MLM Nauka makes triumphant docking to ISS

Russia’s Multipurpose Laboratory Module (MLM) Nauka, meaning “science,” has defied the odds to successfully dock… The post MLM Nauka makes triumphant docking to ISS appeared first on

MLM Nauka makes triumphant docking to ISS

Russia’s Multipurpose Laboratory Module (MLM) Nauka, meaning “science,” has defied the odds to successfully dock to the ISS after a long and arduous journey dating back over 20 years and a problematic propulsion system after launch which had threatened the success of the mission. 

The docking was not without issue, with Russian cosmonauts noting that Nauka wasn’t on the correct course less than an hour before docking; however, a retro burn quickly corrected the issue. After also troubleshooting an issue with the TORU manual docking system, which was used for the final seconds of the module’s approach, Nauka successfully docked to the Zvezda service module’s nadir port at 09:29 EDT / 13:29 UTC, marking the first major expansion to the Russian segment for over 20 years.

Nauka docking

Nauka had been chasing down the International Space Station (ISS) for the last eight days after being launched atop a Proton-M booster from the Baikonur Cosmodrome in Kazakhstan on 21 July.

Immediately after a successful orbit insertion of 190 x 350.1 km, issues with the module’s communications and propulsion systems were noted. Initial troubleshooting was complicated by limited communications during brief periods when the module came within range of Russian ground stations.

The communications issues were resolved in initial orbits; however, the propulsion system issue was more troublesome and believed to be related to a part of the module’s fuel supply being rendered unusable due to gases becoming mixed with the fuel for the main engine.

Reports indicated that pressure in the main engine’s propulsion tanks had risen to unacceptable levels due to an earlier-than-planned equalization of pressure between the tanks. Thus, use of the smaller engines would be needed to relieve tank pressure to a point where the main engine could be used.

That, coupled with continuous limited communications, resulted in several of the initially-planned orbit raising burns being cancelled and then later conducted using the module’s secondary engines.

These replanned first burns were enough to prevent Nauka from reentering the atmosphere within a few days, as was the fear given the low perigee insertion of 190 km. With those first burns, Russian controllers were able to stabilize Nauka, get the main engine working, and keep the module on track for a 29 July arrival at the Station as originally planned.

Approaching the ISS, Nauka used its KURS automated rendezvous system as intended; however, the module was also equipped with a TORU manual docking system, which would have enabled cosmonauts Novitsky and Dubrov aboard the ISS to take control of Nauka and fly it manually if needed.

For the docking, the ISS was placed in a special attitude – essentially pitched up 90 degrees – in order to place Nauka’s docking axis along the velocity vector. This was not the original plan, which would have seen Nauka approach up the R-bar, or Radial velocity vector, with the nadir Zvezda port facing straight down at Earth.

The ISS orientation plan for docking was changed to accommodate Nauka’s as-is condition after launch.

Docking was made to Zvezda’s nadir docking port, which was recently vacated by the Pirs module on 26 July. This port uses a docking system called the Hybrid Drogue Adapter (HDA).

Nauka, just before encapsulation for launch. (Credit: Roscosmos)

HDA is a Russian system which is essentially the combination of the traditional Probe & Drogue (SSVP) system and the Androgynous Peripheral Attachment System (APAS), on which the docking system of Dragon and Starliner is now based.

Specifically, HDA uses the docking collar from the APAS system, but rather than use a capture ring as is the case on the US segment, it instead uses a docking drogue as found on the SSVP system. This enables dockings to occur the same way as they do for Soyuz/Progress vehicles but gives a wider passageway through the hatch, which is useful for permanent modules.

Following docking and hard capture, the next immediate steps will be leak checks and vestibule pressurization followed by hatch opening, first ingress, and module activation.

Future plans:

A total of up to 11 spacewalks will be required in order to fully outfit and commission Nauka, with the first of these set to be performed in September.

Externally, after the module has been connected to the ISS via a series of cables, the first order of business will be to deploy the European Robotic Arm (ERA), which launched attached to the outside of Nauka.

This will involve removing external covers and launch restraints, following which the arm will be activated and fully checked out from the ground. ERA needs to be fully operational in order to proceed with the next phase of operations – which is transferring an airlock and radiator to Nauka.

This radiator and airlock were launched to the ISS attached to the outside of the Mini Research Module-1 (MRM-1) Rassvet on the STS-132 mission in May 2010 by Space Shuttle Atlantis. For the past 11 years, they have waited patiently for the arrival of Nauka.

The deployable radiator will be used to add additional cooling capability to Nauka, which will enable the module to host more scientific experiments. The airlock will be used only to pass experiments inside and outside the module, with the aid of ERA — very similar to the Japanese airlock on the US segment of the station.

The ERA will be used to remove the radiator and airlock from MRM-1 and transfer them over to MLM – with an extension boom being required to allow ERA to reach the airlock. This process is expected to take several months. A Portable Work Platform will also be transferred over, which can attach to the end of the ERA to allow cosmonauts to “ride” on the end of the arm during spacewalks.

Nauka also features a docking port on its nadir which other modules/vehicles can dock to. This port is also of the HDA type (passive side), however it features a special adaptor in order to convert it into a traditional Probe & Drogue port. This adapter converts the APAS docking collar into an SSVP docking collar, which will enable Soyuz and Progress vehicles to dock to MLM.

An internal cut-way showing the layout of Nauka. (Credit: Roscosmos)

In November, Russia will launch the Node Module (NM) Prichal to the ISS, which will dock to the nadir port of Nauka and will add a further four HDA-type ports to the Russian Segment for future expansion – although any expansion plans are now somewhat up-in-the-air following Russia’s decision to focus their future efforts on constructing their own station to succeed the ISS, possibly in cooperation with China.

Prichal will dock to Nauka using the HDA system, which will first require the removal of the HDA-to-SSVP adapter ring from the nadir port of Nauka.

This ring was therefore added as an “insurance policy” in case Prichal failed to make it to orbit, which would have rendered Nauka’s nadir HDA port useless as Soyuz and Progress vehicles would not have been able to dock to it which would have left the Russian Segment with only three usable docking ports.

The first docking to Nauka is planned for September 28, when Soyuz MS-18 will be relocated from Rassvet to Nauka’s nadir port in order to clear Rassvet for the arrival of Soyuz MS-19. MS-18 will then depart Nauka on October 17, whereupon Progress MS-17 will be undocked from MRM-2 Poisk and relocated to Nauka on October 27.

Assuming Prichal is successfully launched on November 24, Progress MS-17 will then undock from Nauka, taking with it the APAS-to-SSVP adapter ring, which will convert Nauka’s nadir port back to HDA configuration ready for the arrival of Prichal.

The planned configuration of ISS after Nauka and Prichal are attached. (Credit: Roscosmos)

In future, it will be standard practice to dock Soyuz vehicles to the nadir ports of Rassvet and Prichal and dock Progresses to the aft port of Zvezda and the zenith port of Poisk.

This is because the transfer chamber which connects to Zvezda’s aft port has a small leak which requires the hatches to remain closed as much as possible, which would block access to a Soyuz if it were docked to Zvezda’s aft port. In addition, Progress crafts are preferred for Zvezda’s aft port as this enables them to perform ISS reboosts using their main engines.

Progresses are also preferred for the Poisk zenith port as Poisk is now serving as the Russian Segment’s airlock following the departure of Pirs, and access to Soyuz craft docked to Poisk is blocked whilst Poisk is depressurized during spacewalks, which presents safety issues in an ISS evacuation scenario.

(Lead image: Nauka arriving at ISS. Credit: Mack Crawford for NSF/L2)

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Rocket Lab returns Electron to flight with dedicated US Space Force mission

Rocket Lab conducted the 21st flight of its Electron small satellite launch vehicle, a return… The post Rocket Lab returns Electron to flight with dedicated US Space Force mission appeared first on

Rocket Lab returns Electron to flight with dedicated US Space Force mission

Rocket Lab conducted the 21st flight of its Electron small satellite launch vehicle, a return to flight mission following a failure over two months ago. The launch carried a satellite for the United States Space Force on a dedicated trip.

Electron launched at the opening of the launch window at 06:00 UTC Thursday.

Electron lifted-off from Rocket Lab‘s LC-1A launch site on Mahia Peninsula, located on the Eastern Coast of New Zealand’s North Island, which has been the launch site for all of Electron‘s previous launches.

This mission was originally meant to mark the first Electron launch out of Rocket Lab’s second launch site, LC-2, located on Wallops Island in Virginia, although the mission was moved to New Zealand after Rocket Lab encountered delays in obtaining certification from NASA regarding Electron’s Autonomous Flight Termination System (AFTS).

The fully integrated launch vehicle was rolled out to LC-1A on July 21, where it successfully completed a full-up wet dress rehearsal, one of the final steps taken by the Rocket Lab team and Electron prior to flight.

Electron undergoing a wet dress rehearsal on July 21 – via Rocket Lab


The flight marked the second payload Rocket Lab has launched for the United States Department of Defense’s Space Test Program (STP), which provides flight opportunities to US military research and development payloads. The previous STP flight launched by Electron, STP-27RD, launched aboard Electron’s sixth flight in May 2019.

Electron Flight 21 UPDATES
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  • Thursday’s flight was named “It’s a Little Chile Up Here” in reference to the Green Chile, a staple food of the US State of New Mexico, where the Space Test Program is based.

    STP-27RM was procured by the Space Test Program and Rocket Systems Launch Program (RSLP) as part of the Department of Defense’s Rapid Agile Launch Initiative (RALI), similar to the STP-27RD mission launched aboard Electron in 2019. The US Air Force originally established RALI to reduce launch services costs and increase procurement speeds for US Military payloads.

    Another RALI mission, STP-VP27A, was launched just last month aboard the first operational flight of Virgin Orbit’s LauncherOne small satellite launch vehicle.

    In regular fashion for defense payloads, very little information had been released regarding the STP-27RM mission. Aside from that, it consisted of one small satellite, known as Monolith, which carries several instruments designed to investigate the ability of small satellites to support large aperture payloads to monitor space weather.

    Flight Plan

    Electron’s nine first stage Rutherford engines ignited two seconds before lift off, providing the rocket with 224 kN of thrust. Once the rocket lifted off, the first stage burned for two minutes and 34 seconds, when the engines shut down, followed by first stage separation and second stage ignition.

    Unlike the previous Electron flight, Rocket Lab did not attempt any kind of recovery test with Electron’s first stage.

    (Tweet caption: Rocket Lab CEO Peter Beck shares a photo of the Electron first stage, which performed nominally prior to a second stage failure on the “Running Out Of Toes” mission, being successfully recovered)

    The second stage’s single vacuum optimized Rutherford engine burned for just over six minutes, with second stage engine cut off (SECO) occurring at eight minutes and 46 seconds into the flight, shortly after Electron reached orbit. Over the course of this burn, Electron also jettisoned its protective fairing, which protects the payload as the rocket makes its way up through the thicker parts of the atmosphere and swapped out the batteries providing power to the Rutherford Vacuum engine.

    Just seconds after SECO, Electron’s kick stage, carrying the payload, separated from the second stage and enter a 40 minute cruise phase. The Curie engine on the kick stage ignited for the final series of burns at 49 minutes and 20 seconds into the flight.

    The kick stage performed the final orbital adjustments, placing the payload into the desired 600 kilometer high orbit with an inclination of 37 degrees. Electron’s mission officially end approximately an hour after launch when the Monolith spacecraft separated from the Kick stage.

    Return to flight

    The launch of Electron on “It’s a Little Chile Up Here” follows an extensive two-month-long investigation into the failure that occurred during Electron’s previous flight, resulting in the complete loss of the launch vehicle and payload minutes after launch.

    The investigation, which was overseen by the Federal Aviation Administration (FAA), officially wrapped up on July 19, with Rocket Lab announcing that they had identified the root cause of the anomaly on Electron’s 20th flight, also known as “Running Out Of Toes,” as an issue which occurred with Electron’s second stage igniter around three minutes and 20 seconds into the flight.

    Due to this issue with the igniter, the computer controlling the single vacuum optimized Rutherford engine powering Electron’s second stage became corrupted, causing the stage’s thrust vector control to deviate from where it was supposed to be. With the engine gimballing outside of limits, the computer commanded the engine to shut down, resulting in loss of the mission.

    It was concluded that the igniter issue was caused by a previously undiscovered failure mode within the ignition system that occurred during specific environmental conditions not previously met during any operational flights or testing of Electron and its components. The company has stated that they have now corrected the failure mode and replicated the conditions experienced by Electron during the failure, allowing the Electron team to implement redundancies to avoid repeating the issue.

    Following the conclusion of the investigation on July 19, the FAA confirmed they were satisfied with the outcome of the investigation and settled that Rocket Lab’s launch license remained active, clearing the way for Electron’s 21st flight.

    (Lead photo via Rocket Lab)

    The post Rocket Lab returns Electron to flight with dedicated US Space Force mission appeared first on

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