The Air Force is preparing to send its mysterious space drone on yet another mission
Leaving from Cape Canaveral, the X-37B space plane will be launched into low orbit aboard an Atlas V rocket for an unspecified amount of time, according to CBS News. While in space, the X-37B will carry out two publicly announced missions - one for the Air Force and one for NASA.
Bloomberg Business reports that the drone will test a "new super-efficient propulsion system" for the Air Force known as a Hall thruster. The X-37B will also carry samples of various materials for NASA in order to study how well they respond to low-earth orbit conditions.
The Hall thruster is an electronic propulsion device which creates thrust by ionizing the noble gas Xenon.
A press release from the Wright-Patterson Air Force Base notes that this type of thruster generates less power than a typical rocket. But it the Hall is significantly smaller, lighter, and has much better fuel economy than a conventional rocket engine. This hypothetically allows the X-37B to carry out more advanced maneuvers in space compared to other orbital vehicles.
The stated goal of testing the thruster aboard the X-37B is to troubleshoot the design and note any modifications that might need to be made before the ion thruster is placed on the military's Advanced Extremely High Frequency communications satellite system.
The upcoming launch for the X-37B will be the space craft's fourth journey into space. On October 17, 2014 the plane returned from a nearly two-year orbit around the earth. The other two missions lasted for seven and fifteen months.
What the X-37B was doing in its previous space missions hasn't yet been publicly disclosed.