NASA has the brains to design a better odometer but navigating by stars and GPS makes more sense.
Also, remember the +/-3% next time you're comparing a used cars. Worrying about 5-6,000 miles on a car with 100,000 is pointless since the odometer itself lies by up to 3,000 miles. Then you have further error introduced by new sets of tires which wear down 6-15mm depending on their tread depth and can vary several mm in diameter despite having the same nominal size as the OEM tires.
Also, remember the +/-3% next time you're comparing a used cars. Worrying about 5-6,000 miles on a car with 100,000 is pointless since the odometer itself lies by up to 3,000 miles. Then you have further error introduced by new sets of tires which wear down 6-15mm depending on their tread depth and can vary several mm in diameter despite having the same nominal size as the OEM tires.