Arianespace is in final stage of preparations to launch a set of European satellites designed for Earth observation, astrophysical research and educational purposes. The spacecraft will be lifted off atop a Soyuz-STA rocket at 5:02 p.m. EDT (21:02 GMT) on Friday, Apr. 22, from the Soyuz Launch Complex (ELS) in Sinnamary, French Guiana.
The mission, designated VS14 in Arianespace’s numbering system, will be the company’s first Soyuz launch this year. The main passenger of VS14 is the European Space Agency’s (ESA) Sentinel-1B Earth-observing satellite. Two smaller missions will piggy back on the flight: a French microsatellite called Microscope, designed to conduct astrophysical research and an educational project ‘Fly Your Satellite!’ – a trio of CubeSats built jointly by three European universities.
The launch campaign started on Mar. 1, when the initial preparations of the rocket’s Fregat upper stage were commenced at the Soyuz launcher preparation building (MIK) in French Guiana. Sentinel-1B arrived in Kourou one week later, while Microscope was delivered on Mar. 10. ‘Fly Your Satellite!’ was shipped to French Guiana much later, on Mar. 25.
Meanwhile, on Mar. 21, the fueling of the upper stage was initiated, together with the integration of first and second stage of the Soyuz launcher in the MIK facility.
During the first week of April, the teams were busy with the integration of the secondary payload on the launch vehicle’s Auxiliary Payload Adaptor Structure (APAS). Sentinel-1B as the main passenger was mated with APAS on Apr. 14. The engineers also conducted pneumatic and electrical tests on the launcher.
APAS mated with the satellites was attached to the Fregat upper stage on Apr. 13 and two days later this stack was encapsulated in the payload fairing. The rocket, integrated with its passengers, was rolled out to the launch pad on Tuesday, Apr. 19. The upper stage will now undergo functional tests and checks, while the launcher will go through final verifications. The launch readiness review is scheduled for Apr. 21.
After the launch on Friday, the Soyuz rocket will embark on a 4-hout trip to deliver the satellites into a low-Earth orbit (LEO). Sentinel-1B will be placed at an altitude of 426 miles (686 km), with an inclination of 98.18 degrees. The Microscope spacecraft will be conducting its research at an altitude of 442 miles (711 km), inclined 98.23 degrees, while the CubeSats will be put into an orbit presenting a perigee at 281 miles (453 km) and an apogee at 413 miles (665 km).
Weighing nearly 2.2 metric tons, the Sentinel-1B spacecraft is about 11 feet (3.4 meters) high and has a diameter of 7.6 feet (2.3 meters). Manufactured by Thales Alenia Space, the spacecraft is based on the PRIMA bus, capable of generating up to 6,000 W of power. The satellite is fitted with deployable solar arrays and is designed to be operational for up to seven years.
Sentinel-1B is a synthetic aperture radar (SAR) type C-band observation satellite. It will join its identical twin, Sentinel-1A, launched two years ago. These two satellites will work together to image any point on the Earth in less than six days. Their powerful radar sensors will provide real-time all-weather coverage of land surfaces and bodies of water in Europe and the polar regions.
Sentinel satellites are part of a research program called Copernicus, managed jointly by ESA and the European Union. The program aims to provide operational information on land masses, oceans and the Earth’s atmosphere. The system consists of Earth observation satellites and in situ sensors such as ground stations, airborne and sea-borne sensors.
Developed by the French space agency CNES, the Microscope is a box-shaped microsatellite with a mass of about 668 lbs. (303 kg). It’s dimensions are 4.6 x 3.3 x 4.9 feet (1.4 x 1 x 1.5 m). The spacecraft, based on the Myriade bus, features two solar cells and is designed to be operational for up to three years.
Microscope will test the equivalence principle described by Albert Einstein by using two concentric cylindrical test masses made of different materials – one titanium and one a platinum-rhodium alloy.
‘Fly Your Satellite!’ consists of three student-built 4-inch CubeSats: OUFTI-1, e-st@r-II and AAUSAT-4. Built by the University of Liege in Belgium, OUFTI-1 will test a new communications subsystem. E-st@r-II from the Polytechnic of Turin, Italy, will demonstrate an attitude determination system using measurements of the Earth’s magnetic field. AAUSAT-4, provided by the University of Aalborg, Denmark, will operate an Automated Identification System (AIS) receiver in order to identify and track the position of ships transiting away from coastal areas.
‘Fly Your Satellite!’ is part of the newly-established ESA Education and Knowledge Management Office’s program. The aim of this project is to give university students across Europe the chance to gain practical experience in key phases of developing a real satellite project – from integration, test and verification to launch and operations.
The 151 feet (46 m) tall Soyuz-STA rocket that will be employed in Friday’s launch is based on the Russian Soyuz-2 developed by TsSKB-Progress. It is a four-stage launch vehicle: four boosters (first stage), a central core (second stage), a third stage, and the restartable Fregat upper stage (fourth stage). It also includes a payload adapter/dispenser and fairing. The rocket is capable of delivering up to 2.7 metric tons into geostationary transfer orbit (GTO), and about 4.5 metric tons in Sun-synchronous orbit (SSO). The STA version was flown for the first time in December 2011.
VS14 will be the third Arianespace mission in 2016 and the sixth Soyuz flight this year. Sentinel-1B will be the 51st ESA satellite launched by Arianespace. The company’s next mission is scheduled for May 24, 2016, when a Soyuz-STB launcher will send two ESA Galileo satellites into orbit.