Progress M-27M Expected to Reenter Wednesday or Thursday EDT

Russia’s failed Progress M-27M cargo spacecraft is expected to reenter Earth’s atmosphere on Wednesday or Thursday Eastern Daylight Time (EDT), Russia’s Roscosmos space agency said today.  Launched on April 28 EDT, the spacecraft and/or its launch vehicle suffered a failure that left it in the wrong orbit and made it incapable of docking with the International Space Station (ISS) as planned.  The failure is still under investigation.

Progress M-27M was launched on a Soyuz 2-1a rocket at 3:09 am EDT on April 28.  Shortly after reaching orbit, Russian flight controllers began receiving conflicting data from the spacecraft about the deployment of solar panels and rendezvous antennas.  Video from an on-board camera showed the spacecraft rotating several times a minute.  Within a day, the Russians declared that the mission was lost. 

The spacecraft is carrying about three tons of food, fuel and other supplies for the ISS crew. This is the second of four planned Progress missions to ISS this year.  Other spacecraft also resupply the ISS (a U.S. SpaceX Dragon is attached there now and three more are planned this year, a Japanese HTV is scheduled for launch in August, and a U.S. Orbital ATK Cygnus may also be launched this year) so the crew members are fine.

Roscosmos today predicted that the spacecraft will reenter on May 8, 2015 between 1:23 am and 9:55 pm Moscow Time, which is between 6:23 pm May 7 and 2:00 pm May 8 EDT. Most of the spacecraft is expected to burn up during reentry, although Roscosmos said some small pieces may survive. Russia’s official Itar-Tass news agency quotes an unnamed industry official as identifying “more than a dozen spherical tanks” made of “thick-walled metal” as the most likely to survive because of their composition and the fact that they are sheltered by the spacecraft’s hull.

Ordinarily, Progress spacecraft make a controlled deorbit into the Pacific Ocean at the end of their mission, but that is not possible this time.  It is almost impossible to forecast where a spacecraft will reenter in an uncontrolled situation other than knowing its upper and lower latitude bounds which are set by its orbit.  In this case, that is between 51.6 degrees north latitude and 51.6 degrees south latitude.  Since 70 percent of the Earth’s surface is water, and much of the land is sparsely populated, the chances of damage to people or homes is small, but does exist.

Anatoly Zak at RussianSpaceWeb.com reports that experts are focusing on the last three seconds of the rocket’s firing and separation between the rocket and spacecraft as the time when the failure occurred.  Evidence increasingly points “toward an explosion aboard the rocket, which damaged the spacecraft, while some considerable force still propelled both vehicles to different orbits,” he writes, adding the spacecraft reportedly never fired its engines and propellant venting from “lines punctured by a nearby explosion of the third stage” set the spacecraft tumbling.