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| Above: The architecture of Spektr-RG orbital observatory as of 2010. | |||||||||||||||||||
Previous chapter: Science satellites Conceived as one of three Soviet "great observatories" at the end of the 1980s, the Spektr RG could become the main window on the Universe for the nation's astronomers. However, economic storms of the post-Soviet transition were continuously delaying and crippling the project.
A brainchild of the astronomical section of the Soviet Academy of Sciences, Spektr RG (where RG stands for Roentgen-Gamma) was designed for astrophysics research. The project was proposed by Academician Rashid Syunyaev, who previously led a team of scientists working with astronomical payload of the Kvant module onboard the Mir space station. By mid-1990s, the Spektr-RG program involved a wide international cooperation, including 20 organizations from Denmark, UK, Germany, Italy, US, Finland, Switzerland, Israel, Hungary, Kyrgyzstan, Canada and Turkey. The 6,000-kilogram spacecraft would carry 2,750 kilograms of scientific instruments, including five telescopes: SODART, JET-X, MART-LIME, FUVITA, TAUVEX, as well as all-sky monitors MOXE in SPIN sensitive to X-ray and gamma radiation. The Proton rocket had to carry Spektr-RG into a highly elliptical orbit with the apogee of 200,000 kilometers above the Earth surface, perigee 500 kilometers and the inclination 51.6 degrees over the Equator. There, the satellite could work up to 80 hours at a time free of interference from the Earth's radiation belts. It would take the satellite four days to complete a single orbit. The spacecraft could be pointed at up to 10 different targets a day. (403) Despite considerable political pressure from international partners, including the weight of the Gore-Chernomyrdin agreements on space cooperation between Russia and the United States, the cash-strapped Russian government ultimately failed to fund the project. With much of science instruments and other hardware manufactured and tested, its launch date kept slipping from 1996 to 1997, 1998, 1999, 2000, 2002 and 2003, before the project was finally declared dead in February 2002. As early as 1998, Western partners spent $300 million on their participation in three Spektr observatories, with most of these funds going to Spektr RG. As a "compensation" for the losses by foreign partners, the Russian government offered a Proton rocket to launch a similar European space telescope, known as Integral. Even some of the Russian scientists, who participated in the Spektr RG project decided to "jump the ship" and banked on the European observatory instead. ESA provided Russian partners 25 percent of available observation time onboard Integral. (402) Ironically, the European spacecraft was launched without problems or considerable delays in 2002. Rebirth of Spektr-RG Developers of sophisticated payloads for the original Spektr RG had to find new carriers for their instruments or surrender them to museums. Yet, with the improvement of Russian financial situation in the first decade of the 21st century, Spektr RG was reborn as a smaller, cheaper project. Once the highest priority for launch among Russian space observatories, Spektr RG was moved behind the Spektr-R (Radioastron) project. Both satellites were redesigned to be based on NPO Lavochkin's standard spacecraft bus, known as Navigator. The original plan was to launch a 2,000-kilogram satellite in 2011, onboard the Soyuz-2/Fregat booster into a 500-580-kilometer circular orbit with the inclination 28 degrees toward the Equator, following a liftoff from Kourou, French Guiana. Later, the Baikonur-based launch into a 600-kilometer orbit with the inclination 30 degrees was considered. Yet later, a Zenit rocket, also with Fregat was deemed affordable. It could carry a 2,400-kilogram spacecraft into the L2 (Lagrange) libration point, an ideal spot for such mission. Spektr-RG would need around three months to reach its final destination, where it was expected to spend four years circling L2 Lagrangian point in an elliptical orbit on a mission to conduct a global survey of the sky. This flight trajectory would essentially make Spektr-RG a deep-space mission. The scientific payload of Spektr RG was ultimately limited to two instruments -- eROSITA built in Germany and Russian ART-XC, developed by VNIIEF nuclear research center in the city of Sarov. Still, project scientists promised a revolutionary data in the field of so-called high-energy astrophysics. Unlike previous orbital X-ray telescopes, such as European XMM Newton and NASA's AXAF Chandra, which were equipped with instruments with narrow angles of view, Spektr-RG would enable a wide-angle survey of the sky. Thus, the spacecraft could be used to compile a global map of X-ray sources. According to Mikhail Pavlinsky, Deputy Director of Moscow-based Space Research Institute, IKI, Spektr-RG would deliver sensitivity and survey depth 30 times greater than possible with previous instruments. Resulting catalog of sources could include a comprehensive list of galaxy clusters, which had formed since the formation of the Universe. Spektr-RG could also detect radiation emitted by hot gas from "dark matter" sources, enabling to map the distribution of this mysterious substance around the Universe. (441) Preparations for launch An improved funding of the Russian space program after 2005 finally gave some confidence to developers that Spektr-RG would eventually fly. Still, the overall poor state of the Russian space science program, particularly problems in the construction of the hardware and payloads, kept pushing the launch date for the "reborn" Spektr-RG years behind schedule. In 2004, the launch was promised in 2006, then delayed to the end of 2007 and 2008. The launch from Kourou into the equatorial orbit was originally considered. In 2008, the launch was expected on Nov. 20, 2011. As of August 2009, the earliest possible launch date was considered at the end of 2012, however by the end of 2010, the launch was likely to slip to the first quarter of 2013. In December 2010, the launch was still officially scheduled for the end of 2012, but was likely to slip to the first quarter of 2013. (441) At the beginning of March 2011, the launch was promised in September 2013, however by December, the launch was set for Nov. 13, 2013. According to NPO Lavochkin, a three-day launch window would be available every three days. Spektr-RG characteristics as of 2010:
Writing and photography by Anatoly Zak Last update: December 13, 2011 All rights reserved |
IMAGE ARCHIVE
The original architecture of the Spektr RG spacecraft planned during 1990s. Credit: IKI
Spektr-RG's sophisticated JET-X telescope became a museum exhibit. Click to enlarge. Copyright © 2010 Anatoly Zak
A one-to-four model of the Spektr RG satellite. Click to enlarge. Copyright © 2010 Anatoly Zak
A European-built eROSITA telescope designed for the Spektr-RG mission. Click to enlarge. Copyright © 2009 Anatoly Zak
A hexagon-shaped Navigator spacecraft bus was expected to serve as a base of the Spektr-RG mission. Credit: IKI |
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