Witch measurement of space would you prefer if Frontier gave you a chose to choose between them? the commonly know Light year based on how long light travels huge distances? or the metric system? just say petameters instead of quadrillion meters. use this http://en.wikipedia.org/wiki/Metric_prefix and you can continue to use the same system for huge distances. Or if you want to go old school you can do astronomical units. 1 AU is like 500 light seconds. it seems to make large light second numbers less huge but its not good for measuring large distances like the distance of stars. me personally like the metric system since you just use prefixes to shrink numbers instead of reinventing a new measurement system. and you can use it for small and large distances.