Swordtail fish. A scientist points to Swordtail fish (Xiphophorus helleri) prior to launch of the NASA Neurolab mission. Neurolab was launched aboard the space shuttle mission STS-90 on 17th April 1998. During the 16 day mission, scientists performed 26 experiments designed to examine the effects of spaceflight and microgravity on the brain and nervous system. The experiments were done in the Spacelab, a laboratory aboad the space shuttle designed for scientific research. Other animals studied during the Neurolab mission included; rats, snails, crickets, toadfish and mice. Image taken 11 March 1998.