A non-profit outfit called Explore Mars has proposed a novel way to look for life on Mars, by using bunker-buster missiles meant to deliver probes, not explosives, into the Martian surface.

While NASA's Mars rover Curiosity can only drill a few centimeters into the Red Planet, missiles could probe deep enough to look for traces of microbes lurking in ice deep below the planet's surface, said Chris Carberry of the Massachusetts-based group.

"Curiosity doesn't go very deep -- it is literally scratching the surface," Carberry said.

The group is seeking funding for an undertaking dubbed ExoLance, in which small projectiles would be dispersed across the Martian surface carrying scientific instruments along with communication systems to send data back to Earth by way of satellites in orbit around Mars.

In order to prove the projectiles and the payload could survive the force of impact; Explore Mars says they plan to test the technology later this year in California's Mojave Desert.

Probes have been tried before; NASA attempted to slam a pair of penetrating probes down into the Martian surface in 1999, but radio contact ceased immediately on impact.

"Penetrators result in huge shocks," European Space Agency researcher Jorge Vago says. "Not many instruments can take this."

Vago is part of an ESA team developing the agency's ExoMars rover, set for launch in 2018, which will have the capability of drilling 6 feet into the ground

NASA is also planning a mission for 2016 dubbed InSight, which will be able to dig as much as 15 feet below the surface.

However, the NASA mission is not designed to look for life, and the ESA rover can only explore a single region at a time.

The bunker-buster projectile technology proposed by Explore Mars, which will sample many sites, "is something we know how to do very well," says Joe Cassady of commercial space firm Aerojet Rocketdyne, which is helping in the development of the project.

The projectiles would be affordable and small enough to be included in any of several proposed upcoming missions to Mars, he says.

"We deploy it, it's passive, and it has no propulsion of its own," he says. "We take advantage of its kinetic energy, pop off the main spacecraft and bury ourselves into Mars. It's important to do this repeatedly, sustainably, and affordably."