SAN FRANCISCO — When U.S. senators angrily denounced President Barack Obama’s 2011 NASA budget request, saying the plan to cancel the Constellation program leaves the United States without any clear goal for human spaceflight, NASA Administrator Charles Bolden responded that the ultimate goal is Mars.

This post is only available to members.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She is a recipient...