ASSET, or Aerothermodynamic Elastic Structural Systems Environmental Tests was an experimental US space project involving the testing of an uncrewed sub-scale
reentry vehicle.
Development and testing
Begun in 1960, ASSET was originally designed to verify the superalloy
heat shield of the
X-20 Dyna-Soar
The Boeing X-20 Dyna-Soar ("Dynamic Soarer") was a United States Air Force (USAF) program to develop a spaceplane that could be used for a variety of military missions, including aerial reconnaissance, bombing, space rescue, satellite maintena ...
prior to full-scale crewed flights. The vehicle's
biconic
Many shapes have metaphorical names, i.e., their names are metaphors: these shapes are named after a most common object that has it. For example, "U-shape" is a shape that resembles the letter U, a bell-shaped curve has the shape of the vertical ...
shape and low
delta wing were intended to represent Dyna-Soar's forward nose section, where the
aerodynamic heating
Aerodynamic heating is the heating of a solid body produced by its high-speed passage through air. In science and engineering, an understanding of aerodynamic heating is necessary for predicting the behaviour of meteoroids which enter the earth's ...
would be the most intense; in excess of an estimated 2200 °C (4000 °F) at the
nose cap.
Following the X-20 program's cancellation in December 1963, completed ASSET vehicles were used in reentry heating and
structural
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such ...
investigations with hopes that data gathered would be useful for the development of future
space vehicles, such as the
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...
.
Built by
McDonnell
The McDonnell Aircraft Corporation was an American aerospace manufacturer based in St. Louis, Missouri. The company was founded on July 6, 1939, by James Smith McDonnell, and was best known for its military fighters, including the F-4 Phantom I ...
, each vehicle was launched on a
suborbital trajectory from
Cape Canaveral's Pad 17B at speeds of up to 6000 m/s before making a
water landing
In aviation, a water landing is, in the broadest sense, an aircraft landing on a body of water. Seaplanes, such as floatplanes and flying boats, land on water as a normal operation. Ditching is a controlled emergency landing on the water s ...
in the South
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
near
Ascension Island. Originally, a
Scout launch vehicle had been planned for the tests, but this was changed after a large surplus of
Thor
Thor (; from non, Þórr ) is a prominent god in Germanic paganism. In Norse mythology, he is a hammer-wielding god associated with lightning, thunder, storms, sacred groves and trees, strength, the protection of humankind, hallowing, an ...
and
Thor-Delta
The Thor-Delta, also known as Delta DM-19 or just Delta was an early American expendable launch system used for 12 orbital launches in the early 1960s. A derivative of the Thor-Able, it was a member of the Thor family of rockets, and the first ...
missiles (returned from deployment in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
) became available.
Of the six vehicles built, only one was successfully recovered and is currently on display at the
National Museum of the United States Air Force
The National Museum of the United States Air Force (formerly the United States Air Force Museum) is the official museum of the United States Air Force located at Wright-Patterson Air Force Base, northeast of Dayton, Ohio. The NMUSAF is the ...
in
Dayton, Ohio
Dayton () is the sixth-largest city in the U.S. state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. The 2020 U.S. census estimate put the city population at 137,644, while Greater D ...
.
Flights
Specifications
*Manoeuvring controls:
Hydrogen-peroxide reaction control thrusters
*Maximum Mach no.: M25
*Downrange:
*Apogee: {{cvt, 50, mi, nmi km, 0
* Hypersonic L/D ratio: 1:1
Related content
Comparable aircraft
*
Molniya BOR-4
*
Martin X-23 PRIME
Winged Gemini
In the mid-1960s,
McDonnell
The McDonnell Aircraft Corporation was an American aerospace manufacturer based in St. Louis, Missouri. The company was founded on July 6, 1939, by James Smith McDonnell, and was best known for its military fighters, including the F-4 Phantom I ...
proposed a variant of the
Gemini capsule that retained the original spacecraft's internal subsystems and crew compartment, but dispensed with the tail-first ballistic reentry, parachute recovery and water landing.
Instead, the vehicle would be heavily modified externally into an ASSET-like
lifting-reentry configuration. Post-reentry, a pair of stowed swing-wings would be deployed, giving the spacecraft sufficient
lift-to-drag ratio
In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under gi ...
to make a piloted glide landing on a concrete runway using a skid-type landing gear (reinstated from the planned, but cancelled paraglider landing system), much like the
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...
.
According to Mark Wade's Encyclopedia Astronautica, the intent seems to have been to field a crewed military spaceplane at a minimal cost following the cancellation of the Dyna-Soar program.
Winged Gemini at Encyclopedia Astronautica
.
References
Glider aircraft
Lifting bodies
Spaceplanes
1960s United States experimental aircraft
Unmanned aerial vehicles of the United States