The members of Penn's Solar Car Racing Team were eager to participate in the American Cancer Society's Relay for Life this weekend, but they wanted to bend the rules a bit.

Instead of competing on foot in the annual walkathon at Franklin Field, they wanted to ride a solar-powered car.

Their plans for the cancer-research fundraiser were turned down. But the team members still plan to take part, walking on the track with all the other participants. And they have bigger races ahead as well.

Team members will be gearing up for this summer's Tour de Sol, a competition for environmentally friendly vehicles from around the country.

Organized by the Northeast Sustainable Energy Association, the competition will go on for four days in May in Saratoga State Park in upstate New York.

There, team members will be able to see how the Keystone -- the vehicle on which have been working all year -- stacks up against the competition.

After being disqualified due to a malfunction at the North American Solar Challenge, a 2,500-mile race from Austin, Texas, to Calgary, Alberta, last year, the team has been putting in extra effort.

The members meet in the basement of the Towne Building every Monday night to build on the work they began back in September.

Building a solar-powered car is a delicate process, team co-leader and Engineering junior Noel Camacho said.

Vehicles tend to weigh about 500 pounds and are covered with solar cells which provide power.

Members say they always build the brakes first to make sure they are up to safety standards. The car must be designed so that its driver can escape in under 10 seconds if an accident occurs.

The team is split into several divisions which deal with different aspects of putting the car together. For example, the business division manages finances; the mechanical division builds battery boxes. There are about 40 active members.

Building a car is "really cool," Engineering freshman and team member Sasha Seletsky said.

The car itself can cost up to $200,000, said Engineering professor John Bassani, who has advised the team.

The team has usually built one car every two years since its inception in 1989.

But the Keystone deserved an extra year, team members say, after its disqualification last year.

They say they continued working on the Keystone for one reason: to race in May's Tour de Sol.

But the team is also ready to compete in a very different race this weekend, walking for cancer research, their car displayed on the sidelines as the mascot.