The Science Definition Team suggested that the radar and Doppler tracking experiments should be facility instruments (i.e., provided by the mission) and that the others be selected through open competition. NASA issued a single Announcement of Opportunity in September 1999, soliciting scientific investigations for the Europa Orbiter, Pluto/Kuiper Express, and Solar Probe missions.
According to current plans, the Europa Orbiter would have a total mass of some 900 kg, including 20 kg of scientific payload and more than 500 kg of fuel for its orbital maneuvering engine. The spacecraft would be powered by a new-generation, radioisotope power source. The Europa Orbiter is tentatively scheduled for launch aboard the space shuttle in November 2003 and will follow a direct trajectory to Jupiter. Following entry into orbit about Jupiter in February 2007, the mission will follow three distinct operational phases. The Science Definition Team dubbed these the satellite tour, the end game, and the Europa orbit. These phases encompass the following activities:
1. S.W. Squyres, R.T. Reynolds, P.M., Cassen, and S.J. Peale, "Liquid Water and Active Resurfacing on Europa," Nature 301: 225, 1983.
2. R.T. Pappalardo et al., "Does Europa Have a Subsurface Ocean? Evaluation of the Geological Evidence," Journal of Geological Research — Planets, 1999, in press.
3. A.C. Clarke, 2010: Odyssey II, Balantine Books, New York, 1982.
4. For a review of current understanding of Europa and the other galilean satellites, see, for example, A.P. Showman and R. Malhotra, "The Galilean Satellites," Science 286: 77, 1999.
5. Space Studies Board, National Research Council, An Integrated Strategy for the Planetary Sciences: 1995-2010, National Academy Press, Washington, D.C., 1994, page 60.
6. Space Studies Board, National Research Council, An Integrated Strategy for the Planetary Sciences: 1995-2010, National Academy Press, Washington, D.C., 1994, page 61.