PDF version of COSPAR - Space Science Research in Canada Report

oundary layer on Mars is generally higher than on Earth—perhaps four to fivekilometres during the day in the Arctic because of solar heating, and less at night.“We think the lidar will be able to tell us is how deep the boundary layer is,” hesaid. “We’re hoping it will detect a horizon—a change in the dust concentration atlevels corresponding to the top of the boundary layer.” This will depend on thesize of the dust particles. If they are large enough to settle out of the atmospheresufficiently rapidly at night, scientists will see the top of the boundary layer.Unfortunately, some Martian dust is very fine and, once stirred up, settles veryslowly, if at all.The MET science team is interpreting the data collected on the planet by usingcomputer models similar to those used for weather forecasting and climateprediction on Earth to analyze the atmospheric chemistry of Mars and the roleplayed by dust.Preparing for the missionLong before landing, while MDA was building the instruments, the Canadianscientific team conducted studies and tests to prepare for the research programduring spacecraft operations. The York team, for example, tested components ofthe temperature sensor taken from the same manufacturing batch as thosedestined for the spacecraft and also built and tested a lidar technically similar tothat destined for Mars.Taylor and his students participated in an investigation that prompted a designchange in the instrument used to collect sub-surface ice samples. From hisprevious research on blowing snow, Taylor knew that when snow is blownaround, it sublimates—changes from a solid to a vapour. He began to wonder ifthis would happen to the ice dug up with a fork-like device on the end of therobotic arm on Phoenix—a laborious process that would take several hours.“It seemed to us that scraping these little chips of ice up and delivering them tothe analysis instrument several hours later could be a problem. We thought theseice chips would sublimate. If it takes them several hours to collect a large enoughsample, they’ll never be able to do it because the sample will vaporize.” His initialcalculations suggested that, at a temperature of –30 degrees Celsius, the chipswould last only half an hour.This theory was greeted with some skepticism so Taylor had a student who wasworking in the Canadian Arctic do some experiments up there. He and someother students also conducted experiments in a chamber at York that simulatesMartian conditions. “We found that if the temperature stays below about –4053