HomeAbout UsFact SheetsDisplay

X-37B Orbital Test Vehicle

The first X-37B Orbital Test Vehicle waits in the encapsulation cell of the Evolved Expendable Launch vehicle April 5, 2010, at the Astrotech facility in Titusville, Fla. Half of the Atlas V five-meter fairing is visible in the background. (Courtesy photo)

The first X-37B Orbital Test Vehicle waits in the encapsulation cell of the Evolved Expendable Launch vehicle April 5, 2010, at the Astrotech facility in Titusville, Fla. Half of the Atlas V five-meter fairing is visible in the background. (Courtesy photo)

In a testing procedure, the X-37B Orbital Test Vehicle taxis on the flightline in June 2009 at Vandenberg AFB, Calif. (Courtesy photo)

In a testing procedure, the X-37B Orbital Test Vehicle taxis on the flightline in June 2009 at Vandenberg AFB, Calif. (Courtesy photo)

Mission
The X-37B Orbital Test Vehicle, or OTV, is an experimental test program to demonstrate technologies for a reliable, reusable, unmanned space test platform for the U.S. Air Force. The primary objectives of the X-37B are twofold; reusable spacecraft technologies for America’s future in space and operating experiments which can be returned to, and examined, on Earth.

Features
The X-37B Orbital Test Vehicle is the newest and most advanced re-entry spacecraft. Based on NASA’s X-37 design, the unmanned OTV is designed for vertical launch to low Earth orbit altitudes where it can perform long duration space technology experimentation and testing. Upon command from the ground, the OTV autonomously re-enters the atmosphere, descends, and lands horizontally on a runway. The X-37B is the first vehicle since NASA’s Shuttle Orbiter with the ability to return experiments to Earth for further inspection and analysis, but with an on-orbit time of 270 days or greater, the X-37B can stay in space for much longer.

Technologies being tested in the program include advanced guidance, navigation and control, thermal protection systems, avionics, high temperature structures and seals, conformal reusable insulation, lightweight electromechanical flight systems, advanced propulsion systems, advanced materials and autonomous orbital flight, reentry and landing.

Background
The Air Force Rapid Capabilities Office is leading the Department of Defense’s Orbital Test Vehicle initiative, by direction of the Under Secretary of Defense for Acquisition, Technology and Logistics and the Secretary of the Air Force. The Air Force OTV effort uses extensive contractor and government investments in the X-37 program by the Air Force, NASA and the Defense Advanced Research Projects Agency to continue full-scale development and on-orbit testing of a long-duration, reusable space vehicle.

NASA’s original X-37 program began in 1999 and was transferred to DARPA in 2004. NASA envisioned building two vehicles, an Approach and Landing Test Vehicle, or ALTV, and an Orbital Vehicle. DARPA completed the ALTV portion of the X-37 program in 2006, executing a series of captive carry and free flight tests. DARPA successfully validated the flight dynamics and extended the flight envelope beyond the low speed/low altitude tests previously conducted by NASA on the X-40A, a sub-scale version of the X-37 developed by Air Force Research Labs. NASA’s X-37 Orbital Vehicle was never built, but its design was the starting point for the Air Force’s X-37B Orbital Test Vehicle program.

The Air Force has successfully flown four X-37B missions, OTV-1 through OTV-4, beginning with its first launch on April 22, 2010 from Cape Canaveral Air Force Station, Fla. OTV-1 through OTV-3 all landed successfully at Vandenberg AFB, Calif., and the most recent mission, OTV-4, successfully landed at Kennedy Space Center, Fla. The first four OTV missions have spent a total of 2,085 days on orbit, successfully checking out the X-37B’s reusable flight, reentry and landing technologies as well as operating experiments to benefit the national space community. The fifth mission, OTV-5, was launched from Cape Canaveral Air Force Station, Fla. on 7 September, 2018, and is currently on orbit.

General Characteristics
Primary Mission: Experimental test vehicle
Prime Contractor: Boeing
Height: 9 feet, 6 inches (2.9 meters)
Length: 29 feet, 3 inches (8.9 meters)
Wingspan: 14 feet, 11 inches (4.5 meters)
Launch Weight: 11,000 pounds (4,990 kilograms)
Power: Gallium Arsenide Solar Cells with lithium-Ion batteries
Launch Vehicles: United Launch Alliance Atlas V (501) and SpaceX Falcon 9

Engage

Facebook Twitter
The #USAF is looking for men and women for the 2019 Armed Forces Triathlon June 19-23, in Ventura County,… https://t.co/Dqjgj02qC8
Part of being in the military involves traveling to foreign countries. The #380AEW Host Nation Coordination Office… https://t.co/6mKtO5NWqj
Sharp eyesight is key to an #Airman’s readiness to fly, fight & win. This #AirForce Tech Report highlights how… https://t.co/MaxAEXIOpz
Next-generation warfighting is all about data...yet sometimes our email doesn’t even load. @USecAF_Official is driv… https://t.co/5DsspMgYv8
Today is #MedalofHonorDay and we take a moment to honor our nation’s greatest heroes who have received the highest… https://t.co/B5CVsuV3vX
From foster kid to #Airman, mentor and raising the #AirForce’s next generation. @TeamMisawa https://t.co/7NmxHqOJGe https://t.co/vVoVVnjEgf
Riveting story! Learn more about Ms. Mae Krier, a #WorldWarII pioneer who joined legions of other Rosies in the wor… https://t.co/0QUBOzh4Rr
RT @HollomanAFB: Happy #NationalPuppyDay! Our #MilitaryWorkingDogs protect and defend us each and everyday. Check out these #adorable photo…
RT @AirForceMag: HIT THE BOOKS: Check out a non-exhaustive list of Air Force Chief of Staff @GenDaveGoldfein's reading recommendations from…
Some of us are women, but we are all Airmen! #WomensHistoryMonth https://t.co/pcBtWWIiE6
.@GenDaveGoldfein: "Celebration of #diversity and making sure we understand the flesh colored band aids is not abou… https://t.co/iUqNbSpCPB
.@RAFMildenhall #KC135 crew strengthened relationship with Romanian #AirForce through air refueling training. For m… https://t.co/8dGvm2HQwC
RT @SecAFOfficial: Mother nature can’t beat the 55th Wing! We will recover @Offutt_AFB from the devastating flood. Amazing American 🇺🇸 spir…
Today the #AirForce announced a new Infrastructure Investment Strategy following a yearlong review that brings a ne… https://t.co/i1yDRQkaPl
RT @Offutt_AFB: As the water has begun to recede, Team Offutt is in full recovery mode. https://t.co/6QPZ96UNZY
RT @SecAFOfficial: Thanks to Iowa leaders who just signed a bill to recognize out of state licenses for our military spouses! @SenJoniErnst
RT @SecAFOfficial: This will make a difference on our bases for decades to come...getting more out of every dollar we spend on #infrastruct
See how our aircraft maintainers keep our #F15s safe and mission ready! @142ndFW https://t.co/H6CrSoCCIg
RT @NASA: During today's spacewalk, we'll be taking questions about our @NASA_Astronauts' excursion outside of the @Space_Station. Ask ques…