The stunning display was produced when the rocket's Fregat strap-on boosters separated from its upper stage, and dropped to the ground.

这个令人目眩神迷的美景展示的是火箭的捆绑式助推器和它的上一级脱离并掉回地上时的情景。

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Without the Fregat upper stage, Grunt cannot travel to Phobos, yet if this powerful and massive stage were jettisoned, some less powerful, but functional, engines would be available for burns.

MSN: Salvaging Science from Stricken Mars Moon Probe: A Scientist's View - Technology & science - Space - Space.com | NBC News

Or, it could mean that they gain control of the spacecraft, but that the Fregat engine still will not ignite, yet the much less powerful propulsion units designed to land the craft on Phobos and propel the return capsule back to Earth are working fine.

MSN: Salvaging Science from Stricken Mars Moon Probe: A Scientist's View - Technology & science - Space - Space.com | NBC News