Jump to content

Recommended Posts

3 hours ago, HebaruSan said:

If it does turn out to be typical, that's yet another thing that needs to be fixed about sci fi "asteroid field" scenes...

  Reveal hidden contents

... at the very least we need big clouds of fine material dispersed on impact; maybe the TIE fighters would even survive!

We've known since Voyager (or possibly Pioneer) that "dodging asteroids" was far easier than dodging satellites in LEO.  I think the ISS has had to maneuver to avoid a near miss multiple times.  I don't think any spacecraft has had to dodge an asteroid (and most of them can't and make it through).

It would make the classic video game "Asteroids" a lot less fun if a single shot turned a "large" asteroid into a fine mist small rocks, although I suspect the "boulders" such as Mount Doom are in fact actual boulders.  I don't think we can tell from Osiris Rex's data, but it would be great if we did.

Link to post
Share on other sites
8 hours ago, IonStorm said:

There are two gas bottles left, but only one sampling head and one sample return capsule.  

So the entire sampling head is put into the return capsule, as opposed to dumping samples out of the sampling head into the return capsule and leaving the head behind? I suppose dumping the samples would be tricky in zero G, anyway.

Link to post
Share on other sites
3 hours ago, Shpaget said:

So the entire sampling head is put into the return capsule, as opposed to dumping samples out of the sampling head into the return capsule and leaving the head behind? I suppose dumping the samples would be tricky in zero G, anyway.

Yes. Plus we want all the adhering dust and the material on the contact pads. 

Link to post
Share on other sites
50 minutes ago, cubinator said:

Wouldn't you like to put the whole asteroid in a bag and land it on Earth...

No.  One of mission objectives is get data not to let Bennu land on Earth in 2175-2199 :D.  But,  several tonnes from different locations and depths would be illuminating.  However, I'll be quite content with a TAGSAM head overflowing with regolith.

Link to post
Share on other sites
1 hour ago, IonStorm said:

No.  One of mission objectives is get data not to let Bennu land on Earth in 2175-2199 :D.  But,  several tonnes from different locations and depths would be illuminating.  However, I'll be quite content with a TAGSAM head overflowing with regolith.

Well, Mars then? Warm up the poles a little? :D 

Link to post
Share on other sites
8 hours ago, IonStorm said:

However, I'll be quite content with a TAGSAM head overflowing with regolith.

With the overflowing amount of samples upon re-entry (which being a Utahn I can't wait for.) is there a chance that the overflowing amount might cause an anomaly in the capsule? Or is the inside of the capsule separated by all the things that preform the tasks on re-entry?

Also it's super cool that you have a forum account. It's nice to have a space craft engineer here on the forums.

7 hours ago, cubinator said:

Well, Mars then? Warm up the poles a little? :D 

Bennu_Orbit.png

chuckles, I don't think there is a possibility of getting it there.

Edited by Guest
Link to post
Share on other sites
9 minutes ago, The Doodling Astronaut said:

With the overflowing amount of samples upon re-entry (which being a Utahn I can't wait for.) is there a chance that the overflowing amount might cause an anomaly in the capsule? Or is the inside of the capsule separated by all the things that preform the tasks on re-entry?

Also it's super cool that you have a forum account. It's nice to have a space craft engineer here on the forums.

chucles, I don't think there is a possibility of getting it there.

The sample return capsule (SRC) is designed to have a separate compartment for the TAGSAM head from the electronics and parachute.  In the below picture (Bierhaus et al. 2018) on the right you can see the capture ring on which the TAGSAM head sits.  When the lid closes the compartment with the sample is dust-tight.  We anticipated that there would be loose material, particularly during spacecraft operations and re-entry, so this is within the scope of testing.  The SRC will land in the Utah Test and Training Range in Dugway, UT at 8:40am MDT on September 24, 2023.  

Also, I'm actually not an engineer, but a scientist (Ph.D. in biochemistry).  There are a few others here.  The deputy PI of the Dragonfly mission is active on the forums.  I've been playing KSP since v0.10.1 (who remembers the Overthrottle light?), but I don't have a lot to time to play and less time for the forums, except for this thread.

As it happens, I gave a short on OSIRIS-REx overview talk today with a colleague at https://www.ustream.tv/recorded/128367108, if you want some additional details on the mission.

And yes, you are correct getting Bennu to Mars would take an awful lot of energy.  The orbital diagram you show from the day before the OSIRIS-REx launch from the old JPL Small Body Database Browser doesn't even give a sense of the inclination change needed.  The new version of the diagram is easier to see.

11214_2018_521_Fig4_HTML.jpg

 

Link to post
Share on other sites
8 hours ago, tater said:

The sample container is dust tight, is it also gas tight? What about volatiles?

The SRC is not a pressure vessel, that would require a lot more mass.  However, the vent to atmosphere is through a filter.  You can see it in panel b in the figure in my previous post above the ne in witness as a circle in the top of the internal canister.  It will be analyzed for trapped volatiles.  See section 7.2-7.6 of Dworkin et al. 2018 if you want details of what is trapped at what efficiency in lab testing.

Link to post
Share on other sites
1 minute ago, .50calBMG said:

Do you have any sense as to how much sample you were able retain after the tag? Is there a way to measure that in the return capsule?

There are a range of models and there is hope to be able to use some of arm motions to generate an estimate.  The top priority was getting the sample safely stored.  That done we can try to look at the data and refine the models.  Though, since we will know for sure in three years and there is nothing we can do with the result other than improve our sample allocation and curation plans, it isn't clear that devoting a lot of engineering time for analysis is necessary now (though it would be interesting).

Link to post
Share on other sites
3 hours ago, IonStorm said:

There are a range of models and there is hope to be able to use some of arm motions to generate an estimate.  The top priority was getting the sample safely stored.  That done we can try to look at the data and refine the models.  Though, since we will know for sure in three years and there is nothing we can do with the result other than improve our sample allocation and curation plans, it isn't clear that devoting a lot of engineering time for analysis is necessary now (though it would be interesting).

I just want to see you guys bring the sample home safe. You know you've got a big container full of rock, and it's finally safely sealed up, so we can all wait to put it on a nice measuring scale back on Earth.

That said, what's the maximum mass of rock that would be in the sample head if it was perfectly full?

Link to post
Share on other sites
13 minutes ago, cubinator said:

container full of rock

Asterisk, possibly very loose dust.

Makes me wonder how much more could have been learned in this instance from directly observing the site as the collection occurred. And are there any images of the hole left behind taken on the way out?

Link to post
Share on other sites
7 hours ago, cubinator said:

I just want to see you guys bring the sample home safe. You know you've got a big container full of rock, and it's finally safely sealed up, so we can all wait to put it on a nice measuring scale back on Earth.

That said, what's the maximum mass of rock that would be in the sample head if it was perfectly full?

It depends on the density you assume. A reasonable number is about 2kg. 

6 hours ago, HebaruSan said:

Asterisk, possibly very loose dust.

Makes me wonder how much more could have been learned in this instance from directly observing the site as the collection occurred. And are there any images of the hole left behind taken on the way out?

It would be nice to go back and look at the site. Lots to learn, but that comes at a cost: in both money and risk. With a collected sample, unfortunately it isn’t worth it.  Two differences from KSP: no F9 and operating a spacecraft also takes funds. 

Link to post
Share on other sites
On 10/29/2020 at 1:54 PM, IonStorm said:

It would be nice to go back and look at the site. Lots to learn, but that comes at a cost: in both money and risk. With a collected sample, unfortunately it isn’t worth it.  Two differences from KSP: no F9 and operating a spacecraft also takes funds. 

Did you already leave from Bennu permanently?

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...