The first computer to use the "clamshell" design which is used in almost all modern laptop designs, was the GRiD Systems Corporation's "GriD Compass, released in April 1982". This computer was one fifth the weight of any other computer used at that time, however, it required mains power, because it had no battery. Despite this, they were very popular with the Military of the United States amd NASA, who used the laptop in its Space Shuttle program, in the 1980s.