Robots Making News: Dante II

Dante II is a famous robot, known best for being the first “successful” terrestrial explorer robot. Successful is in quotations because there were some complications and the robot was eventually lost in a volcano, but this was after Dante II had already gathered the wanted data. Robots started to be used to explore volcanoes after eight scientists were killed in two volcanic eruptions in 1993.

In July of 1994, Carnegie Mellon’s Field Robotics Center launched Dante II into Mount Spurr in Alaska (Aleutian Range). The purpose was to collect data to help researchers understand the inner workings of volcanoes. Dante II was especially unique because of a tether system that allowed the robot to enter the volcano and safely retrace its steps back out. Dante II’s main objective was to sample high- temperature fumaroles gas, but another purpose was to show robotic exploration of extreme terrains that may be found on other planets. 

Dante II making his first and only descent. Note the tether (in red), eight separate legs, and see how many of Dante II's seven cameras you can find.
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 Dante II anchored at the rim of the volcano crater and used its tether cable to lower itself in a rappelling-like manner down into the volcano. The robot was in the volcano for five days; to move around inside, Dante II used both overseen autonomous control and operated control from scientists back at the lab. It was while climbing out of the crater that Dante II lost stability, fell, and the mission ended. Thank fully the computers on board the robot had already relayed all of the information Dante II had to offer.

Dante II had eight legs, all of which could individually adjust vertically to avoid obstacles. The robot had a single drive train that could move the separate frames with respect to each other. The frames could turn to change heading, but it was a slow process. The maximum turn per step was 7.5 degrees, so it was a lot easier to avoid rough terrain as soon as it is noticed. Dante II had seven different cameras and a two-axis laser scanner attached to the main frame. In addition to the cameras, data sensors including gas concentration and temperature were located along Dante II’s undercarriage. There was a satellite communications antenna that allowed data and video from the cameras to be sent to the control station at real time.

Dante II was 3.7 meters long and 3.7 meters high. The robot weighed 770 kg and was able to carry an additional 130 kg. It was able to rappel down the volcano at 1 cm/s up to 300 m. The maximum height which a leg could lift vertically was 1.3 meters.

Dante II was lost at the end of its mission, but it opened the door to robotic exploration in extreme locations. Scientists were able to learn a great deal about locomotion in steep and rocky terrain, as well as, in extreme temperatures. The implications of Dante II’s mission far surpass volcanoes, and technologies that were first used on Dante II are now being used by NASA and other agencies. Data that was once off limits to humans is now available and research is able to advance.
Sources:

Bares, JE, & Wettergreen, DS. (1999). Dante ii: technical description, results, and lessons learned. The International Journal of Robotics Research, 18(7).

http://www.ri.cmu.edu/research_project_detail.html?type=description&project_id=163&menu_id=261