USA-226
Encyclopedia
USA-226 is the first flight of the second Boeing
X-37B
, the Orbital Test Vehicle 2 (X-37B OTV-2), an American unmanned robotic vertical-takeoff, horizontal-landing spaceplane
. It was launched aboard an Atlas V rocket from Cape Canaveral
on 2011, and is currently being operated in low Earth orbit
. Its mission designation is part of the USA series.
The spaceplane is operated by the United States Air Force
, which has not revealed the specific identity of the payload for the first flight. The Air Force has stated only that the spacecraft will "demonstrate various experiments and allow satellite sensors, subsystems, components, and associated technology to be transported into space and back."
in Florida. It was scheduled to launch on the previous day, 4 March, but weather prevented the launch on that day, forcing the reschedule to 5 March.
The launch was conducted by United Launch Alliance
.
The X-37B spacecraft was originally intended to be deployed from the payload bay of a NASA Space Shuttle
, but following the Columbia accident
, it was transferred to a Delta II 7920
. It was subsequently transferred to the Atlas V following concerns over the X-37B's aerodynamic properties during launch.
Prior to the installation of the spacecraft, the Atlas rocket was moved to the launch pad and performed a wet dress rehearsal
on 2011. It was returned to the Vertical Integration Facility the following day for final assembly.
, and land at Vandenberg Air Force Base
. OTV-2 will be the third reusable spaceplane to perform an automated landing after returning from orbit, the first being the Soviet Buran spacecraft in 1988 and the second, its sister craft, the OTV-1.
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
X-37B
Boeing X-37
The Boeing X-37 is an American unmanned vertical-takeoff, horizontal-landing spaceplane. The X-37 is operated by the United States Air Force for orbital spaceflight missions intended to demonstrate reusable space technologies...
, the Orbital Test Vehicle 2 (X-37B OTV-2), an American unmanned robotic vertical-takeoff, horizontal-landing spaceplane
Spaceplane
A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...
. It was launched aboard an Atlas V rocket from Cape Canaveral
Cape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...
on 2011, and is currently being operated in low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
. Its mission designation is part of the USA series.
The spaceplane is operated by the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
, which has not revealed the specific identity of the payload for the first flight. The Air Force has stated only that the spacecraft will "demonstrate various experiments and allow satellite sensors, subsystems, components, and associated technology to be transported into space and back."
Launch
OTV-2 was launched aboard an Atlas V rocket, tail number AV-026, on 5 March 2011 from Space Launch Complex 41 at Cape Canaveral Air Force StationCape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...
in Florida. It was scheduled to launch on the previous day, 4 March, but weather prevented the launch on that day, forcing the reschedule to 5 March.
The launch was conducted by United Launch Alliance
United Launch Alliance
United Launch Alliance is a joint venture of Lockheed Martin and Boeing. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. U.S...
.
The X-37B spacecraft was originally intended to be deployed from the payload bay of a NASA Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
, but following the Columbia accident
Space Shuttle Columbia disaster
The Space Shuttle Columbia disaster occurred on February 1, 2003, when shortly before it was scheduled to conclude its 28th mission, STS-107, the Space Shuttle Columbia disintegrated over Texas and Louisiana during re-entry into the Earth's atmosphere, resulting in the death of all seven crew members...
, it was transferred to a Delta II 7920
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...
. It was subsequently transferred to the Atlas V following concerns over the X-37B's aerodynamic properties during launch.
Prior to the installation of the spacecraft, the Atlas rocket was moved to the launch pad and performed a wet dress rehearsal
Wet dress rehearsal
A Wet Dress Rehearsal tests out the systems of a spacecraft prior to spacecraft integration and launch. Enough elements are in place to verify that a rocket is ready for flight, allowing problems to be seen prior to the mating of a payload with the rocket...
on 2011. It was returned to the Vertical Integration Facility the following day for final assembly.
Mission
Most of the mission parameters for the first OTV-2 flight have not been disclosed. The vehicle is capable of being on-orbit for up to 270 days. The Air Force stated the mission time would depend on progress of the craft's experiments during orbit. On November 29, 2011 a spokesperson for the Secretary of the Air Force announced the mission was extended beyond it's original life expectancy, citing ongoing expirimentation.Altitude and ground track resonance history
| Time period | Periapsis (AMSL Above mean sea level The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach... ) |
Apoapsis (AMSL Above mean sea level The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach... ) |
Resonance(orbits:days) |
|---|---|---|---|
| 2011 Mar 5 – 14 | 317 km (197 mi) | 319 km (198.2 mi) | |
| 2011 Mar 14 – 30 | 317 km (197 mi) | 344 km (213.8 mi) | |
| 2011 Mar 30 – | 323 km (200.7 mi) | 339 km (210.6 mi) | |
Landing
After completing its mission, OTV-2 will be deorbited, enter the atmosphereAtmospheric reentry
Atmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...
, and land at Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
. OTV-2 will be the third reusable spaceplane to perform an automated landing after returning from orbit, the first being the Soviet Buran spacecraft in 1988 and the second, its sister craft, the OTV-1.