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Spektr-RG faces more delays

The final assembly of the Russian-German X-ray orbital observatory hit a snag again, forcing a six-month postponement of its launch. In the meantime, preparations for launch bogged down during the first half of the year.

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eROSITA telescope travels to Russia

On January 20, 2017, the flight version of the eROSITA telescope finally departed Germany for Russia aboard a transport plane, the German Space Agency, DLR, announced. The flight from Munich, Germany, safely landed at Moscow's Sheremetievo Airport few hours later.

Upon eROSITA's arrival to Moscow, both intruments of the Spektr RG spacecraft are now available for installation on the flight version of the Navigator service module at NPO Lavochkin's facility in Khimki, before the fully assembled observatory could be shipped to the Baikonur launch site for a ride to orbit on a Proton/Block-DM-03 rocket then expected at the beginning of 2018.

Spektr-RG assembly begins

On February 16, NPO Lavochkin, the prime contractor responsible for the development of the Spektr-RG spacecraft, hosted the first meeting of the project team in 2017. According to the company, the German side, which provided one of the two instruments for Spektr-RG, confirmed the successful completion of tests on the eROSITA telescope after its delivery to Russia. The German instrument was then expected to undergo entry control by engineers from NPO Lavochkin and Moscow-based Space Research Institute, IKI. Both telescopes of the mission were then slated for electrical tests, which would clear the way for the final assembly of the flight-worthy observatory before its long-delayed launch then planned in March 2018.

However in the subsequent months, work on the Spektr-RG seemingly came to a standstill. During another meeting on May 16, the mission management broke the news that the launch of the Spektr-RG would have to be postponed for another six months from March to September 2018. The main reason for the delay was blamed on a production defect in a component, which prevented the on-time delivery of the onboard radio complex, BRK, for the spacecraft. The delivery of the crucial radio system from the Moscow-based RKS Corporation had been repeatedly promised within a month since the middle of the previous year but had been constantly delayed. Although the testing of the spacecraft could be conducted with a stand-in model of the BRK, the work on the telescopes had also remained stalled due to "missing documents," according to Russian officials. As often happens in international projects, translation of documents and language barriers slowed down the work.

In the official interview published on May 18 by TASS and Roskosmos, the head of NPO Lavochkin Sergei Lemeshevsky said, "In particular, it is necessary to re-program the onboard flight control system, because not everything was designed as planned on the eROSITA telescope. In addition, it will be necessary to check the new software."

Industry sources explained that Lemeshevsky had referred to an issue discovered last fall during the integrated tests of eROSITA. At the time, engineers realized that under some rare circumstances, a main controller failure could lead to the shutdown of the thermal control system in the telescope, if there was no reaction from onboard computers within a few hours. The German team proposed a minor software change in the satellite's flight control system, BKU, which would provide the necessary redundancy by turning the controllers off and on, if they did not respond in a normal fashion.

The software fix would also require some tests of the software after the integration of the eROSITA telescope with the Spektr-RG spacecraft.

According to sources at NPO Lavochkin, eROSITA also had problems sending scientific data via the BRK radio system during tests. The culprit was eventually traced to a misunderstanding between the Russian and the German team of the jointly agreed transmission protocol. The issue was resolved in April 2016 and the prototype of the eROSITA telescope was successfully re-tested in conjunction with the spacecraft. Still, the problem pushed back the completion and testing of the BRK radio system, a source at NPO Lavochkin said. According to Russian sources, the assembly of the BRK was further complicated by organizational problems and by errors during the wiring of electronic boards of the system.

At the time, NPO Lavochkin also faced a 1.4-billion-ruble penalty from Roskosmos for its failure to deliver Spektr-RG on time in accordance with a contract signed in 2011.

Real reasons for the delay

At the May 16 event, the long-delayed delivery of the radio system, BRK, for Spektr-RG was now promised by June 15. In the meantime, a prototype of the BRK was installed on the spacecraft for final tests. In turn, these tests could only begin after the completion of entry inspections on both telescopes, which were not expected to finish until the end of May.

At the beginning of July, NPO Lavochkin hoped to resume electric tests of the spacecraft, this time with flight-worthy models of both telescopes and the operational BRK radio system. The delay in the BRK delivery would push the readiness of the spacecraft for launch until June 2018. However, the next available launch window for Spektr-RG dictated by ballistic conditions would not be available for a few more months, hence the new launch date in September 2018.

The cumulative delays in the project required to formally cut the guaranteed life span for the Spektr-RG telescope in orbit from seven years to 6.5 years.

On the bright side, the IKI team reported that the testing of the Russian-built ART-XC telescope had been completed on April 15.

On July 20, a joint team from NPO Lavochkin and the Max Planck Institute successfully attached the German-built eROSITA telescope to the payload-holding truss, KNA, of the Spektr-RG spacecraft, NPO Lavochkin announced. In the next step of the assembly, the KNA truss would be moved to a clean room chamber for joint electrical tests with the Navigator service module. At the time, the launch of the spacecraft was still planned for October 2018, NPO Lavochkin said. (827)

Spektr-RG completes integrated tests

To meet the October 2018 launch window for the Spektr-RG observatory, NPO Lavochkin implemented a three-shift, seven-day-a-week work schedule.

On the evening of December 18, the Russian-German team successfully completed integrated tests of the spacecraft, which included flight versions of the eROSITA and ART-XC telescopes, as well as the Navigator service module. However, the troublesome BRK radio system was still represented by a qualification model.

The main radio system was fully available, but its backup set was still missing an electronics component known as Field-Programmable Gate Array or FPGA (sometimes abbreviated in Russian as PLIS), industry sources said. The particular system was built in the US and NPO Lavochkin was not able to directly obtain it due to export controls and had to consider redesigning the associated electronics. After a three-month review of the export license, the necessary component was delivered to Germany by the middle of December, but there it also needed an export permission from German authorities, which postponed its delivery to Russia to a period between the end of December 2017 and the beginning of January 2018.

A day after the completion of integrated tests, the Izvestiya daily quoted the head of the Spektr-RG project at NPO Lavochkin Vladimir Babyshkin as saying that continuing delays with the delivery of the BRK radio system required to postpone the launch of Spektr-RG from the end of 2018 to the 2019 window (which would be open from March to April). Industry sources confirmed that the preparations had been under increasing pressure, however, the most recent official schedule had still called for the launch of Spektr-RG in October 2018.

Spektr-RG to fly on a refurbished rocket stage

In 2017, it transpired that Spektr-RG, would have to be launched with a space tug which had passed its original operational warranty and had to be refurbished for the task. The Block DM-03 upper stage required new certification for flight before it could be authorized to carry the irreplaceable X-ray telescope. Following its launch on a Proton rocket, Block DM-03 will have the critical task of boosting the observatory from its initial parking orbit into deep space, toward a Lagrange L2 point behind the Earth relative to the Sun.

After the 2016 decision to switch the planned Spektr-RG launch from the Zenit-Fregat rocket to the Proton-Block DM vehicle, Roskosmos State Corporation made plans to use the Block DM-03 No. 4L upper stage, which had been manufactured in 2011 on an order from the Russian Ministry of Defense. The stage was intended for a trio of the Uragan-M satellites to replenish the GLONASS navigation network, but it had remained unused because of a reduced demand for replacements. The three booster stages of the rocket were manufactured around 2013 for the same GLONASS mission.

As of 2017, the Block DM-03 No. 4L, along with a similar vehicle -- No. 3L -- was in storage at the Experimental Production Plant, ZEM, in Korolev near Moscow. (The ZEM plant mass produces the hardware developed at RKK Energia, including Block DM series.)

The guaranteed life span for the storage and use of Block DM-03 No. 4L was to officially expire on Nov. 23, 2018, which meant that if the launch of the Spektr-RG mission would not take place as then scheduled in September 2018, the upper stage would have to be re-certified for flight after that date. As of the end of 2017, it was increasingly clear that Spektr-RG would not be ready for launch before 2019, thus requiring to re-certify Block DM-03 No. 4L for flight.

However, by 2017, the Soviet-era diagnostics equipment for the Block DM series at the ZEM plant reached such an old age that it had to be upgraded first, before conducting any further testing of vehicles No. 3L and 4L.

To make matters worse, as of September 2017, RKK Energia did not even have the formal permission from the Ministry of Defense to modify the Block DM No. 4L for the Spektr-RG spacecraft. There was also no funding at the time for extending the guaranteed life span of the stage beyond November 2018.

In September 2017, RKK Energia requested 73,785 million rubles (approximately $1.3 million) from Roskosmos to refurbish checkout and power supply components in the diagnostics facility for the Block DM series. This money would also pay for upgrading the diagnostics system for the Block DM series with new computers to check the flight control system aboard Block DM-03.

RKK Energia also requested Roskosmos an additional 35.2 million rubles (approximately $0.6 million) to cover already incurred expenses for the maintenance of Blocks DM-03 No. 3L and No. 4L from 2013 to 2016.

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Article by Anatoly Zak; Last update: July 8, 2019

Page editor: Alan Chabot; Edits: May 19, December 20, 2017

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General architecture of the Spektr-RG spacecraft as of 2017. Credit: NPO Lavochkin


An ART-XC telescope shortly after its delivery to NPO Lavochkin at the end of 2016. Click to enlarge. Credit: Roskosmos


The eROSITA telescope shortly after its delivery to NPO Lavochkin in January 2017. Click to enlarge. Credit: Roskosmos


Spektr-RG project scientists and space officials inspect German-built eROSITA telescope at NPO Lavochkin facility in February 2017.


The KNA payload structure holding eROSITA and ART-XC telescopes is being moved during tests at NPO Lavochkin circa July 2017. Click to enlarge. Credit: Roskosmos


Fully assembled Spektr-RG spacecraft circa end of 2017. Credit: NPO Lavochkin

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