Zenit delivers Elektro-L2
Overcoming political hostility between the two largest Soviet republics, a joint Russian-Ukrainian team successfully launched a fresh weather satellite, whose older sibling dazzled the world with its stunning views of our home planet. A Ukrainian-built Zenit rocket lifted off on Dec. 11, 2015, delivering Russia's Elektro-L No. 2 satellite 36,000 kilometers away from Earth.
Elektro-L2: New and improved
Like its predecessor and a number of foreign equivalents, the Elektro-L No. 2 satellite, or Elektro-L2 for short, will be used to monitor changing weather and climate on Earth from the geostationary orbit.
The new spacecraft was modified to address problems which nearly crippled the first satellite in a series -- Elektro-L1, after it had been launched in 2011. These upgrades were a major reason for a long delay of the mission from the original schedule. However as a result, the second Elektro-L will be able for the first time to produce images simultaneously in all of its 10 spectral ranges, including three optical and seven infrared channels.
At an altitude of 36,000 kilometers, the spacecraft will be able to see the entire disk of our planet and transmit resulting images every 30 minutes under most circumstances or every 10-15 minutes when needed urgently, for example, to monitor natural disasters. The optical photos will discern details down to one kilometer in size, while infrared imagery will reach four-kilometer resolution.
In addition, Elektro-L2 carries a suit of instruments for heliophysics, which will monitor critical "space weather" phenomena, such as solar flares, radiation levels and the condition of the Earth's magnetosphere.
Built at NPO Lavochkin, Elektro-L series comprise the so-called Hydro-Meteorological Geostationary Space System, abbreviated in Russian as GGKS. Like its predecessor, Elektro-L2 consists of a standard service module, known as BMSS Navigator, and a payload platform.
The data from the satellite will be primarily used by Russia's civilian weather agency Rosgidromet. The spacecraft will also be a part of the international constellation of weather-forecasting satellites, providing data to users around the world.
According to the original plans, Elektro-L2 was to be stationed in the geostationary orbit at 14.5 West longitude over the Atlantic Ocean. However, Roskosmos faced challenges to deploy enough dedicated ground antennas to track and control the satellite, which at that position would be at the very edge of visibility from the Russian territory. When the original Elektro-L stationed over the Indian Ocean began experiencing problems, the decision was apparently made to send the second spacecraft into the similar convenient location at 77.8 degrees East longitude.
Key components of the Elektro-L satellite and their developers:
Known specifications of Elektro-L No. 2 satellite:
During 2000s, the launch of the second spacecraft in the Elektro-L series was promised in 2010 or 2011, however during 2010, the mission slipped by two years. (299) In 2011, the launch was scheduled for November 2013, but by 2012, it was postponed again until 2014.
The Zenit-3M rocket for the mission arrived to Baikonur in January 2013, however it did not have a chance to fly until a conflict broke out between Russia and Ukraine in the spring of 2014. All Zenit missions, including launches of the Lybid communications satellite for Ukraine and the Russian Spektr-RG observatory ended up in limbo.
In September 2014, NPO Lavochkin announced that the launch of Elektro-L2 would be possible in January or February 2015. However, in reality, the mission remained on hold, while Russia and Ukraine continued to be embroiled in political and military conflict.
By the end of summer 2015, a Ukrainian team of specialists responsible for launch equipment was able to make a trip to Baikonur to perform routine maintenance at the Zenit launch facility, however the rest of the Ukrainian team remained grounded.
By the end of September 2015, the launch had to be postponed from November 18 until at least mid-December 2015, even though Russian and Ukrainian space agencies finally engaged in negotiations to work out a deal with their respective governments, which would allow the Ukrainian team to travel to Baikonur to support the mission.
The Elektro-L No. 2 spacecraft and its Fregat-SB upper stage were finally shipped to Baikonur on October 16 onboard an An-124 transport plane. By that time, the launch was set for December 11, 2015.
Roskosmos first promised the fueling of the satellite for the mission on October 23, however it apparently was not completed until November 6.
In the meantime, all autonomous tests of the Fregat stage were finished by November 16 and the space tug was prepared for a trip to the fueling station to be loaded with its hypergolic toxic propellants from November 18 to November 24.
On November 26, the fueled Fregat was delivered to the MIK-40 assembly building at Site 31, where the Elektro-L2 satellite was waiting to be installed on top of the stage.
On December 1, the joint vehicles were covered with their protective fairing. The encapsulated payload section was then transferred to Site 42 for integration with the launch vehicle. That operation took place on December 4.
On December 9, 2015, at 13:00 local time, the Zenit-2SB/Fregat-SB rocket left its assembly for a trip to the launch pad at Site 45 in Baikonur to begin a three-day pre-launch processing. The liftoff was scheduled for 16:45 Moscow Time on Dec. 11, 2015.
The launch vehicle headed east and slightly north along an available flight path to align with an orbit tilted 50.4 degrees relative to the Equatorial plane. Zenit's first stage separated two minutes 25 seconds into the flight and eight and half minutes after liftoff, the rocket's second stage inserted the Fregat-SB and Elektro-L2 into a parking orbit. According to pre-launch calculations, the orbit was to have a 554.1 by 167.1-kilometer altitude.
After making nearly a full revolution around the Earth, Fregat-SB first activates its small thrusters to provide initial acceleration for the ignition of the main engine. The firing was initiated as planned one hour 14 minutes into the flight, pushing an apogee (highest point of orbit) to an altitude of 4,306 kilometers. Upon consuming propellant in its strap-on tank, Fregat cut off its engine after a more than eight-and-a-half minute burn. Around half a minute later, the thorus-shaped tank was jettisoned. For the next two hours, the space tug and its cargo was climbing passively toward the apogee of its new orbit.
The Fregat initiates its second engine firing almost three and a half hours into the flight, this time burning propellant from its remaining main tanks. The 11-minute burn stretched the already elliptical (egg-shaped) orbit to a nearly target altitude of 36,000 kilometers above the Earth's surface. However the inclination of the resulting geotransfer orbit was only reduced slightly to 48.6 degrees toward the Equator. The vehicle needed more than five hours to reach the new apogee, where Fregat was programmed to perform its third maneuver eight hours 46 minutes into the flight. The firing conducted at the farthest point from the Earth's powerful gravitational field was used not only to make orbit circular but also to make an energy-hungry inclination tilt to practically match the Equatorial plane.
The satellite separated from its space tug eight hours 57 minutes after leaving Baikonur. The Fregat was then expected to maneuver itself into a burial orbit, where it would not present a collision hazard.
In the meantime, Elektro-L2 should start activating its critical systems. The beginning of the solar array deployment for critical power supply was scheduled to be taken care first, just three minutes after separation from Fregat. While it is slowly opening up, the propulsion system would be armed and pressurized, antennas will be unlocked and unfurled.
The propulsion system onboard Elektro should be open for business around half an hour after the separation from Fregat. Almost immediately, it will come to life to stabilize any tumbling of the spacecraft induced by the separation jolt. Once that done, the flight control system will command the spacecraft to orient itself toward the Sun. With the solar orientation in place, Elektro should be ready for orbit correction and the eventual transfer to its operational position.
Mission timeline for the Elektro-L2 launch on Dec. 11, 2015:
Timeline for the activation of the Elektro-L2 satellite on Dec. 12, 2015:
Shortly after Elektro-L2 separated from its Fregat-SB space tug, a source at NPO Lavochkin reported on the online forum of the Novosti Kosmonavtiki magazine, that the satellite had been in good health and successfully pointed itself toward the Sun. There were few minor interruptions in telemetry transmission, which did not prevent the successful completion of all tasks of the first flight day. The spacecraft received all necessary commands from ground control and ground controllers were estimating the satellite's exact orbital parameters to update the projected move of the satellite to its operational position in the geostationary orbit.
On December 15, 2015, NPO Lavochkin announced that Elektro-L2 successfully switched from solar to orbital orientation and functioned well. The spacecraft was expected to make a controlled drift from its initial point at 55 East to its operational position at 77.8 East longitude over the Equator during a nearly 20-day period with the help of two or three orbit corrections.
In the meantime, the second stage of the Zenit rocket, which delivered Elektro-L2 into its initial parking orbit, was slowly loosing altitude and finally reentered the Earth's atmosphere. The Bangkok Post newspaper published photos and eyewitness accounts from multiple locations in Thailand of a bright meteor in the sky in the early hours of January 2, 2016. Most debris were predicted to fall in the Pacific Ocean, however on the same day, three spheres with a mass of 250 grams, six kilograms and 45 kilograms were found at three locations in the northern provinces of Yen Bai and Tuyen Quang in Vietnam. The smallest object reportedly hit a roof of the house but fortunately caused no harm. Shortly before objects had been found, eyewitnesses reported hearing thunder-like noise, Thanh Nien News reported.
On January 14, 2016, NPO Lavochkin quoted its Deputy Designer General Maksim Martynov as saying that the Elektro-L2 satellite had been undergoing the first phase of flight testing and it had completed planned orbit corrections. According to Martynov, service systems onboard the satellite functioned without problems. At the time, the satellite was approaching its orbital position at 77.8 degrees (East) longitude and was undergoing testing of its payload instruments and the first results were expected soon, Martynov said.
According to industry sources, the satellite conducted its final orbit correction to enter its operational position on Jan. 15, 2016, at 22:00 Moscow Time (2 p.m. EST). The maneuver stopped the controlled drifting of the satellite at 77.84 degrees East longitude in a 24-hour orbit with an inclination 0.3 degrees toward the Equator. Based on the post-maneuver trajectory measurements, mission control scheduled two additional maneuvers to bring the eccentricity of Elektro-L2's orbit to a nearly absolute zero. A pair of engine burns lasting around 45 seconds each with a total velocity change of 0.5 meters per second was scheduled during a period from January 18 to January 20, 2016.
On Jan. 21, 2016, at 12:30 Moscow Time (4:30 a.m. EST), Elektro-L2 had obtained and transmitted its first optical and infrared images in the course of flight testing, Roskosmos announced.
The first image from the Elektro-L2 satellite released on Jan. 21, 2016.
Elektro-L2 moves to a new position in orbit
According to published data from the Combined Space Operations Center, CSpOC, in the United States, on August 6, 2020, Elektro-L2 stretched its previously circular orbit reaching an apogee 307 kilometers above the geostationary orbit, which caused the satellite's drift relative to the Earth's surface toward its new operational position at 14.5 degrees East longitude. The satellite was expected to reach its new point by the middle of August 2020.
Click to enlarge. Credit: Roskosmos
Elektro-L2 shortly after its arrival to Baikonur on October 16, 2015. Click to enlarge. Credit: Roskosmos
Elektro-L2 is being readied for launch. Click to enlarge. Credit: Roskosmos
Elektro-L2 (right) is being prepared for integration with its Fregat-SB stage in November 2015. Click to enlarge. Credit: Roskosmos
Click to enlarge. Credit: Roskosmos
Operations to install payload fairing on Dec. 1, 2015. Click to enlarge. Credit: Roskosmos
Payload section containing Elektro-L2 is integrated with its Zenit rocket on Dec. 4, 2015. Click to enlarge. Credit: Roskosmos
On Dec. 8, 2015, Zenit with Elektro-L2 was loaded on its transporter for a trip to the launch pad. Click to enlarge. Credit: Roskosmos
Zenit with Elektro-L2 leaves the assembly building on its way to launch pad on Dec. 9, 2015. Click to enlarge. Credit: Roskosmos
Zenit rocket with Elektro-L2 arrives at launch pad on Dec. 9, 2015. Click to enlarge. Credit: Roskosmos
Zenit with Elektro-L2 shortly before liftoff on Dec. 11, 2015. Click to enlarge. Credit: Roskosmos
Zenit lifts off with Elektro-L2 on Dec. 11, 2015. Click to enlarge. Credit: Roskosmos
Separation between Elektro-L2 and the Fregat-SB stage as seen through a powerful tracking telescope on the ground. Credit: Viktor Voropaev
Officials in Vietnam review debris from the Elektro-L2 launch in January 2016. Credit: Vietnamnet.vn