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NASA's OSIRIS-REx

archenemy_6

By archenemy_6
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IonStorm

IonStorm

Posted
Posted
9 hours ago, insert_name said:

The lidar altimeter bugged out and the images from the flyover of the backup landing site are likely out of focus :(

http://nasa.gov/feature/goddard/2020/osiris-rex-completes-closest-flyover-of-backup-sample-site-osprey

This can happen either due to random single event errors (i.e. cosmic ray hits) or something deeper.  OLA has been asked to do additional work beyond its requirements due to the extra imaging required for the rocky surface.  It is expected that some fraction of the images will be out of focus by an unknown amount, we will see when it gets downlinked.  There is a Guidance and Navigation LIDAR which was to have been used for sampling--if the asteroid wasn't so rocky.  This could be reprogrammed to help PolyCam focus--this will take time.  Just reflying the pass to retake the bad images would take less time.

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IonStorm

IonStorm

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Here is a 20 cm resolution animation of the shape model and image overlay of Bennu for your amusement.  Again this animation is from 100% real data.  https://svs.gsfc.nasa.gov/vis/a000000/a004700/a004795/Bennu_spin_full_20cm_1080p30.mp4

This was used in this video: 

 

Edited by IonStorm
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IonStorm

IonStorm

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On 2/14/2020 at 8:43 AM, IonStorm said:

This can happen either due to random single event errors (i.e. cosmic ray hits) or something deeper.  OLA has been asked to do additional work beyond its requirements due to the extra imaging required for the rocky surface.  It is expected that some fraction of the images will be out of focus by an unknown amount, we will see when it gets downlinked.  There is a Guidance and Navigation LIDAR which was to have been used for sampling--if the asteroid wasn't so rocky.  This could be reprogrammed to help PolyCam focus--this will take time.  Just reflying the pass to retake the bad images would take less time.

So it was something deeper after all, but restricted to the low power laser not the whole instrument.  The high power laser will be used instead.  It is sufficient resolution for focusing and does not require a big software change:

Quote

The mission has made the decision to use OLA’s High Energy Laser Transmitter (HELT) to provide the ranging data to focus PolyCam during the Mar. 3 flyover of site Nightingale. OLA consists of two laser subsystems, the HELT and the Low-Energy Laser Transmitter (LELT). OLA’s LELT was originally scheduled to provide these data, however, as a result of the anomaly  that occurred during the Recon B site Osprey flyover, the team has determined that the LELT system is no longer operable. Despite the LELT’s condition, the HELT system has continued to operate as expected, and will be used to focus PolyCam for the remaining reconnaissance passes.

OLA has already completed all of its principal requirements for the OSIRIS-REx mission. OLA’s scans of Bennu’s surface were used to create the high-resolution 3D global maps of Bennu’s topography that were crucial for selecting the primary and backup sample collection sites last fall.

https://www.asteroidmission.org/?mission_update=mar-2-2020

 

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IonStorm

IonStorm

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6 minutes ago, Mr. Peabody said:

The cratering concentrated along a linear path (center of image) is interesting to note. What might have caused this phenomenon?

We have speculated, "The retention of large craters on Bennu’s equatorial ridge requires that the surface age predates the expected approximately 10-million-year duration as a NEA. There is no clear geologic indication of the process that formed the ridge, and given its relation to the large craters it could be a feature preserved from the formation of Bennu, which would make it the oldest feature on its surface. Bennu’s surface therefore also recorded processes from its time in the main belt; the formation timescales of the largest craters suggest that Bennu recorded hundreds of millions of years of history during this period."  (Walsh et al., 2019)

https://science.gsfc.nasa.gov/sed/content/uploadFiles/publication_files/Walsh2019.pdf

 

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tater

tater

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22 minutes ago, IonStorm said:

Successful low recon pass over Osprey (20k x 12k image) https://www.asteroidmission.org/osprey-recon-c-mosaic/

Recall that the medium pass images over Osprey were out of focus due to the OLA failure, so this a big improvement of the imaging of the backup site.

WOW.

I DLed the full sized image (200MB!) and started poking around.

The exposure is great—are the (very few) blown areas (exposure wise) just because the rest of the surface is so very dark, or are they very highly reflective, or merely slightly reflective and at just the right angles?

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IonStorm

IonStorm

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3 minutes ago, tater said:

The exposure is great—are the (very few) blown areas (exposure wise) just because the rest of the surface is so very dark, or are they very highly reflective, or merely slightly reflective and at just the right angles?

The surface is super dark with a few comparatively bright spots.  The dark spots are like coal and the bright spots are like the Moon.

You can compare that to the 380MB global mosaic.  It has about 1/10 the resolution but the whole asteroid https://www.asteroidmission.org/bennu_global_mosaic/

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AloE

AloE

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On 3/19/2020 at 5:00 PM, cubinator said:

that's a big picture. Any recommendations on software I can use to actually look at it?

trek.nasa.gov has a Bennu portal listed under "coming soon" which will eventually enable you to view the full resolution from any common browser on average+ computers...

but until that is released then at least on Windows, "Paint.NET" will handle the full resolution (~800mb file) using about 5gb of RAM:

Screenshots: 1) 5cm in paint.net & 2) the NASA treks portal
fZkTHNU.png szV0Orh.png
Edited by AloE
fix links & images
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AloE

AloE

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One way to explore the 3D shape: The NAIF Toolkit utility dskexp.exe does make a 99846 vertices .obj from the public DSK .bds file that opens in SBMT which makes it easy to add co-registered layers:

99846 vertices Bennu Model in SBMT
phuEsea.png

Also, given the beautiful & detailed images from the work of the OSIRIS-REx team, some younger people would like me to make a detailed model for them to load in KSP so that they may explore Bennu via their favorite Kerbal(s) doing EVA jetpack 'floats' around a Bennu...

thus my catching up on the prior such work from the other thread (& using google search: Bennu site:forum.kerbalspaceprogram.com ) :

In case anyone has come across a helpful link or two in this direction, I have not yet spotted in my kopernicus/PQS/Unity heightmap reading if there is a process to  use very large .obj type shapes (e.g. 100k to 200 million vertices) to create height & normal maps for PQS say to make a 10x or 100x larger scale version of Bennu (since RSS Deimos seems to be about as small a celestial as I have seen work mostly ok so far...). Thanks :-)

Edited by AloE
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AloE

AloE

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source: https://www.asteroidmission.org/?latest-news=asteroids-bennu-and-ryugu-may-have-formed-directly-from-collision-in-space

" in a new paper published in Nature Communications, scientists from the OSIRIS-REx and Hayabusa2 teams argue that the YORP effect may not explain the shape [“spinning-top” asteroids] of either Bennu or Ryugu....Bennu, the target asteroid for the OSIRIS-REx mission, and Ryugu, the target of the Japan Aerospace Exploration Agency’s Hayabusa2 asteroid sample return mission, are composed of fragments of larger bodies that shattered upon colliding with other objects. The small fragments reaccumulated to form an aggregate body. Bennu and Ryugu may actually have formed in this way from the same original shattered parent body."

Rather amazing asteroids & missions...while waiting for the public release of Bennu trek, the similar Ryugu trek has just recently been released: https://trek.nasa.gov/ryugu/

Ryugu Trek (note: the image data is not currently as majestic as for Bennu)
1YDY1g5.png
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IonStorm

IonStorm

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Tomorrow is a very important milestone for the OSIRIS-REx mission - the final rehearsal before sample collection! We invite you all to join us for a live play-by-play on Twitter August 11 at 2:30 EDT on Twitter@osirisrex    

The OSIRIS-REx team (following social distancing and wearing masks) will conduct its Matchpoint Maneuver Rehearsal over the Nightingale Site on asteroid Bennu. There will be a 16 minute one-way communication delay between the spacecraft and Earth. So the event commands will be uploaded to the spacecraft and the maneuver will be conducted autonomously. The low gain antenna will transmit data to Earth with images and science data downlinked when the rehearsal is completed.

For more details on the Matchpoint Maneuver and a summary poster.

 

Edited by IonStorm
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