Hi-Ho

NOTS-EV-2 Caleb

Caleb launch vehicle on loading trolley
Function	Expendable launch system Sounding rocket Anti-satellite weapon
Manufacturer	United States Navy
Country of origin	United States
Size
Height	4.9 metres (16 ft)
Diameter	0.6 metres (2 ft 0 in)
Mass	1,350 kilograms (2,980 lb)
Stages	One (test) Two (test) Four (unflown)
Capacity
Payload to LEO	7 kilograms (15 lb)
Launch history
Status	Retired
Launch sites	Point Arguello San Nicolas
Total launches	2 Caleb 2 SIP 3 Hi-Hoe
Successes	1 Caleb (1 stage) 2 SIP 1 Hi-Hoe
Failures	1 Caleb 2 Hi-Hoe
First flight	Caleb: 1960-07-28 SIP: 1961-10-01 Hi-Hoe: 1961-10-05
Last flight	Caleb: 1960-10-24 SIP: 1962-05-05 Hi-Hoe: 1962-07-25

The NOTS-EV-2 Caleb, also known as NOTS-500, Hi-Hoe and SIP was an expendable launch system, which was later used as a sounding rocket and prototype anti-satellite weapon. It was developed by the United States Navy's Naval Ordnance Test Station (NOTS) as a follow-up to the NOTS-EV-1 Pilot, which had been abandoned following ten consecutive launch failures. 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, or SIP, whilst three more were used as sounding rocktets, under the designation Hi-Hoe. These derivatives flew until July 1962, when the Hi-Hoe made its final flight.

The Caleb was originally designed as a fast-response orbital launch system, to place small reconnaissance satellites, 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, who were responsible for all other orbital launches conducted by the US military, and no attempts to launch the vehicle into orbit were made.

Caleb was an air-launched rocket, with its two launches being conducted from F4D Skyray #747, the same aircraft used in the Pilot trials. Hi-Hoe was also air-launched, however 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.