¶Hall thrusters go argon with Starlink V2 mini. Sunday, SpaceX shared photos of a stack of ~790 kg Starlink V2 “minis”. Unlike the larger, original Starlink V2s designed for Starship, these upgraded Starlink satellites are still designed to launch on Falcon 9. The company then proceeded to launch its first batch of 21 to LEO on Monday evening (check out a cool new camera angle captured from their upgraded stack deployment tension rods). Standout features on the new satellites include “more powerful phased array antennas and the use of E-band for backhaul—which will allow Starlink to provide ~4x more capacity per satellite than earlier iterations” and in-house argon Hall thrusters with 2.4x the thrust and 1.5x the Isp of their first generation thrusters (they’ve now hit 1 kW/kg, likely excluding its PPU). These Hall thrusters will be the first to fly in space using argon as the propellant—long deemed too low-efficiency to be appealing as a propellant, argon’s exceptionally low cost makes it attractive for large constellation use (the previous-gen thruster’s krypton costs ~100x, while industry standard xenon is ~1,000x, and both are produced in war-torn Ukraine). SpaceX (and the recently-acquired Swarm team who worked on the thruster) have managed to hit 2,500s Isp and 50% efficiency with these new thrusters using a center cathode design along with other unrevealed optimizations. Here is an exceptionally detailed thread about them. (Semi-related: If you’ve ever wondered what would happen if you stuck your hand in the plume of a Hall thruster, well, you’re reading the right newsletter. Just go here.) SpaceX also released details of astronomy-impact (ultra-black space-rated paint, dielectric mirror film, panels capable of being angled) and space debris mitigations that are included with V2 mini.