Boeing X-37
Operational history
As of March 2019, the two operational X-37Bs have completed four orbital missions and one of them has been in orbit since 7 September 2017; they have spent a combined 2635 days in space.

Boeing X-37

Section Title: Operational history
Table Section Text: As of March 2019, the two operational X-37Bs have completed four orbital missions and one of them has been in orbit since 7 September 2017; they have spent a combined 2635 days in space.

Flight	Vehicle	Launch date	Launcher	Mission	Duration	Notes

OTV-1	1	22 April 2010 23:52 UTC	Atlas V 501	USA-212	224 days and 9 hours	First launch of Atlas V 501 configuration First American autonomous orbital runway landing First X-37B flight

OTV-2	2	5 March 2011 22:46 UTC	Atlas V 501	USA-226	468 days and 14 hours	First flight of second X-37B

OTV-3	1	11 December 2012 18:03 UTC	Atlas V 501	USA-240	674 days and 22 hours	Second flight of first X-37B

OTV-4	2	20 May 2015 15:05 UTC	Atlas V 501	USA-261	717 days and 20 hours	Second flight of second X-37B First landing on the Shuttle Landing Facility at Kennedy Space Center

OTV-5	?	7 September 2017 14:00 UTC	Falcon 9	USA-277	Elapsed: 549 days and 11 hours	First launch of an X-37B on SpaceX's Falcon 9 vehicle

Sentence(s)

The OTV-3 mission was in orbit for 674 days and 22 hours.

final_sentence: The OTV-3 mission was in orbit for 674 days and 22 hours.