totm oct 2023 NASA's OSIRIS-REx

[Scotius]

What do you think? Will there be any detectable effects of OSIRIS's visit on orbital  motion of Bennu? Probe is minuscule compared to the asteroid, but it was in orbit for many months.

[IonStorm]

3 minutes ago, Scotius said:

What do you think? Will there be any detectable effects of OSIRIS's visit on orbital  motion of Bennu? Probe is minuscule compared to the asteroid, but it was in orbit for many months.

The spacecraft isn’t much of a gravity tractor. It moved all over, so the forces didn’t add up much. We monitored the position for Yarkovsky measurements and the spacecraft impacts were below the limit of detection. As you indicate, though Bennu is small (7E+10kg) the spacecraft is much smaller (2E+3kg). 

[Hannu2]

1 hour ago, IonStorm said:

Yes. After the “large” 40cm/s burn to leave the TAG site, the spacecraft is still drifting away from Bennu. 

Is there some technical reasons why it is impractical to make maneuvers, totally less than 1 m/s based on my understanding, and return to investigate Bennu from orbit? Or is it so much safer to wait time for return maneuver by coasting far from asteroid that it is better choice? Cost savings sound quite strange reason if there is a scientific probe with ten number pricetag near the interesting target.

[IonStorm]

2 minutes ago, Hannu2 said:

Is there some technical reasons why it is impractical to make maneuvers, totally less than 1 m/s based on my understanding, and return to investigate Bennu from orbit? Or is it so much safer to wait time for return maneuver by coasting far from asteroid that it is better choice? Cost savings sound quite strange reason if there is a scientific probe with ten number pricetag near the interesting target.

Cost and risk is the reason, nothing technical.  The spacecraft returned to orbit after similar departures after the rehearsals. 

OSIRIS-REx is a cost capped mission.  Every dollar spent in mission operations is a dollar that is not available for sample analysis.  NASA strongly encourages fiscal restraint and discipline in avoiding cost growth and "science creep."  The cost of the maneuver is not in ∆V, but in labor.  It is several weeks of intensive planning to perform the delicate maneuvers to return the spacecraft to orbit.  The team to do that work is exhausted.  Furthermore, there is non-zero risk of damaging the spacecraft.  At this point, any risk to the sample: the prime mission objective, is unacceptable. 

More lessons KSP doesn't teach.

[Shpaget]

47 minutes ago, IonStorm said:

Furthermore, there is non-zero risk of damaging the spacecraft.

Is the main risk the collision with Bennu itself, or with debris kicked up from the surface? I suppose those rocks will take their time to settle down.

Again, thank you for the time you spend here talking to us about this. It's totally cool to have an inside man we can ask these questions.

[IonStorm]

21 minutes ago, Shpaget said:

Is the main risk the collision with Bennu itself, or with debris kicked up from the surface? I suppose those rocks will take their time to settle down.

Again, thank you for the time you spend here talking to us about this. It's totally cool to have an inside man we can ask these questions.

Debris is an unknown (and monitoring the rocks would be good science).  But there are always risks with spacecraft component failures, some could result in a collision or loss of communication.  Space is unforgiving, though OSIRIS-REx has performed impressively well, past performance is no guarantee of future results.  The risk is low, but the consequences of total mission failure after success for an optional observation is not acceptable.  The risk is heightened by the operations team being so tired and/or are being transferred to other projects.  I would personally love to go back and look at the cool stuff, but the decision to stand down makes sense.   

I'm delighted to share with this community.  You all make up a segment of the public with a greater understanding of and interest in spaceflight due to KSP, which is fun.

Edited November 3, 2020 by IonStorm

[AloE]

On 10/23/2020 at 11:50 AM, AloE said:

more views of the disturbed sight & those ejected materials as the craft backs away...

The sequence released on APOD shows a nice bit of the particle motion  with a good shadow angle:

Bennu tag particle ejection: 

[the nature of the 'soft dimpled looking' craters especially near the equator ( link: trek.nasa.gov/bennu ) has been of interest since this past summer...

while looking at the Bennu Trek with some children  and talking about this mission...(& the idea of rubble pile asteroids hitting Earth's Moon, etc. )

& wondering about a person in an EVA suit (or similar stone, etc.) moving near Bennu ,who might experience a ballpark order of magnitude 'weight' of about the same as one pea or raisin on Earth...

led us to wonder, if there are no ices, or magnetic, or electrostatic, or other forces affecting the surface of Bennu to bind materials,  how 'loose' behaving might be some areas of the surface if that 'hypothetical EVA person' tried to grab hold of something in order to 'pretend' to walk while floating around...]

[Scotius]

Huh. It could be like trying to climb a "mountain" of packing peanuts Held together only by their weight - which is minuscule.

[AloE]

 

6 hours ago, Scotius said:

climb a "mountain" of packing peanuts

admittedly kids might like that idea, perhaps even better than squishing dimples in 'Bennu marshmallows'...please overlook the abysmal technical approximations & limitations of terrestrial kitchen materials ;-)

We did consider that the large presumably ridged 'boulders' like this tower might have better hand holds & relative mass ratio for EVA 'climbing/handrail' activities...I still have not figured out how to make a good height & normal map...Bennu is really a tricky size for KSP...eventually I hope at least to have a 10x model that looks at least similar to the Bennu Trek...

Earlier publications regarding particle ejections: 

Why Is Asteroid Bennu Ejecting Particles Into Space? (link jpl.nasa.gov )

& open access article collection regarding particle ejection

for easier visual study of particle motion induced by TAG, here is a gif of the  last part of the same video (again the source video:  https://apod.nasa.gov/apod/ap201103.html )

 

Edited November 6, 2020 by AloE

[magnemoe]

On 11/3/2020 at 5:33 PM, IonStorm said:

Debris is an unknown (and monitoring the rocks would be good science).  But there are always risks with spacecraft component failures, some could result in a collision or loss of communication.  Space is unforgiving, though OSIRIS-REx has performed impressively well, past performance is no guarantee of future results.  The risk is low, but the consequences of total mission failure after success for an optional observation is not acceptable.  The risk is heightened by the operations team being so tired and/or are being transferred to other projects.  I would personally love to go back and look at the cool stuff, but the decision to stand down makes sense.   

I'm delighted to share with this community.  You all make up a segment of the public with a greater understanding of and interest in spaceflight due to KSP, which is fun.

I assumed the return window determined the stay time, you could wait to the next one but this would increase cost and risk but not give much new science. 
As the sampling was the most dangerous part you did that at the end. 
 

[RealKerbal3x]

Vaguely topical:

 

[IonStorm]

For your viewing pleasure, the complete TAG movie from both cameras with their view footprints mapped on the sampling site https://www.asteroidmission.org/tag_cpe/ 

 

[IonStorm]

On 11/19/2020 at 9:54 AM, IonStorm said:

For your viewing pleasure, the complete TAG movie from both cameras with their view footprints mapped on the sampling site https://www.asteroidmission.org/tag_cpe/ 

Just before TAG both cameras could see the surface at the sampling spot at about the same resolution.  Here is a stereo pair (left is SamCam and right is TAGCam with a the image of the sampling head artificially added to help make the 3D look better) constructed from this data by OSIRIS-REx collaborator Dr. Brian May on his Instagram page https://www.instagram.com/p/CHJ7EJPh8GF/ 

If you can't do the thing with your eyes, it works well on a phone with a VR headset or other stereo viewer.

[cubinator]

That's a really cool view of the asteroid surface!

[StrandedonEarth]

Dr Brian May of Queen? That is so awesome that he’s working on this!

Was he humming “Another One Bites the Dust” when Bennu was TAGged? Or was he all Radio Gaga?

Edited November 24, 2020 by StrandedonEarth

[IonStorm]

Just now, StrandedonEarth said:

Dr Brian May of Queen? That is so awesome that he’s working on this!

Was he humming “Another One Bites the Dust” when Bennu was TAGged? Or was he all Radio Gaga?

Yes, that Brian May. He didn’t participate in person, but he has a passion for stereo images, so solving this problem was right up his alley.  He also did Benben from approach images https://www.asteroidmission.org/bennus-boulder-1-stereo-pair-stereoscope-version/

[IonStorm]

The Planetary Society has named OSIRIS-REx “Planetary science mission of the year" and sample collection from Bennu “Most exciting planetary science moment” of 2020.

Also congratulations to Juno, JWST, SpaceX, LightSail 2, and SimgDe for their wins.

[IonStorm]

The last flyover of the collection site happened this week.  Early data is looking interesting.  More to come soon.

 

[IonStorm]

On 4/9/2021 at 8:15 PM, IonStorm said:

The last flyover of the collection site happened this week.  Early data is looking interesting.  More to come soon.

Here it is.  https://www.nasa.gov/feature/goddard/2021/nasas-osiris-rex-leaves-its-mark-on-asteroid-bennu 

Edited April 15, 2021 by IonStorm

[tater]

 

[IonStorm]

At the 4pm EDT nasa.gov/live broadcast today we will release the animation with ALL maneuvers around Bennu. #ToBennuaAndBack for questions on Instagram

[HebaruSan]

12 minutes ago, IonStorm said:

At the 4pm EDT nasa.gov/live broadcast today we will release the animation with ALL maneuvers around Bennu. #ToBennuaAndBack for questions on Instagram

It's not this one, is it? The NASA Goddard Youtube channel may have jumped the gun.

Watching that made me think a lot of propellant was needed, but then the speeds are so low that maybe it's not so bad?

[IonStorm]

14 minutes ago, HebaruSan said:

It's not this one, is it? The NASA Goddard Youtube channel may have jumped the gun.

Watching that made me think a lot of propellant was needed, but then the speeds are so low that maybe it's not so bad?

Awesome.  I wasn't sure what time it would be out.  These are tiny maneuvers. The smallest was 0.11 mm/s!  

[tater]

 

[IonStorm]

Here's the departure special.  Yours truly appears 32 minutes in.  With Bennu in the (figurative) rear-view mirror, it is time to rehearse the recovery and perfect our lab methods.  Also, look to where to go with the fuel we have left after delivering the samples to Earth.