Space 'Harpoons' Could Snatch Samples of Asteroids and Moons

Artist's concept of a tethered "penetrator" heading toward a celestial body to take a sample. 

Credit: Chad Truitt, University of Washington

Why bother landing softly on an alien world to collect samples if you can just snag material with a harpoon from afar?

Using a set of long-lined, hard-hitting harpoons would allow a mission to grab large samples from multiple locations on an asteroid or moon — and to get them from beneath the surface, where some of the most interesting material lies, say researchers developing the idea.

Robert Winglee

"This technology will be able for the first time to pull samples of the order of a few kilograms from depths of a few meters, which could greatly enhance our knowledge of solar system objects and the resources therein," Robert Winglee of the University of Washington and his colleagues wrote in a NASA report detailing their project.

"Moreover, it offers the opportunity to take multiple samples (from either multiple objects or from multiple areas of a few objects) at little extra cost so that it will provide much greater flexibility and greatly enhance the science return for any given mission," they added.


The team's concept currently calls for a sample-return spacecraft to carry six lightweight, rocket-shaped "penetrators," which would be swung down at the target object(s) from orbit or during a flyby using a miles-long space tether.

The penetrators would hit at high speed — up to 2,240 mph (3,605 km/h, or 1 km/sec) or so — and go deep beneath the surface.

During the impact, they would collect several kilograms of material, which would be reeled back to the parent probe by the tether for eventual return to Earth.

The six-shooter approach enables the collection of multiple samples — an enticing prospect for scientists, Winglee said.