Without any fanfare, the OTV-4 mission came to an end over the weekend, landing at Kennedy Space Center’s Shuttle Landing Facility following 718 days in orbit.:
As with the previous three Orbital Test Vehicle missions, the majority of its activities remain undisclosed. However, this time the Air Force did disclose two payloads: an experimental ion thruster built by Aerojet-Rocketdyne and a NASA payload called METIS (Materials Exposure and Technology Innovation in Space) that exposed over a hundred samples of materials, such as polymers, ceramics, and more.
The fifth OTV mission has not yet been announced.
The historic return to flight for LC39A, last used for STS-135 and still sporting most of the Shuttle-era Fixed Service Structure and Rotating Service Structure, has been delayed at least a day, after a scrub at T-15 seconds. The launch was set to take off this morning, but was scrubbed due to “slightly odd” behavior in the upper stage — a routine preflight hydraulics check revealed something off-nominal in the behavior of an upper stage steering hydraulic piston (presumably part of the engine gimbaling system). The Falcon 9 with Dragon attached has been lowered back to the horizontal position, but SpaceX is pressing ahead towards the second opportunity, tomorrow at 9:38:59 a.m. EST. This will be the first commercial spaceflight from Kennedy Space Center. (Prior Falcon 9’s launched from Air Force pads.)
Meanwhile, in other KSC news, a NOTAM (Notice To Airmen) was issued earlier this week which strongly suggested the X-37 that has been orbiting the Earth for nearly two years might be coming down again. The NOTAM expired the same time the range opened up for Falcon 9. It seems plausible, then, that X-37 may make a landing attempt once the Eastern Range becomes available again.
Stuff going up, and stuff coming back down . . . it’s gotta be exciting at the Cape and on Merritt Island!