Featured Research

from universities, journals, and other organizations

NASA-funded Robotic Sub Finds Bottom Of World's Deepest Sinkhole

Date:
June 2, 2007
Source:
Carnegie Mellon University
Summary:
A robotic vehicle designed for underwater exploration plunged repeatedly into the depths of Mexico's mysterious El Zacatón sinkhole in late May, finding its previously undiscovered bottom 318 meters below the surface and generating a sonar map of its inner dimensions. The vehicle employed autonomous navigation and mapping systems developed by Carnegie Mellon University's Robotics Institute.

The DEPTHX vehicle, 2.5 meters in diameter, included 56 sonars that the Carnegie Mellon team used to determine the location of the vehicle as it explored the cenote. It also used the sensors to create maps of the sinkhole's interior via a technique called simultaneous localization and mapping, or SLAM.
Credit: Deep Phreatic Thermal Explorer (DEPTHX) Project

 A robotic vehicle designed for underwater exploration plunged repeatedly into the depths of Mexico's mysterious El Zacatón sinkhole in late May, finding its previously undiscovered bottom 318 meters below the surface and generating a sonar map of its inner dimensions. The vehicle employed autonomous navigation and mapping systems developed by Carnegie Mellon University's Robotics Institute.

During a two-week NASA-funded exploration led by Bill Stone of Stone Aerospace, the Deep Phreatic Thermal Explorer (DEPTHX) revealed that the geothermal sinkhole, or cenote, did not have a tunnel or any other obvious underwater connections with neighboring cenotes in the Mexican state of Tamaulipas. It also obtained numerous samples of water and the gooey biofilm coating the cenote's walls.

"We're very pleased about the performance of the DEPTHX system," said David Wettergreen, an associate research professor who headed Carnegie Mellon's contingent of the research team. "We hit our technical objectives in creating a system that could explore and map autonomously."

In addition to gathering information regarding geothermal sinkholes, DEPTHX tested technologies and methods that might be useful in other underwater explorations, including the long-term possibility of exploring the oceans hidden under the icy crust of Europa, one of Jupiter's moons. For the near term, NASA recently approved a project that will use these technologies to explore underneath the ice of West Lake Bonney in Antarctica's Taylor Valley.

The DEPTHX vehicle, 2.5 meters in diameter, included 56 sonars that the Carnegie Mellon team used to determine the location of the vehicle as it explored the cenote. It also used the sensors to create maps of the sinkhole's interior via a technique called simultaneous localization and mapping, or SLAM. Prior to the DEPTHX field experiment, SLAM had been used for navigating in buildings and mines, but had never operated in an underwater environment or with such sparse sensor input.

Robots typically navigate by recognizing features, but cenote walls, while irregular, lack distinctive features. To overcome this challenge, DEPTHX had to navigate by recognizing a more global response from all of its sensors.

Wettergreen said demonstrating that SLAM could work in such a featureless environment suggests that it will have applications in environments with similarly sparse features, like rivers or mines.

Though initially operated on a tether, DEPTHX eventually operated autonomously, without a tether or human guidance, for eight hours at a time. "The fact that we never lost it, never required a rescue mission, is an achievement itself," Wettergreen added.

In addition to Wettergreen, the Carnegie Mellon team included graduate student Nathaniel Fairfield, undergraduate David Stone, senior research programmer Dominic Jonak and project scientists George Kantor and Peter Coppin. Other members of the DEPTHX team included scientists from the University of Texas at Austin, the Colorado School of Mines and the Southwest Research Institute.


Story Source:

The above story is based on materials provided by Carnegie Mellon University. Note: Materials may be edited for content and length.


Cite This Page:

Carnegie Mellon University. "NASA-funded Robotic Sub Finds Bottom Of World's Deepest Sinkhole." ScienceDaily. ScienceDaily, 2 June 2007. <www.sciencedaily.com/releases/2007/05/070531142103.htm>.
Carnegie Mellon University. (2007, June 2). NASA-funded Robotic Sub Finds Bottom Of World's Deepest Sinkhole. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2007/05/070531142103.htm
Carnegie Mellon University. "NASA-funded Robotic Sub Finds Bottom Of World's Deepest Sinkhole." ScienceDaily. www.sciencedaily.com/releases/2007/05/070531142103.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) — Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) — TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) — Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) — When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins