PARIS — After months of launcher-related delays, the European Space Agency (ESA) launched its Soil Moisture and Ocean Salinity (SMOS) Earth observation satellite and the Proba-2 technology demonstration spacecraft Nov. 2 aboard a Russian Rockot vehicle operated from the PlesetskCosmodrome in northern Russia.
The launch, performed by the German-Russian Eurockot Launch Services GmbH of Bremen, Germany, followed the successful May launch by Eurockot of ESA’sGoce gravity-field Earth observation spacecraft. Accompanying the 658-kilogram SMOS into low Earth orbit was ESA’s 130-kilogram Proba-2 technology demonstration satellite.
SMOS successfully deployed its principal observing instrument, the Y-shaped MIRAS — Microwave Imaging Radiometer using Aperture Synthesis — in a maneuver that program managers had said was far from simple.
MIRAS was folded against the main satellite body for launch into polar low Earth orbit. It was deployed the day after the launch in a two-step maneuver in which its 12 explosive bolts were activated to permit deployment of the three MIRAS arms, on which 60 receivers are mounted.
SMOS’ instruments will be calibrated for about six months. The satellite’s payload is expected to be switched on Nov. 17.
SMOS cost some 315 million euros ($467 million) including the satellite’s construction, launch and three years of in-orbit operations. SMOS uses the French Proteus multimission satellite platform that was developed by ThalesAlenia Space of France and Italy for the French space agency, CNES. It is the fifth Proteus platform launched since 2001.
The SMOS program includes an unusual collaboration between Spain, France and ESA. Spanish authorities spent more than a decade developing MIRAS, which is Spain’s first major satellite instrument aboard an ESA satellite and was built by EADS CASA Espacio of Madrid.
The MIRAS instrument’s 69 receiver modules will use L-band microwave frequencies to measure the reflection of the Earth’s surface to derive information on both soil moisture and ocean salinity levels. It will operate from a near-polar sun-synchronous orbit at an altitude of 760 kilometers.
The 130-kilogram Proba-2 is the second in the Proba, or Project for On-Board Autonomy, satellite series ESA has developed to test technologies deemed promising for future government and commercial satellites.
Proba-2 was budgeted at about 18 million euros ($26.7 million), not including its share of the 15 million euros ESA paid for the Rockot launch. Proba-2, which is designed to operate for two years in a polar orbit around 725 kilometers in altitude, was built by Verhaert Design and Development NV of Belgium.
Its broad suite of instruments includes a new star tracker to be tested for eventual use with ESA’sBepiColombo mission to Mercury and built by Galileo Avionica of Italy; a new lithium-ion battery design from Saft of France; and a new design for xenon-gas satellite propulsion provided by Surrey Satellite Technology Ltd. of Britain and Bradford Engineering BV of the Netherlands.
ESA’s SMOS project manager, AchimHahne, who has spent 10 years on the project, said the SMOS mission faced logistical challenges well beyond its complicated MIRAS payload. Because of a timing coincidence, satellite test equipment that ThalesAlenia Space needed for the satellite was delayed in China for a ThalesAlenia Space commercial satellite launch and was not easily shipped from China to Russia.
Just before shipment, the ThalesAlenia integration facility in Cannes, France, was partially flooded by torrential rainfall in September. “We have a waterproof [satellite transport] container, but it’s not supposed to float,” Hahne said, adding that the SMOS team was just barely able to deliver the satellite to the nearby airport in time to make a long-reserved aircraft takeoff slot.
Cramped facilities at the PlesetskCosmodrome meant SMOS and Proba-2 teams had to alternate in the satellite preparation facility. About 100 people were required for the launch campaign, although no more than 50 people were there at any given time in part because of the lack of hotel facilities.
The satellite staff included a doctor, and even kitchen crew imported for the occasion from Europe. “That was one of the lessons of the Goce launch,” Hahne said in an Oct. 21 SMOS prelaunch press briefing. “People weren’t too happy with the food, so we brought our own staff this time.”