Soyuz delivers Resurs-P3
In the midst of a hectic launch campaign in Baikonur, Kazakhstan, Russian specialists succeeded with their second attempt to orbit the latest "eye in the sky" for the nation's fleet of Earth-watching satellites. The nearly six-ton Resurs-P No. 3 was the fourth spacecraft in the series operating in orbit as of March 2016.
Designed to operate in orbit for at least five years, Resurs-P3 was identical to its older siblings -- Resurs-P2 and Resurs-P1, all designed for multi-spectral observation of our planet. According to various sources, the mass of the latest variant is 5,730 or 5,920 kilograms.
The main payload onboard is a high-resolution optical telescope Geoton-L1 intended for taking images of the Earth's surface with a resolution up to one meter in black and white, while looking directly below its flight path (in nadir). The spacecraft can also conduct imaging tilting sideways up to 45 degrees from the nadir orientation in 45-second intervals. All photos taken by Resurs-P3 can be correlated to their locations with an accuracy from 10 to 15 meters without the use of ground reference targets.
Relying on a single receiving ground station, Resurs-P3 can photograph 80,000 square kilometers of the Earth's surface in high-resolution mode and should be able to revisit imaged areas within three days.
Like its predecessors, Resurs-P3 also carries an image storing and conversion system dubbed Sangur-1U developed at NPP Opteks, a branch of TsSKB Progress in Samara. Sangur-1U converts optical images into digital signal and then processes, compresses and transmits this data to the satellite's X-band radio system for a downlink to ground stations.
The satellite also carries a hyper-spectral imaging payload, GSA, and a wide-angle multi-spectral camera system collectively known as KShMSA. Both instruments were previously launched on Resurs-P1 and Resurs-P2.
To process and relay produced images back to Earth, the satellite is equipped with the BA SSSI storage system and the BA VRL high-speed radio-transmission system developed at the NII TP design bureau.
Known specifications of the Resurs-P No. 3 spacecraft:
Resurs-P development team:
Resurs-P No. 3 satellite minus its solar panels during pre-launch processing in Baikonur on Feb. 26, 2016.
In 2012, TsSKB Progress was also preparing for a tender conducted by Roskosmos to develop a new-generation remote-sensing satellite. (569) During that year, the company was expected to get one billion rubles for the development of the spacecraft, which was to take a total of three years to build. As of 2012, the launch was expected in 2015 or 2016. At the time, TsSKB Progress was in process of preparing contracts with suppliers of avionics for the spacecraft.
On June 27, 2013, at a press-conference dedicated to the activities of TsSKB Progress in the first half of the year, the head of the company Aleksandr Kirilin confirmed the launch of Resurs-P3 in the fourth quarter of 2015. Around the same time, Kirilin also said that the spacecraft would be proposed as the first payload to be launched from a yet-to-be-built launch pad for Soyuz-2 rockets in Vostochny.
When the satellite was delivered to Baikonur at the end of December 2015, Roskosmos promised the launch in March 2016. The spacecraft underwent vacuum testing in February 2016. On February 26, 2016, test activation of the satellite's systems had been conducted, Roskosmos said.
On March 2, the satellite's propulsion system was fueled and pressurization system was filled with gas. The tests of the pyrotechnic deployment system for the spacecraft's solar panels were scheduled for March 4.
On March 9, 2016, the payload section and third stage of the Soyuz-2-1b launch vehicle was integrated with the first and second stages of the rocket inside the assembly building at Site 31 in Baikonur.
The fully assembled Soyuz-2-1b rocket was rolled out to Pad 6 at Site 31 in Baikonur on March 10, 2016.
First launch attempt aborted!
The launch of the Soyuz-2-1b No. 016 rocket was originally scheduled for March 12, 2016, at 21:56:00 Moscow Time (1:56 p.m. EST; 18:56 GMT) from Pad 6 at Site 31 in Baikonur. The countdown was proceeding seemingly well until the very last moment before the engine ignition, when the AVD command, which stands for "automated engine cutoff" was issued. The rocket appeared to be safe by the time the video broadcast from the launch pad was discontinued seconds after the incident.
The mission had only a 10-second launch window which would not reopen until 24 hours later. Before the first launch attempt was scrubbed, the backup liftoff had been scheduled for 21:56:00 Moscow Time on March 13, 2016.
In less than two hours after the incident, a poster on the web forum of the Novosti Kosmonavtiki magazine said that the launch abort had been caused by a lack of signal in the flight control system confirming the ignition of one of pyrotechnic devices, known by Russian abbreviation as PZU, which are mounted on light wooden bars placed under the rocket to initiate the operation of first-stage engines. Because the process was stopped before the actual ignition, the propellant could be drained from the rocket and it could be refueled for another launch attempt within 24 hours, the poster said.
Although the nature of the problem was positively identified, specialists were conducting careful analysis of the launch sequence and checks of electrical circuits and pyrotechnics to isolate the exact culprit before the next launch attempt.
In 2006, several attempts to launch a Soyuz-2 rocket came close to the liftoff time, but had to be scrubbed due to technical reasons.
The State Commission overseeing the launch was expected to meet at Facility 80 at Site 31 in Baikonur on March 13, at 18:00 Moscow Time (11 a.m. EDT, 15:00 GMT) to make an official decision on the new launch attempt.
As expected, the new attempt was set for 21:56:00 Moscow Time (2:56 p.m. EDT).
The second launch attempt went without a hitch on March 13, 2016. The Soyuz-2-1b rocket lifted off at 21:56:00.333 Moscow Time.
To deliver Resurs-P3 into orbit, the launch vehicle headed almost exactly north to reach a near-polar orbit giving the satellite an almost global coverage of the Earth's surface.
The core (second) stage of the rocket continued firing until 4.7 minutes into the flight and then separated, reentering the dense atmosphere and crashing in Drop Zone No. 401 near the border of Sverdlovsk and Perm Regions of Russia. In the next two seconds, the tail section of the third stage, which served as an interface with the core stage, split into three sections and fell off, aiming to impact the common drop zone with the second stage. The same area received two halves of the payload fairing, which was jettisoned 1.2 seconds after the separation of the tail section.
The third stage firing completed the orbital insertion of the satellite into an initial parking orbit. Its engine was cut off nine minutes 17 seconds into the flight, followed by the release of the satellite three seconds later.
Planned timeline of the Soyuz launch with Resurs-P3 satellite on March 12-13, 2016:
Shortly after reaching orbit, Resurs-P3 successfully established contact with ground control and before it left the range of ground stations, the telemetry confirmed that the spacecraft had unlocked its power-generating solar panels. However, it soon transpired that one of the solar panels had failed to open completely. Mission officials hoped that it would still be possible to latch the panel in fully open position, possibly, after planned maneuvers of the satellite, industry sources said.
The semi-open solar panel was apparently blocking a pair of navigational star trackers, which failed to lock on their celestial targets. Fortunately, the satellite was equipped with additional systems, which could be used to orient it in space.
According to the original plan, Resurs-P3 was scheduled to enter a 290 by 475-kilometer initial orbit with an inclination 97.276 degrees toward the Equator, which would ensure a quick decay of the empty third stage, which delivered the spacecraft into orbit, while the Resurs itself was expected to use its own propulsion system to reach an operational altitude. After the launch, the NORAD cataloged the satellite as No. 41386 and reported it in a 279 by 452-kilometer orbit with an inclination 97.29 degrees toward the Equator. The second object, most likely the third stage of the Soyuz rocket, was in the 293 by 467-kilometer orbit with an inclinaton 97.3 degrees.
Immediately after reaching the initial orbit, Resurs-P3 was to deploy its power-generating solar panels and pressurize its propulsion system. The satellite should have also oriented itself within the orbital coordinate system and then activate its synchronization mechanisms, navigation systems and onboard GPS and GLONASS receivers. Navigation signals were to be used to conduct a dual orbit-correction maneuver scheduled during 37th and 69th revolution around the Earth. The first maneuver giving the spacecraft 74.7 meters per second in extra velocity would be conducted near the apogee of the elliptical orbit to make it nearly circular, while the subsequent 12.5-meters-per-second firing on the opposite side of the planet, should have made the orbit a perfect circle at an altitude of 477.5 kilometers.
On March 17, Roskosmos announced that Resurs-P3 successfully reached its operational orbit following the first of the two planned maneuvers. The 70-second engine firing was initiated at 17:02:46 Moscow Time on March 17, while the second maneuver was now scheduled for March 20, 2016, the agency said. The statement stressed that at the time, all onboard systems had functioned as planned and enabled to fulfill the satellite's mission. According to Roskosmos, the spacecraft had positive balance of power onboard (with a total output from solar panels exceeding 100 amperes). Also, a normal temperature and the required attitude control were also maintained. The satellite continued stable communications with ground control, downlinked telemetry and was receiving commands, despite the incomplete deployment of one of the solar panels, Roskosmos said.
According to the agency, a joint team of RKTs Progress (the satellite manufacturer) and the TsNIIMash Research Institute, which operates ground control, was analyzing the situation and was working on the solution to the problem. Known, as GOGU, the joint team was behind the decision to conduct planned maneuvers in orbit, Roskosmos said.
The final orbital correction was conducted on March 20, 2016, Roskosmos said three days later.
Despite a problem with one of its solar arrays, on March 23, Resurs-P3 delivered its first test photos, using the Geoton telescope and the wide-angle camera, Roskosmos announced.
A wooden ignition bar -- a likely culprit in the aborted launch attempt of the Soyuz rocket on March 12, 2016.
General architecture of Resurs-P3 satellite. Credit: Roskosmos
The Geoton telescope developed for Resurs-P series. Credit: Roskosmos
KShMSA multi-spectral camera onboard Resurs-P series. Credit: Roskosmos
Resurs-P3 during vacuum chamber testing in Baikonur on February 26, 2016. Click to enlarge. Credit: Roskosmos
On March 5, 2016, the final major components of the Resurs-P3 satellite -- its solar panels -- were attached to the spacecraft in Baikonur. Click to enlarge. Credit: Roskosmos
Click to enlarge. Credit: Roskosmos
Soyuz-2-1b with Resurs-P3 during rollout and installation on the launch pad at Site 31 in Baikonur on the morning of March 10, 2016. Click to enlarge. Credit: Roskosmos
An early test image obtained by Resupr-P3 on March 23, 2016. Click to enlarge. Credit: Roskosmos