It will be used to relay signals for the United States Air Force Navstar Global Positioning System (GPS).

A problem with spacecraft telemetry was detected, but resolved in time for an attempt to be made at the end of the window, however it recurred during the last minutes of the countdown.

[7] The launch was rescheduled for 24 May 2010, between 03:17 and 03:35 UTC, but scrubbed early in the countdown to allow further time to resolve the problem which had occurred during the previous attempt.

[8] An attempt on 25 May 2010, targeting the start of an eighteen-minute window at 03:13, resulted in a scrub after a hold was called less than ten seconds before the rocket was scheduled to launch, due to a problem with the thrust vectoring of the solid rocket motors.

Launch attempts on 26 and 27 May 2010 (UTC) were not possible as the Eastern Range had to be reconfigured to support the final landing of Space Shuttle Atlantis, returning from STS-132.