By Neal Singer A tournament featuring remote-controlled model vehicles able to "lock on" to each other with remote sensing devices and then fire Velcro-covered Ping-Pong balls at each other's turrets is the major attraction scheduled for the 75th annual Engineering Open House at the UI. The open house, one of the largest of its kind in the nation, will take place from 9 a.m. to 4 p.m. Friday and from 9 a.m. to 3 p.m. Saturday. More than 20,000 people are expected to attend. Programs listing the events and maps indicating where they'll take place will be available at an information booth in Kenney Gymnasium. All events are free and open to the public. "Crater Conquest!," a creative design contest for engineering students, will involve 60 teams from the UI, Georgia Institute of Technology, University of Michigan and Purdue University. Four to six teams will bombard opponents' vehicles in each five-minute round, aiming at turrets built of stainless steel salad bowls 15 inches in diameter and covered with Velcro. The cars can be up to 2 feet tall and weigh as much as 50 pounds. With light-emitting diodes providing a kind of radar, the cars will use student-programmed microcon- trollers to "stay with the target and tell their guns where to shoot," said engineering student Christopher George. Fifty points will be awarded for each ball that sticks to an opponent's target until the end of the round, and 15 points will be subtracted for each incoming hit on a team's turret. The winning team will receive $1,000. Other awards, of $100 each, will be given for "most sensationally decorated" vehicle, "most ingenious design," "most spectacular failure" and "best use of microcontroller." The contest, to take place both days in Kenney Gym, is sponsored annually by Advanced Micro Devices Inc. and is intended to recognize and encourage students with a talent for design. The open house will include more than 150 other exhibits, ranging from the lighthearted to the serious. In the crane bay of the Newmark Civil Engineering Laboratory there will be an experimental car that can tell a driver the best trip route to take. Other displays will include a demonstration of how Slime, a popular children's toy, is made (Roger Adams Laboratory) and the role of nuclear engineering in saving the environment (Loomis Laboratory). The U.S. Air Force is expected to contribute a 15-foot model of a jet fighter for visitors to inspect. MCI will display a trailer similar to ones it provides during natural disasters and allow visitors to make free long-distance calls in the continental United States. Chrysler, Ford and General Motors will be displaying a variety of vehicles, including electric vehicles and their latest model cars. Visiting Illinois grade-school students can participate in a sailboat-design contest. Thirty-five Illinois high school teams, in an event called "Wimbledon," will design devices capable of shooting tennis balls at a moving target. Besides educating the students who participate in the open house, the aim of the event is to better acquaint the public with engineering innovations, as well as with the facilities and work of the college. Since the 1920s, the open house has featured demonstrations considered innovative at the time, including dial-telephone systems, model hydroelectric plants and power-transmission lines, radio broadcasting and receiving equipment, sound movies and television. The UI College of Engineering is consistently ranked among the nation's best. Six of its degree holders have gone on to win Nobel Prizes.