Three months after successfully lofting South Korea’s KOMPSAT-5 environmental monitoring satellite, Russia is primed to launch its next Dnepr rocket early Thursday, 21 November, carrying a record 32 payloads devoted to Earth observations, remote-sensing applications, astronomical research, and numerous other scientific, technological, and educational disciplines. If successful, this will establish the mission as the record-holder for the largest number of discrete satellites orbited by a single rocket, surpassing the recent achievement of Tuesday’s 29-satellite mission by a Minotaur-1 vehicle. Thursday’s launch—which marks the 19th flight by the three-stage Dnepr since its debut back in April 1999—is scheduled to begin from Site 13 at the Yasny base, near the village of Dombarovsky in Russia’s Orenburg Oblast. Liftoff is presently scheduled for 1:10 p.m. local time (2:10 a.m. EST) Thursday.
The mission is being conducted under the auspices of International Space Company (ISC) Kosmotras, a commercial launch services provider, owned and operated jointly by Russia, Ukraine, and Kazakhstan. The Dnepr stands 113 feet (34 meters) tall and has delivered a number of international payloads into orbit since Britain’s UoSAT-12 in April 1999. In particular, it carried Bigelow Aerospace’s Genesis-I (July 2006) and Genesis-II (June 2007) inflatable modules and has ferried satellites for Thailand, Italy, Malaysia, Saudi Arabia, Argentina, Germany, France, Belarus, Japan, South Korea, Norway, Colombia, and the United States. In 18 successful launches, it has suffered one failure, back in July 2006, during which BelKA—intended to be the first satellite of an independent Belarus—was lost. Subsequent investigation confirmed that the accident was caused by a malfunction in the pumping hydraulic drive of a combustion chamber, which induced controllability problems.
The Dnepr is a converted, Soviet-era SS-18 “Satan” intercontinental ballistic missile, decommissioned from military service with Russia’s Strategic Rocket Forces as part of the provisions of the 1991-signed Strategic Arms Reduction Treaty (START). This treaty has since been replaced by NewSTART, which received the signatures of U.S. President Barack Obama and Russian President Dmitri Medvedev in April 2010. As a potential weapon of war, the SS-18 flew 160 times and achieved a 97 percent success rate. Since April 1999, as a launch vehicle, it has flown six missions from Yasny and 12 from the Baikonur Cosmodrome in Kazakhstan. All three of its stages utilize unsymmetrical dimethyl hydrazine, with an oxidizer of nitrogen tetroxide, and the vehicle can inject up to 8,000 pounds (3,600 kg) of payload into low-Earth orbit or up to 5,000 pounds (2,270 kg) into Sun-synchronous, geocentric orbit, both up to an operational altitude of 180 miles (300 km).
Launched from an underground silo, the Dnepr is ejected by means of a hot gas generator. When it attains an altitude of about 66 feet (20 meters), the RD-264 engine of its first stage will ignite, producing 1.02 million pounds (462,000 kg) of thrust and burning for 130 seconds. After the separation of the first stage, the second stage and its RD-0255 engine will pick up the baton with 170,000 pounds (77,100 kg) of propulsive yield and burn for 190 seconds. Finally, the third stage’s single RD-869 engine will ignite to insert the satellite payloads into low-Earth orbit.
The number of satellites aboard for Thursday’s flight is substantial, for Dnepr missions typically carry a large primary payload and a secondary payload of miniaturized satellites or CubeSats. However, according to Spaceflight101, this mission’s tally of 32 discrete satellite passengers establishes it as the new world record-holder for the number of payloads deployed by a single launch vehicle. In doing so, it will beat by less than 48 hours the previous record set by a Minotaur-1 booster from the Mid-Atlantic Regional Spaceport (MARS) on Wallops Island, Va., on Tuesday, 19 November.
The Dnepr’s two principal payloads are DubaiSat-2, provided by the Emirates Institution for Advanced Science and Technology (EIAST), and STSat-3, supplied by the Korea Aerospace Research Institute (KARI). Both were delivered to the Yasny launch site on 24 October. DubaiSat-2 is an electro-optical satellite for Earth observations and its three-axis-stabilization system and attitude and orbit control subsystem enables it to point itself with sufficient accuracy to acquire single-strip, multi-strip, and single-pass stereo images of the Home Planet. It carries a High Resolution Advanced Imaging System, capable of resolving ground features of 3.3 feet (1 meter) for panchromatic images and 13.2 feet (4 meters) for multispectral images. Meanwhile, STSat-3—the acronym stands for “Science and Technology Satellite”—is a multi-purpose spacecraft. It carries the Multi-purpose Infrared Imaging System (MIRIS), whose Space Observation Camera will survey the Galactic plane to detect cosmic background emissions and whose Earth Observation Camera will conduct Earth observations. A second instrument, the Compact Imaging Spectrometer (COMIS), will acquire hyperspectral images over 17 miles (28 km) swathes, with spatial resolutions of 100-200 feet (30 or 60 meters).
In addition to the DubaiSat-2 and STSat-3 principal payloads, no fewer than 30 smaller satellites will also fly aboard this mission. On 18 October, five CubeSats—SkySat-1, GOMX-1, WNISat-1, BRITE-Poland, and ISIPOD—arrived at the Yasny launch site, together with their deployment mechanisms for integration, with the remainder following shortly afterward. The satellites have been developed by research teams around the world, from Poland to Peru, from South Africa to Singapore, and from Germany to Ecuador, and also include Pakistan’s first CubeSat. They are devoted to a variety of objectives, including Earth observations, monitoring of weather over the Arctic Ocean, space debris, wide-field observations of stars, particle detection, radio science, space weather forecasting, analysis of space optics degradation over time, technology development, education, ionospheric research, and testing of new solar cells.
On Wednesday, 13 November, all of the payloads were integrated within the Dnepr’s Space Head Module (SHM), ahead of installation atop the launch vehicle at the pad on Friday, 15 November. “The final checkout and tests of the launch vehicle with the SHM are presently in progress,” Kosmotras noted on its website, with liftoff targeted for 1:10 p.m. local time (2:10 a.m. EST) Thursday.