Mission to the outer limits
By Ron Cowen
NASA’s New Horizons spacecraft has taken up temporary residence at the Kennedy Space Center in Cape Canaveral, Fla., where engineers are doing final testing before the craft begins its 9-year voyage to the outer solar system.
If all goes according to plan, the craft will be launched in January 2006, swing by Jupiter for a velocity boost from the planet’s gravity in early 2007, and in 2015 become the first mission to fly past Pluto and its moon Charon. These two small, icy bodies, and the collection of frozen miniworlds that lie beyond them in a disk-shaped reservoir known as the Kuiper belt, have never before been explored close-up.
Weighing nearly 1,000 pounds and carrying seven detectors, the probe will map the surface composition, temperature, and geology of the two distant bodies and will search for icy rings and additional, smaller moons around Pluto. By counting craters on Pluto, Charon, and perhaps several other bodies, scientists hope to determine the number of objects in the Kuiper belt.
Direct measurements of the rate at which Pluto’s atmosphere of hydrogen and helium escapes into space may reveal how Earth’s atmosphere evolved.