Video: Mars Pathfinder pre-launch preparations

United Launch Alliance called off the launch of a Delta 2 rocket from California’s Central Coast early Tuesday after boats ventured into a restricted safety exclusion zone and engineers ran out of time to resolve a technical problem on the launcher.

NASA’s Mars Pathfinder probe dropped to the surface of Mars for an airbag-cushioned landing 20 years ago Tuesday, bouncing 15 times across an ancient flood plain before deploying a mobile robot to usher in two decades of uninterrupted Martian exploration.

United Launch Alliance plans to assemble leftover parts for a Delta 2 rocket display at the Kennedy Space Center Visitor Complex in Florida alongside other icons of U.S. rocketry, the company announced Saturday soon after the final Delta 2 launch.