According to NASA, the trap with regolith samples was overfilled, could not close tightly - and scatters small particles into space.
On October 20, 2020, the American space probe OSIRIS-REx automatically performed a successful operation to take samples from the surface of asteroid (101955) Bennu. On the 23rd, NASA released images from the vehicle that had already moved away from the asteroid at a safe distance. Judging by these images, the trap where the TAGSAM sampling unit placed the regolith samples a few days ago is overflowing.
The NASA report notes that the mission's key objective - collecting at least two ounces (60 grams) of matter from Bennu's surface - has been completed. And it looks like it was even overfulfilled: the mylar flap, which serves as a lid for the sample trap, did not close hermetically, because of this, some of the small particles slowly scatter from it into space. “We have become victims of our own success,” said Dante Lauretta of the University of Arizona, one of the mission leaders, speaking to the press.
As a result, the agency canceled a planned operation to measure the mass of the collected regolith. To do this, OSIRIS-REx had to perform several "somersaults" in flight, so that the gyroscopes would record the effect of the additional weight on its rotation. Now it was decided not to turn over the load without critical need, so as not to lose too much.
Nevertheless, the device itself remains fully functional and continues to fly. Therefore, mission leaders only postponed the operation to move the trap into a protected Sample Return Capsule (SRC) - now it should take place on October 27. The sealed volume of the SRC is able to accommodate all collected samples, saving them for delivery to Earth, which is scheduled for September 2023. In the meantime, OSIRIS-REx continues its flight, leaving behind a cloud of asteroid dust.