The fate of the Russian Proton-M rocket that crashed in Kazakhstan last week may have been sealed by critical sensors that were installed "upside down." According to reports in Russian media, the investigators have determined that human error was to blame, as faulty preparations lead to the rocket launching with velocity sensors at incorrect polarities.

"As a result," writes Anatoly Zak on Russian Space Web, "the flight control system was receiving wrong information about the position of the rocket and tried to "correct" it, causing the vehicle to swing wildly and, ultimately, crash." A source speaking to Interfax concurs: "The angular velocity sensors were wired up with the wrong polarity. Therefore, the rocket was orientated incorrectly."

The investigative team is yet to officially confirm the results of its probe. Previously, it was estimated that it would take until the end of July to ascertain the cause of the explosion, which may have seriously contaminated the area surrounding the launch site.