Five levels ago.

I'm Level 174 and am half-way through researching wormhole relays. The reactors really only help at leveling time, but the relays make a huge difference all day, all the time.
After the relays are up, I'm researching to get better planet structures. I already did the +10's, so next up is weapons to get Null Mine Fields and shields to get Obviation barriers. Then scanners for another round of planets.
