By the third decade of this century, NASA expects astronauts to  be living and working on the moon. And that means they'll need a steady supply of water. Now, getting one liter of the stuff in space costs $20,000. 

That's the cost of transporting a kilogram of supplies such as water to the International Space Station. Getting it to the moon will be even more costly. (NASA's even sending a rocket to punch a  crater into the moon in search of water.)

So, NASA is asking students to figure out how to manage the water issue with its Waste Limitation and Management of Resources Design Challenge.

So, if you're a fifth through eigth grader and have up to five classmates, get designing and testing that water recycling system.

The top three teams will win awards and the first place team will receive an all expense-paid trip to NASA's Kennedy Space Center in Florida.

They're looking for teams of up to six students and one teacher or mentor. They'll need to  submit proposals and results to NASA for evaluation by Feb. 1. Teams can be based in U.S. schools, science museums or science centers. Home school groups are also welcome.

The winners will be announced in May. 

The students who end up in Florida, will learn about NASA missions, get behind-the-scenes tours of launch facilities and learn about future aerospace and engineering careers.

NASA is hoping the competition will not only help solve a problem but bring some attention to science, technology, engineering and math disciplines that the space agency depends on.

For information about the contest and learn how to apply, click on this NASA site. 

Baltimore Sun file photo of a full moon over E. Lafayette Avenue in Baltimore/Karl Merton Ferron