Officials at the Jet Propulsion Laboratory in California bid a "reluctant goodbye" this week to the Mars Pathfinder and its roving sidekick, Sojourner. For US space scientists, this was a hugely successful mission - both in generating fresh data about the fabled red planet, and in demonstrating that planetary exploration could be done on a budget.
In the long term, the latter accomplishment could prove more important than the former. It became clear years ago that open-ended, Apollo-type projects were no longer an option. That approach got men to the moon, but it wouldn't carry them - or their technological surrogates - far beyond that. Politics and cost can be tougher to overcome than gravity.
Pathfinder operated longer than its creators anticipated. Its pictures and chemical analyses will feed scientific curiosity for years. And all on $266 million - peanuts by space standards.
Will Pathfinder mark a milestone in the evolution of space travel? Some scientific thinkers, such as physicist Freeman Dyson writing in the current Atlantic Monthly, emphasize the need for a more economical approach to space travel, with a time frame of 100 years out. To what end? Ultimately, human colonization of Mars and even more distant spheres.
The space age has only begun.