Heliosynchronous

Today I learnt that a satellite can be positioned over a planet such that it always faces its sun, almost but not quite polar. This is used for always-illuminated satellites such as are observing, in fact, the Sun -

- or, we just didn't add batteries for cargo. It's being planned for data-centres.

This is possible where the planet is oblate. Earth is oblate; so is Mars. The wider middle perturbs the orbit. (Slowly-rotating Venus is too global, so has no heliosynchronous altitude. So this is not joining my many many Venuspoasts.)

Earth's altitudes for that, for easy access and low Van Allen, trend 600–800 km and 98° (so a bit retrograde, like Uranus' actual orbit). Cockamamie data-centre ideas aside, such orbit is a thing. That's actually a problem with the ideas: satellites are already using these bands. Also with always-on solar, cometh solar panels (inbound) and heat-radiators (outbound). It's getting crowded up there. The energy demands will force wide panels and wide radiators, increasing the likelihood of Kessler-messler.

I think this might be best for between the two Van Allen belts. Or just ship some batteries bro.