As Magellan leaves Earth behind on its 15-month journey to Venus, scientists and NASA officials are beginning to draw up plans for exploration of the Solar System into the next century that will probably not include a return mission to the planet most like Earth. NASA's first planetary mission in 11 years will allow a breathtaking look at Venus. But because no detailed understanding of the planet's interior or atmosphere will be gained, major questions may remain unanswered for many years.
A long-term agenda to supplement the NASA Office of Space Science and Applications' strategic plan is described by one planetary scientist as a balance between the spirit of discovery and the need to pursue a basic science program. What really drives the debate, however, is money and politics; budget crunches have shaped Magellan and other missions, and a short supply of space policy may make future strategies vulnerable to sudden initiatives from the administration.