A Russian Mars probe launched early Wednesday failed to reach its intended orbit after separation from the launch vehicle, Russia\'s Federal Space Agency said. The Phobos-Grunt probe that lifted off from the Baikonur space center atop a Zenit-2 rocket was supposed to use its own booster to reach the designated orbital trajectory but failed to do so, RIA Novosti reported. \"It has been a tough night for us because we could not detect the spacecraft [after the separation],\" Roskomos head Vladimir Popovkin said. \"Now we know its coordinates and we found out that the [probe\'s] engine failed to start. \"We will attempt to reboot the program. The spacecraft is currently on a support orbit, the fuel tanks have not been jettisoned and the fuel has not been spent.\" Technicians have three days to start the on-board engine and put the probe on it proper trajectory before the batteries run out, he said. The ambitious $163 million Phobos-Grunt mission is meant to bring back soil samples from the Martian moon Phobos in 2014 to pave the way for the exploration of the Red Planet. Grunt in Russian means \"soil.\" The spacecraft carries 20 instruments designed to gather and transmit data from the vicinity of Mars and from the surface of Phobos.