Things floating away etc.

Did they not lose a camera in a similar accident a couple of years back?

Maybe there is a case for some netting to catch such things.

Mind you, that could be more of a problem in itself.



Its the law of Sod you know. The one time you want something to hold, it
will fail or not be attached securely enough in the first place.


Brian

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On Nov 19, 7:53�am, "Brian Gaff" wrote:
Did they not lose a camera in a similar accident a couple of years back?

Maybe there is a case for �some netting �to catch such things.

Mind you, that could be more of a problem in itself.

Its the law of Sod you know. The one time you want something to hold, it
will fail or not be attached securely enough in the first place.

Brian

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everything outside is supposed to allways be attached by a minimum of
one tether.

wonder how hard it would be to take a soyuz and pick it up? if its a
danger to the station?

Not easy. Inertial still exists, as they found out on Mir with the
collision!

In the case of the bags inside the bag, or indeed other items inside bags or
attached to suits, these do seem to have a history of coming undone either
by being nudged open or just not working correctly and latching shut.

It was interesting to listen to the station before the Shuttle arrived when
they were packing toolkits and the observed differences in stiffness and
other parameters on some of the items.

Maybe there needs to be regular checks on things like this. It seems that
although the items came up on Shuttle, the various bags etc, were already on
orbit and had been used already.

Brian

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"bob haller safety advocate" wrote in message
...
On Nov 19, 7:53?am, "Brian Gaff" wrote:
Did they not lose a camera in a similar accident a couple of years back?

Maybe there is a case for ?some netting ?to catch such things.

Mind you, that could be more of a problem in itself.

Its the law of Sod you know. The one time you want something to hold, it
will fail or not be attached securely enough in the first place.

Brian

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?graphics are great, but the blind can't hear them
Email:
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everything outside is supposed to allways be attached by a minimum of
one tether.

wonder how hard it would be to take a soyuz and pick it up? if its a
danger to the station?

On Nov 19, 8:22*am, bob haller safety advocate
wrote:
On Nov 19, 7:53 am, "Brian Gaff" wrote:





Did they not lose a camera in a similar accident a couple of years back?

Maybe there is a case for some netting to catch such things.

Mind you, that could be more of a problem in itself.

Its the law of Sod you know. The one time you want something to hold, it
will fail or not be attached securely enough in the first place.

Brian

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graphics are great, but the blind can't hear them
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everything outside is supposed to allways be attached by a minimum of
one tether.

wonder how hard it would be to take a soyuz and pick it up? if its a
danger to the station?- Hide quoted text -

- Show quoted text -

Bob,

It seems at this point, that the distance between ISS and the bag is
opening so the following is maybe more of a rhetorical “what-if”
reply.

Consider why Soyuz is left in orbit with ISS. It is the way home for
the crew, not only when scheduled, but in case the ISS crew
experiences a moderately bad day on orbit. It would be like using a
ship’s life raft to run an errand.

To chase the bag down would represent a large use delta-V, something
that Soyuz may or may not have given that it had to complete its first
rendezvous and still must maneuver after final separation for its
landing. My first guess is that if there was enough to actually
enough to go chase the bag down and return to ISS. . . it would be
close. Secondly, while EVAs have been done from the orbital workshop
part of the vehicle, is it something the members of the current crew
have trained for?

I know you hate the darned thing, but it would seem that at first
glance, that the Orbiter has better EVA facilities (not just an
airlock, but handles, lights, etc.) It probably has better fuel
margins, although again the fuel used to chase the bag might exceed
what mission rules would allow to ensure there is enough fuel for
other contingencies.

This is not a slam against Soyuz. It does what it does very well and
I admire a lot about the vehicle, except perhaps the designer’s idea
of accommodations for three.

While ad-libs during EVA have been accomplished many times with a
really good rate of success, they come with risks. I am a little
surprised given your previously stated aversion to risk, that you
would have suggested the idea.

John

Since NASA screwdrivers probably cost a million dollars each, wouldn't
there be a financial incentive to go and get that bag ? :-)

Does NASA have any policies/procedures/training to retrieve lost objects
should there be a decision that the object is mission critical ?

For instance, would NASA ever authorise the astronaut to use SAFER to go
and get the object and bring it back ? (assuming the object is really
important) ?

Or would they authorise the astronaut to use a long enough theter and
propel him/herself toward the objecrt and then use safer to adjust
trajectory to get to the object and then just pull hiM/her self back to
the station using the thether ?

Or would the simplest solution be to use the station's engines to get
station near the object and use the new fancy canadian robot hands to
grab the object ?

(the RMS by themselves have no object grabbing capabilities, but the
Dexter robot does).

In this case, wouldn't the delta V given to the bag be rather small and
be quite cheap to give station similar delta V to close the gap with it ?

"John Doe" wrote in message
...
Since NASA screwdrivers probably cost a million dollars each, wouldn't
there be a financial incentive to go and get that bag ? :-)

Since they probably don't, no.


Does NASA have any policies/procedures/training to retrieve lost objects
should there be a decision that the object is mission critical ?

For instance, would NASA ever authorise the astronaut to use SAFER to go
and get the object and bring it back ? (assuming the object is really
important) ?


No. Human lives are more important.


Or would they authorise the astronaut to use a long enough theter and
propel him/herself toward the objecrt and then use safer to adjust
trajectory to get to the object and then just pull hiM/her self back to
the station using the thether ?


I believe the answer is no. Tethers are backups, not primary means of
staying safe.


Or would the simplest solution be to use the station's engines to get
station near the object and use the new fancy canadian robot hands to
grab the object ?

(the RMS by themselves have no object grabbing capabilities, but the
Dexter robot does).

In this case, wouldn't the delta V given to the bag be rather small and
be quite cheap to give station similar delta V to close the gap with it ?

Too high risk. Far easier to just forget about it.




--
Greg Moore
Ask me about lily, an RPI based CMC.

Greg D. Moore (Strider) wrote:


Too high risk. Far easier to just forget about it.


For a simple replaceable toolkit, correct. But what if they lost
something *really* important to the station ?

(or lost an astronaut for some reason).

Shouldn't they have procedures or at least concepts of manoeuvering the
station within grapple range of the object/astronaut ?

And in terms of risks with thethers, weren't the very first EVAs done
that way on mercury ?

John wrote:

While ad-libs during EVA have been accomplished many times with a
really good rate of success, they come with risks. I am a little
surprised given your previously stated aversion to risk, that you
would have suggested the idea.

I'm not surprised at all. Bbo has strong aversion to risk but has
demonstrated little to no ability to rationally weigh risks. He has, on
multiple occasions, proposed mitigating risks by means even riskier than
the original risk - sometimes, as he has admitted openly, merely in the
name of "PR". It is not likely he does so out of hypocrisy because that
would require having the intelligence to realize the gap between his
stated values and his stated means. Whatever. I've long given up trying
to figure out what combination of idiocy and hypocrisy motivates him.

Well, in this case, it was annoying, yes, but mission critical? No, the
grease guns are simply modified ordinary guns, and the other items in the
bag are not anything special. They have a lot of grease still in hand, and
can use some of the wipes, which they also seem to have loads of, with
grease already on them to pat up the debris, so in my view at least, the
fact that there is now only one set of guns is becoming academic, at least
for this Sarj.

One would have thought that with Nasa's attention to detail, at least one
spare of each sort of gun would have been flown. Its surely true that a gun
might get away during handling on orbit, so why was this not done.

As for chasing down the bag, well, I cannot see any form of justification of
the unknown risk. I'm surprised that more training on free floating and
tether pull back is not done though, as it might have been helpful in many
cases during construction to get away from structure to get a potentially
dangerous free floating object.

Of course you do not want, as Heidi said yesterday to end up with two free
floating objects, one of them her.
Maybe you need one of those concertina shaped gadgets with a grasping pincer
on the end that elderly people use to increase their reach, shoved down a
pocket in the suit!

Bring
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Email:
__________________________________________________ __________________________________________________ __________


"John Doe" wrote in message
...
Since NASA screwdrivers probably cost a million dollars each, wouldn't
there be a financial incentive to go and get that bag ? :-)

Does NASA have any policies/procedures/training to retrieve lost objects
should there be a decision that the object is mission critical ?

For instance, would NASA ever authorise the astronaut to use SAFER to go
and get the object and bring it back ? (assuming the object is really
important) ?

Or would they authorise the astronaut to use a long enough theter and
propel him/herself toward the objecrt and then use safer to adjust
trajectory to get to the object and then just pull hiM/her self back to
the station using the thether ?

Or would the simplest solution be to use the station's engines to get
station near the object and use the new fancy canadian robot hands to
grab the object ?

(the RMS by themselves have no object grabbing capabilities, but the
Dexter robot does).

In this case, wouldn't the delta V given to the bag be rather small and
be quite cheap to give station similar delta V to close the gap with it ?

"John Doe" wrote in message
...
Greg D. Moore (Strider) wrote:


Too high risk. Far easier to just forget about it.


For a simple replaceable toolkit, correct. But what if they lost
something *really* important to the station ?

Anything *really* important is either multiply redundant, or if it's a tool,
they'll have multiple copies of the tool. As the Boy Scout motto says, be
prepared.

(or lost an astronaut for some reason).

Shouldn't they have procedures or at least concepts of manoeuvering the
station within grapple range of the object/astronaut ?


One word: SAFER

And in terms of risks with thethers, weren't the very first EVAs done
that way on mercury ?

The first US EVA was done on Gemini. Gemini EVA's were done with an
umbilical connection to the Gemini capsule, so there was zero possibility of
an astronaut floating away. The same was true for Skylab EVA's. I'm not
sure about the "stand-up" Apollo EVA's, but it's pretty easy to see the
umbilicals in pictures since they're so much ticker than the tethers used on
shuttle/ISS EMU EVA's.

The shuttle was really the first vehicle to feature routine EVA's without
umbilicals. And in the case of the shuttle, you could always maneuver the
shuttle to rescue an astronaut who floated free. That is, until the shuttle
started doing docked missions with space stations. Which is exactly why
SAFER was developed.

Jeff
--
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