The anomaly that caused an International Launch Services (ILS) Proton M/Breeze M rocket to deliver a Russian telecommunications satellite into the wrong orbit last month has been attributed to a workmanship error, according to ILS President Frank McKenna.
McKenna says officials knew within a week that the Aug. 18 launch mishap, which dropped the Russian-owned, Astrium-built Express-AM4 satellite into a useless orbit, was caused by a worker who fed a faulty parameter into the rocket’s flight software system.
Evert Dudok, president of Astrium Satellites of Europe, says the Express-AM4 is now operating nominally, albeit in an orbit far from its intended dropoff point (Aerospace DAILY, Sept. 13).
McKenna says it took several days for Astrium, ILS and their customer, the Russian Satellite Communications Co. of Moscow, to establish communication with the spacecraft, though officials knew “within 12 hours” after the satellite was delivered to the wrong orbit that the cause of the launch mishap was not an equipment failure.
“It was a human error and it was an individual input,” McKenna says, adding that “the verification was run, but it was not caught.” However, “all the Proton stages operated properly from an equipment standpoint,” he says, and “all the mission parameters . . . were nominal.”
Based on the findings of an interagency failure review board convened in Russia shortly after the launch mishap, McKenna says three or four corrective actions will be taken, including verifying human input into the launch vehicle flight software and the process of running flight-software simulations on the ground prior to missions, as well as checking equipment and programming at the launch site prior to liftoff.
“All of that’s being verified now for every upcoming mission in terms of its flight software, including the two that are going to be launched in September,” McKenna says. “Additional checks are to be done at the launch base in this area, as we will do [for] every mission from this point forward.”
ILS is planning a “relatively quick return-to-flight program” as the company implements corrective actions in advance of seven remaining planned missions on tap this year, including launch of a Russian military satellite and the SES Quetzsat-1 this month, both of which have been delayed roughly three weeks as a result of the launch mishap.
McKenna notes that ILS has conducted 21 successful commercial missions with the Proton M/Breeze M since its last launch failure in March 2008.