Spaceflight Insider

U.S. Air Force’s X-37B space plane nears one year on orbit

USAF X-37B space plane at Edwards Air Force Base in California photo credit USAF posted on SpaceFlight Insider - Copy

USAF X-37B space plane at Edwards Air Force Base in California photo credit USAF posted on SpaceFlight Insider – CopyPhoto Credit: USAF

CAPE CANAVERAL, Fla. — The fifth, and latest, mission for the U.S. Air Force’s (USAF) X-37B uncrewed space plane nears a milestone that all but one of its predecessors met (and exceeded): one year on orbit.

The secretive spacecraft — also called the Orbital Test Vehicle (OTV), which looks like a miniature Space Shuttle — launched atop a SpaceX Falcon 9 rocket on Sept. 7, 2017, from Launch Complex 39A at NASA‘s Kennedy Space Center, and marked the first time the USAF launched the OTV with a provider other than United Launch Alliance (ULA).

This fifth mission, officially designated OTV-5, had to compete with the weather for its launch window. Hurricane Irma, which would later graze the Florida coast and cause some damage to the launch complex, was targeted to hit the Cape Canaveral area and threatened to scrub the launch as conditions deteriorated ahead of the approaching storm.

Though much of the mission is shrouded in secrecy, some information has been made public. One of the payloads carried aloft is the second version of the Advanced Structurally Embedded Thermal Spreader (ASETS-II). The hardware, designed to test a thermal management system optimized for the space environment, was developed under a program managed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate at Kirtland Air Force Base in Albuquerque, New Mexico.

Additionally, the vehicle carried with it several small satellites as part of a ride share in order to demonstrate the opportunities that result from quick access to space.

Other information discovered about the mission has come from ground-based observations. As much as the USAF tries to hide the mission of its assets, both amateur and professional skywatchers are quick to figure out where the spaceplane is, even if not knowing what it is doing.

Initially, the spacecraft was deposited in an orbit with an altitude of 220 miles (354 kilometers), and inclined 54.5 degrees to the equator. The highest inclination for any previous mission had been 43.5 degrees, and shows that the USAF is making good on its statement that they will continue to push the boundaries of what the spacecraft can do. The craft has since lowered its orbital altitude to 201 miles (324 kilometers).

“The many firsts on this mission make the upcoming OTV launch a milestone for the program,” stated Randy Walden, the director of the Air Force Rapid Capabilities Office, in a release issued by the USAF. “It is our goal to continue advancing the X-37B OTV so it can more fully support the growing space community.”

Though its landing date has not been stated, it will likely follow the lead of OTV-4 and land at the Shuttle Landing Facility at KSC.

Boeing X-37B spacecraft at Vandenberg Air Force Base in California. Photo Credit: Boeing

Archive Photo Credit: Boeing


Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.

Reader Comments

Richard Robertson

In the English language things are “in orbit” NOT “on orbit”. I know Spanish-native speakers mix up the prepositions frequently but the author clearly isn’t. “On” is used in relation to a physical surface; “in” is used in relation to a volume. An orbit has no physical surface.

Within the space industry, ‘on orbit’ is a perfectly acceptable phase. Think of it more of a “on mission” type phrose as opposed to a physical orientation to an object.

Looks like we will build a fleet of that as we scale up Space Force in the future. What missions will be performed , I have no idea. Perhaps we will have soldiers orbiting in space for some weird missions..

wow…I dorked up the word PHRASE twice. Huzzah!

How about “On station”?

Aug. 20, 2018

The phrase “on orbit” has an identical (or nearly identical) meaning as “in orbit,” but is used by those in the space industry. Many of our staff have worked for/with NASA and other space organizations. As such, we think the phrasing was acceptable. Thank you so much for your interest and feedback!
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

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