Traffic Jam at the Space Station

Space traffic control will be needed at the International Space Station as a busy timeframe of missions and resupply flights continue for our home port in space. In a choreographed ballet of spaceships, ESA’s first Automated Transfer Vehicle (ATV) resupply ship and NASA’s Space Shuttle Endeavour are scheduled to liftoff on March 9 and 11, respectively, to dock with the ISS, while a third – Russia’s Soyuz – is due to arrive early in April. The heavy traffic comes just a few weeks after Space Shuttle Atlantis left the ISS on February 18, delivering the Columbus science lab to the station. With Endeavour scheduled to be docked to the ISS from March 13 – 24, the ATV must patiently wait in a “parking orbit,” travelling in a holding pattern below the station, and will then dock after the shuttle leaves.

As of now, everything is “go” for all three flights. Endeavour will ferry Japan’s Kibo science lab to the ISS, along with the Canadian Space Agency’s two-armed robotic system called Dextre. STS-123 is commanded by Dominic Gorie with Greg Johnson serving as pilot. The crew also includes Mission Specialists Rick Linnehan, Robert Behnken, Mike Foreman, Garrett Reisman and Japanese astronaut Takao Doi. Reisman will stay aboard the station, trading places with ESA astronaut Léopold Eyharts, who has been on board since Atlantis’ February mission to the ISS.

But in the meantime, the ATV will be waiting in the wings to deliver its cache of supplies to the station. “After launch, we will have an opportunity to show and demonstrate to our ISS partners exactly what the ATV is capable of doing,” said Alberto Novelli, ESA’s Mission Director for the ATV. “And we can place ATV in a holding orbit for an extended period, if necessary, before doing the final, actual docking,”.

The ATV is scheduled to dock on March 29. However, if there are any slips or technical issues to delay the ATV’s docking, there are only four subsequent days on which the actual docking can take place. One limitation causing this is illumination conditions: astronauts on board the station must not be blinded by sunlight while monitoring the approaching vehicle’s progress.

Another limitation is caused by more traffic: Russia’s Progress M-63, docked since February 7, will undock on April 7 and a new Soyuz arrival and docking is scheduled for April 10. Additional limitations on the ATV docking window could come about if Endeavour’s launch is delayed or if its docked phase extends past March 27. For example, last month, Atlantis’ docked phase was extended by one day to facilitate the installation of Columbus.

“It’s an extraordinary time. While we face a tight window, the intense activity at the ISS these weeks – with European, American, Russian, Canadian and Japanese payloads or vessels in flight – highlights the fantastic international character of the Station,” said Bob Chesson, ESA’s manager for Human Spaceflight Operations.

Check out the ATV blog to follow the mission live, and NASA’s STS-123 launch blog.

Original News Source: ESA Press Release