Issue No. 247

The Orbital Index

Issue No. 247 | Dec 6, 2023

🚀 🌍 🛰

Pangea Aerospace tests ARCOS. Last month, Catalonian startup Pangea Aerospace successfully tested their novel bi-metal combustion chamber (video). Although the chambers have a de Laval nozzle, when arranged into a 24-chamber ring they form a 300 kN toroidal aerospike engine, which the startup has dubbed ARCOS—Pangea has a nice aerospike explainer video. Previously, Pangea built and tested both a tiny 1 N bi-propellant cubesat propulsion solution called U-nyx, with a first flight planned for next year, and P1, a 20 kN demonstration aerospike engine. Check out this fabulous deep dive into the additive manufacturing processes developed to build it and ARCOS. The ARCOS chamber went through tests at a DLR facility featuring two different single-piece injector heads, a move focused on reusability and quick turnaround refurbishment and repair. The chambers are 3D printed out of the NASA-developed GRCop-42 copper alloy and regeneratively cooled with both fuel and oxidizer, making their work some of the most cutting-edge engine tech being developed in Europe. To top things off, they run on liquid oxygen and biomethane (e.g., CH4 captured from bioreactors/digesters, which tends to have lower purity than other rocket-grade varieties), which the company touts as a greener fuel option. (We’re not saying this isn’t a good thing, but watch Tim Dodd’s rocket pollution video from a while back if you’re not familiar—the scale of launch fuel-related climate pollution today is minuscule.) All this together puts ARCOS in a class of its own as the only additively manufactured, many-chambered, methalox-burning modern aerospike we know of. Pangea plans to offer ARCOS as a propulsion solution for both first- and second-stage boosters, and refreshingly, so far it doesn’t appear to have any plans to take on rocket development in addition to propulsion. ESA has been a significant supporter and funder of the work to develop ARCOS and recently re-confirmed their support by selecting the company to be part of the Cassini Business Accelerator.

Pangea’s planned 24-chamber ARCOS aerospike engine.

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Weird Papers. 
  • Chinese researchers proposed an automated AI-powered robotic chemist for synthesizing catalysts on Mars (paper), which would be used in situ to improve the electrolysis of water into hydrogen and oxygen.
  • Want to explore a contact binary asteroid? How about we just make our own by colliding a spacecraft with near-Earth binary asteroid (350751) 2002 AW (paper)? (Relatedly, ​​Dinkinesh’s contact binary Moon discovered by the Lucy mission now has a name, “Selam,” which means ‘peace’ in Amharic. This makes sense, as Dinkinesh is the Ethiopian name for the Lucy fossil and means "you are wonderful," also in Amharic.)
  • Over the next billion years, there’s a ~1% chance that the solar system will encounter a passing star within 100 AU of the Sun. If that happens, there’s a 95% chance that all our planets would survive such an encounter (paper), although the orbital dynamics of the solar system could still be thrown dramatically out of whack, with the Earth, for example, ending up in the Oort cloud… which wouldn’t be great. In that 5% chance of a planet being lost, the odds are it’d be Mercury ending up in the Sun (2.5% chance) or Mars in the Sun (1.2%). Other exciting options include Venus hitting another planet (1.2%), Uranus (1%) or Neptune (0.8%) getting ejected, or Earth itself ramming into another planet (0.5%). ☄️🎲
  • Did Pluto have a supercryovolcano explosion, releasing ~1,000 km3 of icy cryomagma, sometime in the last few million years (paper)?
  • Meanwhile, Mercury may have salt glaciers composed of flowing halite with temperatures as high as 500° C (paper).

The formation geology of Mercury’s proposed halite glaciers.

News in brief. SpaceX launched South Korea’s first military spy satellite along with 25 additional spacecraft Ursa Major raised a $138M Series D to develop their solid rocket motor program and scale their existing space and hypersonic propulsion ones Something exploded at China’s Jiuqan spaceport according to satellite imagery iSpace revealed their final micro rover design for their second mission to the Moon—their first failed to make a soft landing on the lunar surface in April Amazon signed a three-launch deal with SpaceX, a commsat competitor, to launch their Project Kuiper satellites (they already have 77 launches planned with ULA, Arianespace, & Blue Origin) NASA administrator Bill Nelson visited India, stating that NASA will train an Indian astronaut for an ISS voyage and also help them build their own space station Turkish company DeltaV launched its Sounding Rocket System (SORS), becoming the first hybrid rocket to exceed 100 km using paraffin & LOX Angola signed the Artemis Accords, the 33rd country to do so Mary Cleave, two-time space shuttle astronaut, passed away at age 76 SpaceX quietly acquired Pioneer Aerospace, the supplier for Dragon’s drogue parachutes, via bankruptcy court for just $2.2M (SpaceX rarely acquires companies—this is their first public acquisition since Swarm in 2021) Kenya-based climate startup Amini raised a $4M seed with aims to bridge the EO data gap in Africa and launch their own six satellite constellation Russian ISS resupply mission Progress MS-25 launched and then had to be manually docked due to issues with its automated rendezvous system Avio lost (as in… misplaced?) two of the four propellant tanks for the fourth stage of Vega’s final flight and can’t produce new ones Firefly Aerospace completed their first hot fire test of the Miranda engine that will power the first stage of both the Northrop Grumman-co-developed Antares 330 and Firefly’s forthcoming Medium Launch Vehicle - the company also has a fourth launch of its Alpha rocket coming up in December from Vandenberg AFB.

Firefly Aerospace’s kerolox Miranda engine spewing green plume during its hot fire test. The green exhaust is TEA-TEB and not a “copper-rich” burn.

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China’s Tiangong space station, as photographed recently by a departing Shenzhou spacecraft.

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