I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life. It would add a little weight at launch but could extend orbital life by many years. It would need fractions of a gram of thrust, run off the current solar electricity budget, and could easily make them endure for 10+ years. When the satellite had failed or aged out, it could be used for improved de-orbiting at end of life. I also suspect that a mobile stream at a lower frequency could be added that would provide intermittent stream down loads of news directly to the Russian people via recently tested cell phone comms ability

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vardump 3 days ago | parent | next [-]

> I have often wondered if a a very small Ion thruster, used intermittently, gravitationally stabilised, could be used to offset the variable atmospheric drag caused by inflation/deflation of the tenuous upper atmosphere to extend satellite life.

Isn't that exactly what Starlink is doing?

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brcmthrowaway 3 days ago | parent [-]

starlink sats have thrusters?

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MarkusQ 3 days ago | parent | next [-]

Yes.

https://www.reddit.com/r/SpaceXLounge/comments/11cnh0w/starl...

	▲	aurizon 2 days ago \| parent [-]
		Yes, I see, dated 2018 using rarified air as ion source. Totally solves the reaction mass needs and the electricity is solar

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literalAardvark 2 days ago | parent | prev [-]

All sats have thrusters.

Station-keeping must be active for very many reasons, and sats with broken thrusters fall down fairly quickly.

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mlindner 2 days ago | parent [-]

Not all sats in general have thrusters. There's many types of satellites, especially smaller ones, that use magnetorquers, and somtimes reaction wheels as well, to maintain orientation but have no propulsion.

There's also satellites with no active attitude control at all and use passive means to maintain a somewhat static orientation. That can permanent magnets causing a tumbling linked to Earth's magnetic field, passive aerodynamic stabilization, or using Earth's gravity gradient to align the satellite.

	▲	literalAardvark 20 hours ago \| parent [-]
		My bad. I meant all of these useful, long lived sats. I knew "all" would bite me in the ass, but it's a reasonable generalisation. Sats without active control last what... Weeks in LEO?

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numpad0 2 days ago | parent | prev [-]

ESA GOCE and JAXA SLATS did that. SLATS went as low as 167km(104mi). Neither was air breathing.