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Post-Sampling & Earth Return
Hungry4info
post Sep 14 2021, 01:40 AM
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The OSIRIS-REx team used an alternative method to determine the sample mass.

Alternative Sample Mass Measurement Technique for OSIRIS-REX Sample Collection Phase
https://arxiv.org/abs/2109.05561

QUOTE
...The alternative SMM technique utilized reaction wheel momentum data from identical TAGSAM movements prior to and following the TAG event to estimate changes in spacecraft moment of inertia. Conservation of momentum was used to isolate the sample mass from this inertia change. Using this new method, the spacecraft team was able to successfully estimate collected sample mass to be 250.37 +/- 101 g.


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-- Hungry4info (Sirius_Alpha)
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vjkane
post Sep 14 2021, 03:11 PM
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QUOTE (Hungry4info @ Sep 13 2021, 05:40 PM) *
The OSIRIS-REx team used an alternative method to determine the sample mass.

Alternative Sample Mass Measurement Technique for OSIRIS-REX Sample Collection Phase
https://arxiv.org/abs/2109.05561

That's a clever approach. They collected ~4-6 times more material than their mission success criteria! I was thinking that with the sampling head literally overflowing, it might be even more. Perhaps a lot of porosity?

Looking forward to the return of the samples.


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fredk
post Sep 14 2021, 04:24 PM
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QUOTE (vjkane @ Sep 14 2021, 04:11 PM) *
They collected ~4-6 times more material than their mission success criteria!

They collected 150-350g, so 2.5 to almost 6 times the 60g requirement.

They reported (250.37 +/- 101)g - to be pedantic, that's a pretty severe example of overstated precision! (0.25 +/- 0.10)kg is more realistic.

But it is indeed a cool application of momentum conservation (as was the original plan).
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Phil Stooke
post Nov 7 2021, 10:37 PM
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I have updated my Bennu map to include the date of the final flyover of Nightingale, and to add the crater names approved by the IAU last year.

Phil

Attached Image


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... because the Solar System ain't gonna map itself.
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JRehling
post Nov 7 2021, 11:41 PM
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Beautiful work, Phil. And it's fun to see a global map where objects this small and their shadows and texture show up.
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