Earth Return & Sample Science Options

[Marcin600]

Since the pictures shown at the conference have not yet appeared on the main NASA website or the OSIRIS-REx blog, I am posting this:
better quality pictures of Bennu's samples from the mylar flap are here: https://www.facebook.com/NASAastromaterials
1: https://www.facebook.com/photo.php?fbid=726...0000&type=3
2: https://www.facebook.com/photo.php?fbid=726...0000&type=3
Credit: NASA/Erika Blumenfeld & Joseph Aebersold

Attached thumbnail(s)

 

[Marcin600]

As for the "bedrock" of Bennu, it must be remembered that it is highly probable that this asteroid, like Ryugu, may be a so-called "rubble pile", i.e. a body entirely consisting of rather weakly "glued together" fragments resulting from cosmic collision, so there may be no such thing as „bedrock” at all.

As for Bennu's current orbit (relatively close to Earth), it is also highly probable that it has been there relatively recently (on the cosmic time scale) as a result of some perturbations in the "recent" past, and it was formed in an orbit further from the Sun.

Questions about the origin and evolution of this asteroid and its minerals will be answered by the analyzes of the provided samples, which have only just begun. Let's wait for the conclusions of these studies...

[Bill Harris]

I'm sure we'll find that there are differing structures or internal makeups of asteroids. With larger and larger components making up the body we get away from rubble piles to loosely accreted to well-accreted. We'll know more once we get spacecraft on the bodies that can do CT Seismology and make accurate density measurements.
From the initial views of the loose material on the outside of the sampler I have the impression that the light-toned ("white") are spherical beads, while the dark irregular fragments are brecciated or accreted. But with no scale included this is a guess.

--Bill

[Holder of the Tw...]

They are continuing to slowly gather up the returned sample, including a bit from just inside the sampler head around the mylar flap. They've hit a snag removing that flap, so may be awhile before they get all of the material. Up to now they've collected 70.3 grams, so they have already passed the 60 gram goal.

Link to current blog entry: Sample mass milestone

In the last week, the team at NASA’s Johnson Space Center in Houston changed its approach to opening the TAGSAM head, which contained the bulk of the rocks and dust collected by the spacecraft in 2020. After multiple attempts at removal, the team discovered two of the 35 fasteners on the TAGSAM head could not be removed with the current tools approved for use in the OSIRIS-REx glovebox ...

As a first step, the team successfully accessed some of the material by holding down the head’s mylar flap and removing the sample inside with tweezers or a scoop, depending on material size. The collection and containment of material through this method, combined with the earlier collection of material located outside the head, yielded a total mass exceeding the 60 grams required.

[stevesliva]

Parachute deployment investigation results:
https://gizmodo.com/nasa-asteroid-sample-pa...ause-1851076738

Drogue basically didn't work as intended because the primary parachute was described as the "main" while some of the devices in the system also had a "main" side.

Those are tricky buggers! Last time-- Genesis-- they conspired to be installed backwards.

[rlorenz]

Parachute deployment investigation results:
Drogue basically didn't work as intended because the primary parachute was described as the "main" while some of the devices in the system also had a "main" side.

They were lucky. Lines to the drogue got cut instead of the mortar firing to deploy it. Then later when the lines were supposed to be cut to pull out the main, the drogue deployment was actuated and somehow the main came out and inflated ok....

[mcaplinger]

I know nothing about this except as a bemused bystander.

The press release https://blogs.nasa.gov/osiris-rex/2023/12/0...yment-sequence/ seems inconsistent.

My impression is that there were three events and three signals:

1) deploy cover and drogue;

2) cut away drogue;

3) deploy main.

and these were supposed to be fired in the order 1, 2, 3, but in fact were fired in the order 2, 1, 3 because they swapped 1 and 2. But if you read the text in the press release it sounds like they swapped 1 and 3, which would have been order 3, 2, 1 and might have had similar effects assuming that deploying the main with the cover still on wasn't a big deal (I'd have thought it would be, these deployments can be pretty energetic.)

I hope it's the press release that's confused and not the real failure analysis!

[stevesliva]

Given the low altitude deployment, I assume the 2,1,3 sequence makes sense. Monty Python Holy Hand Grenade joke almost required here.

[rlorenz]

...
My impression is that there were three events and three signals:
1) deploy cover and drogue;
2) cut away drogue;
3) deploy main.

In missions I am familiar with, there is no separate actuation of (2) and (3). (2) is performed by e.g. separation nuts, or boltcutters on the spools holding the bridle lines to the drogue. Once the drogue is released, it pulls away, and drags on a lanyard that pulls out the bag containing the main. When the bridle and line to the main become taut, the bag is stripped off and the main inflates.

Thus there are only 2 sets of pyros (1) and (2), and 2 associated signals and function (3) is performed passively as a result of (2).

(1) is done on the deceleration history, and (2) on a pressure trigger, but apparently (1) and (2) were switched here, as I understand it (I eagerly await the final report)

[mcaplinger]

In missions I am familiar with, there is no separate actuation of (2) and (3).

I don't know for sure, but there's a lot of information in the Genesis failure report at https://ntrs.nasa.gov/api/citations/2006000...20060008607.pdf and this clearly shows three events and three sets of pyros (Table 2-3, below). I assume that the Genesis and OREx capsules are pretty similar electrically (though Genesis was supposed to use a parafoil.)

I didn't find anything with a similar level of detail for Stardust (all the best info is in failure reports. )

[Explorer1]

Some amazing footage I hadn't seen before of the sample return capsule re-entry

Some very glum faces when the drogue failed, and such relief when the main deployed!

[stevesliva]

An explanation for why the triumphal news stopped.

2 of 35 fasteners refuse to un-fasten:
https://gizmodo.com/nasa-osiris-rex-asteroi...iner-1851102598

They stopped trying with the available glovebox tools awhile back (Nov?) and are developing alternative methods.

(Note: I am surprised to be sourcing Gizmodo twice in a row here, though twice the MS edge landing page has shown me news that turns out to have been originally reported at Gizmodo. Good for them.)

[Floyd]

I saw this a few weeks back--I believe from NASA. Not something kept quiet. They switched to lifting the flaps and scooping it out.

[mcaplinger]

I saw this a few weeks back--I believe from NASA. Not something kept quiet. They switched to lifting the flaps and scooping it out.

https://blogs.nasa.gov/osiris-rex/2023/10/2...mass-milestone/ from October 20. I think the only value-added that Giz is providing is getting some sort of timetable statement out of NASA PAO ("we anticipate it will be opened in the first quarter of 2024").

https://www.nature.com/articles/d41586-023-03978-4 has a bit more recent info from AGU.

I sympathize with the PR problem NASA is having; almost everyone has experience with a balky screw and taking months to resolve it seems like a glacial pace.

I thought I saw an article that tried to link the drogue chute snafu with the stuck screws, but I'm not sure where, and it doesn't sound all that plausible.

[Explorer1]

If they have to order custom tools just to open those two screws, I'm not surprised it's taking this long. Supply chains, etc. There's probably faster ways to get in, but they don't want to take any risks.