Quill (satellite)
| General information | |
|---|---|
| Manufacturer |
Boeing Goodyear University of Michigan's Willow Run Laboratories Lockheed (Agena) |
| Country of origin |
 United States |
| Bus | Agena-D |
| Applications | Radar imaging |
| Orbit regimes | Low Earth |
| Operator | US National Reconnaissance Office |
| Lifetime | 4 days |
| Derived from | KH-4 |
| Production | |
| Status | Out of service |
| Built | 3 |
| Launched | 1 |
| Retired | 1 |
| First launch | OPS 3762, 1964-12-21 |
| Last retirement | OPS 3762, 1964-12-25 |
| Typical spacecraft | |
| Average mass | 1,500 kg (3,300 lb) |
Quill was an American reconnaissance satellite programme of the 1960s, which employed synthetic aperture radar to produce images of the Earth's surface. Only one satellite, OPS 3762,[1] was launched.
Two more units, a backup flight model and an engineering model, were produced. These first radar imaging spacecraft were not intended to be deployed operationally, since it was known that this system’s resolution, inferior to that of concurrent airborne systems, would not serve that purpose. Instead, its goal was to prove that radar-wave propagation through a large volume of the atmosphere and ionosphere would not dangerously degrade the performance of the synthetic aperture feature.
Quill satellites were based around the Lockheed RM-81 Agena-D, which also served as the upper stage for orbital insertion.[2] Boeing, Goodyear and the University of Michigan's Willow Run Laboratories designed and constructed the payloads.
After OPS 3762 was launched on 21 December 1964, imaging was commanded intermittently during both day and night for four days by ground controllers with radio contact from two U.S. locations. Imaged swaths were therefore limited to North American areas within the line-of-sight horizons of those stations, and further, by the controllers, to areas within NORAD (North American Air Defence) territory.
On-board photographic films, containing the highest-quality image data, were returned in the same type of vehicle used on U. S. photo satellites of that time. Slightly lower quality down-linked real-time data allowed image interpreters to define the boundaries and contents of early swath images before the on-board film was released from the satellite (a capability not then possible with film-camera sensors), and even to measure the velocities of some recognized ground objects.
An incidental result of the experiment was several vivid demonstrations that images having Quill’s detail (and even considerably coarser detail, such as that of the 14-years-later SEASAT spacecraft) would indeed be useful for wide-area environmental monitoring and research studies of the earth and other planets. One especially notable such image showed, in spite of intervening dense cloud cover and very heavy rainfall, a clear depiction of not only the extent of flooding of a Pacific coastal area, but also the extent of the debris-laden invasion of a river’s flood current several miles into the ocean, an information-gathering capability not otherwise available.
The programme was declassified on 9 July 2012.[3]
See also
External links
References
- ↑ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 8 June 2010.
- ↑ Krebs, Gunter. "Quill". Gunter's Space Page. Retrieved 8 June 2010.
- ↑ "Declassified Records". National Reconnaissance Office. Retrieved 15 July 2012.
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