Wednesday, March 26, 2014

Russian Spacecraft Misses ISS Rendezvous

Extraordinary night view of the launch of the Soyuz booster from Kazakhstan, as seen from the International Space Station passing overhead. Picture captured by NASA astronaut Rick Mastracchio, part of the first half of the Expedition 39 crew.

The crew of Expedition 39/40 will have to spend a couple more days in their cramped Soyuz spacecraft. Everything seemed to go well during the launch of TMA-12M, carrying Soyuz commander Alexander Skvortsov, Flight Engineer Oleg Artemyev and NASA Flight Engineer Steven Swanson. The Soyuz FG Booster lifted off beautifully, and placed the Soyuz spacecraft on its preliminary path using the high-precision navigational shortcut which allows Soyuz crews to reach the ISS in about six hours after liftoff.

Diagrams of Soyuz spacecraft and comparison to other capsule types. Click to enlarge.

The shortcut maneuver relies on a series of precise navigational changes made by computer-controlled thruster burns at specific moments during the trip. On the third burn attempt, the computer detected that the spacecraft was not in the correct positional attitude to affect the burn, and so it did not occur. Having missed the thruster burn opportunity, the crew are now consigned to follow the backup planned standard two-day approach to the ISS. There is plenty of supplies for this approach, and the crew has practiced this flight plan previously. However, it places additional stress on the crew as the spacecraft capsule is cramped and uncomfortable just as the crew is trying to deal with possible spacesickness and lack of mobility.

The crew of TMA-12M as they boarded their Soyuz rocket.

The new plan is for a rendezvous to occur on Thursday night. Ground engineers in Russia are studying the flight data to try and figure out how the spacecraft got into the wrong position. Once the crew arrives at the ISS, they will remain and eventually become the Expedition 40 crew. These three are due to return to Earth in September.

Blog update: Due to a very busy work schedule I've missed making my normal blog entries. This has provided me with time to reexamine the blog mission and what I want to do with it. Over the next couple of months I'll be making some changes, but also trying to catch up with manned spaceflight posts and my following of events from 50 years ago.

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