Two weeks to travel to Mars

Excerpt from an announcement dated
Thursday, 04 Jan 2001 10:47:30 -0500

Beer-Sheva, December 28, 2000 -- Scientists at Ben-Gurion University of the Negev have shown that an unusual nuclear fuel could speed space vehicles from Earth to Mars in as little as two weeks. Standard chemical propulsion used in existing spacecraft currently takes from between eight to ten months to make the same trip. Calculations supporting this conclusion were reported in this month's issue of Nuclear Instruments and Methods in Physics Research A (455: 442-451, 2000) by Prof. Yigal Ronen, of BGU's Department of Nuclear Engineering and graduate student Eugene Shwagerous.

In the article, the researchers demonstrate that the fairly rare nuclear material americium-242m (Am-242m) can maintain sustained nuclear fission as an extremely thin metallic film, less than a thousandth of a millimeter thick. In this form, the extremely high-energy, high-temperature fission products can escape the fuel elements and be used for propulsion in space. Obtaining fission-fragments is not possible with the better-known uranium-235 and plutonium-239 nuclear fuels: they require large fuel rods, which absorb fission products.

Ronen became interested in nuclear reactors for space vehicles some 15 years ago at a conference dedicated to this subject.

Speaker-after-speaker stressed that whatever the approach, the mass (weight) of the reactor had to be as light as possible for efficient space travel. At a more recent meeting, Prof. Carlo Rubbia of CERN (Nobel Laureate in Physics, 1984) brought up the novel concept of utilizing the highly energetic fragments produced by nuclear fission to heat a gas; the extremely high temperatures produced would enable faster interplanetary travel.

From: Andrew Yee

ayee@nova.astro.utoronto.ca
Jet Propulsion Laboratory,
Pasadena CA