Lockheed Martin to Build Nuclear Powered Spacecraft

LouisvilleDebugger writes "The BBC reports that Lockheed Martin have received a $6M contract to develop the nuclear powered JIMO, or Jupiter Icy Moons Orbiter. (According to the NASA project site, the first probes would not launch before 2011 due to development lead time.) On arrival at Jupiter, the extra power allows the probe to orbit each of three of the Galilean moons (Ganymede, Callisto, and most challenging from a radiation exposure standpoint, Europa) in turn, presumably helping to establish the possibility of liquid water and hence, life within the Jovian system. JIMO is a sub-project of Project Prometheus, initiated by NASA this year for the purpose of demonstrating that nuclear powered and propelled spacecraft may be safely designed and tested."

Comments

For 6 Million?

[saden1]

Should that have said 6 Million? You can't build anything these days for 6 million. Hell, payroll alone will be 6 million.

Why go to Jupiters moons?

[Aardpig]

For those who wonder why Jupiters moons are interesting, and worth visiting, I'll try to give a brief summary here. JIMO will be visiting Jupiters four Galilean moons, named after their initial discovery by Galileo Galilei (through his now-famous telescope). In order of distance from Jupiter, they are Io, Europa, Ganymede and Callisto.

Io is the only moon in the solar system to show volcanic activity; plumes of gas ejected from its volcanos, rising up to 250km above the surface, have been detected from Earth. The energy to keep the interior of Io molten comes from the tidal friction generated as the moon moves through Jupiter's strong gravitation field. Io is a great laboratory for understanding volcanic activity in general.

Europa, the next moon out, is one of the most likely places for life to exist in the Solar System (excepting, of course, Earth). Images of the moon reveal a very smooth surface (in fact, the smoothest in the Solar System), criss-crossed by long, narrow, straight features. These features appear to be fissures in the surface; combined with the fact that the surface is almost pure ice (which we know from spectroscopy studies), it appears that Europa may have a large sub-surface ocean of liquid water, covered by a crust of ice.

Support for the existence of this ocean comes from the discovery of ice rafts on the surface, much like found in polar regions on Earth, and from the detection of a weak magnetic field by the Galileo spacecraft. Europa is too small to have its own magnetic field, but if it contains a large quantity of conducting fluid (such as water with a high concentration of dissolved minerals), then its motion through Jupiters magnetic field will generate a field of its own.

The significance of the sub-surface water on Europa is that liquid water is one of the principal prerequesites for life (as we know it). Speculation as to whether life does indeed exist on Europa is ongoing; to find out, a cryobot/hydrobot mission to the moon is required. The cryobot would melt its way through the icy crust, and the hydrobot would descend through this hole and explore the oceans underneath. Interest incryobot/hydrobot technology was spurred on by the discovery of Lake Vostok in Antarctica, the world's fourth-largest freshwater lake, which is trapped under 2km of ice sheet, and may contain prehistoric lifeforms.

Ganymede is the largest moon in the Solar System, larger even than the planet Mercury. Both Ganymede and Callisto have heavily-cratered surfaces, indicative of millenia of meteorite bombardment. Both are a mixture of rock and ice, although the detection of a weak magnetic field around Callisto indicates that it may have a sub-surface ocean, like Europa. The existence of this ocean is puzzling, since Callisto is too far from Jupiter for tidal heating to be able to melt ice. Some have suggested that Calliso's ocean contains an antifreeze (maybe ammonia), which keeps the water liquid well below its normal solidification temperature.

IMHO, I think Europa is the jewel in the crown of the Galilean moons, due to the possibility that life may exist there. Unfortunately, as one can tell from JIMO's full name (Jupiter Icy Moons Orbiter), there are no plans to land on this fascinating world. In "2010: Odyssey Two", Arthur C. Clarke writes about a manned landing on Europa which discovers life; it would be great for me to see this happen in my lifetime, let alone by 2010.