X-37B Ready For Its Fourth Flight – UPDATE 2

UPDATE, May 20, 2015, 11:15 am ET:   The X-37B and its accompanying payloads lifted off on time at 11:05 am ET.

UPDATE, May 20, 2015, 4:45 am ET:   ULA has announced refined launch times.  There are two windows today:  11:05-11:15 am ET and 12:42-12:52 pm ET.  ULA will webcast the launch.  Coverage begins at 10:45 am ET.

ORIGINAL STORY, May 19, 2015: The Air Force is getting ready to launch the reusable X-37B spaceplane into orbit tomorrow, May 20.  There are at least two X-37B Orbital Test Vehicles (OTVs) and it is not clear which is being launched, part of the mystery surrounding these ultra-classified space missions.

The Boeing-built X-37B looks like a small space shuttle orbiter and, indeed, has its origins at NASA.  Originally designed as an Orbital Space Plane to transport and rescue International Space Station crews, NASA cancelled the program in 2004 after President George W. Bush reoriented the human spaceflight program towards returning astronauts to the Moon rather than ISS utilization.  The program then was transferred to DOD.  It does not carry a crew.

Photo of X-37B.  Photo credit Boeing (via Spaceflightnow.com)

DOD will not say specifically what the X-37B does while it is in orbit.  Generally, it is described as a vehicle to test technologies.  Each of the three missions to date also seem focused on determining how long it can function on orbit, which each mission’s duration exceeding the previous record.   The first X-37B mission, OTV-1, was a 224-day flight in 2010.  The second, OTV-2, was a 469-day flight from March 2011 to June 2012.  The third flight, using the same vehicle from OTV-1, made a 675-day mission from December 2012 to October 2014.  The Air Force has not announced which vehicle will be used for this mission.

Launch of AFSPC5, as the mission is known, aboard a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral Air Force Station (CCAFS), FL, is scheduled for May 20 between 11:05 am – 2:45 pm ET.  The weather forecast is 60 percent favorable.

How long the X-37B will remain in orbit is not publicly known, but apparently it will be at least 200 days.  NASA is conducting materials science tests on the mission and announced that its Materials Exposure and Technology Innovation in Space (METIS) will expose almost 100 materials samples to space condition for “more than 200 days.”

The Air Force also has revealed that it will be testing a modified Hall thruster for the Air Force Research Laboratory.  Hall thrusters are a type of electric propulsion used on many satellites for in-orbit operations.  This test is related to improvements the Air Force wants for its Advanced Extremely High Frequency (AEHF) communications satellites.

This flight is getting more pre-launch publicity than usual because it is carrying several unclassified payloads.  In addition to METIS and the Hall thruster test, a National Reconnaissance Office (NRO) “Ultra Lightweight Technology and Research Auxiliary Satellite” (ULTRASat) pallet of 10 CubeSats from five organizations will ride-share on the launch.  Nine of the CubeSats are sponsored by NRO and one by NASA.  The CubeSats are housed in eight Poly-Pico Orbital Deployers (P-PODS).

The NRO-sponsored CubeSats include three from the U.S. Naval Academy, three from California Polytechnic Institute (which built the structure for the P-PODs), two from the Aerospace Corporation, and one from the Near Space Launch and Air Force Research Laboratory.  The NASA-sponsored CubeSat is for The Planetary Society (TPS) to test its LightSail concept for solar sailing.  There will be no sailing on this mission — that’s expected next year.  Right now, TPS is just testing the sail deployment sequence.

Typically the Air Force says nothing about X-37B missions after launch until shortly before landing. The three previous missions landed at Vandenberg Air Force Base, CA.  This one could land there or at NASA’s Kennedy Space Center (KSC) adjacent to CCAFS.  In 2014, NASA and the Air Force signed an agreement for the Air Force to use two of KSC’s Orbiter Processing Facilities, once used for the space shuttle, and said that tests were conducted to demonstrate it could land at KSC’s shuttle landing facility.