NASA’s nuclear proving ground

by Chris Bergin

NASA’s continued utilisation of nuclear elements for their mission of exploration began another milestone event today, with the safe launch of New Horizons, part of an on-going process to gain support for a form of energy which may become an integral part of the agency’s future.

The spacecraft was safely launched on an Atlas V from Cape Canaveral this evening, for a journey that will take at least nine years en route to Pluto.
The success of its performance will be largely based on how its RTG (radioisotope thermoelectric generator) ‘space batteries’ manage to keep the probe alive.

Developed by the Department of Energy’s Idaho, Oak Ridge and Los Alamos national laboratories, the well-used technology will play a key role in the first NASA mission to the outer reaches our solar system.

“This technology is a tremendous example of how DOE’s (Department of Energy) national laboratories are helping to significantly expand scientific research and discovery,” said Energy Secretary Samuel Bodman. “Because of our outstanding scientists and engineers at our national labs, the sky truly is the limit.”

The RTG provides an uninterrupted and reliable source of heat and electricity in remote and harsh environments such as deep space – and will provide power and heat to the New Horizons spacecraft and on-board scientific equipment through the radioactive decay of nuclear material. The heat generated by this nuclear material is converted into electricity by solid-state thermoelectrics.

RTGs, which have been used by NASA for nearly forty years, enable spacecraft to operate at significant distances from the Sun or in other areas where remote solar power systems would not be feasible.

Oak Ridge National Laboratory developed and fabricated the material used to encapsulate the plutonium; Los Alamos National Laboratory purified, pelletized into a ceramic form and encapsulated the plutonium; and Idaho National Laboratory assembled and tested the RTG and safely delivered the flight-ready RTG to the Kennedy Space Center (KSC).

However, NASA’s nuclear ambitions aren’t limited to space batteries for long-haul missions, as the technology is set to play a major role in manned missions to Mars.

The manned vehicle to the Red Planet is expected to utilise NTR (nuclear thermal propulsion), while counterpoints are being evaluated on bimodal nuclear thermal propulsion (BNTR) and nuclear electric propulsion (NEP) – the latter being the focus of a series of Mars transit option reports during 2002 and 2003.

Every success with the use of nuclear technology on space missions will help NASA take another step towards public reassurance on safety, setting the right environment to incorporate nuclear elements into their ambitious plans to help man explore and set up bases throughout the solar system.

Fresh off the back of the hugely successful Stardust mission – which returned to Earth on Sunday – NASA aren’t holding back on another great start to an ambitious mission, one that will be another first in the increasingly competitive international space industry.

‘The United States of America has just made history by launching the first spacecraft to explore Pluto and the Kuiper Belt beyond,’ said Dr. Alan Stern, New Horizons principal investigator, after the launch during a NASA press conference.

‘No other nation has this capability. This is the kind of exploration that forefathers, like Lewis and Clark 200 years ago this year, made a trademark of our nation.’

New Horizons has a date with Jupiter for its gravity assist that will help gain a boost in speed to save journey time en-route to Pluto and its surrounding neighbourhood. Johns Hopkins University Applied Physics Laboratory (APL) will perform tests during the transit to the giant of the solar system.

‘This is the gateway to a long, exciting journey,’ says Glen Fountain, New Horizons project manager from APL. ‘The team has worked hard for the past four years to get the spacecraft ready for the voyage to Pluto and beyond, to places we’ve never seen up close. This is a once-in-a-lifetime opportunity, in the tradition of the Mariner, Pioneer, and Voyager missions to set out for first looks in our solar system.’

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