Pasadena, Calif. ? The California Institute of Technology is making a little green off the red planet.

Caltech, which runs the Jet Propulsion Laboratory for NASA, patented the twin rovers it sent to investigate the surface of Mars and is licensing their images for commercial use.

Models of the six-wheeled Spirit rover are already on store shelves. Caltech has inked three deals so far and expects perhaps three more.

Officials of the private university didn’t say how much money they hope to make, but they pledged to donate half to educational outreach programs and use the rest for Caltech research.

“We did it more for publicity than as a commercial hit,” said Frederic Farina, assistant director of Caltech’s office of technology transfer.

Danish toy maker Lego Co. was one of the first companies to sign an agreement and is already selling a build-it-yourself toy version of Spirit, the rover that arrived on Mars on Jan. 3 and has wheeled away from its lander to explore the landscape. Its twin rover, Opportunity, is scheduled to touch down Saturday.

The toy was based on drawings supplied by Caltech, said Jeff James of Lego’s community development office in Enfield, Conn. The set retails for $89.99 and contains 858 plastic pieces. It’s recommended for children ages 10 and up.

“It’s on the high end of challenging to put together,” James said.

Among the first to receive the kits were the Nobel laureates, industry executives, astronauts and others who sit on Caltech’s board of trustees.

Frederic Farina, assistant director in the office of technology transfer with the California Institute of Technology, is seen behind a Lego model of the Mars Exploratory rover. Caltech patented the twin rovers it launched to Mars and is licensing their image for commercial use.

“All these super scientists, Nobel Prize winners, were totally gaga over it,” Farina said.

Another company is producing a collectible, 1/10th scale model rover that sells for $150. A third is making larger models destined for museums.

NASA also signed its own Space Act agreement with CKE Restaurants Inc., the parent company of Carl’s Jr. and Hardee’s.

The fast-food restaurants are selling children’s meals that come with a NASA-approved toy spacecraft, including the Mars rovers, said Debbie Rivera, head of strategic alliances for NASA’s office of public affairs. CKE expects to distribute as many as 3.5 million.