Progress Failure Blamed On Unforeseen Interaction With Upper Stage

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WASHINGTON — The loss of a Russian Progress spacecraft that started spinning out of control shortly after its April 28 launch is being blamed on an unexpected interaction between the spacecraft and the upper stage of its Soyuz rocket, the Russian space agency Roscosmos said June 1.

In a statement, Rocosmos said a “design peculiarity” between the Progress M-27M spacecraft and the upper stage of its Soyuz-2.1a rocket led to the accident. The statement did not discuss in detail how that design issue caused the accident other than citing the “frequency-dynamic characteristics of the linkage” between the spacecraft and upper stage.

The launch of the Progress started off normally, with the spacecraft appearing to separate into its planned orbit and on a trajectory to dock with the International Space Station six hours later. However, shortly after reaching orbit, the spacecraft went into a slow roll. Roscosmos deferred the docking to April 30, then canceled it entirely.

Controllers ultimately were unable to restore control of the spacecraft. It reentered over the Pacific Ocean without incident May 7.

The Roscosmos statement June 1 said that the problem “was not fully taken into account” during the design of the interface between the upper stage and the spacecraft. The launch was only the second time this updated version of the Soyuz rocket had been used for Progress launches. The issue, Roscosmos added, does not affect other satellite launches using the Soyuz-2.1a.

NASA was not directly involved in the investigation, but was kept informed of its work. “Roscosmos has regularly updated NASA International Space Station program personnel that work with our Russian counterparts on a day-to-day basis on the status of the investigation,” NASA spokesman Dan Huot said June 1.

Roscosmos said in its statement an updated schedule of Progress and Soyuz spacecraft missions to the ISS will be published by June 9. In May, the ISS partners agreed to delay the launch of the next crew, previously scheduled for May 26, to late July, after a Progress launch moved up from early August to early July.

That launch delay also pushed back the departure of three of the six people currently on the ISS: American astronaut Terry Virts, Italian astronaut Samantha Cristoforetti, and Russian cosmonaut Anton Shkaplerov. Originally scheduled to leave the station on their Soyuz TMA-15M spacecraft May 13, the three are now expected to return home by mid-June.

The Expedition 44/45 crew has a little longer to wait for their upcoming Soyuz launch to the International Space Station. Credit: NASA/Bill Ingalls
The Expedition 44/45 crew has a little longer to wait for their upcoming Soyuz launch to the International Space Station. Credit: NASA/Bill Ingalls