The scenes of Howard in space were accomplished by filming in a Space Station replica in Canoga Park, California. Only 20 feet of station were available, so over the course of this episode and the next, creative camera angles and framing made it look like there were many different sections. Weightlessness was created by supporting the actors on a very thin platform and have them simulate the effects of microgravity.
While Howard (Simon Helberg) is video chatting with Bernadette (Melissa Rauch) from the International Space Station, the clipboard next to the computer can briefly and clearly be seen, twice, with a letter clipped on top. The address section of the letter is to Varese Saraband Records, best known in Hollywood as a prime record label specializing in film scores, soundtracks, and original cast recordings.
When Amy mentions the praying mantis "ravishing their mates" she is referring to the observed (though debated) behavior of sexual cannibalism among mantis when mating.