The design of the modern satellite has taken several different evolutionary paths during the past five years. They have both grown and shrunk. The variety of their capabilities has both expanded and become more specialized. We examine how launch service providers are investing to improve capabilities and the services they offer operators.
The methods in which satellites network with each other and form unique architectures have changed to serve today’s cultivated market with larger quantities of customers demanding higher quality services. Working alongside this evolution, the commercial launch industry also has advanced and developed new rocket technology to keep up with the needs of its operator clientele. And while the impetus of the satellite industry discussion on the launch sector has focused on pricing, increasing competition and reliability, operators and service providers now see launch provider business models spreading out to new markets based on the specific technology they’ve chosen to develop.
Operating out of the European spaceport in Kourou, French Guiana, commercial launch service provider Arianespace is preparing for the inaugural flight of its lightweight Vega rocket. Arianespace, which generates a large portion of its business from its workhorse Ariane 5 launcher, began development on the Vega rocket in early 2003 within a European program organized under the aegis of the European Space Agency (ESA). The four-stage launcher represents the third rocket in Arianespace’s family of commercial vehicles and was envisioned and tailored to carry a growing number of small scientific spacecraft and other lighter-weight payloads under development worldwide with a payload capacity of 1,500 kilograms into polar orbit at 700 km altitude.
A P80 advanced solid propellant motor, featuring a novel filament-wound casing structure, powers Vega’s first stage. The second and third stages, designated Zefiro 23 and Zefiro 9, respectively, also use solid propellant motors, and the launcher is topped off by the bi-propellant liquid upper stage, which is called the Attitude and Vernier Upper Module (AVUM). The liftoff mass of Vega will be 139 metric tons.
Vega also was conceived in parallel with another medium-lift option and a revamped edition of the Russian veteran rocket, Soyuz. Arianespace’s Soyuz received tweaks and upgrades for its commercial service, while maintaining the key characteristics of a vehicle that has launched 1,700 manned and unmanned missions dating back to the 1957 launch of Sputnik, the world’s first satellite.
“We did not make that many changes to the rocket,” says Arianespace CEO Jean-Yves Le Gall. “We added a new digital control system that incorporates both a digital computer and inertial measurement unit, which improves the rocket’s navigation accuracy and control capability. The new digital control system also provides a more flexible and efficient attitude control system — crucial for controlling the enlarged Soyuz ST payload fairing at a diameter of 4.11 meters and an overall length of 11.4 meters. The control system gives the rocket with the ability to perform in-flight roll maneuvers as well as in-plane yaw-steering maneuvers.”
The Soyuz’ first stage is composed of four boosters that are assembled around the launcher’s central core featuring tapered cylinders. The boosters’ RD-107A engines are liquid oxygen- and kerosene-powered — the same propellants used on each of the Soyuz’ three main stages. One Aerofin per booster and two movable vernier thrusters per booster encompass the rocket’s three-axis flight control.
Le Gall says his team believes that the market will continue to develop as new technology becomes available and that launchers will have to focus their efforts on keeping pace with variety. “The Soyuz and Vega give us far more flexibility when it comes to launching smaller satellites. The Soyuz will allow us to launch all the non-GTO satellites that we cannot launch on Ariane 5. There are a number of projects in Earth observation where Soyuz and Vega will be very important. The three launch systems allow Arianespace to provide a launch opportunity for any type of mission.”