Ultrasonic Tools Aid Planetary Exploration

Ultrasonic Tools Aid Planetary Exploration

When searching for extinct or extant life on Mars it is, without a doubt, highly desirable to drill deep below the rock or regolith surfaces to obtain samples for later analysis.

With the extinction horizon for oxidants in the subsurface being several centimetres and damaging ionising radiation penetrating to depths of around one meter, it is clear to see the extreme importance that precision drilling takes on.

Previously hammering or percussion have both been used to improve the drilling performance in hard and brittle materials, however existing hammering drilling techniques still have disadvantages, including:

“Clearly, traditional percussion drills are not ideally suited to power and mass constrained applications such as those prevalent in planetary exploration missions,” says Andrew Bowyer, commercial director at Magna Parva. “Our solution is to use ultrasonic axial excitation of the drill head to achieve cutting.”

The principle of ultrasonic drilling is to axially oscillate a cutting head at high frequencies (~20-30 kHz) to produce a small axial motion (~10 µm) at relatively high velocity (typically 1-20 m/s). The impact of the drilling head against the rock surface causes micro-cracking of the rock along the crystal and mineral fracture planes causing the surface to break off and allow cutting / drilling to be achieved. The progress of the drill bit through the medium is achieved by the application of a modest / low preload to the drill bit.