Transatmospheric orbit
A transatmospheric orbit is an orbit around a celestial body in which a portion of the orbit intersects with the defined atmosphere. Transatmospheric Earth orbits generally use the FAI defined Kármán line of altitude to differentiate between transatmospheric Earth orbits or low Earth orbits but altitudes such as the U.S. defined line may be used. Such orbits are subject to significant atmospheric drag, causing rapid orbital decay if left unchecked.
A number of artificial satellites have been placed into transatmospheric Earth orbits, usually due to a launch vehicle malfunction. Such satellites include EOS 02 and AzaadiSAT, which were deployed into a transatmospheric orbit due to an upper-stage malfunction on the SSLV rocket. Transatmospheric orbits have limited practical applications because objects placed into such orbits are subject to rapid orbital decay. One such application was used to test the reentry of the IXV spaceplane. It was launched into a transatmospheric orbit.
The Boeing Starliner spacecraft was placed in a transatmospheric orbit by the Atlas V launcher. It used its onboard propulsion to reach the International Space Station in LEO.
Astrobotic Technology's Peregrine lunar lander was moved to a transatmospheric orbit following a fuel leak to avoid becoming hazardous space debris.