On Monday, 30 May, Space Shuttle Endeavour undocked from the International Space Station as planned at 09:55 CEST after being docked to the orbital outpost for almost 12 days. Endeavour and its crew, including ESA astronaut Roberto Vittori, are headed for a landing at Kennedy Space Center on 1 June at 08:32 CEST.
Immediately after undocking, Endeavour conducted a double orbit of the ISS to test advanced sensor technologies designed to make it easier for future spaceships to dock at the orbital outpost.
At the request of ESA, the crew also took ten minutes to snap photos of ATV Johannes Kepler, docked to the rear-most end of the Station's Zvezda module. But these weren't just tourist photos.
The purpose was to obtain images of ATV's Antenna Deployable Boom (ADB), a long 'boom' antenna that enables as ATV's proximity radio communication link direct to the ISS when in free flight before docking and after undocking (we've covered the proximity radio link in earlier posts).
The boom antenna is stowed in a folded configuration for launch on board Ariane 5, but then snaps open to its deployed position after separation from the launcher.
"The reason we asked for the images is that there was some delay in the locking of the boom after deployment and we wanted to see if there was anything to be learnt from the imagery that might shed some light on the reason for this delay," says ESA's Nico Dettmann, Head of the ATV Production Programme.
The astronauts on board Endeavour had a perfect photo opportunity with good illumination conditions about 45 minutes after undocking. Once on the ground, the images will be sent to the ATV team at ESA to help troubleshoot and determine the cause of the boom deployment issue, which has not affected any aspects of the Johannes Kepler mission and is not considered serious.
"This is an excellent example of how the ISS partners work very closely to conduct day-to-day operations. Everyone helps each other particularly when it comes to the astronauts or in helping solve problems like this one," says Dettmann.