Author Topic: SpaceX COTS Demo 2 Updates (Read 448897 times)

N45deg · « **Reply #880 on:** 08/21/2011 01:16 am »

I was wrong.
It is on the silly scissor lift.

dragon44 · « **Reply #881 on:** 08/21/2011 01:35 am »

Quote from: N45deg on 08/21/2011 01:16 am

It is on the silly scissor lift.

I'm going to put my SpaceX fanboi hat on for a minute. The previous pictures we have seen show that Dragon is usually not worked on while it is attached to the trunk. So, normally the ventilator would just be sitting on the ground. For the fit test (or whatever it is we are seeing here), they probably needed a way to temporarily get air to Dragon on top of the trunk. You could go buy longer ducts (provided the ventilator supports that), build a special platform, etc. I'm guessing one of those technicians said, "What about that scissor lift over there?" If it is good enough for people, it is good enough for a ventilator. It isn't like they stacked a bunch of phone books. The lift is a completely legitimate way to temporarily raise work materials (men or ventilators) when a permanent fixture would be a waste of money.

dragon44 · « **Reply #882 on:** 08/21/2011 01:37 am »

Quote from: corrodedNut on 08/20/2011 01:15 pm

Here's a platform in use. I think we can assume it and any others were moved out the way only temporarily.

Would they have done this cargo test while attached to the trunk? If not, it could be that the platform is too small for a Dragon/Trunk combo.

sdsds · « **Reply #883 on:** 08/21/2011 01:46 am »

It points to differences in what people hope (or expect) to see in Dragon production at this stage. Some of us apparently hope or expect to see something like a carefully planned assembly line; others expect to see something more improvised.

There's a bit of irony when comparing Orion and Dragon production. LM will be lucky to produce six or eight Orions in the next decade, yet every piece of production tooling appears optimized for an endless production run. SpaceX on the other hand are hoping to produce many more than six or eight Dragons, yet it still looks rather like production of each one is being carried out using equipment that might be suboptimal for mass production.

AnalogMan · « **Reply #884 on:** 08/21/2011 02:15 am »

Nothing that we don't know from Chris B's news article, but this was noted in the latest CCDEV report from NASA:

NEXT SPACEX CARGO DEMO FLIGHT
"... SpaceX wants to deploy two commercial satellites (Orbcomm) from the F9 second stage. The addition of Orbcomm's payloads to the combined mission is under review. If the risks associated with the secondary payloads are determined to be acceptable, NASA will give formal approval to the combined mission execution."

Also this note:

"The C2 Falcon 9 launch vehicle is currently at Pad 40, Cape Canaveral, and is undergoing final preparation for the mission. The integrated Dragon spacecraft is preparing for electromagnetic compatibility and thermal vacuum testing to verify the spacecraft's compatibility with ISS environments. The Dragon spacecraft is planned to be shipped from SpaceX’s Hawthorne facility to Cape Canaveral in September."

See http://forum.nasaspaceflight.com/index.php?topic=26495.0

simonbp · « **Reply #885 on:** 08/21/2011 06:24 am »

Honestly, I was thinking more in terms of floor space and rental costs for the lifts, but I understand the safety concerns.

SpaceX has seemed to have an enthusiasm for building support structures in the past (look at the rest of the picture!), so again, I'd be surprised if the lifts were permanent.

jwade · « **Reply #886 on:** 08/21/2011 10:23 am »

Any guesses what the silver coating is over the TPS? The COTS1 flight had the native PICA-X brown color: See http://www.spacex.com/assets/img/20101001_dragonc1.jpg and http://www.spacex.com/assets/img/20101001_rotating.jpg

apace · « **Reply #887 on:** 08/21/2011 10:42 am »

Quote from: jwade on 08/21/2011 10:23 am

Any guesses what the silver coating is over the TPS? The COTS1 flight had the native PICA-X brown color: See http://www.spacex.com/assets/img/20101001_dragonc1.jpg and http://www.spacex.com/assets/img/20101001_rotating.jpg

Looks like an additional protection. Perhaps it will be removed before flight.

cambrianera · « **Reply #888 on:** 08/21/2011 11:45 am »

Quote from: apace on 08/21/2011 10:42 am

Quote from: jwade on 08/21/2011 10:23 am
Any guesses what the silver coating is over the TPS? The COTS1 flight had the native PICA-X brown color: See http://www.spacex.com/assets/img/20101001_dragonc1.jpg and http://www.spacex.com/assets/img/20101001_rotating.jpg

Looks like an additional protection. Perhaps it will be removed before flight.

Mmmhh.. it seems not covered by a protection, but integral.
Moreover Phenolic is quite a tought stuff relating to normal launch environment.
I'm thinking at the charring of COTS1 capsule, maybe they are partially reformulating PICA-X to reduce charring.
If they think to resell Dragon as Dragonlab, reducing the cost of refurbishment is a good thing.

ugordan · « **Reply #889 on:** 08/21/2011 11:54 am »

PICA-X is ablative so I don't know how you plan to reduce charring. In any case, the dark deposit is mostly on the external insulation.

apace · « **Reply #890 on:** 08/21/2011 12:00 pm »

It looks really like a protection foil or something like this which needs to be removed before starting. Or they have added some foil which can be there and will be burn in seconds at entry. We will see soon ;-)

kraisee · « **Reply #891 on:** 08/21/2011 12:16 pm »

Quite likely that they found some moisture retention (mass penalty to LEO) in the PICA-X on flight one, so they've added a barrier layer to prevent it happening in future.

Ross.

cambrianera · « **Reply #892 on:** 08/21/2011 12:27 pm »

Quote from: ugordan on 08/21/2011 11:54 am

PICA-X is ablative so I don't know how you plan to reduce charring. In any case, the dark deposit is mostly on the external insulation.

Changing the composition of the Phenolic (i.e. adding some charges to the plastic) you can reduce the buildup of carbon sooth that causes charring.
But I said maybe (and is a big one).
To Apace: Yes, we will see soon
To Kraisee: Yes, maybe moisture control is the reason, and this is an aluminium foil layed at the end of the manufacturing process of PICA tiles (this way it seems integral - following the shape of single tiles).

ugordan · « **Reply #893 on:** 08/21/2011 12:43 pm »

Quote from: cambrianera on 08/21/2011 12:27 pm

Changing the composition of the Phenolic (i.e. adding some charges to the plastic) you can reduce the buildup of carbon sooth that causes charring.

That implies three things:

1) they didn't know there'd be dark residue beforehand
2) they think it's a big deal
3) they went on to redesign PICA-X on a short notice and redo all the testing again they did a couple of years ahead of first flight. Even though they said the TPS performed great.

apace · « **Reply #894 on:** 08/21/2011 12:56 pm »

Quote from: ugordan on 08/21/2011 12:43 pm

Quote from: cambrianera on 08/21/2011 12:27 pm
Changing the composition of the Phenolic (i.e. adding some charges to the plastic) you can reduce the buildup of carbon sooth that causes charring.

That implies three things:

1) they didn't know there'd be dark residue beforehand
2) they think it's a big deal
3) they went on to redesign PICA-X on a short notice and redo all the testing again they did a couple of years ahead of first flight. Even though they said the TPS performed great.

On the first new photo of SpaceX it looks like there are air bubbles under this silver foil, so I think it will be simply a protection layer.

Nomadd · « **Reply #895 on:** 08/21/2011 03:56 pm »

Quote from: ugordan on 08/21/2011 12:43 pm

Quote from: cambrianera on 08/21/2011 12:27 pm
Changing the composition of the Phenolic (i.e. adding some charges to the plastic) you can reduce the buildup of carbon sooth that causes charring.

That implies three things:

1) they didn't know there'd be dark residue beforehand
2) they think it's a big deal
3) they went on to redesign PICA-X on a short notice and redo all the testing again they did a couple of years ahead of first flight. Even though they said the TPS performed great.

4) They wanted the data from the previous configuration.
That would be more characteristic of the way Spacex does things. If there's no worry about failure, test different configurations by putting them on a flight.

Prober · « **Reply #896 on:** 08/21/2011 05:41 pm »

Quote from: apace on 08/21/2011 12:56 pm

Quote from: ugordan on 08/21/2011 12:43 pm
Quote from: cambrianera on 08/21/2011 12:27 pm
Changing the composition of the Phenolic (i.e. adding some charges to the plastic) you can reduce the buildup of carbon sooth that causes charring.

That implies three things:

1) they didn't know there'd be dark residue beforehand
2) they think it's a big deal
3) they went on to redesign PICA-X on a short notice and redo all the testing again they did a couple of years ahead of first flight. Even though they said the TPS performed great.

On the first new photo of SpaceX it looks like there are air bubbles under this silver foil, so I think it will be simply a protection layer.

Shipping prep?

cambrianera · « **Reply #897 on:** 08/23/2011 08:32 pm »

So new other hints (or fancies!) regarding the new look of PICA-X?
By the way, good catch jwade!
For sure: metallic look (aluminium?) but not too shiny.
Follows the pattern of singular tiles (not a single foil covering the entire TPS for shipping protection).

Personally I believe kraisee got it right (moisture control, very thin aluminium or plastic/al foil at the end of PICA-X manufacturing).

My original idea (composition change) seems less likely.
Reducing the charring could be good and the risk is minimal (lot of margin in the TPS), but without other information moisture control seems much more likely.

go4mars · « **Reply #898 on:** 08/23/2011 09:30 pm »

Quote from: cambrianera on 08/23/2011 08:32 pm

So new other hints (or fancies!) regarding the new look of PICA-X?
By the way, good catch jwade!
For sure: metallic look (aluminium?) but not too shiny.
Follows the pattern of singular tiles (not a single foil covering the entire TPS for shipping protection).

Personally I believe kraisee got it right (moisture control, very thin aluminium or plastic/al foil at the end of PICA-X manufacturing).

My original idea (composition change) seems less likely.
Reducing the charring could be good and the risk is minimal (lot of margin in the TPS), but without other information moisture control seems much more likely.

If Pica-X is absorbent (and reusable for multiple re-entries), I wonder how it gets cleaned and dried from its dunk in the drink before it goes on the next ride. Maybe it is only reusable in conjunction with propulsive landing and touch-down legs. Perhaps, rather than a film for moisture, it is a metal shield to keep the pica-x from getting accidentally poked or scraped during non-launch-day shuffling; to be removed before launch.

krytek · « **Reply #899 on:** 08/23/2011 09:35 pm »

Why would it need to be cleaned and the char removed if it's meant to reusable and passes safety checks.
Does a car have to be necessarily washed before every drive?