Author Topic: SpaceX COTS Demo 2/3 Updates (THREAD 2) (Read 787818 times)

hyper_snyper · « **Reply #340 on:** 10/24/2011 11:22 pm »

It sure is a handsome capsule.

Lars_J · « **Reply #341 on:** 10/24/2011 11:27 pm »

Quote from: Jason1701 on 10/24/2011 11:13 pm

The mold lines around the thrusters aren't actually that different. The Dragon C1 picture Lars posted was before they installed the fairings seen in nother's picture.

What "fairings"? The C1 as pictured in my post mostly had some insulating liner/paste inserted in the space between the panels - otherwise it pretty much flew as shown in the picture. Contrast that with the larger molded panels on the C2 Dragon.

Space Pete · « **Reply #342 on:** 10/25/2011 12:16 am »

Aww, they removed the portholes - they would've made for some great unique-angle photos of the exterior of the ISS.

Probably an obvious question, but why is the heatshield silver as opposed to the previous yellowy colour? Some kind of ablative coating to protect against long-duration spaceflight (temperature fluctuations)?

Concur that it's a sexy capsule.

go4mars · « **Reply #343 on:** 10/25/2011 12:54 am »

Quote from: ugordan on 10/24/2011 08:54 pm

There's also some video of the unwrapped s/c posted by WeshTV: http://www.wesh.com/r-video/29573227/detail.html

Are those numbers from the video about dollars spent updated figures? Or just inaccurate?

kevin-rf · « **Reply #344 on:** 10/25/2011 12:55 am »

Quote from: Space Pete on 10/25/2011 12:16 am

Probably an obvious question, but why is the heatshield silver as opposed to the previous yellowy colour? Some kind of ablative coating to protect against long-duration spaceflight (temperature fluctuations)?

Didn't they have a heat shield moisture issue with the last capsule? Water barrier?

mr. mark · « **Reply #345 on:** 10/25/2011 01:45 am »

I think the heatshield is also a lot less thick as well. Compare it to pre launch photos of COTS 1 and you will see what I mean.

Lars_J · « **Reply #346 on:** 10/25/2011 01:50 am »

Quote from: mr. mark on 10/25/2011 01:45 am

I think the heatshield is also a lot less thick as well. Compare it to pre launch photos of COTS 1 and you will see what I mean.

No, I think it is mostly the different camera angles that make it seem that way. But you could be right.

Complete speculation here - The reflective layer for the Pica-X outer tiles (and white for the inner) is probably for thermal issues, since the capsule will be spending weeks in space vs. a few hours. I don't think it has anything to do with protecting against moisture at splashdown, since that top layer is the first part that will be eroded during reentry.

Lars_J · « **Reply #347 on:** 10/25/2011 02:35 am »

Universe Today has a few more pictures after the unpacking: http://www.universetoday.com/90184/here-there-be-dragons-spacexs-spacecraft-arrives-at-launch-complex-40/

Ronsmytheiii · « **Reply #348 on:** 10/25/2011 02:46 am »

SO my question is, where is the trunk? I would imagine still at the plant....

Comga · « **Reply #349 on:** 10/25/2011 04:20 am »

Quote from: Lars_J on 10/24/2011 08:37 pm

Nice pictures! And finally a great shot of the front.
Misc observations:

- No hatch window.
- The bay door has three points that look like they will align with the 3 points above the door (when swung open), presumably for added structural support for the grapple fixture mounted behind the door.
- Lots of changes to mold lines around the thrusters and hatch compared to the COTS1 Dragon.
- The open area next to the bay door must be the new location for the capsule umbilicals, OR the trunk umbilical connection port.

Definitely some significant changes... A Block 0 vs Block 1, I suppose.

I am surprised by the extensive changes, redesigns, in the area below the hatch. It seems unlike SpaceX to build features that are moved after one or two builds, particularly for elements that have been long planned.

Also the hatch itself. There is still an outline of the hatch, but not for the windows.

Curious

But it is a delight to see flight hardware, (and answer the question about how long it takes to truck from Hawthorn to CCAFS instead of the question about what to call a group of Dragon capsules.

) Those mating three point elements answers a long standing question about putting the grapple fixture on the door.

mr. mark · « **Reply #350 on:** 10/25/2011 04:46 am »

"SO my question is, hwere is the trunk?"

I'm very interested in the SpaceX trunk section (I know Jim doesn't like the word trunk

) Will it resemble what we've seen in the reuse video?

docmordrid · « **Reply #351 on:** 10/25/2011 04:48 am »

Quote from: Lars_J on 10/25/2011 01:50 am

Quote from: mr. mark on 10/25/2011 01:45 am
I think the heatshield is also a lot less thick as well. Compare it to pre launch photos of COTS 1 and you will see what I mean.

No, I think it is mostly the different camera angles that make it seem that way. But you could be right.

Complete speculation here - The reflective layer for the Pica-X outer tiles (and white for the inner) is probably for thermal issues, since the capsule will be spending weeks in space vs. a few hours. I don't think it has anything to do with protecting against moisture at splashdown, since that top layer is the first part that will be eroded during reentry.

Looks thinner to me too, and I'm used to comparing images obtained from different perspectives.

Outer tiles look metallic. Metalized ceramic coating to minimize the cleanup from deposition?

mr. mark · « **Reply #352 on:** 10/25/2011 05:38 am »

Here is an illustration of the lower hatch with it opened. I take it the grapple feature is inside the hatch?

Lars_J · « **Reply #353 on:** 10/25/2011 06:32 am »

Quote from: mr. mark on 10/25/2011 05:38 am

Here is an illustration of the lower hatch with it opened. I take it the grapple feature is inside the hatch?

Yes. But that image does clear up one thing (assuming this specific design element hasn't changes) - the open area next to the hatch is the attachment point for the trunk systems. (power and cooling)
------
docmorbid - from what I can tell, there is nothing in the images to indicate that there is a difference in the heatshield shape. Again, I could be proven wrong... But I consider myself pretty good at taking into account perspectives and camera angles.

But consider that IF the heat shield was thinned, it would probably be thinned from the inside to keep the outer geometry the same - I'm sure they have done plenty of work to find the optimal shape that works for them. One would not change the outer mold line of the capsule base without considerable validation work.

ugordan · « **Reply #354 on:** 10/25/2011 07:35 am »

Quote from: kevin-rf on 10/25/2011 12:55 am

Didn't they have a heat shield moisture issue with the last capsule? Water barrier?

That was speculation by some forum members here only.

Ben the Space Brit · « **Reply #355 on:** 10/25/2011 10:16 am »

Just out of interest, why was the COTS-1 capsule was in the work area? Are they using it as a guide for some modifications or is it bein refurbished for a future cargo or DragonLab mission?

subzero788 · « **Reply #356 on:** 10/25/2011 11:07 am »

Could also be purely for photo ops or simply to motivate and inspire the workforce. But I expect the major reason would be more practical, as you suggest. This is just a guess, but I think it's unlikely that they would refly C1--it was more of a protoype Dragon and they have made quite a few modifications to the design. It also has symbolic value and hopefully it ends up in a museum in the non-too-distant future.

Comga · « **Reply #357 on:** 10/25/2011 02:26 pm »

Quote from: mr. mark on 10/25/2011 05:38 am

Here is an illustration of the lower hatch with it opened. I take it the grapple feature is inside the hatch?

That was an illustration of a DragonLab, not a CRS Dragon. There is an exposure plate, with little hexagonal samples, instead of the grapple fixture, on the inside of the door.

Edit. The images is quite archaic. Recent images show the solar panels will be stowed in pontoons outside the cylindrical body of the trunk, not recessed into it like in the illustration.

simonbp · « **Reply #358 on:** 10/25/2011 03:31 pm »

Quote from: docmordrid on 10/25/2011 04:48 am

Outer tiles look metallic. Metalized ceramic coating to minimize the cleanup from deposition?

No, it's probably just white and silver paint on top of regular PICA-X. This is the part of the heat shield that extends beyond the trunk, so the relative proportions are likely designed to keep the PICA at a certain temperature (the same as the rest of the vehicle) when exposed to direct sunlight.

Paint for thermal control is a nice KISS approach, and nothing new...

gladiator1332 · « **Reply #359 on:** 10/25/2011 04:59 pm »

Great images! Can't wait for this flight.