With a $1 million grand prize up for grabs, amateurs and pros alike tried to prove over the weekend that their rockets could shoot the moon — and leave it, too.

Four teams initially threw their hats in the ring — and their rockets in the air — for the 2009 Northrop Grumman Lunar Lander Challenge, which aims to accelerate development of new rockets that can land on and leave the lunar surface.

"NASA’s exploration vision calls for putting humans back on the moon in the next decade. But the vehicles to land on the moon no longer exist," explained Dr. Peter H. Diamandis, chairman of the X Prize group that runs the competition. "We believe that entrepreneurial companies can build these lunar spaceships." And the compeition was designed to inspire them.

SLIDESHOW: The Lunar Lander competitors

Three teams large and small remain in the Challenge, from both billion-dollar companies and backyard rocketeers hoping to make a name for themselves. Over the weekend, teams made their last attempts at the prize; an awards ceremony is scheduled for Thursday in Washington D.C.

To win, a rocket must fly 50 meters (55 yards) into the air, transition to a pad 100 meters (110 yards) away, and safely land on the second pad before returning home. There are two levels of difficulty, each with a prize purse: In Level I, the ship must land on a smooth pad. In Level II, the rocket navigates a more challenging boulder-strewn terrain that replicates the lunar surface.

Over the past week, team Unreasonable Rocket encountered more ups and downs than the rockets they shot off. A father-son team, both named Paul Breed, is responsible for Unreasonable Rocket, which entered two vehicles in the competition based on the same technology.

On Sunday, the team's Blue Ball craft fought admirably to complete the Level I challenge. However, it was unable to return to the original landing pad, and thus wasn't eligible for the prize purse.

Sadly, Paul Breed Sr. later was force to declared the slightly larger Silver Ball rocket "dead," after a leg punctured the rocket's tank later in the day. The Breeds wouldn't make it into Level II of the challenge either.

Masten Space Systems qualified for the Level 1 purse on October 7. The team's rocket, named Xoie, successfully completed Level 2 on Oct. 30, qualifying for the million dollar grand prize.

The X-Prize competition's blog, The Launch Pad, noted that "Masten completed two beautiful flights with good landing accuracy, although [the team] maintained nail-biting levels of anticipation as they came up against the clock at the end of the attempt (2 hours and 15 min are allotted for each attempt)."

Finally, there's Armadillo Aerospace, the company founded by video game pioneer John Carmack. Armadillo's Scorpius Super Mod rocket successfully completed Level 2 of the challenge on Sept. 2, but the group wasn't involved in the weekend's activity.

The Challenge aims to foster an industry of American companies capable of routinely and safely flying vertical take-off and landing rocket vehicles, and comes with $2,000,000 in prize money, $1,000,000 per level of the competition. Four teams registered for a total of six different prize winning attempts in 2009.