A Russian Proton-M rocket upended itself less than a minute after launch Tuesday from the Baikonur Cosmodrome in Kazakhstan, exploding in a fireball of toxic chemicals.
The rocket was supposed to put three of Russia's Glonass global positioning satellites into orbit, but during its ascent, it rolled over and blasted its way back downward toward the Kazakh steppes, breaking apart just before hitting the ground.
Russian news media said there were no immediate reports of injuries, but a toxic cloud of rocket fuel drifted toward the city of Baikonur, about 40 miles (64 miles) downwind. Residents were told to stay indoors and close all windows. The Interfax news service reported that areas of the Baikonur launch complex were evacuated.
"A bad failure in the highly politically sensitive program in the days of political crisis," Igor Lissov, an editor for Russia's Cosmonautics News, wrote in a posting on the independent NASASpaceflight.com discussion forum. "Pretty bad, even without casualties."
The cost of the satellite loss was estimated at $200 million. The flaw behind the failure was not immediately determined: It could lie in the rocket hardware, or in the launch guidance software.
Russia's Nauka laboratory module is due to be launched on a Proton-M rocket late this year as an addition to the International Space Station. If the investigation of Tuesday's failed launch identifies a problem with the Proton's first stage, that mission may well have to be delayed.
NBC News space analyst James Oberg spent 22 years at NASA Mission Control and has written several books about the U.S. and Russian space programs. Alan Boyle is NBC News Digital's science editor.