The NOTS-EV-2 Caleb, also known as NOTS-500, Hi-Hoe and SIP was an

expendable launch system An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are destroyed during reentry or impact with Earth, or discarded in space. ELVs typically consist of s ...

, which was later used as a

sounding rocket A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are often ...

and prototype

anti-satellite weapon Anti-satellite weapons (ASAT) are space weapons designed to incapacitate or destroy satellites for Military strategy, strategic or Military tactics, tactical purposes. Although no ASAT system has been utilized in warfare, a few countries (China, ...

. It was developed by the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

's Naval Ordnance Test Station (NOTS) as a follow-up to the NOTS-EV-1 Pilot, which had been abandoned following ten launches officially classified as failed missions. Two were launched in July and October 1960, before the cancellation of the project. Following cancellation, two leftover Calebs were used in the Satellite Interceptor Program (SIP), while three more were used as sounding rockets, under the designation Hi-Hoe. These derivatives flew until July 1962, when the Hi-Hoe made its final flight.

Development

The Caleb was originally designed as a fast-response

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

al launch system, to place small

reconnaissance satellite A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. The ...

s, and other military payloads, into orbit at short notice. The orbital configurations were four-stage vehicles, whilst test launches used one- and two-stage configurations. The project was cancelled due to pressure from the

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

, who were responsible for all other orbital launches conducted by the US military, and no attempts to launch the vehicle into orbit were made. F4D with Caleb

Caleb was an air-launched rocket, with its two launches being conducted from

F4D Skyray The Douglas F4D Skyray (later redesignated F-6 Skyray) is an American Carrier-based aircraft, carrier-based supersonic Fighter aircraft, fighter/Interceptor aircraft, interceptor designed and produced by the Douglas Aircraft Company. It was th ...

#747, the same aircraft used in the Pilot trials. Hi-Hoe sounding rocket on F4H Phantom

Hi-Hoe was also air-launched. It was released from an F4H Phantom II, which provided greater performance. SIP launches were conducted from a ground launch pad on San Nicolas Island. The aircraft used for the airborne launches took off from Point Arguello, which later became part of

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg S ...

, currently

Vandenberg Space Force Base Vandenberg Space Force Base , previously Vandenberg Air Force Base, is a United States Space Force Base in Santa Barbara County, California. Established in 1941, Vandenberg Space Force Base is a space launch base, launching spacecraft from the ...

Operational history

The Caleb made its maiden flight, in a single-stage test configuration, on 28 July 1960. Its second flight was made on 24 October of the same year, and used a two-stage configuration. It was unsuccessful, due to the second stage's failure to ignite. Both test launches were suborbital. Both SIP launches used the two-stage configuration. The first was conducted on 1 October 1961. It was successful and reached an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

of . The second test, launched on 5 May 1962 was also successful, and reached the same apogee. The three Hi-Hoe launches were conducted on 5 October 1961, and 26 March and 25 July 1962. On the first two launches the second stage failed to ignite, however the third was successful, and reached an apogee of . Despite the program's turn towards success, the project was cancelled soon after the final Hi-Hoe test, the

Department of Defense The United States Department of Defense (DoD, USDOD, or DOD) is an executive department of the U.S. federal government charged with coordinating and supervising the six U.S. armed services: the Army, Navy, Marines, Air Force, Space Force, ...

choosing to concentrate on the U.S. Air Force's Blue Scout sounding rocket program.Comments on "Caleb" by Joel W. Powell and K.W. Gatland
''Spaceflight'' magazine.

Launch history

References

{{Air-launched launchers Air launch to orbit Equipment of the United States Navy Sounding rockets of the United States Anti-satellite missiles Abandoned military rocket and missile projects of the United States

Development

Operational history

Launch history

See also

References