The public sees the launch. The spectacle of fire and thunder. They rarely see the mission. STS-90, Neurolab, was a mission. For sixteen days in April 1998, the seven astronauts aboard Columbia were not explorers of space, but technicians of the inner self. Their laboratory was the European-built Spacelab module, a cluttered, humming cylinder packed with over two dozen experiments. Their subjects were themselves, along with rats, mice, crickets, and snails.
The focus was the nervous system. How does the brain interpret signals without gravity's constant pull? How does balance recalibrate? The astronauts conducted experiments on each other, measuring eye movements, testing reflexes, documenting sleep. It was meticulous, repetitive, and profoundly intimate science. The grand stage of space was reduced to the scale of a synapse.
This was the last of the dedicated Spacelab flights. The module represented an era where the shuttle was a true space truck, delivering a working laboratory into orbit. After Neurolab, the focus would shift to the assembly of the International Space Station, a permanent outpost. The science continued, of course. But something was lost. The self-contained, hyper-focused, start-to-finish campaign of discovery that was a Spacelab mission had a particular purity. It was science for science's sake, conducted in a temporary workshop that, once its work was done, was packed away and brought home, leaving only data and a changed understanding of our own biology in the void.