By Dr David Whitehouse
BBC News Online science editor
British scientists want to send two mini-spacecraft to explore Phobos and Deimos, the mysterious moons of Mars.
The orbit of Phobos is slowly getting lower
The satellites, which are thought to be captured asteroids, have never received a direct mission - although passing US probes have taken images of them.
Dr Andrew Ball of the Open University says new technologies, such as low-mass propulsion systems, make this a good time to visit the moons.
The proposal may become part of a European Mars exploration initiative.
Dr Ball told the UK National Astronomy Meeting being held in Milton Keynes: "The latest developments in spacecraft technology allow us to contemplate some very exciting new missions.
"Although only a small mission, M-Pads - Mars Phobos and Deimos Survey - would do what all of the previous, large missions have so far been unable to achieve at the Martian moons."
Mars' two satellites were discovered in 1877. They are very small - less than 30km (18 miles) in width - and potato-shaped.
They have been seen in close-up by several spacecraft but the only missions to have had one of the moons as their primary objective - the Soviet Union's Phobos 1 and 2 spacecraft, launched in 1988 - both failed.
And yet these tiny objects are of great research interest, believes Dr Ball. New missions would help astronomers understand where the rocky bodies came from and how they have evolved.
M-Pads would consist of two mini-spacecraft stacked on top of each other. One spacecraft would carry instruments for remote observations of the moons while the other would carry a small lander to be delivered to either Phobos or Deimos.
Deimos is about 16 by 12km and circles Mars every 30 hours
Each spacecraft would use solar-electric propulsion to reach Mars orbit. Lightweight solar panels would provide electrical power for an ion engine similar to the one being used to take the Smart-1 spacecraft to the Moon.
M-Pads is being offered as a possibility for the Mars Micro Mission slot in the European Space Agency's proposed Aurora programme. Detailed planning work could begin in 2007.