COSPAS-SARSAT

Established in principle by the USSR, US, Canada, and France in 1979, COSPAS-SARSAT is designed to relay distress signals from the site of aircraft and ship accidents or other emergency situations to special Local User Terminals (LUTs) which in turn notify the appropriate search and rescue teams. Distress signals are transmitted on either 121.5MHz (15 km location accuracy) or 406 MHz (2 km location accuracy) and rebroadcast on 1544.5 MHz to LUTs. Over 600,000 beacons are deployed worldwide, saving more than 4,500 lives since the system began operations via Kosmos 1383 in September, 1982. The number of deployed beacons could double by the end of 1995 (References 444-445).

The Ukrainian Musson Corporation of Sevastopol has been-the primary supplier of COSPAS distress beacons for the Russian Federation. The ARB (Emergency Locator Beacon)- 121 system employs the 2.2 kg Poisk-R emergency locator beacon and the 1.8 kg Poisk-R emergency distress signal transmitters for the COSPAS lower band, while the more popular 4.5 kg ARB-406 emits the higher frequency distress signal every 50 seconds for up to 48 hours with a power of 5 W (Reference 131). Veteran cosmonaut G. S. Titov is now President of a new Russian firm called Kosmoflot which will also manufacture navigational equipment and COSPAS beacons. The primary Russian LUTs are located at Arkhangelsk, Moscow, Novosibirsk, and Vladivostok. The Russian Federation has also proposed the creation of a rocket-borne rescue system called VITA which would employ converted SS-18 or SS-19 ICBM's to send rescue equipment to the site of an accident identified by the COSPAS-SARSAT system (Section 2.9)

1976-1980 KOSPAS-SARSAT

The idea of using satellites to perform a search and rescue [SAR] function dates back to 1959 when Space Electronics Corp. made the proposal to NASA and DARPA. This gained no support until the mid-1970s, when a U.S. interagency group recommended NASA to evaluate the technique. Initially this called for the distressed craft to carry a small emergency locator transmitter which would be turned on by impact or manually and transmit a distinctively modulated signal at 121.5 MHz and 243 MHz, the civil and military distress frequencies. The satellite would rebroadcast the received beacon signal to a ground station, which would determine the satellite's position at the instant of zero beacon-doppler shift. The distressed craft would be somewhere along the line perpendicular to the satellite's ground-track at that time and the rate of change of the received beacon-frequency would be a measure of its distance from the sub-satellite point.

Congressional action resulted in distress beacons becoming mandatory after July 1974 but similar action to establish a network to monitor such signals was not forthcoming. Scientists at NASA's Goddard SFC found that the distress beacon carrier frequency, especially from the very low cost units developed for general aviation, was not sufficiently stable for direct processing by the method outlined above. A new 406 MHz beacon system, still under evaluation, was specially designed for satellite system use. The more stringent requirements on transmitter-frequency stability should permit rapid, simple beacon-doppler processing on board the satellite using microprocessor techniques. This means that the position-fix, made by the satellite can be stored on board and later transmitted to Earth when the satellite comes in range of a local user terminal, ensuring global coverage for all distressed craft, regardless of whether there is a local user terminal in the region. In order to avoid possible interference from other beacons in the same area, the beacon will transmit for 440 milliseconds every 50 s. The silent interval will be changed slightly every cycle to prevent two beacons repeatedly transmitting simultaneously. (89)

The processed signal would be transmitted to Earth digitally in the L-band at 1.544 GHz. In March 1977, a technical team from the Soviet Union was briefed at Goddard SFC by NASA on ways in which the Soviets might participate in the proposed NASA-Canada SAR demonstration. A proposed experimental program was developed in which one or more Soviet satellites would be equipped with SAR transponders and Soviet ground stations would be established for SAR operations. In addition, the Soviet activity was to be compatible technically and in schedule with the NASA-Canadian program. (90)

By the beginning of 1980, NASA had commenced modifications of NOAA spacecraft and signed interagency understandings with the U.S. Department of Transportation, NOAA, and DOD. Internationally, an agreement had been signed during 1979 between NASA, the Canadian Department of Communication [DOC], and the French National Center for Space Study [CNES] which provided for SAR instrumentation to be carried onboard three U.S. NOAA operational meteorological spacecraft for a 15-month demonstration (called SARSAT). A second agreement signed between the SARSAT parties and the Soviet Union during 1979 established interoperability between the SARSAT system and a similar Soviet system (called KOSPAS). The KOSPAS-SARSAT agreement, which entered into force in August 1980, provided for a cooperative effort which would allow a more effective demonstration and evaluation to take place than would have been possible for either system alone. The Soviets were to launch at least two interoperable spacecraft beginning in mid-1982.

Roman Chernyayev, Deputy Director of the Central Institute of the Merchant Marine in Leningrad, speaking to TASS in 1981, said that full-scale testing of the system was planned for 1983 and that test operation of the system was scheduled for 1984. (91)

Further details of the Soviet approach are given in their submission to the Second United Nations Conference on the Exploration and Peaceful Uses of Outer Space and in Agadzhanov's booklet on Communications Satellites. (92)

The KOSPAS-SARSAT system (KOSPAS is a Soviet acronym for "Satellite System for Locating Vessels and Aircraft in Distress") operates in close cooperation with Inmarsat, IMCO and the International Consultative Committee on Radiocommunication [C.C.I.R.J. The latter is a body within the I.T.U., engaged, in particular, with the coordination of developments and experiments conducted by countries in choosing optimal principles of transmitting signals from marine EPIRBs (Emergency Position-Indicating Radio Beacons) and aviation ELTs via satellites.

A Radio Moscow home service report at the beginning of 1983 made reference to the "Moscow information receiving center for the Poisk (Search) satellite system." 55 This name has not come into general usage. The center was reported to be testing a new type of emergency position indicating radio beacon (EPIRB) which would make it possible to determine the location of an accident to an accuracy of 2 to 3 km rather than the 10 to 20 km possible at that time. New information-receiving centers were to be built in Vladivostok and Arkhangelsk. Later that year it was reported that the project had already saved more than 30 lives. 56

The KOSPAS-SARSAT project consists of two distinct experiments involving separate frequencies. The first experiment uses the existing family of ELTs and EPIRBs which transmit at 121.5 and 243 MHz. The second experiment uses ELTs and EPIRBs specifically designed to transmit at 406 MHz. The key advantage of use of 406 MHz is that its higher power and improved frequency stability will greatly enhance the overall system performance by comparison with the 121.5/243 MHz system. In addition, the 406 MHz data message can be transmitted with information containing the vessel's code, its flag, type of vessel, the nature of damage or the time elapsed. The parties have agreed upon emergency procedures and the formats of exchange of emergency and operational information between the KOSPAS and SARSAT centers. Both systems are being developed so that their technical characteristics will be compatible and they will be able to function effectively both independently, separately, and together, in coordination.

Some satellites of the system will be placed in circular circumpolar orbits at an altitude of about 1000 km, as currently employed by navigation satellites in the Kosmos series. When the signal received is decoded a determination is made of the coordinates of the object in distress (initially with a precision of 2 to 4 km). It is calculated that, in the initial stages of experimental operation, it will take an average of no more than 2 hours from the moment the distress radio buoy is switched on until its signal is received by the "rescue" satellite. Calculations have also shown that the chances for saving objects in a state of distress and people having met with catastrophe increase dramatically with this short notification period.

Local User Terminals [LUT's], ground stations for the reception of satellite search and rescue information, are being established in Moscow, Archangel'sk, and Vladivostok for the KOSPAS system, and in the United States (in Illinois, California, and Alaska), Canada (in Ottawa), and France (in Toulouse) for the SARSAT system. Head of the Kospas project is Yuri Zurabov and Yuri Makarov is its technical manager.

Levels of financial contributions, in millions of U.S. dollars, have been estimated at U.S.S.R., approximately 40; U.S.A. 29.0 (NASA 24.0, DOD/USAF 2.5, DOT/Coast Guard 2.5); Canada, 14.0; and France, 10.0.

References:

A. SOVIET SPACE PROGRAMS: 1976-80 (WITH SUPPLEMENTARY DATA THROUGH 1983), UNMANNED SPACE ACTIVITIES, PREPARED AT THE REQUEST OF Hon. JOHN C. DANFORTH, Chairman, COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION, UNITED STATES SENATE, Part 3, MAY 1985, Printed for the use of the Committee on Commerce, Science, and Transportation, 99th Congress, 1 st. session, COMMITTEE PRINT, S. Prt. 98-235, U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1985

55. Moscow home service, 1500 GMT, Jan. 23, 1983.

56. TASS, 1357 GMT, May 3, 1983. By the end of 1987, more than 1000 lives had been saved by COSPAS/SARSAT.

88. Yasharoff, N. Spaceflight, vol. 20, No. 5, May 1978, p. 178.

89. Klass, P.J. Aviation Week & Space Technology, vol. 118, No. 9, Feb. 28, 1983, pp. 75-81.

90. Protocol on Cooperation in an Experimental Satellite System for Search and Rescue of Vessels and Aircraft in Distress, signed at Greenbelt, MD, Mar. 18, 1977.

91. Moscow, Tass in English, Aug. 17, 1981, 1554 G.m.t.

92. Agadzhanov, P.A., et al. National Paper: U.S.S.R., Sept. 2, 1981, p. 73.