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Prospects of Small Geostationary Communication Satellites
Vladimir KIRILLOV
Current space telecommunication problems
At present telecommunications are the most profitable sphere of space commerce. It comprises not only services to transmit TV broadcasts, telephone conversations, data etc., but also the manufacture of spacecraft ensuring such services.
A geostationary orbit (GSO) in the equatorial plane at the altitude of about 36,000 kilometers is the best for such spacecraft. In such an orbit a spacecraft makes one revolution around the globe during the same time as the Earth makes a revolution around its axis. As a result the satellite remains at the same point above the equator of the Earth simplifying the orientation of the antennae of ground users on it.
This weight of geostationary communication satellites made around the world has been steadily growing throughout the past two decades. While in 1985 the average weight of a satellite was 1,800 kilos, in 1999 it reached some 3,850 kilos. If the trend continues by 2005 the average weight of spacecraft placed in geostationary transfer orbits (GTO) should be around 4,500 kilos. According to Lockheed Martin forecasts, the weight of some may reach 5,500 kilos with the spread being ± 680 kilos.1
The forecast is compatible with the latest contracts for the production of communication satellites. Thus, at the beginning of 2002 the INTELSAT international satellite communication company officially announced that it had ordered two satellites of the INTELSAT 10 family based on the Eurosat 3000 basic platform each weighing 5,700 kilos from Astrium, the aerospace division of the European company EADS. The satellites are to be launched to a GTO2 in 2003 with a Proton-M LV of International Launch Services company and a Zenit-3SL LV of Sea Launch company.3 However, both launch vehicles will have to be upgraded to increase their payload in order to place such heavy spacecraft as INTELSAT 10 in orbit.
A world leader in commercial launches - Arianespace of Europe - foreseeing such a growth of communication satellite weights in the 1990s developed a new family of Ariane 5 LVs. So far Ariane 5G LV has placed a payload of 6.3 tonnes in GTO. However, already now the company is developing modifications with greater payloads taken to GTO: Ariane 5ECA - 10 tonnes (the first launch is slated for July 2002), Ariane 5 ECB - 12 tonnes (2006) and Ariane 5ECB with the new Vulcan 2 engine of the main stage - 15 tonnes (2008).
The rise in the satellite weight stems from the landslide growth of the telecommunication service market in the 1990s. The number of space communication operators has been steadily growing while the number of positions in GSO is steadily shrinking. According to international technical requirements, satellites broadcasting in the same frequencies should not be placed in GSO at a distance of less than ±1 degree. Hence the International Telecommunication Union is conducting complex adjustments between numerous applicants for frequency positions in GSO.
The market of telecommunication services continues to expand despite several economic crises in Asia and South America. Leading telecommunication operators are trying to resolve the problem of growing demand for transponders on GSO in two ways. One way is to further boost the weight of communication satellites through installing an increasing number of transponders. However, in this respect there are certain restrictions related to the weight of space buses, their energy supplies and the capability of existing LVs to place payloads in GTO and GSO. That is why several companies have started placing several communication satellites in their orbital positions and thus partly resolving the problem of overcrowding in GSO.
However, during the past few years several space companies (mainly Russian) have come out with projects of small communication satellite that fundamentally differ from the general tendencies on space telecommunication market. Still, their designers believe that small satellites will seize a fairly big market segment in the nearest future.
Small communication satellite segment
The latest small satellites have a number of advantages compared to the traditional big-sized communication satellites. They facilitate the stage-by-stage introduction of space communication services on regional markets adapted to the development of the ground infrastructure, changing requirements of operator companies and existing frequency resources. The latter is especially important. In the past few years the process of international coordination of satellite networks has become especially cumbersome. It requires much time and significant material resources (as rule coordination drags out for several years) without always producing positive results. The main reason for this is the avalanche of applications that clearly exceed the capabilities of GSO and the existing frequency resources. The registration of new telecommunication networks in C and Ku bands is extremely complicated, if not impossible. For instance, the COM 4/4 BKP-2000 resolution of the Radiocommunication Bureau of the International Telecommunication Union admits that the bureau had such a large number of applications for coordinating satellite networks that with the existing speed of processing and even without new applications it could take the bureau over three years to handle them. Hence, communication administrations and operators will probably have to wait for at least three years for the bureau to publish their coordination applications because of delays with handing applications for satellite communication and broadcasting networks submitted to the bureau. Due to the five-year deadline for commissioning networks they will face a shortage of time for coordination. This seriously undermines the possibilities of the networks to offer services and correspondingly gain returns on their investments. The use of small satellites gives a chance to offer telecommunication services even in relatively small, conflict-free frequency bands.
The application of small communication satellites opens up the opportunity to increase the throughput capability in any orbital position occupied by some satellite (on condition that there remains an unused frequency resource) by launching another satellite as the payload and demand for onboard capacity grow.
The gradual application of the frequency resource of an orbital position allows optimizing the make-up and parameters of the payload of each following small communication satellite to better satisfy the needs of operator companies that in their turn depend on the constantly changing requirements of end users.
Today the lifetime of heavy communication satellites reaches 15 years. During such long period information technologies develop so rapidly that the requirements of end users to the range and nature of space telecommunication services can change radically. At the same time after placing a satellite in orbit it is impossible to alter the makeup or configuration of the payload equipment to better satisfy the new market needs. The launch of a relatively cheap small spacecraft can resolve the problem.
Besides, small communication satellites have a greater launch potential. They can be launched as accompanying payload by heavy launch vehicles. They also have a wider choice of light and medium LVs and consequently a greater choice of launch schedules. As a rule small satellites are less important for the owners of heavy LVs because their contribution to launch fees is quite insignificant. In contrast the status of the main payload irrespective of the LV class or the size of the satellite gives its owner greater chances of managing the launch process, influencing the launch date, defining the destination orbit etc, which is very difficult or impossible, if a satellite is launched as accompanying payload on a heavy LV. There is also one more significant advantage: cuts in spending on satellite production (serial factor), on orbit placement and on risk insurance, which reduces the transponder cost.
In a certain sense the launch of a small satellite is also less risky because in case of an accident only a small part of the tied capacity is lost. The commercial production of satellites and broad access to launch facilities allows for the creation of a reserve of standard space buses and payload modules for rapid response to emergencies involving operating orbital systems as well as to market demands. Small satellites can also be used as an orbital reserve ready for fast transfer to virtually any position in a GSO required by the consumer (the operator company losing a satellite in orbit or its onboard capacity, or an insurance company).
The initial cost of deploying a communication system relying on small satellites is also minimal. The range of potential clients expands significantly also thanks to the reduction of the cost of starting the commercial operation of the space segment of the system. The projects become affordable for investors having or capable of attracting limited financial resources and for countries with small or medium traffic needs. The projects will offer them access to the latest information technologies.
There is also one more factor of the high economic efficiency of small communication satellites. The profitability of their use increases because a smaller number of transponders, compared to heavy communication satellites, significantly reduces the time for selling the entire capacity of an operating satellite.
Besides, small communication satellites make it possible to observe information security requirements. The armed conflict in Kosovo showed that the international nature of operator companies is no guarantee that they will stand by their obligation to offer the capacity of the space segment in a conflict situation. For instance, the broadcasting of the Serbian satellite channel RTS via Eutelsat II-F3 satellite was stopped at NATO orders. However, it is precisely in times of political or military turmoil that the task of guaranteeing communications and broadcasting becomes especially acute, in particular for conducting what is known as information warfare.
The commercial attractiveness of communication satellites depends on the price of placing a transponder in a corresponding orbital position. Economic estimates indicate that with the same standard of services and operating service life of 10-12 years, a small communication satellite is superior to a large one in the cost of placing a transponder in orbit.
A comparison of telecommunication and broadcasting systems relying on traditional heavy full-sized satellites with the cluster approach allowing for the stage-by-stage application of the frequency resource of an orbital position through the deployment of several small communication satellites launched by light LVs demonstrates the certain competitive advantages of the latter. According to the Intersputnik International Organization of Space Communications, it costs $200 million to manufacture and launch a big Express-A satellite with 24 transponders, and $34-40 million to launch a small Dialog communication satellite with 10 transponders. The production and launch times are 2-3 years and 6-9 months respectively.
However, it would be wrong to speak of small communication satellites as an all-embracing alternative to traditional heavy satellites. There are a number of tasks that can be effectively resolved only by heavy satellites. For instance, this applies to mobile personal satellite communication systems (at the present stage of development of broad aperture unfolding antennas) and multi-band military communication satellites that have to be better protected against interference and be capable of guaranteed switching of subscribers operating in different frequency bands.
Under present circumstances on the international space telecommunication market it is difficult and economically inexpedient for Russian communication satellite manufacturers to compete with world leaders in the satellite industry. But they do have a chance of seizing such a promising segment of the market as small communication satellites. However, this can hardly be done without all-round government support.
Dialog project of the Khrunichev Center
In 1999 the Khrunichev State Research and Production Space Center (the Khrunichev Center) at the Paris Air Show in Le Bourget demonstrated its advanced Yakhta generic space bus. Simultaneously it showed two of its applications: the Monitor land remote sensing satellite and the Dialog small communication satellite. The Khrunichev Center developed the space bus and its application options fully at its own expense.
The distinctive feature of Yakhta is its reliance on electric thrusters (ET) consisting of two SPD-100 stationary plasma engines manufactured by Fakel Design Bureau. There is no combustion in such engines; instead ions of inert gas are put into motion by a powerful electromagnetic field. Such engines have a much smaller thrust (merely 8.4 grams) than conventional liquid fuel rocket engines, but their specific impetus (2,500 s) is almost an order higher than in liquid fuel rocket engines. For this reason spacecraft propelled by ET cannot make fast power-consuming movements, such as the transfer of heavy satellites to GSO in a few hours. Hence, the transfer of a satellite from a low orbit to GSO is expected to take the Dialog about half year. The transfer will be conducted with the help of the Briz-KM booster, an additional solid fuel booster and ET. On the other hand, the fuel consumption on such a maneuver will be radically smaller than in spacecraft propelled by a liquid fuel rocket engine, which will reduce the overall satellite weight. As a result a small communication satellite will require a lighter LV and consequently launch expenses will be reduced.
However, the system has its shortcomings as well as evident advantages. The longer transition of spacecraft to GSO creates the need for additional protection from the radiation belts of the Earth that affect the special equipment of the satellite as well as its solar panels. Therefore, experts from the Khrunichev Center have put forward strict requirements to the designers of special equipment to ensure its protection against radiation. In addition, Khrunichev has launched additional efforts with Kvant-Radiolokatsia radar system research institute and using foreign experience to increase the stability of solar panel elements. But considering the time required for the manufacture of a Proton LV and the bureaucracy involved in obtaining permissions, it may prove much faster to launch a Rockot LV. So in the long run a Dialog may be placed in orbit even faster than a full-sized communication satellite after a contract date.
The SPD-10 engines are attached in gimbal mount in the Dialog, which enables a change of the thrust vector without having to turn the entire spacecraft. The xenon store in the satellite tanks allows boosting of the characteristic velocity to about 2,000 mps. Dialog was designed with an eye on being launched with the light Rockot LV and advanced Light Angara-1.1 and Angara-1.2 LVs. The system consists of the Yakhta generic space bus and payload module. The space bus has a weight of 375 kilos. Its body is not air tight and consists of six cell panels. The paload of the space bus is 110 kilos. Its planned service life is 8-10 years.
The payload module for the basic model of Dialog to be launched by Rockot has a weight of 110 kilos and power consumption of 1,000 W. It contains nine transponders with a bandwidth of 36 MHz: four C-band (6/4 GHz) and five Ku-band (14/11 GHz).
In addition to the basic model, the Khrunichev Center has developed several modifications of the payload module: a single-band modification with transponders for only C or only Ku bands, and dual-band for Ku-band fixed communications and L-band (1,6/1,4 GHz) for mobile communications.
In 1999-2000 the Khrunichev Center worked on the geostationary communication system project relying on Rockot light LV and Dialogue small communication satellite. The system was meant for the following purposes:
relaying telephone, facsimile and telecoded communication signals, transmitting digital data, television signals between ground stations in Russian territory,
rendering communication services to countries in Asia, Africa and South America,
supplementing or replacing one of the operating satellites, inducing Russian satellites of the Gorizont, Ekpress and Yamal types in any orbital position.
The completion of development work on the basic model of Dialog (October 2000) almost coincided with the announcement of the Intersputnik tender for its Intersputnik-100M system. The system was supposed to employ 51 communication networks (15 networks in C and Ku bands and 36 networks in S, Ka and V bands) in 15 positions of GSO (from 97o West to 153.5o East) requested by Intersputnik from the International Telecommunication Union.
On January 25, 2001 Intersputnik signed a contract with the Khrunichev Center for the manufacture and launch of Intersputnik-M1 and Intersputnik-M2 communication satellites in the framework of the Intersputnik-100M project. The satellites are to be launched from Plesetsk space center with the Rockot LV in 2003.
On February 8, 2001 the Khrunichev Center concluded a $23 million deal with the Canadian EMS Technologies Inc. for the delivery of four C/Ku band transmitter modules in keeping with the parameters announced for Dialog communication satellites. Three of the modules will be operational and one a technical mockup. The transmitters will be manufactured by the Montreal-based Space & Technology group of EMS Technologies. The company has been supplying Russia with elements for satellite communication systems for a decade.
On February 22, 2001 the Russian-European Eurockot GmbH JV founded by the Khrunichev Center (49%) and Astrium (51%) confirmed the report and described it as Eurockot's first success in marketing Rockot LV. It also said that the contract with the Canadians implies the manufacture and placement in orbit of satellites to be developed on the basis of Yakhta generic space bus. However, at the end of December 2002, Khrunichev Center CEO Alexander Medvedev complained that though almost year had passed since the signing of the contract, Intersputnik had failed to start funding the program, hence the Khrunichev Center did not hurry to build the satellite for Intersputnik.
Another project involving Dialog is likely to be carried out much faster. The Russian Satellite Communication Company (RSCC) and the Khrunichev Center signed a cooperation agreement in Moscow on October 24, 2001, under which the Khrunichev will manufacture a Dialog communication satellite and place it in an orbital position to be agreed by the sides later. The satellite should be used for commercial purposes as well as the needs of the federal government. It was tentatively decided that the satellite would function in 53o East. The size of the contract was not disclosed, but official reports said that the deal between RSCC and the Khrunichev Center observed the condition under which price of a transponder could not exceed $3.7 million.
Meanwhile, the Khrunichev Center is planning to launch the first experimental Dialog-E ?1 in 2003 and unfold a group of three Dialog small communication satellites by 2005.4
Ruslan-MM project of NPOmash
On June 22, 2001, the Machine-Building Research and Production Association - NPOmash from Reutov, near Moscow signed an agreement with Intersputnik to manufacture and put into orbit two small communication satellites of the Ruslan-MM series The first was supposed to be taken to a GSO with the Strela LV within 30 months of the effective date of the agreement. Both the satellite and LV are developed at NPOmash.
According to independent estimates, it usually costs about $60 million to make and launch one satellite of this class. The sides have not disclosed any details of the contract so far. NPOmash has done the bulk of the work under the Ruslan-MM project at its own expense. According to reports in the open press, the launch of one Strela LV costs about $10 million.
NPOmash embarked on the Ruslan-MM project in 1998-2000. As with as Dialog of the Khrunichev Center, it employs an electric thruster (ET) consisting of two SPD-100 stationary plasma engines. Therefore, the pattern of placing Ruslan-MM in GSO is approximately the same as Dialog. The Ruslan should be placed in orbit by the Strela light LV developed at NPOmash on the basis of RS-18 (SS-19 Stiletto) intercontinental ballistic missile5 decommissioned in keeping with the START-2 treaty. The LV will take off from a silo at Svobodny space center in Amur region in the Far East. The transfer from GTO to GSO will be conducted with the help of a booster applying a liquid fuel rocket engine, additional solid fuel booster and electric thruster. The transition will last for some 150 days.
Ruslan-MM service systems are largely harmonized with the generic space bus of a small land remote sensing satellite made at NPOmash under a government contract. The satellite will have an orbit weight of 560 kilos and a payload of 125 kilos. The power supply system used by the payload is 1,000 W, and the satellite keeping accuracy is ±1o E-W and N-S. The operational service life of Ruslan-MM should be at least 10-12 years.
The satellite's onboard systems will rely on the latest achievements of the Russian industry and employ the latest computer elements as well as advanced technical solutions of the best foreign manufacturers.
The payload will be adapted to the needs of customers to the maximum. Two Russian companies - FSUE Radio Research Center (NII Radio) and the Russian Space Instrument-Making Research Center (RNII KP) - are to guarantee the payload using foreign-made components. Several Western companies have also expressed interest in supplying the onboard equipment.
The satellite is capable of carrying up to 12 conventional transponders.
NPOmash has not signed any contracts for Ruslan-MM except the one with Intersputnik. There have been reports, though, that it is taking part in tender for a communication satellite for Vietnam and Iran. However, there have been no official reports about the results.6
Express-1000 project of NPO PM
Another project of a small communication satellite called Express-1000 has been proposed by the leader in Russian communication satellite production - the Academician Reshetnev Applied Mechanics Research and Production Association (NPO PM) in Zheleznogorsk, Krasnoyarsk territory, Siberia. Unlike the Khrunichev Center and NPOmash it opted for the traditional propulsion system and rejected the use of advanced electric thrusters.
The space bus of Express-1000 has a weight of 600 kilos and the satellite - no more than 840 kilos. The satellite should be placed in orbit by a Proton LV with the DM-01 booster traditionally used for full-size communication satellites. The LV is capable of placing three satellites on the Express-1000 bus in GSO simultaneously. The satellite can also be launched with the modified Soyuyz-2 LV (Rus program) with Fregat booster.
According to NPO PM, in its throughput capacity a satellite of the Express-1000 space bus belongs to the medium class of communication satellites. Three standard modifications of its onboard transmission equipment are planned:
the hybrid system consisting of 10 Ku-band transponders each with a capacity of 35 W, four transponders of the C-band (20W each) and one transponder of the L-band (20 W),
12 transponders of the C-band (40W each),
12 transponders of the Ku-band (50 W each).
The bandwidth of each transponder in all modifications would be 36 MHz.
The same as Dialog and Ruslan-MM the Express-100 platform has a non-airtight version. Its operational lifetime is planned at 15 years. The power of solar panels by the end of the service life should be no less than 2,200 W. The station keeping accuracy in GSO is ±1 o E-W and N-S.
NPO PM has been developing the Express-1000 bus since 1999. As has been customary during the past few years it tries to attract non-budget funds, preferably from abroad. The main hopes in this respect are pinned to Vietnam, which is conducting a contest for the delivery of a dual-purpose communication satellite (the satellite should serve the needs of the civilian communication administration as well as the military and security forces). Announced in 2000 the tender has not been completed yet.
On March 23, 2000 the Russian Aerospace Agency and NPO PM signed a 50 million ruble ($1.8 million) contract for the development of the space bus under which in 2000 NPO PM issued production forms and records for the new product and developed its equipment. By the end of 2001 Intersputnik was expected to sign a contract with NPO PM for one or two communications satellites on the Express-1000 space bus in the framework of the Intersputnik-100M program. However, the contract has not been signed yet.7
The RSCC may become another client. Even though RSCC signed a contract with the Khrunichev Center for Dialog small communication satellites it does not rule out the use of other Russian-made small satellites. "We work with all manufacturers, the continuation of our work with NPO PM on the Express-1000 apparatus and the agreement with the Khrunichev center does not signify the renunciation of other manufacturers," Boris Antonyuk, RSCC CEO has said.
Conclusions
Russia is so far only developing small communication satellites. A handful of contracts for their use have been signed and the customers have been extremely cautious. Thus, evidently to be on the safe side, Intersputnik concluded deals with two out of three manufacturers of small communication satellites - the Khrunichev Center and NPOmash. In this way it clearly wanted to guarantee itself against the failure of either project.
Abroad, the use of small satellites is also considered only as a matter for the future so far. Russian designers of such satellites are taking part in several international tenders but have not won any yet. Evidently, foreign companies engaged in the precarious telecommunication business do not want to increase their risks by purchasing satellites that have never been launched before, especially with such a complex propulsion system and GSO placement pattern as Dialog and Ruslan-MM.
Only successful flight tests can change the attitude to small satellites. It seems that the designers will have to make the tests at their own expense. In this case the Khrunichev Center is in a more advantageous position because its other businesses are profitable (Proton and Rockot LV launch services, the construction of commercial modules for the International Space Station). That is why even before signing contracts for its Dialog communication satellite Khrunichev already planned to launch three such satellites with an eye on building its own communication system and offering its services to domestic and foreign clients.
Nevertheless, NPOmash and NPO PM also seem capable of manufacturing small communication satellites at their own expense. Their federal funding is meager but they operate successfully thanks to their commercial programs: NPOmash is making missiles that are exported to foreign countries, while NPO PM is virtually the sole contractor of the main Russian satellite communications operator - RSCC.
Evidently after Russian clients start using small communication satellites, foreign companies will be able to evaluate all the pros and cons of their operation. And if it succeeds, Russia may occupy a key position in this science-intensive business sector.
1 www.ilslaunch.com.
2 Most foreign communication satellites are launched to GTO with an apogee of 36,000 km from which they move to GSO with the help of their own engines.
3 INTELSAT press release, 15.01.2002.
4 Materials of the Khrunichev Center, RSCC, Intersputnik, Eurockot GmbH and EMS Technologies Inc.
5 Rockot LV is made on the basis of the same missile.
6 Materials of NPOmash, Intersputnik, Interfax and ITAR-TASS news agencies.
7 Web server of the Zheleznogorsk Municipal Fund for Small Business (www.fondpp.krasnoyarsk.su); Gazeta NPO PM #1 (68), April 2000; Segodnyashnyaya Gazeta, Krasnoyarsk, #52 (1137), 08.04.2000; Telesputnik, #4 (54), April 2000, press service of NPO PM, www.fondpp.krasnoyarsk.su/w000405.html.
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