The NOTS-EV-I Pilot rocket was a five-stage vehicle, but NOTSNIK is sometimes called a six-stage system, when the launching aircraft is counted as the first stage. All Pilot launches used a modified F4D-1 Skyray fighter, which carried the NOTS-EV-1 on an underwing pylon. The rocket was released in a 50° zoom climb at a speed of 740 km/h (460 mph) at an altitude of 12500 m (41,000 ft). The first and second stages of the rocket used a common airframe, and consisted of two HOTROC solid-fueled motors each, mounted diagonally opposed in a two-by-two pattern. Three seconds after release, the first stage fired for 4.9 seconds, followed by 12 seconds of coasting and the firing of the second stage. At about 80 km (50 miles) altitude, the first/second stage structure was jettisoned, followed by a 36 second burn of the ABL X-241 third stage. The fourth stage was a small NOTS-100 solid rocket, which burned for 5.7 seconds and placed the payload into an "orbit" with an extremely low perigee (about 2400 x 60 km (1500 x 37 miles). The perigee was raised to a safe 2250 km (1400 miles) by the fifth stage, a tiny motor integrated with the payload. The latter had a diameter of 20 cm (8 in), weighed only 1.05 kg (2.3 lb) and had a single instrument, a very primitive infrared line-scanning device to make crude IR images of the ground. This device effectively meant that the NOTSNIK satellite could be seen as a space-based surveillance platform, and therefore the whole effort was top secret at that time.
After two failed ground launches of the first/second stage HOTROC motors in early July 1958, the first air-launch of a Pilot vehicle was attempted on 25 July. The launch was successful as long as the vehicle was visually tracked, but there was no confirmed radio contact afterwards. During August 1958, five additional NOTSNIK launches were attempted, but all except one ended very early after release of the rocket because of failures of a rocket motor and/or the vehicle's structure. On that second possibly successful flight, on 22 August, again no definite radio contact could be established with the possibly orbiting payload. Although it is reported that ground stations received a few very weak signals, which could have come from the satellite, it remains very doubtful whether the payload did actually reach the planned orbit.

Project Caleb was a follow-on program to the Pilot (NOTSNIK) program of the Naval Ordnance Test Station (NOTS) at China Lake. Originally, the Caleb vehicle, also designated NOTS-EV-II, was to be a launcher for small orbital payloads, like quick-reaction reconnaissance satellites. However, the orbital Caleb program was soon cancelled, reportedly because of pressure from the USAF which wanted to monopolize the satellite launching program. The NOTS-EV-2 was designed as an air-launched four-stage all-solid rocket vehicle. The stages were a NOTS-500, an ABL X-248, a NOTS-100A and a small spherical NOTS motor.
The first test launch, with one live stage only, occurred on 28 July 1960 from an F4D-1 Skyray aircraft (the same as used for the Pilot tests), and was successful. A second flight in October that year was to fly a vehicle with two live stages, but the second one failed to ignite. 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 aircraft for higher performance. The first two Hi-Hoe flights were unsuccessful because of upper-stage failures, but the final one on 26 July 1962 reached an altitude of 1167 km (725 miles). The Caleb vehicles for Hi-Hoe were of a significantly modified design, but the drawing is apparently of a proposal for a sounding rocket based on the AIR-2 Genie.
The NOTS-EV-2 rocket was also used in the SIP (Satellite Interceptor Program) project, an attempt to develop an air-launched ASAT (anti-satellite) missile. Two NOTS-EV-2 vehicles were ground-launched in SIP-related tests in October 1961 and May 1962, respectively. The ASAT project was possibly also known as "NOTSNIK II".