Resurs-F

One of the oldest and still highly capable methods of performing space-based Earth observations is basic photography in one or more spectral bands with return of the film to Earth for development and analysis. This technique was first perfected in the USSR in 1962 but was not officially converted into a civil-oriented system until 1979. Until recently, two similar types of 3rd generation spacecraft, Resurs-F1 and Resurs-F2, have been flown several times a year for the Russian Ministry of Ecology and Natural Resources. The Resurs-F1 program apparently ended in 1993, and the last Resurs-F2 mission was expected in 1995. Plans to introduce improved Resurs-F1 M and Resurs-F2M may be abandoned.

With two missions in 1993, the Resurs-F1 program achieved 50 orbital flights (and two launch failures) during its 14-year operation with missions lasting up to 23 days. Based on the Vostok spacecraft developed in the late 1950's, Resurs-F1 spacecraft were designed and manufactured at the Samara (formerly Kuybyshev) Photon Design Bureau and the Progress Plant both of the Central Specialized Design Bureau. The Resurs-F1 vehicle, launched by the Soyuz-U booster from Plesetsk, is 7 m long with a maximum diameter of 2.4 m and a mass of 6,300 kg and is comprised of three major modules.

The central portion of the spacecraft is a sphere of 2.3 m diameter and a mass of about 2.4 metric tons containing the photographic apparatus, electronic control equipment, and the recovery system. This section is secured to a 3 m long, 2.4 m wide service and reentry propulsion module with four straps which are released after retrofire. On the opposite end of the recoverable capsule is a 1.9 m by 1 m propulsion unit used for minor orbital adjustments. The propulsion unit is also jettisoned prior to reentry and may carry additional, releasable payloads (up to 75 cm by 90 cm) for secondary missions. Secondary payloads up to 30 kg or more can also be carried inside or outside the recoverable capsule for return to Earth.

Two photographic systems are normally available on Resurs-F1 missions: the SA-20M with a KFA-1000 camera and the SA-34 with its KATE-200 camera. The former operates in two spectral bands (0.57-0.68 µm and 0.68-0.81 µm) with a ground swath of 80 km and a resolution of 5-8 m. Up to 1,800 frames measuring 300 mm by 300 mm may be taken on each mission. The SA-34 operates in three spectral bands (0.51-0.60 µm, 0.60-0.70 µm, and 0.70-0.85 µm) with a ground swath of 225 km and a resolution of 15-30 m. The SA-34 has a capacity of 1,200 frames, each 180 mm by 180 mm. All film frames of both systems are etched with codes to identify vital camera parameters, including camera and frame number, film number, focal length, and timing codes (References 704-709).

Each Resurs-F1 spacecraft carries multiple camera systems. The Priroda 4 payload configuration includes two SA-20M and three SA-34 devices. One of the SA-34's is linked to a SA-33 stellar camera to provide simultaneous star backgrounds for precise geographical location determination. The SA-34 survey regions are aligned with common axes, but the SA-20M cameras are each oriented 8 degrees off nadir for a total separation of 16 degrees between the camera axes, permitting a 5% image overlap when both systems are operated simultaneously. Six modes of operation are possible with 2-5 camera systems operating at one time. Although the maximum spacecraft lifetime is 25 days, the electrical system fed only by storage batteries limits active operations to no more than 14 days. The last two Resurs-F1 missions were flown in 1993 as Resurs-F 18 (June-July) and Resurs-F 19 (August-September), both on 17-day missions.

In 1987 a more capable version of the Resurs-F1, called Resurs-F2, began operations. The most significant improvement was the addition of two small solar arrays attached to the base of the orbital propulsion unit which permitted active missions for up to a full month. The first mission in late 1987 by Kosmos 1906 was not entirely successful, and the spacecraft was intentionally destroyed in orbit. Four more missions were conducted during 1988-1990, followed by three flights in 1991-1992.

The Resurs-F2 photographic system differs from that of its predecessor. The SA-M system with its MK-4 camera combines the high resolution of the SA-20M with the multi-spectral capability of the SA-34. Resurs-F2 offers a ground swath of 150 km with a resolution of 5-8 m in six spectral bands from 0.40 µm to 0.86 µm. As many as 2,700 photographs with image motion compensation and frames 180 mm by 180 mm can be shot on a single mission. The SA-M is also linked to the SA-3R stellar camera which serves the same purpose as the Resurs-F1's SA-33 (References 704-709).

Prior to 1991, Resurs-F2 spacecraft would normally maintain a mean altitude of between 260 km and 270 km, requiring only two orbital maneuvers per 30-day mission. Beginning with Resurs-F 10 (21 May 1991), a new profile was chosen with mean altitudes between 225 km and 235 km but with a corresponding requirement to perform orbital adjustments more frequently, e.g., six times per mission. This pattern had previously been used primarily by the fourth generation, topographic mapping satellites which debuted in 1981 and are flown at inclinations of 65 degrees and 70 degrees. The subsequent Resurs-F2 flights, Resurs-F 13 (21 August 1991) and Resurs-F 14 (29 April 1992), were virtually identical to Resurs-F 10, both in character and duration. Resurs-F 17 (May-June 1993), the only Resurs-F2 of the 1993-1994 period, also followed this pattern.

Reference to a Resurs-F3 spacecraft appeared in 1994, and it now appears that this designation applies to the Resurs-T satellite flown for the Ministry of Defense. The spacecraft is virtually identical to the Resurs-F1 but carries the KFA-3000 camera system with 2-3 m resolutions. Two Resurs-T missions were flown during 1993-1994: Kosmos 2260 (July-August 1993) and Kosmos 2281 (June 1994) (References 708 and 710).

During 1992 the Russian Federation made available to the commercial market Earth observation photography acquired by military photographic reconnaissance satellites. In particular, two types of analog optical images taken by the more modern fourth-generation satellites were made available. Ten-meter resolution stereo photographs taken by the TK-350 camera, which is a product of the Belorussia Optical Camera Company, cover a region of 180 km by 270 km with 256 gray values. Higher resolution, two-meter photographs from the KVR-1000 camera provide similar gray-level sensitivity but over a much smaller area of 40 km by 40 km (References 711-713). Since these missions remain primarily of a military nature, they are described more fully in.