January launch to Pluto poses more risk than usual
FLORIDA TODAY jan 10, 2006
CAPE CANAVERAL - The White House has given NASA the go-ahead on plans to launch a plutonium-powered spacecraft on the world's first mission to Pluto, an official said Monday.
The green light came when John Marburger, who is director of the White House Office of Science and Technology Policy, signed final launch approval papers earlier this month.
"It is the culmination of an extensive review and interagency oversight of preparations for the mission," OSTP spokesman Donald Tighe said.
NASA aims to launch its New Horizons spacecraft Jan. 17 from Cape Canaveral Air Force Station on a nine-year journey to Pluto. White House launch approval was required for the mission because the power source the spacecraft will use plutonium to generate electricity.
The spacecraft will carry a Radioisotope Thermoelectric Generator, or RTG. The device will convert heat from the natural decay of 24 pounds of radioactive plutonium-238 into electricity to power spacecraft systems on a four-billion-mile journey.
Conventional solar power systems cannot provide ample electricity on a mission destined so far from the sun.
Similar or identical nuclear generators have been used on 25 previous missions, including Apollo moon landings and robotic flights to Mars, Jupiter, Saturn, Uranus and Neptune.
The New Horizons mission to Pluto will complete the nation's initial reconnoitering of all nine known planets in the solar system.
The White House launch approval capped a lengthy series of environmental and safety assessments that are required by law. NASA and the Department of Energy, which manufactured the nuclear generator, conducted assessments.
Also weighing in was an Interagency Nuclear Safety Review Panel that included safety experts from other agencies such as the Department of Defense, the Environmental Protection Agency and the Nuclear Regulatory Commission.
Safety experts from academia and industry supported that panel.
Government studies show that the mission poses more danger to Central Florida than a typical rocket launch.
There is a 1 in 350 chance that a launch area accident could result in a release of radioactive material.
The regional risk will drop to nil 40 seconds after the spacecraft lifts off aboard an Atlas 5 rocket.
By that time, the rocket will have arced out over the Atlantic Ocean, and the studies found no chance of a plutonium release if the rocket crashes into water.
