A European space freighter as big as a double-decker bus is set to blast off from a South American spaceport Saturday night, heading toward a docking test with the International Space Station.
Weighing 20 tons, the unmanned spacecraft is almost four stories tall and is equipped with an automated docking system never tested in orbit.
Independent investigators raised concerns last year about trying to dock it at the station without a test flight to a target spacecraft first.
Two orbital dress rehearsals are planned before it attempts to dock at the station, and project officials insist the hookup can be performed without endangering the $100 billion outpost or its crew.
"We're absolutely confident with the safety aspects of this spacecraft," NASA station program manager Mike Suffredini said.
The Automated Transfer Vehicle, or ATV, is a key component of the European Space Agency's $7.4 billion contribution to the station project.
Launch of the first ATV, which is named after pioneering 19th-century science fiction writer Jules Verne, is the culmination of a $1.9 billion project that dates back to 1995.
HT Florida Today
Launch tonight is targeted for 11:03 p.m. EST, and we will have live coverage of the countdown. We will have live video of the launch, via NASA TV, and a second feed from the European Space Agency. Our coverage will pick up with fueling, around 7 p.m. EST. The live video webcast begins just after 10 p.m.HT Flame Trench here.