NASA and National Nuclear Security Administration engineers lower the wall of a vacuum chamber around the Kilopower reactor system. The chamber will help test how the system performs in space-like conditions. (Credit: NASA)Sign up for our email newsletter for the latest science news1 free article leftWant More? Get unlimited access for as low as $1.99/monthAlready a subscriber? or Want more?Keep reading for as low as $1.99!Already a subscriber? or Related ContentStay CuriousJoinOur ListSign up for our weekly science updates.SubscribeTo The MagazineSave up to the cover price when you...…NASA and National Nuclear Security Administration engineers lower the wall of a vacuum chamber around the Kilopower reactor system. The chamber will help test how the system performs in space-like conditions. (Credit: NASA)Sign up for our email newsletter for the latest science news1 free article leftWant More? Get unlimited access for as low as $1.99/monthAlready a subscriber? or Want more?Keep reading for as low as $1.99!Already a subscriber? or Related ContentStay CuriousJoinOur ListSign up for our weekly science updates.SubscribeTo The MagazineSave up to the cover price when you...WW…