SpaceX COTS Demo 2 Updates

[Jason1701]

This just in COTS 2/3 to be combined mission....
http://www.itar-tass.com/en/c154/162275.html
 

That article and assertion was discussed in this thread a few posts ago. Seems the consensus is that it provides nothing new.

[Peter NASA]

No decision yet. End of the month.

[Chris Bergin]

Yeah, expected to be positive, but we had nothing updating and I see Peter's noted the same, as has Philip.

[Lurker Steve]

Aviation Week....

>
Gerstenmaier said. “We were thinking around the October/November time frame — maybe September.” Fossum, assisted by Furukawa, is prepared for Dragon’s arrival.
>

“It’s my job to reach out and grab it,” Fossum said in a pre-mission  interview in March. “That’s a potentially very challenging task. I’ve  trained hundreds of hours.”

Well, that answers one question about going for berthing on the next Dragon flight.  Fossum has trained for the capture, berthing, and release.  It had been mentioned (can't remember where) that a combined mission was not possible on the previous COTS-2 flight schedule because the trained astronauts were not yet on the ISS.

Is grabbing the cargo ships really that difficult that it takes hundreds of hours of training ? Each crew will need hundreds of hours of training just to keep berthing these supply ships ? How much time do the Russians spend on training for the manual Progress dockings ? (it's usually automated, but someone always has their hands on the controls just in case).

[baldusi]

Is grabbing the cargo ships really that difficult that it takes hundreds of hours of training ? Each crew will need hundreds of hours of training just to keep berthing these supply ships ? How much time do the Russians spend on training for the manual Progress dockings ? (it's usually automated, but someone always has their hands on the controls just in case).

I would guess that the problem is training on all the contingencies, and that requires a deep understanding of the berthing mechanism, robotic arm and the berthing vehicle. In other word, if nothing went wrong, you'd probably wouldn't need training. But if something does, you'd better get a super expert because those supplies are necessary and there's no AAA up there.

[Prober]

Aviation Week....

>
Gerstenmaier said. “We were thinking around the October/November time frame — maybe September.” Fossum, assisted by Furukawa, is prepared for Dragon’s arrival.
>

“It’s my job to reach out and grab it,” Fossum said in a pre-mission  interview in March. “That’s a potentially very challenging task. I’ve  trained hundreds of hours.”

Well, that answers one question about going for berthing on the next Dragon flight.  Fossum has trained for the capture, berthing, and release.  It had been mentioned (can't remember where) that a combined mission was not possible on the previous COTS-2 flight schedule because the trained astronauts were not yet on the ISS.

Is grabbing the cargo ships really that difficult that it takes hundreds of hours of training ? Each crew will need hundreds of hours of training just to keep berthing these supply ships ? How much time do the Russians spend on training for the manual Progress dockings ? (it's usually automated, but someone always has their hands on the controls just in case).

Nothing better than training....remember the bad experience of a craft crashing into Mir.
 
 

[telomerase99]

Ok, I understand that yesterdays announcement is at the least controversial as now these two sites are claiming that Dragon will be berthing with station by years end.

http://www.spacetimesnews.com/news/2011/jun/10/spacex-dragon-to-dock-at-iss-at-2011-end/

http://www.portaltotheuniverse.org/blogs/posts/view/121270/

I wonder why, if this is the case, we have not heard anything from SpaceX? Do you think that Gerstenmaier is just being taken out of context or something?

[dsobin]

Ok, I understand that yesterdays announcement is at the least controversial as now these two sites are claiming that Dragon will be berthing with station by years end.

http://www.spacetimesnews.com/news/2011/jun/10/spacex-dragon-to-dock-at-iss-at-2011-end/

http://www.portaltotheuniverse.org/blogs/posts/view/121270/

I wonder why, if this is the case, we have not heard anything from SpaceX? Do you think that Gerstenmaier is just being taken out of context or something?

I believe the two links you posted are not actually making any claims but just repeating what they read on other speculative sites. No news here.

[Jkew]

Any comments over this NAC meeting minutes from February ?

http://www.nasa.gov/pdf/532002main_Space_Ops_Minutes_Feb_8_2011.pdf
(thanks to yg1968 who posted the link in another thread)
.... SNIP ....t

There is also a problem with the grapple fixture on the Dragon capsule;

and when the vehicle berths, it plumes the solar rays.

One thing which has not been discussed (afaik) is the solar array plume issue. This seems particularly important during a slower berthing process. I suspect most vehicles plume the station to some degree, but for it to be called out like this makes me wonder what the limits for the ISS are and if there are ways of mitigating this issue.

So, what are the limits here? What are the options?

[Comga]

Any comments over this NAC meeting minutes from February ?

http://www.nasa.gov/pdf/532002main_Space_Ops_Minutes_Feb_8_2011.pdf
>
There is also a problem with the grapple fixture on the Dragon capsule;
>

The first time it was illustrated, I was surprised that the grapple fixture was on the inside of a door, rather than fixed to the body of the spacecraft.  I can see several ways this could cause problems, including being insufficiently rigid for changing the orientation of the capsule.  Yes, it puts the deployed grapple fixture outside the OML, perhaps reducing the size of the door, but does this configuration seem logical to anyone here?  What other aspects make this a better choice?

[douglas100]

Any comments over this NAC meeting minutes from February ?

http://www.nasa.gov/pdf/532002main_Space_Ops_Minutes_Feb_8_2011.pdf
>
There is also a problem with the grapple fixture on the Dragon capsule;
>

The first time it was illustrated, I was surprised that the grapple fixture was on the inside of a door, rather than fixed to the body of the spacecraft.

Yes, you would think that mounting it on the trunk (maybe covered with a small fairing to protect it during ascent) would be a simpler solution.

[rjholling]

Any comments over this NAC meeting minutes from February ?

http://www.nasa.gov/pdf/532002main_Space_Ops_Minutes_Feb_8_2011.pdf
>
There is also a problem with the grapple fixture on the Dragon capsule;
>

The first time it was illustrated, I was surprised that the grapple fixture was on the inside of a door, rather than fixed to the body of the spacecraft.  I can see several ways this could cause problems, including being insufficiently rigid for changing the orientation of the capsule.  Yes, it puts the deployed grapple fixture outside the OML, perhaps reducing the size of the door, but does this configuration seem logical to anyone here?  What other aspects make this a better choice?

Reentry would be my guess.

[Comga]

Any comments over this NAC meeting minutes from February ?

http://www.nasa.gov/pdf/532002main_Space_Ops_Minutes_Feb_8_2011.pdf
>
There is also a problem with the grapple fixture on the Dragon capsule;
>

The first time it was illustrated, I was surprised that the grapple fixture was on the inside of a door, rather than fixed to the body of the spacecraft.

Yes, you would think that mounting it on the trunk (maybe covered with a small fairing to protect it during ascent) would be a simpler solution.

That sounds reasonable.   It would certainly remove the criticality of the door closing before reenty.  The SpaceX way would be to include it in the same volume as a solar array, so that a single door would cover both, but that could have issues with being too far from the CG or causing ineterference between the SSRMS and the solar array.

Edit: OTOH, the Apollo SM thrusters survived launch while exposed.  A graple fixture is even simpler, smaller profile, and more rugged.  It should be able to survive launch exposed on the side of the trunk.

[renclod]

I may be wrong, but in my mind this grapple fixture is a mechanical and electrical-power and data connection. = expensive and fragile = you would want to recover-and-reuse it if the budget is tight.

[Comga]

I may be wrong, but in my mind this grapple fixture is a mechanical and electrical-power and data connection. = expensive and fragile = you would want to recover-and-reuse it if the budget is tight.

There are Power and Data Grapple Fixtures and Flight Releaseable Grapple Fixtures.  Does anyone know which type is supposed to be on Dragon?  Neither looks particularly fragile or expensive.  However, the shaft would stick out quite a long way. (10.8")

[Chris-A]

Now we get the threads back on topic with this. Dragon COTS Demo 2 electrical and avionics have just been booted up the other day.
Ralph Ewig: http://ralphewig.tumblr.com/post/6672269431/starting-a-dragons-heart-this-morning-we-booted

[AnalogMan]

I may be wrong, but in my mind this grapple fixture is a mechanical and electrical-power and data connection. = expensive and fragile = you would want to recover-and-reuse it if the budget is tight.

There are Power and Data Grapple Fixtures and Flight Releaseable Grapple Fixtures.  Does anyone know which type is supposed to be on Dragon?  Neither looks particularly fragile or expensive.  However, the shaft would stick out quite a long way. (10.8")

Amendment 3 of the Space Act Agreement covering COTS provides for the loan of one Flight Releasable Grapple Fixture (FRGF) to SpaceX by NASA.  And interestingly is to be returned to NASA not later than 2 months following completion of demonstration flight 3 (along with a load of other loan items).

[robertross]

Now we get the threads back on topic with this. Dragon COTS Demo 2 electrical and avionics have just been booted up the other day.
Ralph Ewig: http://ralphewig.tumblr.com/post/6672269431/starting-a-dragons-heart-this-morning-we-booted

Sweet. Another big step forward.

[docmordrid]

Link looks removed

[robertross]

Link looks removed

Certainly does. Well, they said in the blog that all powered up good.