How fast could we travel in space with existing technology?
On October 28, 1998 the Deep Space 1 mission flew the first-ever ion rocket engine as a primary propulsion system for an interplanetary spacecraft. Meanwhile, a twin engine has been running continuously on Earth for 24,750 hours (1.8 years) under the supervision of a team of engineers led by Anita Sengupta at the Jet Propulsion Laboratory. The thrust of this 1300-watt, 1200-Volt engine (about 0.02 pounds) is microscopic by comparison with the million-pound thrust engines used to launch the Space Shuttle. But, this little motor can operate continuously, and could propel a 25-pound payload to a speed of 18,400 miles per hour after three years, or a whopping 65,000 miles per hour after 10 years. Newer designs using nuclear electricity and not solar cells, would easily quadruple this performance and get us to 100,000 miles/hour in only four years or so. This technology is already space-qualified with DS-1. And, oh by the way, the total weight of the propellant for DS-1 was only about 100 kilograms!
