Using military-grade GPS signals, the MDARS robot knows where it is, within a few inches, at all times. Its programmed electronic brain knows precisely where it's going, and its laser vision and cameras spot any obstacles in its way.
MDARS - a mobile detection assessment response system - is a four-wheeled, high-tech robot that has been conducting security patrols on the vast Nevada National Security Site for almost a month.
The Rhode Island-size swath of desert and arid mountains is where the U.S. military tested hundreds of nuclear weapons during four decades of the Cold War. Formerly called the Nevada Test Site, the area is pocked with craters left from above-ground and underground nuclear explosions, and it has been identified as one of the most radioactively contaminated places in the United States.
Even though nuclear test explosions were halted in 1992, an area now referred to as "Plutonium Valley" remains so radioactive that it is used for radiation detection training. On other parts of the 1,360-square-mile test site, storage tanks hold radioactive material, and burial sites receive a steady stream of low-level nuclear waste.
The remains of concrete and steel bunkers and other test structures jut from the parched ground where they were built to determine how well they would withstand nuclear blasts.
There are historic areas, such as Jackass Flats, where engineers in the 1960s tested a nuclear ramjet engine and a nuclear rocket motor. And there's a 300-foot-deep, 1,300-foot-wide crater dug by a 1962 test to see whether nuclear weapons might be used to dig harbors and canals.
At a transportation incident exercise area, emergency personnel train for radiological terrorist attacks using decommissioned helicopters, planes, trucks, trains and cars as props.
Meanwhile, nonexplosive testing of nuclear weapons continues in test site laboratories. There are 1,100 buildings, 700 miles of roads, a pair of airstrips and 10 helicopter landing pads.
Once a month, the site admits tourists. Photo identifications are required; no cameras, recorders or binoculars are allowed.
Security has always been tight at the test site, but now it's getting tighter "to be compliant with what's being buried at the site," said Stephen Scott, a security engineer at the site.
Security requirements for the site's waste burial areas are that "you have to be able to observe it," Scott said.
Posting guards around the clock was deemed prohibitively expensive. Installing cameras and motion detectors would require towers and lighting and miles of buried power lines, an undertaking priced at more than $6 million.
By comparison, patrolling robots that cost $590,000 apiece seemed a bargain.
About the size of a golf cart, the MDARS robots are powered by four-cylinder diesel engines that propel them up to 20 miles per hour. As they move, the robots keep watch over the area they're patrolling with an intrusion-detection video camera during the day and an infrared video camera at night.
Those cameras work in conjunction with a high-resolution radar that is tuned to detect crawling, walking or running intruders in the dark and through smoke, fog, dust and precipitation at a range of 1,200 feet.
If the robot spots something suspicious, it alerts an operator, who decides what to do next. He has a couple of options: call in security personnel, or send the robot in to take a closer look. Using a two-way audio system on the robot, the operator can question suspicious persons, said Brian Frederick, MDARS program manager for the robot's maker, General Dynamics.
For now, at least, the robot is unarmed, so if it detects intruders, the operator will have to dispatch security personnel to the scene, Frederick said.
In addition to searching for intruders and other threats, the robot is able to read radio frequency identification (RFID) tags that tell it whether locks are locked and gates are properly shut, whether vehicles are parked where they're supposed to be, and whether earth-moving equipment used to bury nuclear waste is accounted for, Scott said.
Using RFID tags, MDARS robots can also conduct inventory checks of weapons bunkers and warehouses along their assigned patrol routes.
"These things are really extremely intelligent," Scott said. They can be set in "mission mode" to patrol along predetermined routes, searching for intruders, checking locks and the like. Or they can be set in "scripted mode," in which they will patrol for a while, then stop and turn off their engines and "go into silent surveillance mode," during which the cameras and radar operate on battery power. "Then they will start up again and resume regular patrolling," Scott said.
When a new robot arrives, its operators must program it to perform the work they want done. All roadways, intersections, way points, terrain, buildings and other details must be recorded in the robot's memory. So, too, must the security checks to be performed and actions to take when potential threats are detected.
That process can take months. The Nevada site received three robots this summer and has had one on patrol since Sept. 30, Scott said. A second one is being programmed and is expected to be ready for use in January, and a third by April. Two more are expected to arrive after that.
When it's ready to begin work, a robot follows the instructions placed in its electronic brain, and uses ladar - laser radar - and optical avoidance cameras to detect obstacles in its path. If a tree has fallen or a vehicle is blocking the road, for example, ladar and cameras will detect it and prompt the robot to slow and eventually stop.
The robot may try to go around the object, but it won't pull into lanes of oncoming traffic without permission from its operator, Frederick said. If it can find a new path to avoid the obstruction, such as going around the block, it may do that. But it won't venture off the road and across the countryside unless instructed to do so by an operator, he said.
"We see this as a real force multiplier," said Brad Peterson, the National Nuclear Security Administration's chief and associate administrator for defense nuclear security. "We're not looking to replace security guards; this enables guards to do their job better. It leverages technology" so that protective force personnel can concentrate on the most critical areas.
There are other interested customers, Frederick said.
Commercial airports are considering the robots for patrolling perimeter roads, the U.S. Army has experimented with them for security and inventory control around ammunition bunkers, and at least one is being evaluated for use along the U.S.-Mexico border.
"We're always looking for ways to improve them," Frederick said. Better sensors, being able to see better at higher speeds and ballistic protection are some improvements under consideration, he said.