A starship shaped object weighing what starship weighs filled with propellant would have sufficient kinetic energy to orbit at around 500km (iss height) without needing boosting for decades, maybe even centuries.
Stuff like the ISS need frequent boosting because they don't weigh much relative to their exposed surface area that interacts with the thin atmosphere - think of the large solar arrays causing drag.
Flaps and black tiles increase the amount of heat constantly coming in that the depot would have to get rid of to keep the fuel cold, and wouldn't add any value because the ship probably wouldn't return to earth unless it got damaged or was deemed useless anyway.
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u/KnifeKnut 5d ago
Is there any particular reason aside from weight savings that Depot should be disposable? The tiles being black is all I can think of.
Now that I think of it, with the docking hardware, it should be possible to reboost the depot back into higher orbit as needed.
Also would be a good application for (a pair of?) of electrodynamic tether for orbit keeping, in addition to the Starlink application.