Soyuz rocket launches a 28-satellite cluster
Closing Russian space activities in 2018, a Soyuz-2-1a rocket launched a pair of Kanopus V Earth-watching spacecraft, accompanied by 26 hitchhiking payloads on December 27. It was the 4th launch from Vostochny since the introduction of the new spaceport in 2016.
Soyuz mission with Kanopus-V-5 and V-6 satellites at a glance:
Kanopus-V No. 3 and No. 4 satellites
The main payload of the mission will be two remote-sensing satellites to join Russia's Kanopus constellation.
The Kanopus-V No. 5 and No. 6 satellites are virtually identical to a previous pair of Kanopus satellites launched at the beginning of 2018. Like their predecessors, they are officially intended for monitoring natural and man-made disasters, such as forest fires and environmental contamination. They can also be used for monitoring agricultural activities, water resources and land use, cartography and other observations in the interests of ministries and agencies of the Russian Federation, according to Roskosmos.
The pyload section with Kanopus-V5 and -V-6 satellites (center) and secondary payloads (left).
In addition to the Kanopus pair, the Soyuz rocket will carry 26 small commercial satellites, including 20 spacecraft from the US, three from Germany and single satellites from Japan, Spain and South Africa. All but one are tiny box-shaped spacecraft known as cubesats. Their rides to orbit on the Soyuz were booked via Moscow-based Glavkosmos, a subsidiary of the Roskosmos State Corporation, formed to market Russian rockets to foreign customers since the mid-1980s. After the Russian government had discontinued the launches of small commercial satellites on the Ukrainian-built Dnepr launcher, its commercial operator called ISC Kosmotras formed a joint venture with Glavkosmos called GK Launch Services, aimed at re-routing small satellite customers to Soyuz. For the latest mission, GK Launch Services contracted a total of 15 payloads out of 26.
The heaviest hitchhiker in the group is the 100-kilogram GRUS micro-satellite developed by Axelspace based in Japan. It will be the first satellite in the AxelGlobe constellation designed to produce images of the Earth's surface with a resolution around 2.5 meters with a swath of 60 kilometers on a daily basis and on a global scale. The satellite is expected to operate for at least five years.
The largest group among the secondary payloads is the Flock-3K satellite cluster. It consists of 12 DOVE remote-sensing cubesats developed by Planet Labs Inc. of San Francisco. The Flock-3K should join a constellation of more than 100 DOVEs, which provide users with on-demand images of the Earth's surface. The 5-kilogram satellites are meant to be continuously replaced after the around three years of their projected life span.
The integration of the DOVE payloads on the Soyuz rocket was contracted to the Innovative Space Logistics, ISL, a division of the Innovative Solutions, ISIS, based in Delft, Netherlands. The company developed QuadPack containers for the release of multiple cubesats. During this latest mission, the QuickPack system will house 12 DOVE satellites and two other payloads. An avionics unit, also developed at ISIS, will control the deployment sequence. According to the company, it has previously launched 300 such satellites, including 50 on the Soyuz.
The 2.5-kilogram Lume-1 cubesat was built within the so-called 2U standard, (comprised of two cubsat modules) by the Vigo University in Galicia, Spain. Designed for two years of operation, it will represent the orbital segment of the FIRE-RS system, providing early warning about natural disasters, including fires.
The 3.5-kilogram ZACube-2 experimental satellite was developed at Cape Peninsula University of Technology, CPUT, and the French South African Institute of Technology, F'SATI. The spacecraft, designed to operate for two years, carries an automatic identification system, AIS, for sea vessels and a camera operating in near-infrared range for detecting forest fires.
Another cluster of cubesats in the so-called 12U format was integrated on the Soyuz by ECM Space Technology GmbH of Germany. ECM provided a container system, which carries a total of 11 cubesats.
The group includes eight Lemur satellites developed at US-based Spire Global Inc. for identification of sea vessels. The satellites can also be used for weather forecasting using radio occultation of signals, GPS-RO, and aircraft tracking via the ADS-B system. The latest group will join previously launched spacecraft in the Spire's constellation.
In addition, two D-Star satellites, were built within the 3U format, by German Orbital Systems GmbH. They are designed for technology demonstration, including amateur radio. Each satellite carries a new ADS-B transmitter developed by the company and to be used in space for the first time.
Finally, the UWE-4 satellite built by University of Wuerzburg, Germany, within 1U format will attempt to demonstrate the operation of an electric propulsion system.
An overview of payloads carried during the Soyuz-2-1a launch on Dec. 27, 2018:
Three SAMSON nano-satellites built in Israel and the 80-kilogram ICEYE remote-sensing satellite from Finland were originally booked for this flight as well, but their developers were not able to meet the launch deadline. On the Fregat payload adapter, the missing passengers have been replaced with mass simulators to preserve the calculated dynamics of the mission. The simulators will be released from the Fregat according to the original launch timeline.
The Soyuz-2-1a rocket for the mission arrived at Vostochny on June 18, 2018. The payload fairing and the Fregat upper stage were delivered on November 9, 2018. By the end of November, the launch was rescheduled from December 25 to December 27.
On December 18, Roskosmos announced that the fueling of the Fregat for the mission had been completed and that the space tug had been brought to the spacecraft processing building for the assembly of the payload section. (The move apparently took place on December 17.) By that time, the secondary payloads of the mission had already been installed on their launch vehicle adapter, while the Kanopus-V No. 5 and No. 6 satellites, which represented the primary payload, were in process of preparation for mounting on the same adapter, Roskosmos said.
The final integration of the payload section was scheduled for December 20 and, the next day, it was transported to the launch vehicle assembly building for integration with its Soyuz-2-1a rocket. In the meantime, the preparation of the launch vehicle had entered the final phase, according to Roskosmos. The final integration of the rocket with its upper composite, including the payload section, took place on December 23. On the same day, the State Commission overseeing the launch convened to review the status of the preparation and gave a green light to the rollout of the rocket to the launch pad, which took place on December 24.
Launch and ascent scenario
After a few seconds in a vertical ascent under power of the four boosters of the first stage and the core booster of the second stage, the rocket headed northwest across eastern Russia, aligning its trajectory with a polar orbit inclined around 97.46 degrees toward the Equator. The strap-on boosters of the first stage were scheduled to separate at T+117.767 seconds in flight and were projected to crash at Drop Zone No. 981 in the Amurskaya Oblast (Amur Region) on the border between Tynda and Zeya Districts.
The fairing protecting the payload then split in two halves and separated during the operation of the second stage at T+222.883 seconds in flight. The payload fairing was projected to fall at Drop Zone No. 983 in the Aldan District in the Sakha (Yakut) Republic.
Moments before the second stage completed its firing less than five minutes into the flight, the RD-0124 engine of the third stage should fire through the inter-stage lattice structure, which should then separate along with the second stage at T+287.25 seconds in flight.
Just two seconds later, the tail section on the third stage split into three segments (T+289.05 seconds). Both the second-stage booster and the segments of the tail section were aiming to fall at Drop Zone No. 985, in the Vilyusk District, located farther north in the Sakha Republic.
The third stage continued firing inserting the Fregat upper stage and its payloads into a ballistic trajectory just short of orbital velocity. As a result, after its engine cutoff (at T+525.23 seconds) and separation from Fregat (at T+528.53 seconds), the third stage will reach the peak of its ballistic arch and will then begin a long free fall back to Earth over the Arctic Ocean. Its trajectory was designed to bring the flaming debris of the stage crashing into the middle of the Northern Atlantic.
Space tug maneuvers
In the meantime, seconds after its split from the third stage, the Fregat fired its stabilization thrusters and less than a minute later, the stage ignited its main engine over the Arctic Region for slightly more than a minute, which ensured its insertion into an initial transfer orbit. The stack then climbed passively for around 45 minutes before Fregat fired its main engine for the second time near the apogee of its initial orbit, this time over the southern polar region of the planet. The maneuver, lasting less than a minute inserted the vehicle into a nearly circular orbit. Less than two minutes later, the pair of Kanopus-V satellites was ejected from Fregat's payload adapter, completing the main task of the mission.
Both initial engine firings were performed by the Fregat beyond the view of Russian ground stations and their completion was confirmed during the subsequent passes of the vehicle over Russia.
Next, the Fregat embarked on a complex preprogrammed sequence, including several firings of its main engine to form two different orbits for the separation of the secondary payloads, a task completed arond 4.5 hours after liftoff.
Timeline for the Soyuz mission on Dec. 27, 2018:
The fueled Fregat upper stage is installed in its processing rig on Dec. 17, 2018, for integration with payloads. Click to enlarge. Credit: Roskosmos
The payload section is integrated with the third stage of the Soyuz launch vehicle on Dec. 22, 2018. Click to enlarge. Credit: Roskosmos
Final integration of the upper composite with the booster stages of the Soyuz launch vehicle on Dec. 23, 2018. Click to enlarge. Credit: Roskosmos
GRUS-1 satellite. Click to enlarge. Credit: GK Launch Services
Deployment containers provided by ECM launch services carried eight Lemur, two D-Star and one UWE-4 satellites. Click to enlarge. Credit: GK Launch Services
Soyuz lifts off with 28 satellites on Dec. 27, 2018. Click to enlarge. Credit: Roskosmos