With a sixth commercial launch planned by year-end, the Euro-Russian Starsem has hit the market with a bang
Tim Furniss/LONDON
The Euro-Russian Starsem commercial satellite launcher consortium is an international success story.
Starsem plans three more commercial Soyuz launches of 12,450kg (27,400lb) Globalstar low earth orbit (LEO) mobile communications satellites from the Baikonur Cosmodrome in Kazakhstan, over 90 days this year. This adds to the trio of launches which dispatched 12 satellites into orbit over 66 days earlier this year.
Starsem is operated by the Russian Samara company, which builds the Soyuz booster; the Russian Space Agency (RSA); and Europe's Aerospatiale and Arianespace. Aerospatiale's share in Starsem is 35%, Arianespace has a 15% stake, the RSA 25% and Samara 25%.
Two pairs of four Globalstar satellites have also been launched by Boeing on its Delta II, bringing to 20 the total in orbit.
Globalstar has amended its satellite launch schedule this year so that 32 more satellites will be in orbit by December, with initial commercial services starting in September.
The selection of launchers has not changed, but the flight sequence has, pushing into next year the Arianespace Ariane 4 satellite launches planned for September, bringing forward a Delta II launch in June and scheduling a sequence of the three Starsem Soyuz flights.
The schedule includes four Delta II launches, one this month, two in July and one in August. Three Soyuz launches will take place in September, October and November, to be followed by another Delta II. In addition to the three Globalstar launches, Starsem is contracted by the European Space Agency (ESA) for two launches of pairs of Cluster 2 mission spacecraft. ESA is also expected to contract the Soyuz for the launch of the Mars Express in 2001.
Starsem offers to place up to six microsatellites, weighing 150kg each, into LEO, complementing a service provided by Arianespace, which can carry piggyback satellites on Ariane 4 and 5 missions with large commercial satellites.
Crucial to Starsem Soyuz' success is the projected market for constellations of mobile communications satellites, such as the Globalstar, and multimedia satellites, like the Teledesic, into low earth orbit. Predictions by the Teal Group indicate that over 80% of commercial launches to 2008 will be to place these types of spacecraft into LEO.
The potential demise of Motorola's Iridium worldwide mobile telephone satellite system, which has 74 operational satellites in space, is creating doubts that all the projected LEO systems will become a reality. Commercial LEO launchers may not get as big a slice of the market as originally anticipated.
Starsem, however, is "confident that we will get a usual share of whatever market transpires". Whatever that market might be, Starsem believes that the role of medium launchers, such as the Soyuz, to launch multiple payloads will be more prominent than that of small launchers contracted to launch single payloads.
The Soyuz is the workhorse of the Russian space programme. It is a veteran of more than 1,000 launches since 1973, with the latest Soyuz U notching up over 700.
Crucial to its commercial success has been the introduction of an upper stage, the Ikar, initially for the Globalstar launch work, while another stage, the Fregat, which will be flown on a Soyuz next year.
The Samara Space Centre, formerly known as TsSKB Progress, and the Samara design bureau, based in the city of the same name, the former Kuibyshev, developed the Soviet R-7 intercontinental ballistic missile, on which the Soyuz is based, in 1957.
The name Starsem is derived from "Space Technology Alliance based on R-7 [SEMyorka] launch vehicles".
Samara developed the 820kg Ikar stage, based on the Kometa unit, which has been used on about 30 missions by the Soyuz, carrying Soviet reconnaissance satellites. It has a KBKhM 17D61 engine, which can be restarted 50 times to perform the necessary manoeuvres required to place satellites into accurate orbits. The 662,000lb-thrust (2,945kN) engine uses hypergolic hydrazine-based and nitric-oxide propellants.
Another feature of the Globalstar launcher stack is the Aerospatiale-built launch dispenser, which allows the Soyuz to carry four satellites. Three Globalstars are installed vertically around the dispenser unit's cylinder, while the fourth is mated horizontally to a plate atop the cylinder. The satellites are deployed at T+3h 32min at an orbital altitude of 940km (585 miles). The Soyuz-Ikar can place 3,300kg into 1,400km orbit, but the Fregat upper stage will increase this to a maximum 4,600kg. The Fregat will also be used to place the Clusters - and Mars Express - into solar orbit. The 6,535kg Fregat is an uprated version of a stage used on Proton K launches of two Phobos launches to Mars in 1988 and the failed Mars '96 mission launch.
It is built by NPO Lavotchkin and uses a single 19.6kN hypergolic engine, which can be restarted 20 times, if required, firing for a maximum 877s. It is complemented by three clusters of four hydrazine thrusters for attitude control and ullage. The main engine alone was also fitted to more than 30 other Russian interplanetary probes.
Starsem will soon add two more vehicles to its inventory, the improved Soyuz 2 and the four-stage Soyuz-based vehicle, the Molniya.
Source: Flight International
