NASA and the Worcester Polytechnic Institute (WPI) in Worcester, Mass., are looking for entrants for a robotic sampling competition with a $1.5 million prize purse, the agency and the university announced.

The 2013 NASA-WPI Sample Return Robot Challenge is slated for June 2013 and is a follow-up to a NASA-Worcester Polytechnic competition that wrapped up in June. There was no winner in this year’s competition, the objective of which is to design a robot capable of automatically retrieving a geologic sample from a simulated extraterrestrial environment.

Anyone may participate, but only teams of U.S. citizens are eligible for prize money, according to the competition’s officials rules.

The competition is part of the NASA Centennial Challenges program. Nonprofits run the challenges and pick up the tab for hosting them; NASA provides the prize money. The goal of the Centennial Challenges program is to solve technological challenges “of interest to the agency and the nation,” according to NASA. NASA said it has held 23 Centennial Challenges since 2005 and has awarded $6 million in prize money to 15 different teams.