Are you the kind of person who could lie in bed for 70 days for science? If so, you could make $18,000 in a NASA study of microgravity. The catch (because lying on your back for 70 days wasn’t already enough of a catch): The bed will be tilted 6 degrees towards your head, forcing bodily fluids upwards and replicating what happens to your cardiovascular system in microgravity environments.