LIVE: SpaceX Dragon CRS-1 (SpX-1) (EOM) Unberthing, Entry, Splashdown

[Antares]

Having grown up in the 60s watching Gemini and Apollo, I think it's very cool that they can recover Dragon with such a minimal recovery fleet, from an economic standpoint.  No aircraft carrier task force necessary.

Not quite apples for apples; I would imagine that the recovery support for a manned capsule would be significantly larger.

Huge difference between a government operation in the 60s and a private operation today.  SpaceX will spend what it needs and no more.  The government throws money at risks to control them.

[baldusi]

Huge difference between a government operation in the 60s and a private operation today.  SpaceX will spend what it needs and no more.  The government throws money at risks to control them.

I do wonder if the fact that they were on a Cold War and the Apollo had all sort of interesting technologies didn't weight on sending a whole carrier fleet. After all, the whole point of the Apollo Program was to awe the rest of the world. SpaceX is trying to make a profit on a very tight market and competing on price. And they have a PR company for creating hype.

[Thunderbird5]

I do wonder if the fact that they were on a Cold War and the Apollo had all sort of interesting technologies didn't weight on sending a whole carrier fleet. After all, the whole point of the Apollo Program was to awe the rest of the world. SpaceX is trying to make a profit on a very tight market and competing on price. And they have a PR company for creating hype.

Well, they are in serious competition with the Chinese. Not quite the same I grant you but your comment makes me wonder to what measure ITAR obligations, as well as just commercial, might require of SpaceX (or any other US space operator) in securing the technology when off of US soil.

Of course, from what we've seen, it would appear not a lot, but curious to know?

[Jim]

Well, they are in serious competition with the Chinese.

No, they aren't.  No one in the US is.

[kevin-rf]

Anyone else notice the post mission heatshield photo Steve Jurvetson had posted on his flicker feed (when you scroll down?) http://www.flickr.com/photos/jurvetson/8234368600/in/photostream/

[corrodedNut]

Looks like they've taken sample cores from several places.

[Antares]

makes me wonder to what measure ITAR obligations, as well as just commercial, might require of SpaceX (or any other US space operator) in securing the technology when off of US soil.

Rules apply everywhere, to the owners of the hardware.  If an export controlled yet jettisoned piece of hardware washes up, the launch company is obligated to go retrieve it.

[oiorionsbelt]

From where do you see 'core samples' removed?
Can anyone describe why the seems between tiles are so pronounced as compared to before flight?

[corrodedNut]

From where do you see 'core samples' removed?
Can anyone describe why the seems between tiles are so pronounced as compared to before flight?

The more it's handled, the more black char rubs off. IIRC the joints are filled with a high temperature silicone "caulk", perhaps the char there comes off more easily.

[krytek]

DRAGON SCALES! 

[smoliarm]

Can anyone describe why the seems between tiles are so pronounced as compared to before flight?

It's because some part of protective material was ablated (blown away).
This kind of heat-shield (PICA-X) is quite different from Space Shuttle tiles. Under intense heat of reentry, it gradually burns away. Well, it's not exactly 'burning' - there is not much to burn. It is 'ablation' - evaporation mostly. This process takes almost all the heat away. The shield material is originally ~ 2" thick, on the photo it looks like about 0.5" is gone, although it's difficult to tell with this picture size.

Here is the article with more details on Dragons heat protection:
http://www.nasa.gov/offices/oce/appel/ask/issues/40/40s_space-x.html

[guckyfan]

The shield material is originally ~ 2" thick, on the photo it looks like about 0.5" is gone, although it's difficult to tell with this picture size.

Here is the article with more details on Dragons heat protection:
http://www.nasa.gov/offices/oce/appel/ask/issues/40/40s_space-x.html

Very interesting article.

Are you sure about the 2 inches? I used a photo of the heatshield to determine its thickness and got ~11cm=4,33 inches.

[smoliarm]

Are you sure about the 2 inches? I used a photo of the heatshield to determine its thickness and got ~11cm=4,33 inches.

No, I'm not, it's my estimate based on this photo:

http://www.nasa.gov/images/content/489072main_40s_spaceX_tile_placement_1024.jpg

I did not measure anything, I just compared thickness of the plate with the right hand of worker.

If you used the full diameter of the shield on your photo for the scale - this will work ONLY if the shot was made with normal focal length (or, zoom = 1.0). Any zoom other than 1 distorts proportions.

Anyway, 11 cm is wider than typical width of human hand (palm). It's not the case on the picture I refer. But who knows, may be the guy has large hands

[guckyfan]

Are you sure about the 2 inches? I used a photo of the heatshield to determine its thickness and got ~11cm=4,33 inches.

No, I'm not, it's my estimate based on this photo:

http://www.nasa.gov/images/content/489072main_40s_spaceX_tile_placement_1024.jpg

I did not measure anything, I just compared thickness of the plate with the right hand of worker.

If you used the full diameter of the shield on your photo for the scale - this will work ONLY if the shot was made with normal focal length (or, zoom = 1.0). Any zoom other than 1 distorts proportions.

Anyway, 11 cm is wider than typical width of human hand (palm). It's not the case on the picture I refer. But who knows, may be the guy has large hands

I see where your estimate comes from.

Different focal length does distort perspective, not proportions in the same part of the photo. But my measurement from that photo is also not precise.

Looking at your photo it seems to me the shield is thinner in the middle, where you take your estimate from than at the perimeter where I took my measure. That may explain part of the difference and the rest is insufficient solution to make better guesses.

If the heatshield is really thicker to the edge and the edge has actually less than my measure of ~11cm my calculation of ~600kg for the heatshield would be substantially too high.

Edit: That photo was taken with a wide angle, so it would make the part where I took the measure, would be enlarged. So my 11cm would be on the high side.

[AnalogMan]

SpaceX say the following about their heatshield tiles:

"We produce the PICA-X material in-house in large billets, then cut and machine them into separate tiles, each as large as a cafeteria tray, but over 8 cm (3 inches) thick, and weighing only about a kilogram (2.2 pounds) each. During reentry, less than 1 cm (1/2 inch) chars away from the surface of the PICA-X tiles, providing plenty of safety margin."

http://www.spacex.com/F9-001.php

[Elmar Moelzer]

SpaceX say the following about their heatshield tiles:

"We produce the PICA-X material in-house in large billets, then cut and machine them into separate tiles, each as large as a cafeteria tray, but over 8 cm (3 inches) thick, and weighing only about a kilogram (2.2 pounds) each. During reentry, less than 1 cm (1/2 inch) chars away from the surface of the PICA-X tiles, providing plenty of safety margin."

http://www.spacex.com/F9-001.php

Interesting info on the heatshield. I am not sure how current this info is, but I do remember that at one point after the first flight, Elon Musk claimed that they were suprised by how little the heat shield was lost and they might be able to reuse it 100 times. Now this sounds more like they might be able to use it two or 3 times at most prior to replacing it. That would be a lot less... Anyone know which information is the more current?

[guckyfan]

Interesting info on the heatshield. I am not sure how current this info is, but I do remember that at one point after the first flight, Elon Musk claimed that they were suprised by how little the heat shield was lost and they might be able to reuse it 100 times. Now this sounds more like they might be able to use it two or 3 times at most prior to replacing it. That would be a lot less... Anyone know which information is the more current?

I noticed that discrepancy too. As Elon Musk made that remark after the first flight, it must be the more recent. It stll sounds a bit too optimistic. But even 10 times would be great news. No Dragon is likely to fly more times than that as it looks at the moment.

[Chris Bergin]

We should close this one now and more to the CRS-2 thread:
http://forum.nasaspaceflight.com/index.php?topic=30700.0