ZENIT Space System
ZENIT Space System
In 1961 all activities related to the development and manufacturing of observation satellites were put under the responsibilities of the enterprise. In autumn 1962 the first Zenit-2 SC reworked and manufactured at the Progress plant was injected into orbit. After successful performance of the test program, the Zenit-2 SC was put into regular operation.
The construction of Zenit-2 consisted of the spherical descent module and the instrument module. The service lifetime of the first in our country imaging spacecraft was only 4 days. That was great achievement even for those times.
On the expiry of the service lifetime, the retropack turned on, the descent module separated from the instrument module and re-entered into the Earth atmosphere. At an altitude of approximately 10 kilometers, the parachute system activated and the descent module landed. On the place of landing a search-and evacuation team opened the descent module, took out cassettes, and delivered them to a customer, where films were processed further. Received information was used for a wide range of important for our country tasks, from strategic to national economic.*
The Zenit-4 SC
The Zenit-4 SC was a version of Zenit-2 with increased lifetime in orbit and imaging efficiency, improved spacecraft stabilization accuracy, which enabled imaging without distortion, and other enhanced performance characteristics for imaging by long-focus photographic equipment. A brand new imaging hardware with focal distance up to 3 meters was developed for the Zenit-4 SC. The Zenit-4 SC went on its maiden flight on November 16, 1963. Over a year, as ordered by S.P. Korolev, all activities related to the development and manufacturing of automated low-orbit remote sensing systems were put under the responsibilities of the ОКB-1’s subsidiary №3 headed by D.I. Kozlov and the Progress plant. In course of flight tests and regular operations there were 179 successful launches of Zenit-4 in all.*
The Zenit-2M SC, the Zenit-4M SC
In 1964, design activities on modernization of already operating spacecraft of the Zenit type were commenced. The activities resulted in two new SC: Zenit-2M for remote sensing and Zenit-4M for detailed observation. Both spacecraft were put into regular operation in 1970.*
In 1969, on the basis of the Zenit SC JSC SRC «Progress» produced Zenit-2n/h for national economic development. Its imaging hardware was charged with black-and-white, colored, and multispectral films. Zenit-2n/h successfully accomplished its mission and completely performed the flight test program.*
The Zenit-4MT SC
Zenit-4MT was developed on the basis of the former designing. Its wide-swath imaging hardware, accurate reference to the stellar sky and the spacecraft orbital altitude enabled to use received information for making various types of map materials.
For improving its performance Zenit-4MT was equipped by the orbit-adjustment propulsion system ensuring spacecraft maneuvering into predetermined observation areas. The Zenit-4MT was injected into orbit on December 27, 1971.
The unique information received by the Zenit-4MT made it possible for making new and correcting old large-scale topographic maps of national and foreign territories.*
* The article was written based on the materials taken from book - Spacecraft building:research and development by JSC SRC «Progress» / edited by A.N.Kirilin- Samara: Publishing House, AGNI, 2011-p.280.