The ARPA mini-RPV program began shortly thereafter (NITE GAZELLE), in early 1972, as an effort
toward the type of lightweight, compact, low-cost sensor/laser target designation system
that had been recommended by Dr. Foster and the DSB. The resulting PHILCO-FORD
RPV had exchangeable modular payloads, the RPV carrying the daytime TV-laser target
designator configuration called PRAEIRE, and the same RPV carrying a lightweight FLIR
and laser target designator combination, called CALERE. The propulsion system was an
adaptation of an engine that had been used in lawn mowers. The radio command was also
adapted from one commercially available, and was operated by a pilot and a sensor
controller. Vehicle stabilization was provided initially by an electrical field sensing system
developed by John Hopkins Applied Physics Laboratory; later, gyro stabilization was
apparently used. Optical stabilization was provided for the high resolution TV, and the
laser designation systems used the same optical sighting train as the TV, as had been done in NITE GAZELLE. PRAEIRE I, the first of two versions produced under the ARPA
program, weighed 75 lb and had a 28 lb payload and a two-hour flight time. It was
described as an austere, low-cost system, with a cost estimate, in mass production, of
$10,000/copy. The first flight of PRAEIRE I occurred in 1973 after a joint ARPA-Army
program had been started. However, there were some difficulties with performance of
the CALERE IR payload, requiring further development.
The Army's effort in response to the DoD initiative included, besides the joint
program with ARPA, trials of several other types of available mini RPV's in a program
intended to gain a better determination of requirements, called "little r." Part of the 'little
r" program also was a phased developmental effort of an entire RPV system, together with
ground control and support, which led to the Lockheed AQUIJLA, beginnin'g in late 1974.
During the 1972-1975 period, ARPA produced PRAEIRE II and CALERE II,
again built by Ford, based partly on the experience with the previous vehic!es, and partly to
reduce radar and IR signatures. Sensors and propulsion were also improved, with flight
time capability extended to nearly six hours. The extended range vehicle PRAEIRE IIB
had nearly twice the weight of PRAEIRE I. An electronic warfare payload was also
developed. CALERE III was also produced, including a new, lighter FLIR-laser target
designator combination.
In late 1978, a joint ARPA-Army effort commenced to develop an integrated
communication-navigation system. A little later a PRAEIRE RPV successfully
demonstrated the capability of designating a tank target for the Army's COPPERHEAD
cannon-launched guided projectile.