Robotic helicopter helps NASA study Mars-like arctic crater

17 Jun 2002

A robotic helicopter will help NASA with experiments on a meteorite crater in the Arctic Circle, preparing NASA for similar terrain characteristics during future Mars exploration missions.

A 20-member team of scientists from NASA, Carnegie Mellon University, and other research organizations are exploring the Haughton Impact Crater on Devon Island between June 22 and July 26. Because the island's ice-enhanced terrain, ancient lake sediments, and networks of small valleys bear a resemblance to the features of Mars, the experiments may provide a view of Mars' earlier history when the planet may have been wetter and warmer.

The experiments consist of a field spectrometer experiment, ground-penetrating radar experiment, drilling experiment, stereo camera experiment, camera network experiment, the autonomous helicopter experiment, and human mission tests, as well as an education outreach program.

The experimental robotic helicopter has vision-based stability and position control along with an on-board navigation computer, laser rangefinder, and video capture hardware for site mapping. The helicopter holds immense promise for supporting surveying activities such as systematic mapping and field reconnaissance. During the Haughton mission the helicopter will undergo testing for future aerial surveys and remote field scouting activities.

The payload on the helicopter will include a video imaging system with live broadcast capability and a laser altimeter flown separately. Digital terrain models will be constructed by combining imaging and altimeter data.

The 160-pound helicopter began in 1991, when Omead Amidi of Carnegie Mellon's Robotics Institute was working on his doctoral thesis. An electrical model mounted on a swiveling arm platform was attached to poles by graphite rods. Amidi spent the next three years perfecting position estimation and control systems, and by 1995 he had developed a machine which could fly autonomously. He then worked on free flight and vision issues, and a year later the system could take off and land autonomously as well as sense its position in the field, track multiple objects, discriminate colors, and build aerial maps in winds up to 40 to 45 miles an hour.

The Ocean Optics 300-1000 nm field spectrometer will be deployed to determine the site's reflective qualities as well as to obtain information about its compsitional evolution. The field spectrometer, which was developed to aid robotic exploration missions for Antarctic meteorites, was tested earlier this year during an Antarctic mission.

The ground-penetrating radar experiment was also tested during that mission. The radar system will be used to map ground-ice and other subsurface conditions within and outside the crater's 20 kilometer diameter. The echoes will be contrasted to near-surface core drilling samples which will be extracted at the same locations. The Carnegie Mellon University GSSI SIR System-2 operates at 100 MHz, 500 MHz, and 1 GHz frequencies.

Carnegie Mellon scientists also developed the portable stereo camera system, which will be sued to acquire high-resolution images and overlapping 360-degree panoramas for the virtual reality project of NASA's Ames Intelligent Mechanisms Group which requires imaging data sets from multiple vantage points to develop surface image merging capabilities. The Nomad rover camera was previously used in a Chilean desert exploration project last summer.

The camera network experiment will conduct preliminary field surveys which will study active layer detachment slides, mass wasting, stream flooding, and icing formation by monitoring the rates of change.

In addition to NASA and Carnegie Mellon, support is being provided by the Geological Survey of Canada, the Polar Continental Shelf Project of Canada, the Nunavut Research Institute, the National Geographic Society, and NovAtel Communications.