Tuesday will see the launch of a third unmanned X-37B Orbital Test Vehicle by the Air Force from Cape Canaveral.

The secret mini-shuttle will be carried by Atlas V Rocket. The launch was confirmed on Friday while the officials are quite sure about the perfection of the rocket engine which is similar to that of the Delta IV which reported fault in its engine.

The shuttle will take off on Tuesday afternoon from Cape Canaveral, as per the statements of the Air Force and United Launch Alliance (ULA). Earlier on October 4, Delta IV employing similar engine reported fault; the case is under scrutiny now.

As per the investigation, the fault occurred due to fuel leakage in the thrust chamber of Pratt & Whitney Rocketdyne engine as soon as it started. The rocket, however, successfully launched the GPS satellite despite the fault.

The mini shuttle came to existence in 1999 in hands of NASA and was later shifted to Defense Advanced Research Projects Agency (DARPA) in 2004 and finally went to the US Air Force in 2006. Its initial development by NASA and Boeing incurred a total cost of $208 million while another $301 million was invested into the project in 2002. It is a solar powered shuttle that will remain in space for about 270 days.