[4][5] To perform their Pakistani mission, the two prototypes were equipped with high-gain phased array antennas in their wingtips, an extended radome, and a canister package developed by HRB-Singer known as "System 365" installed in the bomb bay.

The wing design created tremendous lift even at idle speeds; the aircraft was airborne after a takeoff roll of only 2,600 feet (790 m) at sea level.

Despite some shortcomings the design had shown exceptional performance and Big Safari authorized the First Chip production program in August 1963 for the fabrication of 19 more RB-57Fs from existing B-57 airframes.

They returned to the United States in February 1964 and were assigned to the 58th Weather Reconnaissance Squadron at Kirtland Air Force Base, New Mexico.

In March 1968 the 63-13286 prototype was also upgraded to the First Chip standard and the two phases renamed in accordance with newly established Big Safari nomenclature that required two-word code names beginning with "Rivet."

[8] Two aircraft[N 7] were additionally modified to carry the Bulova 707-1000 long range camera, which had a 240-inch (6096mm) focal length that resulted in its reference designation of Big Item.

These high-altitude side-looking cameras, secured by a roll-stabilized mount, could take oblique shots at 5 to 15 degrees below the horizon up to 60 nautical miles (110 km) range from the aircraft and provide 30-inch (76 cm) high resolution images.

[N 11] Older accounts of the Little Cloud operation give the original reason for the RB-57F deployment to Pakistan as being the monitoring of Communist Chinese nuclear tests, which began in October 1964.

[18] All three aircraft were involved in directing attacks on an Indian radar station at Amritsar, and during these operations, one of the PAF B-57Bs was shot down in error by Pakistani anti-aircraft artillery.

Despite the plane's suffering major structural damage and sustaining over 170 holes, the pilot managed to nurse the aircraft back to Peshawar, where he made a successful forced landing.

From April to October 1965 the two RB-57s each underwent an annual three-month depot maintenance recycle at the General Dynamics plant in Fort Worth required by Big Safari rules, which was where Pee Wee III No.

[20] One member of the USAF crew sent by the Big Safari office to retrieve the damaged RB-57 doubts that the aircraft was used in the role described as its sensors were tailored specifically for the telemetry mission and of no value in combat, and that it operated in an area away from Indian airspace.

[22] The Rivet Flash B-57 was overflying a Pakistani radar site at Rahwali, 70 miles (110 km) from Amritsar, when it was shot down on 11 September 1965 by its own AAA, mistaken for an IAF Canberra.

[19] The death of the PAF squadron leader flying it, who was the key Pakistani member of the Little Cloud operation, precipitated the rapid exit from Pakistan of the RB-57Fs.

On 14 December 1965, operating TDY from Incirlik Air Base in Turkey as "Big Rib 06", it disappeared during a mission over the Black Sea whose route passed through telemetry range for Soviet ICBMs.

Although searches for the wreckage continued until 28 December,[23] only small bits and pieces of it were recovered, although unsubstantiated reports asserted that the two crew members had been captured alive by the Soviets.

[20] Single- and double-engine engine flameouts plagued the program between June 1965 and July 1967, when fuel control problems were finally corrected.

By May 1968 stress cracks began appearing in the wing spars and ribs of all the RB-57Fs outboard of the main engines and numerous groundings forced the cancellation of many operational missions.

Rivet Chip 10 (63-13297) crashed on 7 November 1966 when it descended below its assigned altitude while on Instrument Flight Rules during a night approach to Kirtland AFB in bad weather and struck the summit of Sandia Crest.

NASA first provided funding to modify and operate RB-57F 63-13501 to support the Earth Resources Satellite Program, with modifications taking place at Fort Worth between 26 September 1968 and 14 July 1969 as Project Rivet Rap.

The Rivet Rap was therefore modified to carry aerodynamically faired, plug-in pallets developed by General Dynamics to house both NASA and Air Force primary mission equipment.

[27] They are designated the NASA High Altitude Research Project at the Johnson Space Center in Houston, Texas, and operate from Ellington Field JRB.

Three of the four WB-57F aircraft used by NASA remain in operational service with registries expiring in 2021 or 2022, conducting a variety of civil tasks worldwide: For NASA operations, the aircraft often carry a three-ton (2,700 kg) data-gathering sensor pallet in the former bomb-bay underneath the center fuselage that can include the Airborne Remote Earth Sensing (ARES) instrument to calibrate satellite data, a combined hyperspectral imager/radiometer with a two-dimensional focal plane array, and a variety of cameras.

At the end of the assigned track the boxes then automatically close at high altitude and after landing the adhesive strip is removed and returned to the U.S. for analysis.

After some local sorties, possibly to test the onboard equipment, the aircraft departed to Kandahar Airport, Afghanistan via NSA Souda Bay, Crete.

The aircraft then flew a number of sorties out of Kandahar, presumably carrying a classified sensor package and returned to Ellington Field via Souda Bay and Mildenhall.

Through 28 missions, the WB-57 collected AVIRIS (Airborne Visible / InfraRed Imaging Spectrometer) data that could be analyzed to provide information on mineral assemblages that could aid in resource and hazards assessments.

[34] Reports surfaced in March 2011 that NASA 926 was observed performing flights from Nellis AFB testing a new sensor package being carried in its pallet system payload bay over the period from 15 November 2011 until 1 February 2012.

The aircraft was then dismantled and trucked to Sierra Nevada Corporation (SNC) at Centennial Airport, Colorado where it was refurbished to flying condition and flown to Ellington AFB on 9 August 2013.