Once you're in orbit, you are two thirds of the way, energetically, to anywhere -- the moon, to Mars. And today, there's only three vehicles -- the U.S. shuttle, the Russian Soyuz and the Chinese vehicle -- that gets you there.
Jednom kad ste u orbiti, prevalili ste 2/3 puta za bilo kamo, energetski gledano -- do Mjeseca, do Marsa. Danas, postoje samo 3 letjelice – američki Šatl, ruski Soyuz i kineska letjelica – koje vas vode onamo.