A dozen stainless steel spiders descended from a helicopter into the crater of Mount Saint Helens yesterday. As Seattle’s KOMO News reported, the “pods are small and tough enough to reach places no man dares” to go. Scientists hope that data collected by the monitoring machines could one day help them to better predict volcanic eruptions.

Outfitted with precision GPS, motion-sensitive lead plates and pressure gauges, the $3,000 spiders both record and analyze the slumbering volcano’s movements and explosions. They even communicate with each other to determine what data is important enough to pass along. Information about multiple consecutive tremors, rather than one isolated shift, for example, is sent to satellites, which then relay the data to scientists. Each machine runs on just 1 watt of power, reported The Longview Daily News, compared to a standard nightlight, which uses about 15 watts.

“It’s pretty cool,” Rick LaHusen of the U.S. Geological Survey (USGS) told The Longview Daily News. “We took the scientific need and built something from scratch.” The USGS partnered with Washington State University and NASA on the project.

After nearly 30 years of calm, Mount St. Helens rumbled back to life in 2004, building up a new lava dome in its crater and raising fears of a repeat of the devastating 1980 eruption. The volcano quieted back down last year, but not before LaHusen and his team used the activity to garner data and test prototypes of the spiders, some of which were “blasted” to bits, according to The Oregonian.

When will Mount St. Helens wake back up?  “Some of these volcanoes that we don’t think of as active can come to life very quickly,” LaHusen told The Oregonian. For example, a volcano in Chile erupted last year with only a day or so warning.

Scientists can’t predict when Mount Saint Helens will start shaking or spewing lava again, but when it does, the spiders will be ready.

Image of helicopter dropping an early version of the "spider" into Mount St. Helens in 2006 courtesy of USGS