MOSCOW (Reuters) - A U.S. space agency official expressed concern on Wednesday that a decision to suspend Russian space launches in Kazakhstan could delay a vital navigation system from reaching the Mir space station. The last Russian-French crew is to leave Mir in late August, leaving the 14-year-old station unmanned for up to half a year as Moscow tries to raise money to send up a new crew. As a precaution against the unmanned station crashing to earth, Russia had planned to send up another computer system on a Progress resupply ship scheduled to blast off on July 14. Now that launch could be delayed. Kazakhstan has banned all launches from its Baikonur cosmodrome until officials determine the reason for the Monday crash of a Proton rocket carrying a Russian communications satellite. "They definitely need to get that motion control system up there before those guys leave," said Mike Baker, deputy director of NASA‘s Johnson Space Centre, who is based in Moscow. "They have to set it up and test it and so forth." Viktor Blagov, the deputy head of mission control outside Moscow, said officials were still hoping to launch next week, although a delay of a few weeks would not affect Mir‘s safety. "We are clarifying the situation," he said by telephone from the city of Korolyov outside Moscow. "We need it (the new computer) by August 28 when the unmanned period starts." Interfax news agency quoted the head of the Kazakh space agency, Meirbek Moldabekov, as saying the July 14 Progress launch depended on the speed of the investigation into the cause of the Proton crash. Russia uses the Baikonur cosmodrome to send up supplies of fuel and food to Mir every few months. "There is other cargo that could be critical, food for example," Blagov said. He declined to say how much food was on board and how long it would be before it started to run out. Mir usually carries substantial supplies of food. Sergei Gromov, a spokesman for Energiya which owns Mir, said Mir‘s main computer would guide the station after the crew left in August, adding that the new computer was only a backup. Russia has often coped with the unexpected as its finances for space have dwindled in recent years. Cosmonaut Sergei Avdeyev‘s initial six months in orbit were extended by another half year when Russia sold his seat home to a paying foreigner. Two weeks ago Avdeyev set the record for most cumulative time in space after spending his 678th day in orbit. Russia is seeking sponsors to raise the $100 million a year needed to keep Mir afloat. If money is not found, Mir will be retired in early 2000. Vitaly Sevastyanov, a member of parliament and a former cosmonaut, told Reuters last week that an effort to raise contributions had come up with only about $20,000 so far.