Self-healing at the sun: NASA's Osiris-Apex probe better shape than before
NASA's Osiris-Apex probe was not at all designed for its flyby of the sun. It is now clear that two instruments have worked even better since then.
Artistic representation of Osiris-Apex (then still Osiris-Rex) on Earth
(Image: NASA/Goddard/University of Arizona)
NASA's Osiris-Apex probe has not only survived its first close approach to the sun unscathed, one instrument has even functioned noticeably better since then, while a trapped small stone has probably disappeared from another. This has now been made public by the US space agency, thus drawing a much more positive conclusion from the so-called perihelion - the closest point5 of the orbit to the sun - than had been hoped for. After all, the rededicated asteroid probe was not at all designed to approach the sun at distances of up to 75 million kilometers. Before the mission began, only a minimum distance of 115 million kilometers was planned.
Two instruments "repaired" at once
As NASA recalls,after the flyby shortly after the turn of the year, there was already optimismthat everything had worked out. In March, the probe then sent telemetry data that confirmed this and another month later, the distance to the sun was large enough to resume normal work. During the checks that were then carried out, it was found that the MAPCAM camera had around 70 percent fewer "hot pixels" than before the flyby. This means that significantly fewer pixels remain white. We can only speculate about the cause of the self-healing, but those responsible assume that a repair effect has come into play here, which is otherwise deliberately induced during annealing.
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Those responsible have also determined that an obstacle that appeared to have been jammed in a calibration element in the spectrometer of Osiris-Apex before the flyby has disappeared. This was probably a small stone that had been stuck there since the sample was taken from the asteroid Bennu. It may have been dislodged during the subsequent maneuvers and when the thrusters were activated. This means that the probe is apparently in a noticeably better condition after the first perihelion than before. In order to protect the probe, it has adopted a fixed orientation towards the sun and protected particularly sensitive parts behind one of its solar sails. We can therefore be optimistic about the next five flybys.
The current approach to the sun was not part of the original mission, during which Osiris-Apex (then known as Osiris-Rex) visited Bennu and broughta rock sample back to Earthfrom there.Since completing this mission, it has been on its way to the near-Earth asteroid Apophis. The comparatively close flight around the sun was the first of several with which the probe is to set course for the celestial body. As the Osiris-Apophis-Explorer (Osiris-Apex), it is to investigate what changes Apophis will undergo when it passes the Earth in 2029. After its discovery in 2004, it was even temporarily considered dangerous for our home planet. However, we now know that it will keep a safe distance.
(mho)
