Station-bound freighter enters parking orbit
BY STEPHEN CLARK
Posted: March 19, 2008
Europe's Jules Verne space station servicing ship entered a holding pattern early Wednesday to wait out the shuttle Endeavour's visit to the outpost scheduled to wrap up early next week.
Jules Verne, a bus-sized spacecraft named after the visionary 19th century science fiction writer, fired its main engines twice Tuesday evening to transition from the ship's phasing orbit to a parking spot about 1,250 miles ahead of the international space station, said Bob Chesson, head of the European Space Agency's human spaceflight and exploration programs.
The two burns, each changing Jules Verne's velocity by about 11 miles per hour, were conducted Tuesday night, European time. The firings were followed by a series of smaller trim burns to reach the parking orbit by 1200 GMT (8:00 a.m. EDT) Wednesday, Chesson said.
The thruster firings were completed through a propulsion command chain that was automatically shut down during the early hours of the mission. Controllers successfully recovered the chain after successfully reintegrating the circuit into the propulsion system and lowering engineering limits in the pressurization system to prevent another electronics-commanded shutdown.
"In doing the boosts we have tested all the pressure regulators and that worked perfectly fine," said Alberto Novelli, ESA's mission director at the ATV control center. "So as of today we have the proof that the propulsion system as a whole, including all the redundancies, is working fine."
Jules Verne is the first of at least five ESA Automated Transfer Vehicles designed to ferry cargo, fuel, water, oxygen and nitrogen to the space station.
"During the parking orbit phase, the (ATV control center) will conduct normal baby-sitting operations and monitor orbital debris status in case a debris avoidance maneuver is required," Chesson said.
Launched from French Guiana ten days ago, Jules Verne completed a test of a collision avoidance maneuver Friday that would push the ATV away from the station during an emergency in the rendezvous sequence.
Jules Verne lapped the station Tuesday, passing about 20 miles below the complex on its way to its temporary home ahead of the outpost. Cameras outside of the station captured images of the ship, which resembled a shining white star.
The spacecraft will hold in its current parking orbit until the early morning hours of March 27, when controllers will begin moving Jules Verne toward the station for two days of rendezvous tests to demonstrate the ship's ability to safely approach the facility.
The "Demo Days" are scheduled for March 29 and March 31. Jules Verne's docking to the station is penciled in for April 3, if everything goes as planned.