Team Mercury and the 2010 American Solar Challenge
By: Dr. George Rutherford - June 28, 2010

The following account is provided without revision as a testimony of the courage and determination of this group of young people.

The Rayce Team:
-- Al Hackel, a music major
-- Jason Savage, a chemistry major
-- Josh Burnet, a biology major
-- Paul Aplington, a renewable energy major
-- Paul Timmermann, a business information systems major
-- Jim Dunham and George Rutherford, advisors

Others who worked hard in the weeks before the race but who couldn’t go on the trip:
-- Anthony Galassi, a physics/chemistry major
-- Jeff Linden, a business major
-- Ken Jesse, emeritus professor of physics

Saturday, June 12 was originally scheduled as a travel day, but the team was still attaching the newly acquired solar cells (from Sunergy, a Chinese manufacturer) to the solar array, so the team decided to leave early the next morning and drive to the Texas Motorsport Ranch in Cresson, TX.  The race caravan (three privately owned cars – Al’s, Josh’s, and Dr. Rutherford’s – and the truck/trailer, loaned to the team by Timmermann Construction) left Normal at 6:00 the next morning and arrived in Cresson before dark that same day.

Monday, June 14 – The team set up shop next to the trailer, using a couple of collapsible awnings to provide shade from the Texas sun, which raised temperatures into the upper 90s all week.  While Josh, Paul A, and Paul T. attached the last solar cells, Al and Jason took the chassis to the mechanical and electrical inspectors.  The electrical inspectors found little to criticize, apart from a missing warning label on the “kill switch”, a panel gauge to monitor the auxiliary battery pack, and inspection of the umbilical cable that connects the solar array to the chassis electrical system (it could not be fabricated until the solar array was complete).  The mechanical inspectors gave us our first bad news, pointing out the only real deficiency in Mercury III’s design or construction.  The front suspension, a double A-arm design, used rod ends for the connections at each end of the A-arms.  The inspectors convinced us that the size and placement of the rod ends made their structural integrity suspect.  They agreed to allow us to compete in the track race (the “Formuls Sun Grand Prix”) with the existing design, and we volunteered to rebuild a more robust front suspension, which they agreed would be sufficient for us to compete in the road race the next week.  Now all we had to do was find a machine shop that would allow us to fabricate an entirely new front suspension…

Tuesday, June 15 – After Josh, Paul A., and Paul T. finished the solar array, the team took the car to two more inspection stations:  the array station and the driver station.  At the array station, the team received some more disappointing news:  of the four sub-arrays, only one was working properly.  The team put that problem aside for later troubleshooting and proceeded to the driver station.  Here the inspectors made sure the driver’s compartment was sturdy and safe and that the roll cage safely enveloped the driver’s head and shoulders.

They also tested each driver to make sure each could exit the car in less than ten seconds.  Each of the three drivers exited the car in less than eight seconds.  The inspectors required that we add a few composite panels to the driver’s seat and floorboard, which the team accomplished in short order.  Troubleshooting the array kept the team busy for most of the rest of the day.  The last major hurdle before hitting the track was a battery of dynamics tests:  brake, slalom, and figure eight.  We passed the figure eight test with flying colors (the inspectors were constantly telling the driver to slow down!), and the team elected to try the brake test next.  The first test was aborted after Al noticed smoke coming from the back of the array!  The entire team was now intent on troubleshooting the array, and the problem was soon found.  The top of the car’s “wing” was made of fiberglass to keep the solar cells and their connections electrically isolated, but the two halves of the wing were bonded together with carbon fiber seam tape.  Since carbon fiber is electrically conductive, this brought the cells at the very front and very back of the car into electrical contact with each other through the carbon fiber.  We needed some kind of thin, stiff, insulating material that we could slide under the solar cells.  The solution:  a deck of plastic playing cards.  This clever inspiration, together with a few repaired connections, fixed all the problems with the array, which was later to produce almost 1200 watts of power on the road.

Wednesday, June 16 – Adding all the playing cards and fixing the odd solder joint here and there took most of the day, leaving the last hours of the day for our dynamics tests.  The slalom test was passed easily, leaving only the brake test, which required the car to stop on wet pavement from a speed of 25 mph in 3.1 seconds or less.  We made it in 2.8 seconds on the third try.  We were now ready for the track.

Thursday, June 17 – This was our first day on the track in the Formula Sun Grand Prix, which is used as the last qualifier for the road race.

Each team must complete 100 laps around the 1.7-mile track in a single day or a total of 150 laps over two consecutive days.  We were hoping to get our 100 laps done today, which would give us all day Friday to build the new front suspension.  But by now the team had been a few too many days on too little sleep, so we opted for a late start, which still should have given us 100 laps before the end of the race day.  A blown tire late in the race day stopped us just 12 laps short of our goal, requiring that we complete at least 62 laps on Friday.

Friday, June 18 – The team made short work of the final laps, even pushing the speed beyond the safe, measured pace they set for themselves in the beginning.  Their fastest lap (not nearly as fast as the car would go, just the fastest recorded lap) corresponded to an average speed of almost 36 mph, a respectable speed on a course with hills, sharp curves, and no-passing zones.  The team took the car immediately back to the trailer area in order to disassemble the front suspension.  Through former ISU colleague Shaukat Goderya, now at Tarleton State University, we obtained permission to use the shop facilities there.  Jim Dunham, team advisor and modelmaker for the ISU Physics Department, had already driven the 40 miles to Stephenville earlier that morning and had begun machining some of the new parts.

Dr. Rutherford then took the old parts down to TSU and helped Jim with the machining, finishing the job around 2:30 on Saturday morning.  The team owes great thanks to Dr. George Mollick, head of the Engineering Technology department at TSU, for his time and generosity.

Saturday, June 19 --  The team had brought along a small TIG welder and a 3 kW generator, and Jason now prepared to weld up the new A-arms.  We then discovered that our welder couldn’t produce enough heat to weld the now thicker parts together, and the team scrambled to find a welding shop open on Saturday.  Dr. Mollick again saved the day, offering us the use of the TIG welder at TSU.  So the team packed everything up and drove the caravan down to Stephenville, where we discovered a new twist in what was already a rollercoaster of a trip. The TSU welder was broken.  But as happened many times in our travels, the team engineered a solution:  they hooked up our little welder to the TSU power supply, which allowed our welder to produce enough heat to do the job.  But there was still one catch:  the safety system of our welder limited us to a 10% duty cycle.  In other words, we could weld for one minute, but then the welder would shut down for 10 minutes to avoid overheating.  The end result was that a one-hour welding job turned into a 10-hour welding job.  By the time the new suspension was reassembled, it was early Sunday morning, and the American Solar Challenge race was to start at noon in Broken Arrow, OK, a six-hour drive away.  Now the team faced its toughest decision.

To make the start of the race, the team would have to drive through at least part of the night and begin the race with essentially no sleep, on top of several nights of little sleep.  After considerable discussion, the team agreed that this option was unsafe and that we would have to trailer some part of the beginning of the race, a decision that speaks well of the wisdom and maturity of this extraordinary group of students.  Race rules deal out severe penalties for trailering, mainly to make sure that a team can’t trailer up a bothersome hill at the expense of a small penalty.  If a team trailers, they must continue to the end of that two-day stage, no matter where they first begin to trailer.  The team is then penalized the full published time for that stage (essentially the time required to drive that distance at the posted speed limit) plus three minutes for every mile that the car is actually trailered.  The team’s decision to trailer the first stage almost guaranteed a last-place finish among the teams who finished the race, but the team was determined to complete the race, driving every mile on solar power, regardless of their official standing at the end.

Sunday, June 20 – The caravan traveled to Topeka, KS to prepare for the start of the second stage on Tuesday and to allow the team to accumulate some much-needed sleep.

Monday, June 21 – The team used this extra day to perform an alignment of the new front suspension.  Everything was correctly done except the camber, which the team discovered on the road the next day.  (Note to future car technicians:  seven “half-turns” is considerably different from seven “whole-turns”, especially when performed on opposite sides of the suspension!)

Tuesday, June 22 – Having now rejoined the other teams and ASC officials in Topeka, the team passed its caravan inspection, ensuring that all labels, flashing lights, and safety equipment and procedures were in place.  Then a new challenge appeared, with barely an hour to go before the start of the race.  We discovered that the switch that actuated the brake lights was broken, a clear safety issue that would prevent us from starting this stage of the race until it was repaired.

The team found a workable spare, but it was a larger switch, requiring the team to bore out the hole in the welded tab that held the switch.  Drilling caused the weld to break (after all, the tack weld was intended to support the pressure of the switch only), so now the team had to bring over the generator and welder from the trailer, parked in a separate lot a hundred yards away.  By now the race had re-started, and we were more than an hour behind the rest of the teams.  On the road between Topeka and Jefferson City, MO (the next check point along the route), the team changed two flat tires on the left front wheel, our first hint that our alignment might not be correct.  The official end of the racing day found us about twenty miles short of Jefferson City, so we marked the position for an early start tommorow.

Wednesday, June 23 – The hills in this last half of the second stage proved very challenging to many of the teams, ours included.  As we climbed one particularly steep hill, we overtook the team from Northwestern University, whose car had stalled just below the top of the hill.  They had not yet had time to pull their car over to the shoulder, and we couldn’t pass safely so near the top of a hill.  We had no choice but to stop behind them while they pushed their car to the shoulder, but now our car was forced to renew its climb from a standing stop.  The current limit on the motor controller (a safety feature that also prevents an excited driver from drawing down the batteries too quickly) would not provide enough current to the motor to generate sufficient torque to climb the hill, so the team was forced to push the car the remaining few yards to the top of the hill.

Our observer duly noted this – the observer’s job is to note everything – and race officials gave us the appropriate penalty later that day.  This part of the stage also gave us our only experience with the interstate, a six-mile stretch of I-44, complete with hills and a 40 mph minimum speed limit.  (That last combination is not a pleasant one for solar cars!)  Try to imagine what it might be like to be traveling 60 mph in a 700 lb fiberglass and steel tube car, being passed by 2000 lb  SUVs going 70 mph.  As we approached the stage stop in Rolla, the team realized that climbing the hills took too much energy out of our battery pack, and the sun was quickly fading.  We decided to stop for a few minutes and tilt the array toward the sun, allowing the batteries to absorb the most power in a short time. While this gave us enough power to complete the drive, we missed the official closing of the Rolla stage stop by less than fifteen minutes.

Thursday, June 24 – The tires showed uneven wear, and with two flat tires already, the team had little choice but to realign the front suspension.  Unfortunately, this also required a quick trip to the hardware store to replace a special set-screw.  The team also thought it wise to raise the current limit on the motor controller, giving us a bit more torque to negotiate the remaining hills.  Although we ended up with another late start, the team was confident of better racing to come.  What we got was another adventure.  On Highway 47 in Missouri, the driver radioed the rest of the caravan that the chain seemed noisy.  Al and Jason, the experienced hands in the chase car, assured the driver that chain drives were inherently noisy.  A while later, when the driver radioed that the chain was becoming even noisier, the team decided to pull over and check things out.  The Thierbach Orchard parking lot provided a convenient spot, and the owners generously allowed us to use their space (and a bit of their shade) for our troubleshooting.  The problem turned out to be a very worn drive sprocket, which had to be replaced.  While most of the team set up the array to charge the batteries, Al went off to a local farm supply shop to find a replacement sprocket.  He found a sprocket, but it wasn’t attached to the proper sleeve, so the owner offered Al the use of an old arc welder.  Al returned a while later with a working sprocket and, although the team poked good-natured fun at Al’s welding job, the team was able to get back on the road.  Again the team had been met with generous people who shared their space and their resources with us.  Elise, the young daughter of the market’s owner, drew the team a picture of the solar car, so the team let Elise stand in the solar car’s cockpit for a round of pictures.

The delay was a costly one, however, and we missed the closing of the checkpoint in Alton, IL.  We drove until two minutes before the absolute end of the racing day, stopping just 18 miles short of Alton.

We were fortunate to find a wide, concrete area near an Ameren power plant, a perfect place to pull over and charge until 8:00.  Ameren security officials gave us permission to park the truck and trailer there over night, another display of the generosity we encountered throughout the entire race.  A quick mechanical check of the car revealed an extension of an earlier problem.  Al’s welded sprocket was close to failure, and the drive chain had become stretched.  This seemingly insurmountable difficulty was soon overcome by a combination of old and new approaches.  The team members got on their cell phones and, through a network of friends and colleagues, located the required parts and arranged for their transportation to us.  Dr. Rutherford’s son Thomas met Dr. Jesse on the ISU campus, took spare parts from him, and drove them to Springfield, IL on his motorcycle.  Al’s brother met Thomas in Springfield and brought the spare parts to West Alton.  By midnight, the drive train was repaired and a faulty powertracker was also replaced, giving us more power from the solar array.  And it was all done with cell phones and friends from the middle of rural Illinois.  I told you they were extraordinary.

Friday, June 25 – By now, the team had most of the kinks worked out of Mercury III, and it was fairly smooth sailing to the stage stop in Normal.  Even though we missed the official close of the stage stop by 13 minutes, the team was warmly welcomed home by an enthusiastic crowd and the best stage stop of the race.  Kudos to Willy Hunter and Sara McCubbins at the ISU Center for Mathematics, Science, and Technology for arranging such a wonderful stage stop and putting ISU’s best foot forward to an international audience of solar car racers.

Saturday, June 26 – Normal put its other best foot forward with the elegant start and surprising crowd at the Children’s Discovery Museum.  More kudos to Bethany Thomas and her friends at the CDM for the best start of the race!  The team had enough confidence now in the battery pack and solar array that they decided to dig deeper into their energy budget and run the car a little faster today.  Even though we were the last to start from Normal, we passed four teams along the road to Naperville and crossed the finish line an hour before the official close of the finish line.

Of the 15 teams who actually qualified for the road race, Team Mercury came in 13th place, last of the teams who finished the entire race. Even this modest result was the best of any ISU road race team, since Mercury III drove the lion’s share of the race – every mile from Topeka to Naperville – using only the power of the sun.  Given that the road team was only five students and two advisors (the smallest of any team in the race) and that the team’s budget, including gifts in kind, amounted to only about $40,000 (the smallest of any team’s budget, often by a large factor), I stand by my original description of this team:  extraordinary.