Russian scientists still can't contact the lost Martian probe Phobos-Grunt, state media are reporting - and there's a danger it could fall to Earth with a massively toxic explosion.
The probe was launched on Wednesday, but failed to take the right course following the failure of the craft's two engines to fire as planned. It's now drifting in Earth orbit.
If control isn't regained, the spacecraft will remain in the orbit for up to four weeks. After that, though, things could get alarming.
The spaceship would probably fall to Earth sometime towards the end of this month or early in December - and with much of its fuel intact. While the odds are that the fuel would explode some 50 miles above ground, there's always the possibility that it might freeze, survive reentry and cause damage.
It contains about seven tons of nitrogen teroxide and hydrazine, which, according to space expert James Oberg 'will make it the most toxic falling satellite EVER'.
There's little detailed information from Russia’s space agency Roscosmos.
"It sounds like the spacecraft has actually only been heard from once, and that telemetry confirmed that the solar panels had deployed, the spacecraft had oriented on the sun, and the sun was recharging the batteries," says Emily Lakdawalla of the Planetary Society.
"After that point, the transmitter shut off, as expected. But no transmission has been received from the spacecraft since then."
But time is running out. Once the probe's batteries are exhausted, controlling it will be impossible. However, Russian scientists now say that there's a longer window of opportunity before that happens than the three days originally reported.
"A more thorough analysis of the orbit’s parameter and the supply of fuel onboard has shown that such commands must be delivered within two weeks," Vladimir Popovkin, the head of Roscosmos, told Ria Novosti.
Space agencies around the world have made communications stations available to Russia to improve the chances of regaining control. If the problem is a software issue, it should be possible to upload a new set of commands.