The Missouri University of Science and Technology (Missouri S&T) Solar Car Team consists of about 20 students and 4 advisors. All students at Missouri S&T are encouraged to join the team, regardless of major; but the team is comprised mostly of Computer/Electrical and Aerospace/Mechanical engineers.

The first component of the car that is built is the body. The team first builds a “practice” body in order to perfect the construction methods before producing the “real” body. The main component of the body is ½” thick, high density, blue housing foam. A foam core keeps the body light and moldable. The foam is then sandwiched between two layers of Kevlar, sealed on with epoxy. The entire body is 1.8 meters by 5 meters (as regulated by race rules), yet only weighs 55 lbs. The body and chassis are two different components, and the body must be picked up and set down onto the chassis. To increase aerodynamic performance, the body mates with a belly-pan which is attached to the chassis. The wheels stick out of the body and must be covered with a carbon fiber fairing in order to reduce drag.

The internal structure of the car is created with a space frame chassis. The chassis uses 6061 aluminum tubes of varying diameters and thicknesses. In order to meet race requirements, the chassis must be sturdy enough to withstand several test conditions such as a frontal bump, roll-over, and side impact. To ensure that the chassis can meet these safety tests, Missouri S&T’s engineers use computer modeling software to evaluate all chassis designs for strength. The latest chassis designed by Missouri S&T for Solar Miner IV weighed only 16 lbs.

A good suspension is paramount in energy conservation in solar car racing. If a suspension is too hard, it causes excess wear on tires and can lead to flat tires. A suspension that is too soft will waste energy. Furthermore, the suspension must be very strong since it will bear much of the stress incurred while traveling down a pot-hole ridden highway. The Missouri S&T suspension is made from Chromoly steel, and uses bicycle racing shocks manufactured by Fox Racing Shox.

The only energy generated by a solar car must come from solar energy. Thus, the main energy generating component is a photovoltaic array (solar array). Solar Miner IV’s array used 2700 solar cells to convert solar radiation into DC power. Competitive solar arrays are slightly greater than 20% efficient, and can easily cost $80,000 or more. These “high-efficiency” cells are made from Gallium-Arsenide, and are usually created as space-grade cells for satellites (whereas most terrestrial use cells are made from Silicon). Missouri S&T engineers look at each module’s characteristics and carefully group modules that are alike into sub-arrays, because mismatched modules can decrease overall efficiency of the array by several percent. The solar array covers most of the area on the body, and constitutes more than 70% of the total cost of the car.

The next most expensive component of the car is the high capacity battery pack. The battery pack is used to store energy from the sun when solar output is high, and provide extra energy to power the car when solar output is low. At a conservative speed, the Missouri S&T battery pack has enough capacity to power the car for about 250 miles. Most top-end teams use Lithium ion (Li-Ion) or Lithium ion polymer (Li-poly) batteries (much like the batteries found in new cellular phones and laptops); however, some teams use Lead acid or other chemistries. The chemistry of the pack dictates the maximum weight of the battery pack, 360 lbs. of lead acid batteries are allowed, while only 55 lbs of Li-ion batteries are allowed. However, even with this weight difference, the capacities of each pack are similar. Teams continually search for batteries that are on the cutting edge of technology in hopes of finding batteries with higher energy densities.

Solar Miner V (SM5), is one of the finest cars produced by Missouri S&T. SM5’s top speed has not been reached, but is estimated to be above 80 miles per hour. Every aspect of the car is created with energy conservation in mind, and SM5 is one of the most efficient cars in the world.

The Missouri S&T team has created several extremely successful cars in the past 6 years. SM4 competed in Formula Sun Grand Prix (FSGP) 2003, FSGP 2004, and American Solar Challenge (ASC) 2003. SM4 dominated the solar racing field in these races, taking third in FSGP 2003, first in FSGP 2004, and first in ASC 2003. Previous cars built by Missouri S&T also set the pace for solar racing, with such notable finishes as: first place in FSGP 2002, second place in ASC 2001, first place in Sun Rayce (ASC precursor) 1999, and fourth place in World Solar Challenge 2002. More recently, SM5 completed the almost 2,500 mile journey that was the 2005 North American Solar Challenge (NASC). The team placed 4th overall out of 20 teams.