Q: Every Missouri S&T car has been numbered 42. What is the significance of the No. 42?
A: Since 1993, students at Missouri S&T have built eight solar-powered cars, each one emblazoned with the sacred number 42. The tradition started when members of the first team decided that Douglas Adams, author of The Hitchhiker's Guide to the Galaxy, was right when he wrote that the meaning of life, and the answer to everything, is 42.
Q: What time of day do the students race their cars?
A: The students race their solar cars from 8 a.m. - 6 p.m.
Q: How far can the top teams go in a day?
A: In a 2003 race, some teams drove their solar cars more than 350 miles in one day, setting a solar-racing record.
Q: How fast do solar cars travel and what's the average speed?
A: Some solar cars can reach 95 mph on a track. However, during the race, teams must comply with posted speed limits.The average minimum speed will be 25 mph on the main route and 35 mph in sections where they travel the interstate.
Q: How much do these cars cost?
A: Some cars have been built for as little as $50,000. Some cost as much as $1 million. An average competitive car costs around $200,000. It depends on the type of components and materials students use, and how much time and effort they put into design. Advanced composite materials tend to be expensive. Computer-aided design and aerodynamic testing are costly. The more efficient, lightweight electric motors and higher efficiency solar cells add cost.
Q: How much does a set of solar cells cost for one of these cars?
A: Anywhere from $5,000 to $150,000. The price has generally gone down on the higher-priced cells. The cost was $150,000 for a 1,500-1,800 watt array.
Q: What is a solar array?
A: The array is all of the solar cells on the topside of a solar car. Once the sun strikes the array, this energy is converted into electricity to power the vehicle. The top of the car can also be removed and faced toward the sun for charging.
Q: How about batteries? How much do they cost?
A: Anywhere from $2,500 for a set of lead-acid batteries to $20,000 for a set of lithium-polymer.
Q: What is a solar car made of and how does it work?
A: It depends, but all are powered by solar cells (photovoltaic cells) that convert sunlight directly into electricity. That energy is then stored in batteries. The electricity powers an electric motor to propel the car. The car's body can be made of simple fiberglass and plywood or aluminum, or it can be made from advanced, lightweight composite material such as Kevlar, which is commonly used for bullet-proof vests and in racing and aerospace industries. Financing the car depends on the amount of money teams are able to raise and the design strategy they choose.
Q: What happens when it's cloudy?
A: Teams charge their arrays as much as possible. Energy from the sun is stored in the batteries. The solar cars can still run (for a while) on the stored energy on cloudy days. This stored energy may also be relied upon to give the car extra acceleration to make it up a hill. How the teams use up the energy really is up to them. A big component of each team's race strategy is managing energy consumption.
Q: What are the driver requirements?
A: Drivers must be 18 years old and have a valid driver's license from their home state/country. The cars won't accommodate big or tall drivers. Training is mandatory - several hours of operating a solar car are required for any driver.
Q: What happens when a driver weighs less than 85 kilograms?
A: Teams must make up the difference by packing the car with more weight, such as with sand bags, to reach 85 kilograms.
Q: How do you win?
A: Winning is simple - the team that makes it to the finish point in the least total elapsed time, while following all the rules, wins. Road penalties are assessed during the race for violating rules.
Q: What academic disciplines does this race encourage?
A: It's is up to each team to decide which disciplines they need, depending on their strategy. Some of the more typical are mechanical engineering, electrical engineering, electronics engineering, chemical engineering, automotive engineering, business management and marketing.
Q: Are these cars safe?
A: Before a team can officially race, its car must pass rigorous safety and reliability checks at qualifiers. Here, cars are inspected for all safety and performance regulations, including braking, wet braking, steering, avoiding rollovers, surviving crashes and the ability to maintain a minimum speed of 25 mph. Teams that do not pass qualifiers don't race.
Q: Will cars like this be common?
A: You may never drive a solar car with an array on the body, but what you could see are electric cars in every town and on every street, powered by batteries charged by solar panels on garages or carports. This is possible today, but the technologies still need some refinement. It's not much different than the internal combustion engine. These races are just one of the ways to demonstrate how solar power and electric transportation will be common in the future.
Q: Why solar cars if you won't ever drive one that looks like these?
A: These cars demonstrate that solar energy can provide enough electricity to power a car thousands of miles at highway speeds. And if that's true, just think of the hundreds of other applications for solar energy. As the technology improves, solar energy will become a more common way to power our buildings, homes and cars.