ADELPHI, Md. — NASA on July 13 announced three multimillion-dollar contests to build smart robots and launch tiny satellites as part of a program to develop innovations of benefit not only to the U.S. space agency but to the nation at large.

The contests are NASA’s newest Centennial Challenges, which offer cash prizes for technological achievements by teams who work without government funding. A combined prize incentive of $5 million will be split among the three competitions.

The competitions call on teams to repeatedly launch miniature satellites into orbit, develop a solar-powered rover that can run at night on stored energy or build a sample-return robot that can navigate over varied terrain and retrieve an identifiable object.

“NASA sponsors prize competitions because the agency believes student teams, private companies of all sizes and citizen-inventors can provide creative solutions to problems of interest to NASA and the nation,” said Robert Braun, NASA’s chief technologist. “Prize competitions are a proven way to foster technological competitiveness, new industries and innovation across America.”

The contests were announced here at the Space Technology Industry Forum, hosted by NASA’s Office of the Chief Technologist. The office is responsible for direct management of NASA’s space technology programs, and for coordinating and tracking technology investments across the agency.

Centennial Challenges are open to individuals, groups and companies working outside of the traditional aerospace industry. Monetary awards are made after solutions are successfully demonstrated; the participants maintain ownership of their intellectual properties.

Since 2005, NASA has conducted 19 competitions in six challenge areas and has awarded $4.5 million to 13 different teams.

The objective of one of the new competitions, the Nano-Satellite Launch Challenge, is to place a small satellite into Earth orbit twice in one week. The challenge is designed to stimulate innovation in low-cost launch technology and has a potential prize of $2 million.

The Night Rover Challenge has a prize purse of $1.5 million. The objective is to support innovations in energy-storage technologies that could prove valuable in extreme space environments, such as on the surface of the Moon.

Technological advances in this area also could have applications on Earth for electric vehicles and renewable energy systems, NASA officials said.

“With a lot of these things, there could be tremendous spin-offs in other fields,” said Andrew Petro, Centennial Challenges program executive.

The third contest, with $1.5 million in prize money, is the Sample Return Robot Challenge. It calls for teams to build and demonstrate a robot that can locate and retrieve geological samples from wide and varied terrain without human control. The challenge focuses on innovations in automatic navigation and robotic manipulator technologies.

“The Centennial Challenges have been recognized by the White House and the administration as an innovative approach to doing business,” Braun said. “It’s an approach in which we engage a wide variety of innovators across the nation. Through the space technology program, we hope to take that innovation and shine it like a laser on our space program and change the way we do business in the future.”

The program initiatives under the space technology program — including the Centennial Challenges — are subject to congressional approval. The Office of the Chief Technologist has requested $10 million in federal funding each year through 2015 as part of the expansion of the Centennial Challenges.

While the future of the program is contingent upon funding in 2011 and beyond, officials at the Office of the Chief Technologist are confident that NASA’s revised space technology program can help restore the agency’s cutting-edge technological prowess.

“There has been significant debate in Congress already for the need for a program just like this,” Braun said. “We’ve taken all the external input, all the criticisms from NASA’s past, and from that we have shaped the space technology program.”