7 votes United Launch Alliance launches robotic X-37B space plane on sixth classified mission Posted May 17, 2020 by goodbetterbestbested Tags: spaceflight.military, usa, united states space force, rocket launches, spacecraft, united launch alliance, secrecy, author.amy thompson, source.space https://www.space.com/x-37b-space-plane-space-force-otv-6-launch-success.html