> But then again, we live in a world where Boeing has a patent on certain trajectories that use the moon's gravity Interesting. That particular patent was own

> But then again, we live in a world where Boeing has a patent on certain trajectories that use the moon's gravity Interesting. That particular patent was owned by Hughes Electronics, though, not Boeing [1]. EDIT: Apparently in 2000 Boeing acquired that division of Hughes Electronics [2] but the transfer of ownership of the patent was never recorded in the USPTO. The patent expired in 2012 because the owner didn't pay the required "maintenance fee," which is a statutory fee that must be paid every few years to keep a patent alive [3]; see the end of the document to which you linked. [1] http://assignment.uspto.gov/#/search?adv=patNum%3A6116545&sort=patAssignorEarliestExDate%20desc%2C%20id%20desc&synonyms=false http://assignment.uspto.gov/#/search?adv=patNum%3A6116545&so... [2] http://en.wikipedia.org/wiki/Hughes_Aircraft_Company#Hughes_Electronics_Corporation http://en.wikipedia.org/wiki/Hughes_Aircraft_Company#Hughes_... [3] http://www.uspto.gov/patents-maintaining-patent/maintain-your-patent http://www.uspto.gov/patents-maintaining-patent/maintain-you...