Ulysses Status Report - April 2003
The investigation into the anomaly is still in progress. The possible extension of spacecraft operations beyond September 2004 will be discussed by the Solar System Working Group at its meeting on 23 April. The Ulysses proposal to the NASA Sun-Earth Connections (SEC) Senior Review (to be held 10-13 June) will be submitted by the JPL Project to NASA HQ on 30 April. On 1 May, Ulysses will be at a radial distance of 4.84 AU from the Sun, and heliographic latitude 16: north of the solar equator, on its way to aphelion.
For the first time since 1992, Jupiter is starting to figure strongly in the scientific activities of the Ulysses teams. On 5 February 2004, the spacecraft will encounter the giant planet for the second time. Unlike the 1992 fly-by, however, this will be a distant encounter (closest approach will be at 1684 Jovian radii from the planet's centre, compared with 6 Jovian radii in 1992). Another difference between the two fly-bys is that this time, the spacecraft will approach the planet from high northern latitudes. This difference is already apparent in the radio data from the URAP experiment on board Ulysses. In February and March 2003, URAP detected intense radio emission from Jupiter, at levels well above those seen in 1993 when Ulysses was at comparable distance from the planet (approx. 2.8 AU). This bodes well for the data to be acquired in November-December, when Ulysses will be much closer to the planet, and at 75: north of the planet's equator. Of particular interest are periodic auroral phenomena which produce both radio and X-ray bursts. The quasiperiodic X-rays, observed by the Chandra X-ray Observatory were observed primarily from the northern hemisphere.