Ice pick

A powerful drill designed to bore through the polar ice caps of Mars has undergone testing by NASA in the icy wastes of northern Canada.

The drill is unique in that it is capable of boring more than six feet (1.8m) into the Arctic tundra using no more than a light bulb’s worth of power.

A NASA team has spent the past two weeks testing the drill at the Eureka Weather Station on Ellesmere Island in northern Canada — 690 miles from the North Pole, where conditions are said to be very similar to those found on the moon and Mars.

The two-metre drill was jointly developed by engineers from NASA’s Johnson Space Centre and Baker Hughes, a US oilfield services company. When fully developed it should be able to drill several hundreds of metres beneath the surface using no more than 60W of power, produced by an atomic battery or solar arrays.

Engineers on the project, a co-operative effort between NASA’s Johnson and its AMES research facility in California, had to design an instrument that could operate in extreme cold.

However, for project manager Jeff George, the key to the drill’s success was that it removed the need for the large, heavy drill-pipes that connect conventional drills to the base station.

‘The drill is completely self-sufficient and does not need pipes carrying lubricants or coolant, or for removing the drill cuttings from the drill bit,’ said George. ‘On Mars it would just not be feasible to have a series of large interconnecting pipes that would have to be fitted together robotically. We had to think of a way round that.’

The drill system consists of a control box, the drill itself and a support structure that is fixed either side of the projected borehole. As it will be carried on spacecraft in the future, the drill had to be as light and small as possible — and so the entire system weighs no more than 14kg, making it easy to handle.

The drill unit has an internal chamber which collects the drill cuttings and stores the collected samples. The drill itself is housed inside a metal tube known as a ‘spud tube’, an indication of its oil industry heritage — ‘spudding’ means to bore into a new well.

The drill is lowered on a tether and is fitted with pads which anchor it to the inside of the hole. It is periodically pulled to the surface to remove samples and the collected cuttings. A laptop computer connected to the control box sends commands to the bit, and collects data on its progress.

The project team has just completed testing of a second-generation prototype of the technology which is made from aluminium and steel — but George said that the third-generation prototype would probably be made from materials such as titanium.

The next series of trials are planned to involve thermal testing in a vacuum, which will replicate conditions on Mars to an even greater degree of accuracy.