... EMU management issues
that had pre-determined that Christer and not Suni would
make this 4th EVA? I want to make clear to my clients
that Suni's not going outside today had nothing to do
with any performance issues on Saturday -- which,
there weren't any.

Can somebody review again the EMU management issues
that had pre-determined that Christer and not Suni would
make this 4th EVA? I want to make clear to my clients
that Suni's not going outside today had nothing to do
with any performance issues on Saturday -- which,
there weren't any.

On Mon, 18 Dec 2006 15:33:20 +0000, Jim Oberg wrote:

... EMU management issues
that had pre-determined that Christer and not Suni would
make this 4th EVA? I want to make clear to my clients
that Suni's not going outside today had nothing to do
with any performance issues on Saturday -- which,
there weren't any.

Who Lost the Camera? Looks like NASA is going to be going a bit Overboard
to make sure it doesn't happen again. Glued, Screwed and tethered. After
making such a big deal about a tiny light weight golf ball, NASA must be
much more worried about a much heavier camera with almost zero initial
delta V and most likely has a lower drag coefficient than the Space
Station.

But what about the tool lost on an earlier eva this trip. I'm sure I did not
dream that. I understood that the camera issue was a broken catch of some
kind that meant only a light tug loosened it.

I was quite impressed by how she tackled that mess of cables. Goodness
knows how you figure out what goes where, and having to re route some deal
with a jammed cover and some cables joined when they should not have been
etc. I know they all train for this sort of stuff, but it sounded like a
nightmare. I have trouble disentangling my mains leads, so I can relate to
the tether confusion. This is why you have two people out there. I'd be
more worried with all this tethering that goes on pulling something vital
off of the outside of the station a at some future date.

Brian

I wondered if it was because she is now an increment crew member and will
have plenty of opportunity to go outside again.

I don't see any other reason than an arbitrary decision, unless she
actually felt herself she was better employed inside at this time, having
'seen' the thing up close and thus can act as a kind of local expert.

Brian

Craig Fink <WeBeGood@GMail.Com> writes:

Also, I would have thought that someone watching the downlinked video
would have notice the camera so the astronaut could jump out there and
retreive it before it was too late.

I don't think anyone would order an astronaut to jump out just to
retrieve a silly camera...

From the picture, it souldn't have taken more than minute or two to
retrieve the camera at that point. It looked like the astronaut
wouldn't have had to even untether to get the camera.

Untether? I don't think *any* lost part would justify that risk.
Untethering would quite surely mean to be not able to get back at all.


Jochem

lol, I guess it's a matter of perspective. Me, I wouldn't want to be the
guy who ordered the astronaut "not" to jump out there and retrieve a
floating part, that makes the astronaut look "silly" for not traversing
the 10 feet as it slowly drifted away.

You never know when the part might be something more important than a
camera. It would be good practice and something they can't simulate in a
swimming pool.

Craig Fink <WeBeGood@GMail.Com> writes:

lol, I guess it's a matter of perspective. Me, I wouldn't want to be the
guy who ordered the astronaut "not" to jump out there and retrieve a
floating part, that makes the astronaut look "silly" for not traversing
the 10 feet as it slowly drifted away.

Jumping out for 10 feet means you have to *rely* on the tether to come
back and that tether is already your last line of redundancy. If it
snaps, you're doomed. And jumping like that for a cheap camera which was
able to drift away only because its tether *did* break would be really
silly.

You never know when the part might be something more important than a
camera. It would be good practice and something they can't simulate in a
swimming pool.

This wouldn't be practice, it's for real. You don't rely on your last
redundancy for practice, you spare it for an emergency.


Jochem

Can somebody review again the EMU management issues
that had pre-determined that Christer and not Suni would
make this 4th EVA? I want to make clear to my clients
that Suni's not going outside today had nothing to do
with any performance issues on Saturday -- which,
there weren't any.

I wouldn't call one astronauts tether the last line of redundancy. The
other astronaut could always jump out and grab the one who's tether
broke.

But, a very gentle push to traverse 10-15 feet in 30 seconds wouldn't have
much force or tension when the end of the tether is reached. Mountain
climbers often rely on one rope with gravity as the force, not
microgravity.

I certainly wouldn't want to be the guy that orders an astronaut to "not"
jump out and save a fellow astronaut who's equipment failed (broken
tether). I think that qualifies as something more important.

Jumping out for 10 feet means you have to *rely* on the tether to come
back and that tether is already your last line of redundancy. If it
snaps, you're doomed. And jumping like that for a cheap camera which was
able to drift away only because its tether *did* break would be really
silly.

Craig Fink <WeBeGood@GMail.Com> writes:

I wouldn't call one astronauts tether the last line of redundancy. The
other astronaut could always jump out and grab the one who's tether
broke.

I think you underestimate the complexity of doing such a stunt. Being
able to aim, jump and grab the other in time is in no way easy. Note
that as soon as you let go the handrail you're unable to change
direction, rate of rotation or anything else. You will most probably
either miss him or just bump against him, even if your tether is long
enough to actually reach him.

But, a very gentle push to traverse 10-15 feet in 30 seconds wouldn't have
much force or tension when the end of the tether is reached. Mountain
climbers often rely on one rope with gravity as the force, not
microgravity.

Yeah, and they're dying often enough by doing that. Spaceflight is
dangerous enough already as it is.

I certainly wouldn't want to be the guy that orders an astronaut to "not"
jump out and save a fellow astronaut who's equipment failed (broken
tether). I think that qualifies as something more important.

Well, you don't want to be the guy and you aren't. Says a lot, too ;-)


Jochem

They have the SAFER jet packs, don't forget.


"Jochem Huhmann" <joh@gmx.net> wrote

Jumping out for 10 feet means you have to *rely* on the tether to come
back and that tether is already your last line of redundancy. If it
snaps, you're doomed. And jumping like that for a cheap camera which was
able to drift away only because its tether *did* break would be really
silly.

Can somebody review again the EMU management issues
that had pre-determined that Christer and not Suni would
make this 4th EVA? I want to make clear to my clients
that Suni's not going outside today had nothing to do
with any performance issues on Saturday -- which,
there weren't any.