A robot built by the team Formicarum rolls off its starting platform during a level one rerun at NASA's 2015 Sample Return Robot Challenge on Friday, June 12, at the Worcester Polytechnic Institute (WPI) in Worcester, Mass. Sixteen teams are competing for a $1.5 million NASA prize purse.

Robot-toting teams faced off in a NASA contest this week to see which automaton has the right stuff for working on Mars or other locations in the solar system.

The fourth NASA Sample Return Robot Challenge, which ends today (June 13), offers a grand prize of $1.5 million to the winning team able to demonstrate robots that can collect geologic samples without any human help at all.

Developing technologies in autonomous navigation and robotic dexterity is one of the main goals of the challenge, NASA officials explained in a statement. The teams, which include universities and small businesses, have been facing off all week at Worcester Polytechnic Institute in Worcester, Mass. [The Best Space Robot Selfies]

"With missions to other planets and deeper space in our sights, it is increasingly valuable and necessary to see these technologies through," Sam Ortega, program manager for Centennial Challenges at NASA's Marshall Space Flight Center in Huntsville, Alabama, said in a statement.

"Robots are our pioneers, and solving this challenge will be a breakthrough for future space exploration."

There are two levels of competition available this year. In 2013 and 2014, the winners of Level 1 – Team Survey of Los Angeles in 2013 and the West Virginia Mountaineers of Morgantown – each received $5,000. These teams can each compete at Level 2 this year.

Other returning teams include:

Formicarum of Worcester, Massachusetts

Gather of Alexandria,Virginia

Lunambotics of Mexico City

Middleman of Dunedin, Florida.

Oregon State University of Corvallis

The Retrievers of Schenectady, New York

Rensselaer Polytechnic Institute Rock Raiders of Troy, New York

Wunderkammer of Topanga, California

New teams in 2015 are:

Army of Angry Robots of Silicon Valley, California

DT Bozzelli of Ann Arbor, Michigan

MAXed OUT of San Jose, California

Mind and Iron of Needham, Massachusetts

Massachusetts Institute of Technology Robotics Team of Cambridge

RoboRetrievers of Tampa, Florida

Sirius of South Hadley, Massachusetts

Smart Move of Clearwater, Florida

Smart Tools of Gurnee, Illinois

National Autonomous University of Mexico

Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We're also on Facebook and Google+. Originally published on Space.com.