Mysterious Air Force aircraft at 600 days in orbit

The US Air Force's mysterious X-37B space plane has spent 600 days on Earth orbit in its latest mission, nearly reaching the longest record in the program's universe.

The X-37B automatic control plane takes off on the Atlas V rocket back of United Launch Alliance departing from Cape Canaveral air base in Florida, USA, May 20, 2015 on the 4th mission named Call the program's Orbital Test Vehicle-4 or OTV-4, according to Live Science.

If this unmanned aircraft saved an extra 74 days in space, it would break the record set by the OTV-3 mission in October 2014. However, information about the flight time of OTV-4, the purpose of flying around the X-37B's Earth and other details about the aircraft's mission or equipment, remains confidential.

The first OTV mission began on April 22, 2010 and ended on December 3 of the same year with 224 days in orbit. OTV-2 took off on March 5, 2011 and landed on June 16, 2012 after 468 days in orbit. OTV-3 mission set a record with nearly 675 days flying around the Earth from December 11, 2012 to October 17, 2014. All three previous OTV missions landed at Vandenberg Air Base in California, USA, but OTV-4 can land elsewhere.

The X-37B was 600 days in Earth orbit.(Photo: AFP).

The US Air Force is promoting unified operation of the X-37B space jet, including using the Kennedy Space Center (KSC) in Florida as a landing site for vehicles. A former KSC space shuttle facility called the Orbiter Processing Facility-1 (OPF-1) was modified to allow the US Air Force to land, restore, refurbish and re-launch the test vehicle effectively. X-37B orbit, according to representative of Boeing aerospace company.

Development of the vehicle X-37B is led by Boeing Space and Intelligence Systems in El Segundo, California. This is Boeing's center that specializes in space and test systems, as well as commercial and government satellites.

The X-37B looks like a miniature version of the stopped shuttle model of the US Aerospace Agency. The plane is only 8.8m long, 2.9m high, has a wingspan of nearly 4.6m. Meanwhile, the shuttle is 37m long and has a wingspan of 24m.

The X-37B has a large cargo compartment with pickup trucks that can equip robot arms. The aircraft has a weight of 4,990 kg, which is powered by a solar battery made of semiconductor gallium arsenide (GaAs) and lithium-ion battery.

A number of devices on OTV-4 aircraft were identified including Aerojet Rocketdyne's XR-5A Hall Thruster propulsion engine and high-end materials during NASA testing.

Testing equipment is one of the main purposes of OTV missions along with the development of reusable spacecraft technology, according to US Air Force authorities."This is still a useful way to check things out, " said Winston Beauchamp, US Air Force deputy secretary of space, at a meeting of the American Aeronautics and Space Institute (AIAA) in Long Beach, California. , last September.

When asked about the possibility of adding X-37B to the fleet, Beauchamp said the current number of vehicles met the requirements of the US Air Force.