a single (14-Earth-day) lunar day.

The 8 cm wide, 250 g LEV-2, built by Tomy Company (a Japanese toy company), Sony, and Doshisha University uses “expandable wheels and a stabilizer using the transforming technologies for toys.

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Starlink Direct-to-Cell. SpaceX’s first launch of the year—back on January 2nd—featured six Starlink sats equipped with the company’s upcoming direct-to-cell (DTC) capabilities. These are the first of an initial 840 DTC Starlink sats launching over the next six months. Just six days after launch, SpaceX announced successful text messaging between iPhones (pdf test report) and the sats. Wider field testing by T-Mobile, the US cellular partner (there are also carriers signed up from CA, AU, NZ, CH, JP, CL, and PE), is commencing shortly. Initial service will only support text messages due to the bandwidth constraints of the service—around 7 Mbps per beam, with an undisclosed, but “large”, beam size. Service is slated for starting in the second half of the year, and future versions will support voice and data, although this may be dependent on the FCC granting Starlink’s request to add DTC capabilities to its licensed Gen 2 constellation of up to 7,500 satellites. There are multiple competitors to this service, albeit with much less impressive vertical integration. Lynk Global first demoed its service in 2022 and is currently SPAC’ing to raise capital for a large constellation. AST SpaceMobile demoed the massive (and also unacceptably bright) BlueWalker 3 last year. Finally, Iridium, whose DTC service has been on ice since Qualcomm backed out of their partnership, recently announced its newly rebranded ‘Project Stardust’ which will continue the company’s attempts to take part in this nascent market. Related: John Deere just announced a partnership with Starlink for their high-tech farming equipment, much of which has autonomous operation features built-in that require high-speed internet connections in rural areas.

Starlink’s first DTC text messages.

Einstein Probe launches. The Chinese Academy of Sciences, ESA, and the Max Planck Institute for Extraterrestrial Physics in Germany collaborated on the Einstein Probe, an X-ray telescope that launched last week on a Long March 2C. The telescope will observe X-ray bursts from energetic sources such as neutron star mergers and black holes and will monitor how these change over time. It will orbit Earth at 600 km and carry two instruments. The Wide-field X-ray Telescope (WXT) uses hundreds of thousands of square fibers “inspired by the eyes of lobsters” which can collectively image almost a tenth of the celestial sphere at a time. Once sources are identified, they can be imaged in more detail with the narrower but more sensitive, two-module Follow-up X-ray Telescope (FXT).

A test article version of one of 12 “lobster eye” modules that make up the WXT. Each tile contains hundreds of thousands of square fibers to create pores that are ~20 µm across and reflect X-rays onto the focal plane of the sensor.

Peregrine update. “Astrobotic’s current hypothesis about the Peregrine spacecraft’s propulsion anomaly is that a valve between the helium pressurant and the oxidizer failed to reseal after actuation during initialization. This led to a rush of high-pressure helium that spiked the pressure in the oxidizer tank beyond its operating limit and subsequently ruptured the tank.” They have successfully powered on and communicated with all active payloads which will be helpful for payload teams to validate their systems’ initial function in space. Some are also gathering data on cislunar space. While the company could keep the lander in an elliptical cislunar orbit, Astrobotic made the decision to avoid debris and an uncontrollable spacecraft—so the craft will re-enter Earth’s atmosphere and burn up tomorrow. 😔It remains to be seen if and how this affects the rest of NASA’s CLPS program, and especially the VIPER rover, Astrobotic’s next CLPS mission scheduled for November. Regardless of the outcome, Astrobotic has set the gold standard for a company communicating about a mission that has gone sideways—posting eighteen updates is just phenomenal, and we couldn’t support the company more as it embarks on future missions.

News in brief. NASA’s OSIRIS-REx team finally successfully removed two fasteners that have been preventing the disassembly of the TAGSAM module that holds the rest of the Bennu asteroid sample ● Elon says that Starship IFT-2 failed to reach orbit due to venting liquid oxygen, which it wouldn’t have needed to do if it’d had a payloadSpanish satellite operator startup Sateliot raised $6.6M for their constellation of 5G-enabled nanosatellites for IoT connectivity Ingenuity flew for its 71st time but landed earlier than expected due to navigation issues with featureless (sand with minimal rocks) terrain D-Orbit raised a $110M Series C to expand their space logistics servicesThe new Artemis II launch date is September 2025, about a year later than planned, with the (widely predicted) slip blamed on required Orion heat shield and life support system evaluations—Artemis III is now nominally September 2026, which seems unlikely given dependence on HLS Lunar Starship (as well as Axiom Space’s AxEMU spacesuits)France’s space budget for CNES has increased by 16.6% for 2024 Oxford Space Systems raised £3M to invest into their deployable antenna development and manufacturingJapan launched an optical reconnaissance satellite PierSight, a maritime surveillance-focused space tech startup, raised a $6M seed to build their prototype and demo it on the ISRO’s POEM platform ESA is considering launching Sentinel-1C, one of their Copernicus EO satellites, on a Falcon 9 instead of Vega C ABL Space Systems is looking to acquire $100M in new funding, raising $40M so far Blue Origin’s first New Glenn stages are now at Kennedy in Florida after being transported from the company’s nearby factory OrienSpace’s Gravity-1 solid-fueled rocket, with three stages and four boosters, delivered three satellites to LEO—the vehicle can carry 6,500 kg to LEO, a record for Chinese commercial rockets, and is the first to use strap-on boosters.

OrienSpace’s Gravity-1 rocket launched from a sea-based platform off the coast of Shandong, China on the 11th. We recommend checking out the pretty epic video.

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Thor’s Helmet (NGC 2359). 
Credit: Ritesh Biswas

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