Ariane 5 boosts European cargo ship on course to station

CBS News

A powerful Ariane 5 rocket vaulted away from its South American launch pad Wednesday, lofting an unmanned European Space Agency cargo ship on a flight to the International Space Station.

With its first stage engine roaring at full thrust, two strap-on solid-fuel boosters ignited with a rush of flame at 5:52 p.m. EDT (GMT-4; 6:52 p.m. local time), instantly pushing the rocket away from its firing stand on the northeast coast of French Guiana.

Launch was timed to roughly coincide with the moment Earth's rotation carried the pad into the plane of the space station's orbit, a requirement when it comes to catching up with a target moving through space at 5 miles per second.

Tipping the scales at 44,610 pounds, the fully loaded Automated Transfer Vehicle, ESA's fourth and next-to-last space station cargo ship, was the heaviest payload ever launched by the European Space Agency.

The climb to space appeared to go smoothly, with the two large strap-on boosters falling away as planned two minutes and 22 seconds after launch. Six-and-a-half minutes after that, the Ariane 5 first stage fell away and the rocket continued the push to space on the power of its single second-stage engine.

The second stage shut down as planned 17 minutes after launch, putting the spacecraft into a preliminary parking orbit. A second 28-second firing was executed 42 minutes later to complete the launch phase of the mission.

The ATV-4 spacecraft was released from the second stage one hour and four minutes after liftoff, prompting a round of applause in the control center. Solar array deployment was expected about 26 minutes after that.

Named after physicist Albert Einstein, the ATV-4 will fly an automated approach to the space station, gliding to a docking at the Zvezda command module's aft port around 9:46 a.m. on Saturday, June 15.

The ATV-4 will be a welcome addition for the station crew. The spacecraft is loaded with some 7.3 tons of cargo, including 7,584 pounds of propellant, 1,257 pounds of water, 220 pounds of oxygen and 5,465 pounds of dry cargo, including experiment hardware, spare parts, food and clothing.

Expedition 36 flight engineer Alexander Misurkin and ESA astronaut Luca Parmitano plan to monitor the approach from a computer work station in the command module.

Unlike Russian Progress supply ships, ATVs cannot be flown by remote control from the space station. But the crew can send commands to abort an approach if anything goes awry.

One question mark going into the ATV mission is the condition of a laser retro reflector on Zvezda's aft port that may have been damaged or contaminated when a Russian Progress supply ship docked April 26. The reflector is part of the system used by the ATV's flight computers to home in on the aft docking port.

While Russian engineers say they are confident the reflector was not damaged by a jammed navigation antenna on the Progress, cameras will be focused on the docking port when the Russian cargo craft departs on June 11 to look for any obvious signs of damage.

If any problems develop during the actual rendezvous, the ATV can be directed to loiter nearby until the station crew could stage a spacewalk to replace the reflector. But NASA space station managers say they are optimistic that will not be necessary.