Saturday, April 3, 2021

[Bumped] One Final Imaging Pass Over Bennu -- Then Homeward Bound, Is OSIRIS-REx...


[Originally posted 04.01.21 -- late evening.] After these last three dimensional imaging orbits -- on May 10, 2021 -- the graceful lil' craft will fire her engines, and head back home, toward Earth. But that will be a two year return flight, so we will need to be patient -- to see what wonders are in the samples she brings back from the surface and sub-surface of Bennu.

Here's the latest from NASA this afternoon, and a bit:

. . .The OSIRIS-REx team decided to add this last flyover after Bennu’s surface was significantly disturbed by the sample collection event. During touchdown, the spacecraft’s sampling head sunk 1.6 feet (48.8 centimeters) into the asteroid’s surface and simultaneously fired a pressurized charge of nitrogen gas. The spacecraft’s thrusters also mobilized a substantial amount of surface material during the back-away burn. Because Bennu’s gravity is so weak, these various forces from the spacecraft had a dramatic effect on the sample site -- launching many of the region’s rocks and a lot of dust in the process. This final flyby of Bennu will provide the mission team an opportunity to learn how the spacecraft’s contact with Bennu’s surface altered the sample site and the region surrounding it.

The single flyby will mimic one of the observation sequences conducted during the mission’s Detailed Survey phase in 2019. OSIRIS-REx will image Bennu for 5.9 hours, which is just over a full rotation period of the asteroid. Within this timeframe, the spacecraft’s PolyCam imager will obtain high-resolution images of Bennu’s northern and southern hemispheres and its equatorial region. The team will then compare these new images with the previous high-resolution imagery of the asteroid obtained during 2019. . . .

After the Bennu flyby, it will take several days for the data from the flyover to be downlinked to Earth. Once the data are downlinked. . . spacecraft will remain in asteroid Bennu’s vicinity until May 10, when the mission will enter its Return Cruise phase and begin its two-year journey back to Earth. . . .


Normally, we would switch the mastheads to reflect Easter weekend. Not so this year, as other more mortal matters have taken the forefront, in our thoughts. . . so, we will simply say, if you are a believer -- do have a peaceful and contemplative Good Friday tomorrow, and a joyous Easter on Sunday. Whether you believe or not, do try to be excellent to one another -- for I now believe we are all we've got. . . smile.

नमस्ते

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