USA-299, also referred to as USSF-7 and Orbital Test Vehicle 6 (OTV-6), is the third flight of the first Boeing X-37B, an American unmanned vertical-takeoff, horizontal-landing spaceplane. It was launched to low Earth orbit aboard an Atlas V launch vehicle from SLC-41 on 17 May 2020. Its mission designation is part of the USA series.

USA-299

Ground crew approaching the X-37B that conducted USA-299 shortly after it landed on 12 November 2022
Names	Orbital Test Vehicle 6 OTV-6
Mission type	U.S. Space Force classified satellite
Operator	United States Space Force
COSPAR ID	2020-029A
SATCAT no.	45606
Mission duration	−910 days, 15 hours and 27 minutes
Spacecraft properties
Spacecraft type	Boeing X-37B
Manufacturer	Boeing
Launch mass	5,400 kg (11,900 lb)[1]
Power	Deployable solar array, batteries
Start of mission
Launch date	17 May 2020, 13:14:00 UTC
Rocket	Atlas V 501 (AV-081)
Launch site	Cape Canaveral, SLC-41
Contractor	United Launch Alliance
End of mission
Landing date	12 November 2022, 10:22 UTC
Landing site	Shuttle Landing Facility
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Perigee altitude	388 km (241 mi)
Apogee altitude	404 km (251 mi)
Inclination	44.60°
OTV program ← OTV-5 OTV-7 →

The spaceplane is operated by the United States Space Force, which considers the mission classified and as such has not revealed the objectives. However an unclassified secondary satellite, FalconSat-8, was deployed from the X-37B soon after launch.[2]

Mission

OTV-6 is the third mission for the first X-37B built, and the sixth X-37B mission overall. It flew on an Atlas V in the 501 configuration, and launched from Cape Canaveral Space Launch Complex 41.[3] This flight is the first time the space plane has been equipped with a service module to carry additional pieces for experiments.

OTV-6 was deployed into an orbit with an inclination of approximately 44.60°.[4]

OTV-6 landed after a record-breaking 910 days 15 hours 20 minutes, at the Shuttle Landing Facility on November 12, 2022. [5]

FalconSat-8

A rideshare payload for the United States Air Force Academy, FalconSat-8, was deployed from the X-37B a few days into the mission. The satellite provides a platform for the Academy's Cadet Space Operations Squadron to test various technologies.

Onboard experiments include:

• MEP (Magnetic gradient Electrostatic Plasma thruster), a novel electromagnetic propulsion system
• MMA (Metamaterial antenna), a low power, high performance antenna
• CANOE (CArbon NanOtubes Experiment)
• ACES (Attitude Control and Energy Storage), a commercial reaction wheel modified into a flywheel
• SkyPad, off-the-shelf cameras and GPUs integrated into a low power package

See also

• USA-212
• USA-226

References

Wikimedia Commons has media related to X-37B Orbital Test Vehicle 6.