MSL EDL Hardware, Its state & fate Options

[MahFL]

Yes, there's something to be said for a complicated EDL with lots of 'space junk'; it sure makes the slow early days of landing go by faster.
The question of visiting any of these things up-close, even the non-hazardous debris, is still really far off though, we should keep in mind.

A Mission manager said none will be visited, mainly as they were not decontaminated from earth organics as the rover was, so they don't want any chance of a erroneous organic result due to something transported from Earth.

[MahFL]

I seem to remember there was some concern that Opportunity's camera optics got contaminated during its visit to the heatshield, so they might be more careful with Curiosity.

John

Remember MSL's heat shield had a suit of senors built in to measure temperatures, g forces and how much material ablated away, so they will know how well it performed anyway.

[DFinfrock]

Does the parachute act as a windsock and give us the surface wind direction at time of backshell/parachute impact?

The backshell comes to rest before the parachute which then settles on the ground downwind (S) indicating wind from the north at the surface at time of impact.

Good point bigdipper.

A line drawn through the locations of Curiosity and the heat shield should give a pretty good indication of the direction of entry. And the fact that the parachute and backshell landed south of that line confirms that the total of the wind vectors from the altitude at the time the Descent Stage separated from the parachute/backshell until it landed were generally from north to south. But that didn't prove that the surface winds were the same.

But your point about the backshell impacting first, followed by a slow settling of the parachure would certainly confirm that the surface wind was in the north to south )or northeast to southwest) direction.

David

[dvandorn]

I've taken a closer look at the descent stage crash site, and I annotated it a bit to point out a few things I've noticed.

First off, I've drawn red arrows to point out what appear to be secondary impacts, mostly without any streaking of ejecta, just very dark spots where they don't appear to belong. I imagine a few of these are rock shadows, but most of them appear to be freshly disturbed soil. One area I really noticed was a small crater nearly under the stage's flyaway path that has four very dark spots in it. It's about the only sign of disturbance that is uprange of the crash site.

The green arrows point out four distinct plumes that fan out from what appears to be the main impact site. The northenmost of the four plumes are connected, almost just a small side-plume from a main plume. The other two plumes are very distinct and separate from the rest. Looks almost like the descent stage flipped over and hit the ground with the engines firing in the direction of flight, although I certainly don't insist on that interpretation.

Finally, there is this aureole-like feature just uprange of the impact point that I have rather imperfectly tried to outline in yellow. I see a very light disturbance in this area, much less darkened than the ejecta spray downrange of the impact. This uprange feature also appears to show radial spiking around its outside extent.

The combination of the four disturbed points in the crater uprange of the impact point and the plumes fanning forward from the impact point again makes me wonder exactly what happened as the stage came in for its crash-landing. I don't even know if it's possible for the engines to have been firing by the time it impacted; the fans I see may be separate ejecta events from each of the largest pieces of structure that hit at the main impact point. But it does look awfully suggestive.

-the other Doug

[fredk]

And we can see glints off the descent stage debris!
http://mars.jpl.nasa.gov/msl-raw-images/pr...AUT_04096M_.JPG

edit: oops, should've posted in the hardware thread.

[jklier]

Any chance HIRISE caught the skycrane phase of the landing? I'd love to see that as clear as the parachute image.

[B Bernatchez]

Methinks if we ever use a skycrane type of landing again, we're going to have to program a little more smarts into the descent stage and have it either fly farther away or try to kill its velocity before it crashes. I shudder to think of what might have happened had one of those fragments of descent stage come back and whanged the rover real good...

-the other Doug

I think a better use would be to build in some hover capability and maneuverability prior to landing. With an estimated 140Kg of prop left, they should be able to add this in for the next attempt, whenever that might be.

[Explorer1]

If it had, we'd have seen it by now.

[elakdawalla]

There was an interesting discussion about that on Twitter today between @burritojustice (I don't know who he is but I love his Twitter handle) and @HiCommander (Christian Schaller):

@burritojustice: Would it have been possible for HiRise to have gotten a shot of Curiosity dangling from the Sky Crane?

@HiCommander: Yes. Initial desire was to get both: chute sequence, sky crane sequence. However, HiRISE images are huge. (1/n)
@HiCommander: It takes several minutes to read out from instrument to s/c. 5-10 min typically. (2/n)
@HiCommander: So… Not enough time to take chute image, read out, re-point MRO, start new slew, start taking crane image. (3/n)
@HiCommander: MSL team wanted chute image more than crane image, and that was that. (4/4)

@burritojustice: Tough decisions. Thanks for answering (and for taking the picture!) Until the next Sky Crane opportunity!

@HiCommander: You bet. WE actually wanted the crane. Spacecraft-on-parachute is so 2008 for HiRISE. Yawn.

@burritojustice: As I suspected.

[James Sorenson]

Doug, according to the HiRISE images in GM, those dark spots in that crater in the lower right of your picture, were already there before landing.

[fredk]

Here's a flicker gif between two R rhaz frames from sol 0, the first showing the dust cloud, the second showing glints off of what have to be DS debris:

So we can now see that the cloud is a bit to the left of the debris, which is consistent with a wind to the south.

But you can see something else, too. Compare the horizons in the two frames. The near horizons match up perfectly between the two frames on the left side. But, the right side of the near horizon is much less distinct, and lower, in the first frame than in the later frame. To me it looks like there is something obscuring the near horizon in the early frame - maybe dust kicked up during the descent!

[dvandorn]

Doug, according to the HiRISE images in GM, those dark spots in that crater in the lower right of your picture, were already there before landing.

OK, kewl. Those spots just looked really fresh. Sorry I didn't run a comparison with the pre-landing image, there.

Makes you wonder what disturbed that crater, though... again, the disturbances look quite fresh, and the pattern looks quite similar to the one seen in the little crater just downrange of the main descent stage impact, where Occam's Razor would lead you to believe that the disturbances were indeed from the descent stage crash. Maybe a little ejecta from a nearby small impact knocked into the uprange crater sometime in the reasonably recent past?

-the other Doug

[James Sorenson]

Fred that is interesting! Looks the same to me, I really hope we get the full-res picture of that plume to be able to tell for sure. The glint though in the higher res frame, looks to me though like a lens flare from the sun shining through the optics.

[elakdawalla]

I thought "lens flare" too, when I saw it.

[dvandorn]

Well, even if we steer wide and clear of the descent stage crash site, I imagine Curiosity will eventually gain enough altitude along the flank of Mt. Sharp to be able to look back and get a nice view of the crash site. That ought to clear up any mysteries as to what we might be seeing in that first clean hazcam.

So -- someone estimated that the hazcam images were taken 22 seconds after touchdown? I guess that means we couldn't have caught the descent stage in flight, so the RHA must be a post-crash cloud. Although I guess it depends on how long the thing would have stayed up in the air after its translation turn followed by six seconds of thrust.

-the other Doug