Ever wondered what it's like to take a selfie from space? Well, the OSIRIS-APEX spacecraft did just that, snapping a picture of Earth during a recent flyby! This mission, a continuation of the successful OSIRIS-REx, is now on a new adventure to study the asteroid Apophis. This asteroid is a near-Earth object that could potentially pose a threat to our planet in the distant future.
After its initial mission of collecting a sample from asteroid Bennu and delivering it to Earth in 2023, the spacecraft was renamed OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer). Its new mission? To study Apophis, another near-Earth asteroid that could pose a future threat.
On September 23rd, OSIRIS-APEX made a close pass by Earth, coming within a mere 2,136 miles (3,438 kilometers). This was a crucial maneuver, a 'gravity assist', the first of three planned, to slingshot the spacecraft towards its ultimate destination: Apophis. The goal is to rendezvous with Apophis in 2029.
During this Earth flyby, the spacecraft used its three cameras, built at the University of Arizona's Lunar and Planetary Laboratory, to capture images and collect data about our planet. This data helps calibrate the instruments, ensuring they're ready for their primary mission at Apophis.
According to Dani Mendoza DellaGiustina, the mission's principal investigator, this flyby wasn't just about pretty pictures; it was about gathering essential data. She emphasized that the flyby provided a unique chance to calibrate the instruments.
The spacecraft has been through a lot, from its encounter with Bennu, including the extreme temperatures of space. DellaGiustina highlighted the importance of understanding how these experiences have affected the instruments since launch. Dust from Bennu settled on the lenses. This flyby allows the team to recalibrate and ensure accurate measurements at Apophis.
But here's where it gets controversial... The dust collected during the Bennu mission actually provides an unexpected benefit. The instruments were designed for Bennu, one of the darkest objects in our solar system. Apophis, however, is about 10 times brighter. The dust, in a way, helps to darken things a little, and this flyby allows the team to quantify the effect and adjust instrument settings accordingly.
During its cruise phase, the spacecraft spends approximately six years traveling through the inner solar system. While much of this time is spent in empty space, several close passes by Earth are necessary to navigate towards Apophis. DellaGiustina mentioned that the team has already completed three Earth gravity assists, with two more planned. Each maneuver is designed to achieve a slightly different objective.
These gravity assists offer a rare opportunity to use Earth and the Moon to fill the frame of the spacecraft's imaging instruments, including spectrometers. These instruments analyze light signatures to reveal the chemical and physical composition of objects. While stars can be used for some calibration, spectral instruments need a large object to fill the frame.
This most recent flyby was a crucial chance to understand if and how the instruments' behavior has changed.
Other changes in the spacecraft's configuration are a result of its previous mission. For example, the StowCam instrument, used to verify the sample from Bennu was safely stored, now provides a view of the instrument panel. StowCam also captured images as OSIRIS-APEX approached and departed from Earth.
These Earth flybys are valuable opportunities for the OSIRIS-APEX team, comprising both veterans from the OSIRIS-REx mission and new members. They provide a chance to practice operational and observational tasks and hone skills during the otherwise uneventful cruise phase, as DellaGiustina explained.
She noted that this flyby is an opportunity for the team to train in the procedures they will use to observe Apophis, using much of the same software.
In her words, "The bottom-line is we have a healthy, happy spacecraft... We have incredible data coming in from the spacecraft, pulling off this set of observations was a lot of work done by a pretty small number of people, and so to see everything be such a success, is really satisfying."
NASA’s Goddard Space Flight Center manages the mission, providing overall management, systems engineering, and safety. The University of Arizona leads the science team and the mission's science observation planning and data processing. Lockheed Martin Space built the spacecraft and provides flight operations. NASA Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-APEX spacecraft. The mission includes international partnerships, such as the spacecraft's laser altimeter instrument from CSA. OSIRIS-APEX is part of NASA's New Frontiers Program.
What do you think? Are you excited about the OSIRIS-APEX mission and the potential discoveries about Apophis? Do you have any questions or thoughts about the technology or the mission's goals? Share your opinions in the comments below!
