With liftoff scheduled for January, the New Horizons mission to Pluto and Charon (and, if we are lucky, at least one flyby of a more distant Kuiper Belt object) continues to generate excitement in the scientific community. The spacecraft is now at the Kennedy Space Center and will be moved to the launch pad in December, with liftoff planned for January 11. Major testing on the science payload is complete. The next round of major instrument calibrations and testing won’t occur until the early months of the journey as New Horizons moves toward a 2007 flyby of Jupiter for a gravity assist to Pluto.
How do you package enough instrumentation for good science at the edge of the Solar System into a payload that draws only 28 watts of power? The science payload work was led by the Southwest Research Institute (SwRI), whose recent news release lists the seven instruments that will explore these icy worlds:
Centauri Dreams‘ take: a critical part of New Horizons mission will take be the continuous operation, during the ten-year cruise to Pluto, of a dust counter that will trace the distribution of dust particles throughout the Solar System. We’ve had some data on this already — Voyager 2 measured dust impact on the spacecraft’s skin with its plasma wave instrument as it moved past Uranus and Neptune. But the Voyager measurements were taken with a device designed specifically to measure charged particles inside the magnetic fields of these gas giant planets, not one optimized for dust.
Learning how much dust can affect spacecraft will become more and more significant as the speed of our missions increases. At 10 percent of light speed, a grain of sand could destroy an interstellar probe, so a thorough analysis of dust out past the Kuiper Belt and eventually into the Oort Cloud will one day be needed to see what kind of shielding such vehicles would demand.
For more on the problems of interplanetary dust, see see Eberhard Grun, Harald Kruger, and Markus Landgraf, “Dust Measurements in the Outer Solar System,” available at the arXiv site. The specifics on Voyager’s dust measurements are examined in D. A. Gurnett et al., “Micron-sized Dust Particles Detected in the Outer Solar System by the Voyager 1 and 2 Plasma Wave Instruments,” Geophysical Research Letters Vol. 24 (1997): pp. 3125–28.