GLONASS Hunt for Culprits in Launch Failure
December 20, 2010Surplus fuel loaded in error onboard the launch rocket caused loss of three new GLONASS satellites on December 5. The mishap burdened the DM-3 booster rocket with an excess of 1.5 to 2 tons of fuel, causing it to deviate from its course after blast-off and dive into the Pacific Ocean instead of reaching orbit altitude — dashing hopes for an imminent, nearly full global operational GLONASS capability.
“The problem was not with the fuel service unit at the launching site, but with one of the sensors showing the fuel level,” said Gennady Raikunov, the head of the Central Scientific Research Institute of Machine Building. “We do not rule out the factor of human error,” he said, adding that the Russian corporation Energia may be linked to the incident.
News correspondent Peter de Selding, writing in the December 10 issue of Space News, reported that a new version of the Block DM upper rocket stage, which was used for the GLONASS launch, features larger propellant tanks than earlier versions. The DM stage is built by RSC Energia of Korolev, Russia.
“In what appears to have been a remarkable oversight,” de Selding wrote, “the personnel fueling the Block DM stage for the GLONASS launch did not account for the larger tanks. That led to loading between 1,000 and 2,000 kilograms more propellant on the Block DM stage than what had been planned for the mission. As a result of the excess propellant, the Proton’s third stage, suffering from the additional weight it was carrying, underperformed, placing the Block DM stage and the stack of GLONASS satellites into a lower-than-planned suborbital drop-off point.”
There seems to be plenty of blame to go around, and rumors are that heads will roll in various parts of the Russian territory. On December 17, the Russian news agency reported that "The preliminary results of the investigation commission indicate that Energia miscalculated how much fuel needed to be loaded into the DM-3 rocket booster," said Gennady Raikunov, director general of the Central Scientific Research Institute of Machine Building who headed the investigation into the December 5 launch failure. "The amount of oxidant exceeded the norm by 1–1.5 tons and excessive weight prevented the Proton-M rocket from putting the satellites into calculated orbit."
The preliminary report says a new, untested method for fueling the upper stage of the rocket apparently led to the error, but also blames satellite manufacturer Reshetnev Information Satellite Systems for not properly managing launch preparations. Indeed, how launch technicians could have loaded such a greater amount of fuel onboard without asking questions provokes, well, questions.
Get Back on That Horse. On December 12, the next-generation GLONASS-K1 satellite, serial number 11, was shipped to the Plesetsk Cosmodrome about 800 kilometers north of Moscow. According to manufacturer ISS Reshetnev, the satellite will transmit five navigation signals: two signals of normal and two of high precision in the L1 and L2 frequency bands, and a new code-division multiple-access (CDMA) civil signal in the L3 band (1205 MHz). The last is destined to shift the Russian constellation at least partly towards CDMA signal broadcast, in line with GPS and Galileo. It points towards possible and eventual interoperability of some kind between the systems.
Launch is scheduled for December 27 or 28 on a modernized Soyuz-2.1.b rocket equipped with a Fregat upper stage.
March FOC Vowed. Anatoly Perminov, the head of Roscosmos, the Russian Federal Space Agency, has stated that the setback is temporary and he plans to have a full 24-satellite constellation functioning by next March. He plans to accomplish this by repositioning one of the satellites now in maintenance and then bringing it back on line and by launching two more satellites over the next few months.
RSS
Become a Fan
Join our Network
Follow Us
Please send any technical comments or questions to our webmaster.