Caleb (NOTS-EV- 2)

Caleb (1 stage) under F4D-1 Skyray	Caleb (2 stage ground launched, SIP)
Caleb (2 stage, Hi-Hoe)

Project Caleb was a follow-on program to the Pilot (NOTSNIK) program of the Naval Ordnance Test Station (NOTS) at China Lake.

The Caleb (NOTS-EV-2) was designed as an air-launched four-stage all-solid rocket vehicle capable of orbiting tiny satellites. The stages were a NOTS-500, an ABL X-248, a NOTS-100A and a small spherical NOTS motor. Several modification with diferent motors for the third and fourth stage were proposed. The orbital Caleb program was cancelled under pressure from the USAF which wanted to monopolize the satellite launching program, but the NOTS continued the program for suborbital missions.

The air launches in the Caleb program took off from Inyokern, Point Mugu NAS.

The first test launch, with one live stage only, occurred on 28 July 1960 from an F4D-1 Skyray aircraft and was successful. A second flight in October that year was to fly a two stage vehicle but this time the second stage failed to ignite.

The Caleb rocket was also used in the SIP (Satellite Interceptor Program) project, an attempt to develop an air-launched ASAT (anti-satellite) missile. Two two stage Caleb vehicles were ground-launched from San Nicolas Island in SIP-related tests in October 1961 and May 1962, respectively, which apparently both were successful.

Starting on 5 October 1961, three sub-orbital two-stage Caleb rockets were launched under the U.S. Navy's Hi-Hoe sounding rocket program. These flights used an F4H-1 (F-4B) Phantom II aircraft for higher performance. The first two Hi-Hoe flights were unsuccessful, again due to upper-stage failures, but the final one on 26 July 1962 reached an altitude of 1167 km. These versions featured a cylindrical instead of a tapered fairing.