The US Airforce’s X-37B spaceplane, which was supposed to begin its second mission yesterday, has been temporarily grounded after poor weather caused mission controllers to scrub the launch. At the initial time planned for launch, strong winds at ground level caused the flight be postponed for several hours. By the time the second launch window appeared, clouds had swept in bringing heavy rain and the decision was made to scrub the launch. The new plan is to try again today, using the same launch profile, but there is a chance that poor weather will continue to interfere.
As X-37B is a military project, orbital parameters and mission details are kept secret. However it is likely that both this and the first mission are simply test flights – putting the little unmanned craft through its paces and exercising its capabilities before bringing it down for a controlled landing at the Kennedy Space Center.
Update: X-37B launched successfully at 22h46 UTC.