Moggridge returned to the US in 1979 to open another office, called ID Two, first located in Palo Alto, California. An early client was GRiD Systems, for whom he designed what is widely regarded as the first laptop computer, the GRiD Compass. This was the first portable computer with a display that closed over the keyboard, a patented innovation that GRiD licensed for many years. It retailed at $8,150 (£5,097) and flew on board every Space Shuttle mission from 1983 to 1997.