Consider how valuable ancient artifacts are to us. look at this fancy stick! In as little as a few hundred years debris from skylab would be way more valuable. I'm baffled why the agency didn't want to preserve it as a relic. Don't they have any sense of posterity? Don't they want to leave a lasting legacy for future generations to marvel upon? I'd think that skylab would be invaluable as an exhibit for the first orbital museum, or as a field trip for students of the early space age. Instead they just let it crash and burn like useless scrap (which it could have been, but comeon!). I know it would have cost a lot to haul it into a MEO or however far it needs to be to be stable. But wouldn't any price be worth it or am I just being oversensitive?
Short answer is that there were multiple contributors: bad predictions of how long the orbit would last, schedule delays on the Space Shuttle, and cost/benefit analysis of a last minute rescue mission for an aged space station.
Things to keep in mind:
- Skylab reentered and burned up in July 1979
- the last Apollo capsule to fly was the Apollo-Soyuz Test Project in 1975 (and the Skylab 4 mission ended in February 1974)
- the first Space Shuttle mission was STS-1 in 1981
- Skylab was never designed for automated docking or servicing
The final Skylab mission boosted the station into a higher orbit, where the original estimates of orbit duration thought that Skylab would last until the 1980s Wikipedia. At the time, the Space Shuttle was expected to launch in 1979 before Skylab decayed, and there were plans for boosting its orbit that got so far as to award a contract for developing the rocket module and at least plan training for astronauts to use it.
Unfortunately, the models used for the original prediction failed to take into account solar activity (which heats the atmosphere, causing it to expand and increases drag at higher altitudes) and in late 1977 decay was predicted for 1979. Up until December 1978 there were still plans (and nearly completed hardware) for a shuttle mission to save Skylab, but the shuttle simply wasn't going to be ready in time.
By the time it was clear that the shuttle wouldn't be ready before Skylab decayed there weren't many options. The rocket designed to boost it was almost ready, but Skylab wasn't designed for automated docking and a somewhat rushed mission to launch it on existing rockets was deemed too expensive when the money was needed for the Space Shuttle budget. Also, neither NASA nor congress (who controlled the budget) were particularly interested in the station (despite that "microbiologists were excited at the prospect of studying microbes that had been reproducing in the trash for hundreds of generations in a spacecraft"). Skylab's Untimely Fate
I've seen no indication that there was ever a concern for preserving the station as an artifact. There's a big difference between donating artifacts to museums (who will then foot the bill for preserving them), publishing guidelines telling everyone to stay away from your historic sites, and spending at least several hundred million dollars of taxpayer money developing and launching a rescue mission for a station that you don't have the ability to fly astronauts to (especially when you've built a backup but can't afford to launch it because you need the money for developing your next manned spacecraft).