Micro PLB Device

A MicroPLB Type GXL handheld device used to transmit distress signals similar to the one given to Abby Sunderland by Microwave Monolithics Inc. before her journey. She used it send a signal to the U.S. via the international SARSAT network.

NASA's Goddard Space Flight Center, Rebecca Roth

Taking 'Search' Out of the Equation

The NASA-developed Search and Rescue Satellite-Aided Tracking (SARSAT) program that in 2009 helped rescue Clements was responsible for saving 194 other lives that year -- and continues to be effective. In 2012, it prompted the rescue of 263 people in the United States [source: NOAA].

In 2010, however, NASA began rolling out Distress Altering Satellite System (DASS) technology for search and rescue. Unlike SARSAT, the DASS doesn't use NOAA weather satellites. Instead, its distress signal repeater connects to U.S. Air Force Global Positioning System (GPS) spacecraft orbiting Earth. This hook-up creates two important improvements: Distress signals -- and their origins -- can be identified faster and more precisely. For example, DASS technology can precisely locate a distress signal within just a few minutes instead of the hour or more SARSAT may require. According to NASA, the DASS search and rescue technology will be fully operational by 2015 and linked to all the Air Force's Block III GPS satellites. It's expected to speed rescues not only for stranded boaters, but lost aviators and hikers, too [source: NASA].

Not everyone who needs rescue happens to be carrying a satellite-linked rescue beacon, though. What about survivors of tornadoes, earthquakes, hurricanes or tsunamis? Natural disasters like these can strike quickly and leave hundreds (sometimes thousands) in need of rescue.

Technical search equipment is a standard part of most search teams' arsenals and usually includes electronic listening devices (to hear signs of life), viewing devices like fiber-optic cable cameras and GPS receivers with mapping software [source: Stevens].

In addition, specially trained dogs can go into spaces too tight or unstable for humans, which is an important distinction when survivors are trapped beneath rubble or debris. And, because humans constantly slough off microscopic particles that act as a scent fingerprint carried by the wind, rescue dogs don't even need to track a fresh scent on the ground. This is known as "air scenting" and is an effective search technique that's been used to discover lost hikers, locate survivors of train and plane crashes and find skiers buried in avalanches. The dogs and their handlers are assigned specific geographical sections to investigate, and if a dog picks up a human scent, it alerts its handler with a bark [source: Lewis, NASAR].

Search and rescue dogs can get the job done, but they may have competition from another -- very tiny -- member of the animal kingdom.