They'll need velcro (to keep feet and hands secured during the act; otherwise you not going to give/recieve a good hard fuck. Space tourism, a couple goes to space, what do you think they are going to do.......
They'll need to invent a condom that will contain the sperm after ejaculation, afterall, you don't want cum floating around in the air.... for blowjobs its easy, she'll have to swallow....