We could follow stackoverflow and start hashexchange, by creating space.hashexchange.com.
("Hashexchange" sounds either like a market for zero day exploits, or platform to sell eachother drugs, so maybe the name needs work...)
To be serious though:
- If you're talking about software projects by NASA, I feel it's obvious that it's a suitable topic here... It's software after all, right?
- If you just want to talk about quasars and the Hubble constant, I don't know if it's allowed, but I also don't see why you'd want to. You'd get much more intelligent responses by joining an astro forum where people actually know anything about that stuff.