Applied Ion Systems

Open-source R&D, engineering, and testing of plasma and ion thruster systems for nanosatellites at a hobbyist-level budget.

[Applied Ion Systems @Applied_Ion]

Applied Ion Systems Patreon is now officially LIVE! Are you a space enthusiast who would like to contribute directly to development of advanced EP from the only official open source electric propulsion program out there? Let's pioneer the field together! https://t.co/Nh9mqkSA4M

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Actually yes! The @theflametrench is a great one with lots of active cubesat developers. I have been a part of the discord myself for quite a while.

[Applied Ion Systems @Applied_Ion]

@alder_riley @BreakingTaps I think this was a really cool effort! I was actually in communication with @BreakingTaps answering some questions and chatting about propulsion with him during some of his development. FEEP has its challenges, and I'm glad to see some verified measured stable beam by the end!

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @pakhm20 However, you could do an end hall style thruster with a tungsten filament relatively easily (assuming you have gas flow). It's never really used for satellites, (mainly as an ion source in manufacturing), but the fundamentals are the same as other hall thruster styles.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @pakhm20 Gas delivery is a big one. Gridded ion is probably the harder one since you not only need a neutralizer but an extra ionizer inside the discharge chamber. Also they are much more finicky at the small scale and low power, and work more stably with larger/bigger systems.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Very excited to see this! Just finished watching it myself, really fantastic job! I think it was a really awesome overview of the technology and FEEP thruster field, and most importantly, shows just how grueling development can be. But, persistence pays off in the end! Congrats!

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @pakhm20 Actually in terms of DIY, hall and gridded ion would actually be more complicated. I would suggest plasma thrusters instead to get started. PPTs (fueled by teflon) and VATs (solid metal like titanium or bismuth) are extremely easy to build, and can even fire in much worse vacuum

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Congratulations and awesome work! It is absolute hell for sure, just endless iteration after iteration, but if you stick with it you will eventually succeed. Next step is to measure beam current (which will definitively show it is accelerating ions)!

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Nice job! That tiny little dot of purplish glow is exactly what you are aiming for! No breakdowns or arcing, just a stable glow of emission. As your beam current increases, it will get brighter. With a faraday cup you should be able to confirm beam. Just gotta keep going!

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Yeah nylon hardware doesn't like vacuum and high voltage together lol. Nylon outgasses a ton and is very hydroscopic, so it makes for a really poor insulator for high voltage in vacuum. I have always used PEEK bolts from McMaster-Carr, which have never given me any issues.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @AndrewA2061 Another major issue with liquid metals and glass is that when the metal (gallium, indium, etc) solidifies, whether on the surface or wetted in the pores itself, the glass could potentially crack and shatter.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @lougrims Stainless steel should probably work if you can wet it and get sharp enough points, I think I've seen people use it before. I think tungsten is definitely preferred both for longevity as well as its ability to be easily sharpened to extreme levels with electrochemical etching.

[Applied Ion Systems @Applied_Ion]

@lougrims @BreakingTaps Tungsten micro needles should definitely work, and they are quite cheap and readily available. I bought a few packs of them myself for experiments with galinstan fuel but never got around to it.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Also, electrospray systems need to be slowly conditioned at first. This means bringing the voltage up very slowly and monitoring beam current. Over time, as discharges stabilize and you condition emission edges at high field gradients, you can increase voltage and extracted beam.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps Awesome to see you attempting this too! Electrospray was by far the hardest thruster system for me to get working. A few major tips I found: completely degas the tips/fuel in high vacuum for a number of hours prior to firing, chamfer edges on grid holes, electropolish the grid.

[Applied Ion Systems @Applied_Ion]

@BreakingTaps @AndrewA2061 Yeah, typically for liquid metal electrospray you need to use a porous metal emitter like sintered tungsten needles, which you have to also vacuum heat to burn off oxides to allow for wetting. It could wet the porous glass, but that would definitely have its challenges.

[Applied Ion Systems @Applied_Ion]

@lougrims Wow fantastic news, that is super exciting to hear! Congratulations, and I am excited to hear about what new developments you work on there in the future!

[Applied Ion Systems @Applied_Ion]

@jurajko15 @lougrims Actually, my very first tests with Adamantane was utilizing a simple DC discharge with sublimated fuel at a few watts total power. I published these results back in 2021 (AIS-TR-22/23/24/25) as well as the glow discharge cathode and Hall thruster tests: https://t.co/yA6JUvLBNM

[Applied Ion Systems @Applied_Ion]

@jurajko15 @lougrims I still believe Adamantane is a viable propellant, and has many benefits over its more popular cousin iodine (hence why I am still supporting my SWAG thrusters/tanks). That being said, there are a lot of quirks to it where you need to prioritize fuel simplicity vs performance.