NASA’s OSIRIS-APEX spacecraft passed 3,438 kilometers from the Earth’s surface on September 23, 2025, at 1 pm (Brasília time). The maneuver used the planet’s gravity to adjust the trajectory towards the asteroid Apophis, which will be studied in 2029. Durante passing, the probe captured images and data from Terra to calibrate its scientific instruments.
The meeting took place over the ocean Atlântico. The minimum distance recorded was 2,136 miles (3,438 km), greater than the orbit of common satellites, which are up to 2,000 km in altitude. The operation was part of the extended mission of the former OSIRIS-REx, renamed after returning samples from the asteroid Bennu in 2023.
Objectives of the gravity assist maneuver
Passing through Terra increased the probe’s speed in relation to Sol. Esse adjustment is necessary to align OSIRIS-APEX’s orbit with that of asteroid Apophis.
- The maneuver changes the orbital inclination by around 18 degrees.
- The procedure saves fuel and allows for precise arrival at the target in April 2029.
- Other flybys are planned for 2027 and 2029.
Images recorded during the passage
The MapCam camera captured a color composite showing Austrália nine hours after the closest point. The distance was 228 thousand kilometers.
StowCam recorded 424-frame video as the probe flew over Atlântico. The América of the Sul appears in the left corner of the image.
Another photo combined Terra and Lua from 596,000 kilometers away. The reflection of the probe’s instruments appears in the foreground.
Instruments calibrated with terrestrial data
The sensors were tested with a reference known on the planet. The operation verified its functioning after six years in space.
The OCAMS suite, operated by Universidade of Arizona, provided the main images. The Agência Espacial Canadense’s laser altimeter also underwent verification.
Next steps for the OSIRIS-APEX mission
The probe is now heading for another flyby in 2027. The main encounter with Apophis will take place in 2029, when the asteroid will pass 32 thousand kilometers from Terra.
The mission will map the surface, composition and internal structure of the 370-meter-diameter body. The data will help understand the formation of the solar system and risks of future impacts.
NASA maintains overall management at Goddard Space Flight Center. Universidade of Arizona leads the science team, while Lockheed Martin operates the flight.
Technical details of the current trajectory
OSIRIS-APEX has successfully completed the first of three planned gravity maneuvers. The procedure lasted a few hours and did not require additional corrections.
The relative speed increased by approximately 5 km/s. The energy gain allows reaching Apophis without extra propellant consumption.
The ship remains in perfect operational condition. Todos the systems recorded nominal performance during and after the passage.
