SpaceX CEO Elon Musk on Sunday said that the importance of reusable rockets was crucial for humans to become a multiplanetary civilization amid the billionaire’s Mars colonization goals. Cannot Become Multiplanetary Without Reusable Rockets Responding to a post by Tesla Owners Silicon Valley, which shared that SpaceX had reduced costs per kg to orbit by 500x from approximately “$54,500 (Shuttle era) to ~$1,500.” Everyone obsesses over Starship's height and thrust.The number that actually matters