NASA’s OSIRIS-APEX probe has emerged unscathed from its closest-ever brush past our sun on January 2, 2024. This successful maneuver marks a significant milestone for the spacecraft, which is now on an extended mission to the asteroid Apophis after completing its original mission to the asteroid Bennu.
A Brief History of OSIRIS-APEX
Originally known as OSIRIS-REx, the probe was launched in 2016 with the primary mission of collecting samples from the asteroid Bennu.
After successfully gathering samples in 2020 and returning them to Earth on September 24, 2023, the spacecraft was rebranded as OSIRIS-APEX (Origins, Spectroscopic Interpretation, Resource Identification – Apophis Explorer) and redirected towards a new target: the asteroid Apophis.
The probe is scheduled to rendezvous with Apophis in 2029, coinciding with the asteroid’s rare close approach to Earth.
The Challenge of the Sun’s Heat
To reach Apophis, OSIRIS-APEX must endure multiple close passes to the sun, each bringing it closer than it was designed to operate. The first of these passes occurred on January 2, 2024, bringing the spacecraft within 25 million miles (40 million kilometers) of the sun. These close approaches are necessary to set the probe on the correct trajectory to meet Apophis.
Preparing for the Close Encounter
In preparation for the intense solar radiation, the mission team undertook several protective measures. In early December, one of the probe’s two solar panels was positioned to shade its most sensitive instruments, while the other panel faced the sun to ensure the spacecraft remained powered.
This strategic orientation was crucial to protecting the probe from the harsh solar environment.
Ron Mink, the mission systems engineer for OSIRIS-APEX at NASA’s Goddard Space Flight Center in Maryland, expressed his satisfaction with the outcome: “It’s phenomenal how well our spacecraft configuration protected OSIRIS-APEX, so I’m really encouraged by this first close perihelion pass.”
Telemetry and Instrument Performance
Telemetry data downloaded from the spacecraft in mid-March confirmed that OSIRIS-APEX had survived the encounter without damage.
By early April, the probe had moved far enough from the sun to resume normal operations. The mission team was particularly pleased with the performance of the onboard instruments, especially the MapCam camera.
MapCam, a medium-range camera initially used to map Bennu in color, showed a significant reduction in hot pixels—unwanted white spots caused by prolonged exposure to solar radiation.
Since the last test in April of the previous year, the number of hot pixels had decreased by 70%, thanks to the natural spike in heat from the close solar encounter.
Future Encounters and Mission Path
The recent perihelion was just the first of several close passes OSIRIS-APEX will make. The next close encounter with the sun is scheduled for September 1, 2024. In total, the probe will need to survive five more perihelions and undergo three gravity assists from Earth to reach its final destination, Apophis.
The elliptical orbit around the sun brings the spacecraft to its closest point every nine months. This trajectory is essential for the probe’s journey to Apophis, ensuring it arrives at the asteroid in time for its close encounter with Earth in 2029.
Summary
The successful navigation of its first close encounter with the sun marks a promising start for OSIRIS-APEX’s extended mission. The probe’s resilience in facing extreme solar conditions and the continued high performance of its instruments underscore the robustness of NASA’s engineering and mission planning.
As OSIRIS-APEX continues its journey, the mission team remains optimistic about its future encounters and its ultimate goal of exploring the asteroid Apophis.
The next few years will be critical as OSIRIS-APEX undertakes further perihelion passes and gravity assists, each step bringing it closer to unlocking the mysteries of Apophis and contributing valuable knowledge to our understanding of asteroids and their potential impact on Earth.
The information is taken from Yahoo News and India Today
