> 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?