SpaceX COTS Demo 2/3 Updates (THREAD 2)

[Robotbeat]

The metallic coating could also be on-orbit protection of the PICA-X. I also wouldn't be surprised if the PICA-X was thinner. Like Apollo, they probably had a much thicker heat shield than they required because of compound conservatism (and just plain uncertainty). Now that they've tested it and the uncertainty is thus lower, they can thin it out a bit.

And, I'm not at all surprised SpaceX is making numerous modifications to Dragon. They have, after all, only flown it once; it makes a heck of a lot of sense that they'd change things in light of what they learned on the first Dragon flight (and again after testing solar array deployment and ISS berthing, etc). They'll make numerous iterations, I'm sure.

[manboy]

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.

Here's a few more recent ones.

[Lars_J]

Hmm, interesting. That cutaway is the first hint I have seen of a "trunk hatch".

Would it be for late loading of unpressurized cargo, or for crew access to trunk systems or 2nd stage avionics? The interstage has a door as well - so it might serve a similar purpose. (If that is indeed part of the current trunk design)

[Ben the Space Brit]

Would it be for late loading of unpressurized cargo, or for crew access to trunk systems or 2nd stage avionics? The interstage has a door as well - so it might serve a similar purpose. (If that is indeed part of the current trunk design)

At a guess, I'd say it's for easy access to unpressurised racks at the very top of the trunk for the SSRMS or astronauts on EVA.

[woods170]

- The open area next to the bay door must be the new location for the capsule umbilicals, OR the trunk umbilical connection port.

It's likely the trunk umbilical connection port. See the second image in this post.

[Comga]

Here's a few more recent ones.

Great illustrations.  Thanks!

The first shows the three point element on the back of the panel nesting in the three point feature below the hatch, securing the grapple fixture.

The third image still seems archaic, in that the solar panels mount within the cylindrical outline of the trunk.  Perhaps the pontoons are new since January, or at least since these images were generated.

Note that all three images show windows.  It remains to be seen whether windows return to CRS spacecraft at some point after COTS 2/3.

[Lars_J]

The third image still seems archaic, in that the solar panels mount within the cylindrical outline of the trunk.  Perhaps the pontoons are new since January, or at least since these images were generated.

Look closer. The third image has the most accurate trunk shape out of the images - and if you look closer you will see that the trunk is not entirely cylindrical. There is a flatter area where the solar panels attach. The solar panel area is partially recessed - but there is still need for the larger coverings that fall away sometime before panel deploy..

[Comga]

The third image still seems archaic, in that the solar panels mount within the cylindrical outline of the trunk.  Perhaps the pontoons are new since January, or at least since these images were generated.

Look closer. The third image has the most accurate trunk shape out of the images - and if you look closer you will see that the trunk is not entirely cylindrical. There is a flatter area where the solar panels attach. The solar panel area is partially recessed - but there is still need for the larger coverings that fall away sometime before panel deploy..

I did see that. 

This is the first mention, to my recollection, that the pontoons might be jetisoned.  That's not the only possibility, and somewhat counter to the SpaceX philosophy of a minimum number of events during launch.  However, it is not unreasonable.  There was little discussion of the Dragon's nose cap before we saw it tumbling away in the aft-facing, on-board video during launch.  They apparently have at least one jettison mechanism that works.  ;-)

[ugordan]

This is the first mention, to my recollection, that the pontoons might be jetisoned. 

[baldusi]

This is the first mention, to my recollection, that the pontoons might be jetisoned. 

Well, in Elon's opening remarks (the written ones), he didn't mentioned it as a separation event. But from the video, it might be part of second stage separation.

[Robotbeat]

This is the first mention, to my recollection, that the pontoons might be jetisoned. 

Well, in Elon's opening remarks (the written ones), he didn't mentioned it as a separation event. But from the video, it might be part of second stage separation.

It isn't exactly strictly necessary from a crew safety point of view like jettisoning an abort motor is. (still need to jettison the trunk or service module, though... the only capsule immune to that that has flown so far is Soyuz, which apparently has the magic ability of a backup service module jettison system ).

[baldusi]

This is the first mention, to my recollection, that the pontoons might be jetisoned. 

Well, in Elon's opening remarks (the written ones), he didn't mentioned it as a separation event. But from the video, it might be part of second stage separation.

It isn't exactly strictly necessary from a crew safety point of view like jettisoning an abort motor is. (still need to jettison the trunk or service module, though... the only capsule immune to that that has flown so far is Soyuz, which apparently has the magic ability of a backup service module jettison system ).

Actually, it is a design feature. It's designed so aerodynamic and thermal forces are higher than the bolt's resistance. The good thing about questionable manufacturing control, is that designers take it into consideration.

[Space Pete]

Hmm, interesting. That cutaway is the first hint I have seen of a "trunk hatch".

Would it be for late loading of unpressurized cargo, or for crew access to trunk systems or 2nd stage avionics? The interstage has a door as well - so it might serve a similar purpose. (If that is indeed part of the current trunk design)

I've been thinking about this. Let's cast our minds back to STS-134, when there was a payload on ELC-3 in Endeavour's payload bay called STP-H3, which had some protective covers that needed to be removed from some scientific instruments as close to launch as possible in order to prevent loss of scientific data due to the instrument's contact with Earth's atmosphere.

These covers were removed about three days prior to launch when Endeavour's payload bay doors were closed for flight, but the launch then scrubbed, and NASA wouldn't re-open the payload bay doors in order to re-install the protective covers since doing so would cause further launch delay, which lead to a loss of some science data from STP-H3.

I remember thinking at the time, how would such issues be handled in the post-Shuttle era? I think the trunk hatch is for cases such as this - late removal of protective covers from science payloads in the trunk. Otherwise, the covers would have to be removed prior to Dragon's mating to the second stage - which I think occurs well before three days prior to liftoff. The hatch would also allow for easy re-installation of covers in the event of a scrub.

[Jim]

Hmm, interesting. That cutaway is the first hint I have seen of a "trunk hatch".

Would it be for late loading of unpressurized cargo, or for crew access to trunk systems or 2nd stage avionics? The interstage has a door as well - so it might serve a similar purpose. (If that is indeed part of the current trunk design)

I've been thinking about this. Let's cast our minds back to STS-134, when there was a payload on ELC-3 in Endeavour's payload bay called STP-H3, which had some protective covers that needed to be removed from some scientific instruments as close to launch as possible in order to prevent loss of scientific data due to the instrument's contact with Earth's atmosphere.

These covers were removed about three days prior to launch when Endeavour's payload bay doors were closed for flight, but the launch then scrubbed, and NASA wouldn't re-open the payload bay doors in order to re-install the protective covers since doing so would cause further launch delay, which lead to a loss of some science data from STP-H3.

I remember thinking at the time, how would such issues be handled in the post-Shuttle era? I think the trunk hatch is for cases such as this - late removal of protective covers from science payloads in the trunk. Otherwise, the covers would have to be removed prior to Dragon's mating to the second stage - which I think occurs well before three days prior to liftoff. The hatch would also allow for easy re-installation of covers in the event of a scrub.

ELV fairings have doors in them for exactly for this reason.  All spacecraft have covers that need to be removed at the launch pad.

[manboy]

Here's a few more recent ones.

Great illustrations.  Thanks!

If you curious about the source, the first two are from a presentation Ken Bowersox gave back in January. And the third is a screen grab from late the September promotional video.

[Comga]

Here's a few more recent ones.

Great illustrations.  Thanks!

If you curious about the source, the first two are from a presentation Ken Bowersox gave back in January. And the third is a screen grab from late the September promotional video.

Ha!  I remember that presentation.  However, all illustrations of the solar panels show them launched recessed within the cylindrical body of the trunk.  The solar panels deploy flat, which is not how they looked just after the Mickey-Mouse-Ears went away.

[mr. mark]

Enhanced Dragon Capsule Launch Preparations...

http://www.spaceflightnow.com/falcon9/003/111027dragon/

[ugordan]

12 minutes of NASA footage of Dragon's arrival. This looks like it was ripped off NASA's UStream channel, don't know if there's a better quality available:

[mr. mark]

ugordan, darn you, you beat to the punch lol. Wow, great video. Never thought I'd see a complete arrival video.

[jabe]

hate to have the truck driver pop a clutch while backing up..some expensive stuff in that shed
jb