Images of Saturn and asteroid are returned as Pluto mission progresses to plan

NASA's interplanetary spacecraft Cassini, Galileo and Stardust have all passed major milestones on their journeys, while the planned New Horizons mission to Pluto has made a major move towards its launch in 2006.

NASA's venerable Jupiter orbiter, Galileo, launched in October 1989, made its last fly-by of one of the planet's moons on 4 November. Galileo passed to within 160km of the 270km (165 miles)-wide Amalthea at a speed of 66,270km/h (41,160mph). It then passed to within 71,645km of Jupiter's cloud tops on its closest approach during its 34th orbit since reaching the planet in December 1995.

The close fly-by of Jupiter and the intense radiation of the planet could severely damage the craft, which is due to complete its final orbit in September 2003.

Meanwhile, Cassini, with the European Space Agency's Huygens Titan probe in tow, has returned images of Saturn from a distance of 188 million km as it heads towards a rendezvous with the ringed planet in July 2004. A composite of the images shows Saturn's shadow falling across its rings and includes the moon Titan.

NASA's Stardust spacecraft flew to within 3,060km of the 4km-wide asteroid Annefrank at a relative speed of 25,210km/h, taking 70 images on 1 November in a practice run for the 160km fly-by of the nucleus of the comet Wild 2 on 2 January, 2004.

The spacecraft will collect dust streaming off the comet and return it to Earth, together with interstellar dust, in a recoverable capsule in 2006.

NASA's New Horizons mission to Pluto, its moon Charon and the Kuiper Belt of objects beyond the last planet in the solar system has passed its second major system-level evaluation at the Johns Hopkins University Applied Physics Laboratory, Maryland.

Provided funds are approved by Congress, the spacecraft could be launched in January 2006, reaching Pluto and its geostationary-orbiting moon, Charon, in 2015 at the earliest, via a gravity-assist swing-by of Jupiter in 2007. The spacecraft will be launched on either a Boeing Delta IV or a Lockheed Martin Atlas V. Later launch windows in February 2007 and 2008 would extend the flight time considerably.

Source: Flight International