% ruby space.rb simulate public4.in 
=== Starports ===
Earth 1
Vulcan 1
=== Starships ===
Enterprise 2
Voyager 1
=== Travelers ===
Kirk Earth Vulcan 
Spock Earth Vulcan 
McCoy Earth Vulcan 
=== Output ===
Enterprise docking at Earth
  Kirk boarding Enterprise at Earth
  Spock boarding Enterprise at Earth
Enterprise departing from Earth
Voyager docking at Earth
  McCoy boarding Voyager at Earth
Enterprise docking at Vulcan
  Kirk departing Enterprise at Vulcan
  Spock departing Enterprise at Vulcan
Voyager departing from Earth
Enterprise departing from Vulcan
Voyager docking at Vulcan
  McCoy departing Voyager at Vulcan
Enterprise docking at Earth
Voyager departing from Vulcan