Author Topic: SpaceX Falcon 9/Dragon CRS-2 SpX-2 MISSION GENERAL DISCUSSION (Read 379847 times)

Lars_J · « **Reply #780 on:** 03/26/2013 09:21 pm »

Quote from: ap12 on 03/26/2013 09:11 pm

It looks like the inflated torn chute is upwind of the Dragon. How did it get there?

ap12 · « **Reply #781 on:** 03/26/2013 09:26 pm »

Thanks I like the aliens theory but having the other chutes act as a sea anchor seems most likely to me.

Norm38 · « **Reply #782 on:** 03/26/2013 10:26 pm »

Just curious, how much of a g force jolt is it during decent when the parachutes deploy? On a scale of nice and gentle to whiplash?

Lars_J · « **Reply #783 on:** 03/26/2013 11:20 pm »

Quote from: Norm38 on 03/26/2013 10:26 pm

Just curious, how much of a g force jolt is it during decent when the parachutes deploy? On a scale of nice and gentle to whiplash?

They are supposed to inflate gradually, so hopefully not too severe. Plus the drogues have already slowed it down a bit. Here is a video from the Dragon parachute tests that shows how they inflate:

mlindner · « **Reply #784 on:** 03/27/2013 01:36 am »

Quote from: mduncan36 on 03/26/2013 05:27 pm

Quote from: craigcocca on 03/26/2013 05:20 pm
Question: As SpaceX gets additional experience with reentry, splashdown, and recovery of the Dragon, could we start seeing recovery operations a bit closer to the Port of Long Beach? I can understand why they'd want the early missions to splashdown 250 miles from the coast, but wouldn't it be advantageous to get to the point where they can splashdown 30-40 miles off shore to speed up recovery?

The port of Los Angeles, Long Beach, San Diego region is a very heavily traveled area. I suspect the landing location has a lot to do with making certain they don't get Dragon run over by a giant container ship.

At landing time there were two tanker ships within 40km of the landing site. One was roughly 15km away.

manboy · « **Reply #785 on:** 03/27/2013 02:32 am »

A month at the ISS appears to have yellowed the Dragon. I wonder how it would look after six.

mlindner · « **Reply #786 on:** 03/27/2013 02:45 am »

They're using a special space rated coating on the trunk, apparently they opted to not use it on the Dragon as the thermal requirements aren't there. I've noticed bubbling in the paint in past missions as well. They'll probably swap it out for a better paint on manned Dragon.

Lars_J · « **Reply #787 on:** 03/27/2013 03:15 am »

The best angle of the yellowishness almost makes it look like some result of out-gassing - it is so centered around a specific spot.

Quote from: mlindner on 03/27/2013 02:45 am

They're using a special space rated coating on the trunk, apparently they opted to not use it on the Dragon as the thermal requirements aren't there.

Source? The recent article seemed to imply it was a coating for the entire spacecraft, not just the trunk. And why would the thermal requirement for the capsule not be even more severe?

Quote from: mlindner on 03/27/2013 02:45 am

I've noticed bubbling in the paint in past missions as well.

Interesting, can you point to an example image from a past mission?
EDIT: I found the best picture from the last release (attached below), and you are right, there is some yellowing - primarily around the material that fills the spaces between panels and covers bolts. But it is pretty evenly distributed, not like the concentration of this last mission.

But looking at its pattern, it definitely seemed caused by prolonged direct exposure to the sun. Some areas that would mostly be shaded are still pristine white.

Robotbeat · « **Reply #788 on:** 03/27/2013 03:29 am »

Quote from: Lars_J on 03/27/2013 03:15 am

...And why would the thermal requirement for the capsule not be even more severe?...

Because the radiators are on the trunk.

mlindner · « **Reply #789 on:** 03/27/2013 03:45 am »

The yellowing is probably from UV exposure. Same kind of yellowing that happens here on Earth, but more rapid in space because of the concentrated UV. Maybe a chemical/materials engineer could hop in here and mention what types of materials yellow in space. From my basic material science class I had it's mostly synthetic plastic derived coatings and the UV breaks up the chain molecules causing the plastic to become brittle.

As to the heating, yeah the radiators are currently in the trunk so you would want maximum heat dissipation there.

rickl · « **Reply #790 on:** 03/27/2013 04:52 am »

The yellowing seems to be centered on the dark rectangle near the berthing mechanism. Is that a vent of some kind? I wouldn't think that area would get a lot of sunlight when berthed.

nisse · « **Reply #791 on:** 03/27/2013 07:47 am »

According to the Marine Traffic site (http://www.marinetrafic.com) the American Islander carrying Dragon currently is at 130 nm southeast of Long Beach.

Given it's current speed of 7.6 knots it should arrive in port in approx 17h15 m. I.e. around 9 pm local time later today.

Correct?

padrat · « **Reply #792 on:** 03/27/2013 10:45 am »

Quote from: rickl on 03/27/2013 04:52 am

The yellowing seems to be centered on the dark rectangle near the berthing mechanism. Is that a vent of some kind? I wouldn't think that area would get a lot of sunlight when berthed.

It's part of the system that attaches the nose cone.
My opinion on the yellowing: prob UV exposure...

Ben the Space Brit · « **Reply #793 on:** 03/27/2013 02:29 pm »

Is the yellowing only a cosmetic issue or could it represent a long-term thermal protection issue? White is a better thermal reflector than yellow, after all. Maybe, gradually over time, the Dragon capsule would experience increased heat absorption.

mduncan36 · « **Reply #794 on:** 03/27/2013 02:43 pm »

Quote from: nisse on 03/27/2013 07:47 am

According to the Marine Traffic site (http://www.marinetrafic.com) the American Islander carrying Dragon currently is at 130 nm southeast of Long Beach.

Given it's current speed of 7.6 knots it should arrive in port in approx 17h15 m. I.e. around 9 pm local time later today.

Correct?

It isn't driving down a highway so it becomes more than just a speed over distance calculation. Add in time for wind, currents, traffic, etc. and you're probably looking at, broadly speaking, additional hours.

Lar · « **Reply #795 on:** 03/27/2013 03:07 pm »

Quote from: mduncan36 on 03/27/2013 02:43 pm

Quote from: nisse on 03/27/2013 07:47 am
According to the Marine Traffic site (http://www.marinetrafic.com) the American Islander carrying Dragon currently is at 130 nm southeast of Long Beach.

Given it's current speed of 7.6 knots it should arrive in port in approx 17h15 m. I.e. around 9 pm local time later today.

Correct?

It isn't driving down a highway so it becomes more than just a speed over distance calculation. Add in time for wind, currents, traffic, etc. and you're probably looking at, broadly speaking, additional hours.

Can't easily find it now, but in another thread someone posted an estimated ETA into San Pedro of 1 AM, which is about 4 more hours... not sure where they sourced it.

Kabloona · « **Reply #796 on:** 03/27/2013 06:28 pm »

Quote from: nisse on 03/27/2013 07:47 am

According to the Marine Traffic site (http://www.marinetrafic.com) the American Islander carrying Dragon currently is at 130 nm southeast of Long Beach.

Given it's current speed of 7.6 knots it should arrive in port in approx 17h15 m. I.e. around 9 pm local time later today.

Correct?

Last reported position at 12:57 UTC/05:57 PDT was 91 nmi out of San
Pedro, speed 8.4 knots, which works out to roughly 11 hrs transit time, neglecting tides, currents, traffic, etc. So first order estimate puts the ship into port around 5:00 pm PDT today (3/27).

Space Pete · « **Reply #797 on:** 03/27/2013 06:53 pm »

Boats are so slow - it would be so much faster if they could airlift Dragon to shore.

Or better still, propulsively land it in Texas.

russianhalo117 · « **Reply #798 on:** 03/27/2013 07:22 pm »

Quote from: Space Pete on 03/27/2013 06:53 pm

Boats are so slow - it would be so much faster if they could airlift Dragon to shore.

Or better still, propulsively land it in Texas.

... or Hawthorne and if they elect to start refurbing them in the future for reflight then you might as well land next to that planned facility to save on shipping and port costs

Jason1701 · « **Reply #799 on:** 03/27/2013 07:44 pm »

Quote from: russianhalo117 on 03/27/2013 07:22 pm

Quote from: Space Pete on 03/27/2013 06:53 pm
Boats are so slow - it would be so much faster if they could airlift Dragon to shore.

Or better still, propulsively land it in Texas.
... or Hawthorne and if they elect to start refurbing them in the future for reflight then you might as well land next to that planned facility to save on shipping and port costs

Talk about slowing down traffic on the 105...