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#180
by
Sparky
on 07 Mar, 2010 21:28
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I'm not that involved in how the inflatable heat shield work. But as you sad it would be a good way to test the technology which means extra precautions need to be taken that's why I suggested an ocean landing, maybe there are large uninhabited areas on land where it can land. Soyuz is a reliable return vehicle and can't be compared to the test of a new system.
I agree.
You have to remember the equipment inside Pirs when calculating it's weight. I'm sure there are equipment which they plan to stay in Pirs as they de-orbit it.
How much are we talking?
6000kg/12.57m
3 = 477.33kg/m
39000kg/12.57m
3 = 715.57kg/m
312000kg/12.57m
3 = 954.65kg/m
39000kg-3600kg = 5400kg
12000kg-3600kg = 8400kg
By my calculations, Pirs could carry 2 1/3 times it's own weight in equipment and down-cargo, and still just manage to float. (and I'm basing that on fresh water. Sea water will give it even more buoyancy.)
I wonder how much collectors or museums would be willing to pay for ISS jetsam?
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#181
by
hop
on 07 Mar, 2010 21:33
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I wonder how much collectors or museums would be willing to pay for ISS jetsam?
A tiny fraction of the hundreds of millions that designing and implementing this plan would cost.
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#182
by
Sparky
on 11 Mar, 2010 20:06
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I wonder how much collectors or museums would be willing to pay for ISS jetsam?
A tiny fraction of the hundreds of millions that designing and implementing this plan would cost.
Hundreds of Millions would be worth it if it gave ISS reliable down-cargo capabitity as a result.
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#183
by
Jorge
on 11 Mar, 2010 20:10
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I wonder how much collectors or museums would be willing to pay for ISS jetsam?
A tiny fraction of the hundreds of millions that designing and implementing this plan would cost.
Hundreds of Millions would be worth it if it gave ISS reliable down-cargo capabitity as a result.
The only plan that could be implemented for hundreds of millions would be return by the shuttle. Since the shuttle is soon to be retired, that is not a long-term down-cargo capability.
Implementing a new down-cargo capability that could return Pirs would cost billions, not hundreds of millions.
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#184
by
Sparky
on 11 Mar, 2010 21:50
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The way I see it, Pirs is going to burn up anyway.
I don't see the harm in doing this on the cheap, provided, A) it can be reasonably established that it will not interfere with the operation of Progress, and B) it can reasonably be determined that unintended destructive reentry won't rain debris over a populated area.
Few million dollars to add a jerry-rigged system onto a Progess, and a ship to pull it out of the ocean if this hairbrained sceme works. If it doesn't, chalk up the expenses to R&D. That's all.
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#185
by
hop
on 12 Mar, 2010 04:26
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Few million dollars to add a jerry-rigged system onto a Progess, and a ship to pull it out of the ocean if this hairbrained sceme works. If it doesn't, chalk up the expenses to R&D. That's all.
You won't fly anything for a "few million".
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#186
by
Danderman
on 30 Dec, 2010 14:37
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Given that Shuttle won't be around too much longer, most of this thread is moot, so I would like to discuss an alternative - saving Pirs.
As you know, Pirs has to be removed from SM Nadir to make way for MLM. This is to be accomplished by having a Progress dock with Pirs, and after cargo unloading operations, the Progress would depart ISS, taking Pirs with it. Subsequently, MLM would dock with the now uncovered docking port.
It should be noted that MLM has a nadir docking port compatible with Pirs' docking system, and that MLM has a lateral docking port also compatible with Pirs. So .... it may be possible for the Progress that is taking Pirs away to return Pirs to dock with MLM nadir. Subsequently, the European Robotic Arm could translate Pirs to the MLM lateral port. This would leave the MRM small airlock module without a port, but the Node Module will be coming within a year and that does have a open port for the small airlock module.
Why position Pirs at MLM? Because this would give the Russian segment an airlock that does not have a crew vehicle attached to it. Therefore, no Soyuz would be cut off from ISS by an airlock module exposed to vacuum. This may be a significant new capability for ISS.
Can a Progress return Pirs to MLM Nadir? That is an open question. Can the ERA berth Pirs to the MLM lateral port? Probably not without some modifications.
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#187
by
arkaska
on 30 Dec, 2010 18:49
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Will there be an issue with Pirs on the MLM lateral port interfering with clearance for MRM-1 docking?
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#188
by
Danderman
on 31 Dec, 2010 03:38
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Will there be an issue with Pirs on the MLM lateral port interfering with clearance for MRM-1 docking?
Possibly. However, the constraint is merely to allow a 45 degree abort cone from MRM-1 nadir, so Pirs probably wouldn't enter into that prohibited zone. Pirs wouldn't extend any further out than the MLM radiator, which would located above it.
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#189
by
arkaska
on 31 Dec, 2010 09:02
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Didn't think about the radiator!
Can a regular Progress with Pirs re-dock with ISS? Previously it has just the service model of the progress who have docked Pirs and MRM-2 to the station. Or did that just have to do with launch-mass?
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#190
by
Danderman
on 31 Dec, 2010 14:10
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Didn't think about the radiator!
Can a regular Progress with Pirs re-dock with ISS? Previously it has just the service model of the progress who have docked Pirs and MRM-2 to the station. Or did that just have to do with launch-mass?
There is no practical way to connect a "service module" to Pirs. Instead, the baseline plan to remove Pirs is by docking a "used" Progress to Pirs nadir.
It would be challenging to return Pirs via that same Progress. If it were easy, this thread would not exist.
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#191
by
Danderman
on 02 Sep, 2011 17:42
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OK, although my initial post in this thread was pretty clear in stating that return of Pirs in the Shuttle would only be possible IF the Shuttle program were extended, just about everyone told me that it was impossible to return Pirs in the Shuttle program since the Shuttle program was ending. So, let me address the issue of saving Pirs in the current environment where there is no Shuttle.
I am not going to address at the moment WHY saving Pirs is a good idea, we can assume for the moment that throwing away perfectly good space hardware is not an optimal solution.
There are 2 different approaches to saving Pirs that I can think of, but I am sure there are more. Both approaches require that a grapple fixture be attached to Pirs, either at a Strela base point, or at one of the hard points used to transport Pirs on the ground. Whatever adapter is developed for the grapple fixture should also support cabling to an external power port on Pirs, so that the module has power while being moved by the station RMS. And, in all cases, the station SSRMS will use the newly installed PGDF on FGB as a base, and, of course, the Progress docked with Pirs nadir would have to depart prior to the operation.
Scenario 1: around the time of launch of MLM, the station crew would replace the forward hybrid docking adapter on Pirs with APAS. Field replacement of hybrid with APAS is indeed a feature of the system.
After APAS is installed, the station arm would remove Pirs from the Service Module, and translate it to a PMA located at Node 3 nadir. During this time, Pirs would be powered via SSRMS. The arm would berth Pirs to the PMA. The unit used to power Shuttle from ISS would be installed in the PMA to allow for power to flow to Pirs.
Scenario 2: more complicated! Here, the female cone adapter on Pirs nadir would be replaced by a male adapter, prior to the departure of Progress (the male adapter could be removed from a Progress, and the Pirs cone could be mounted on Progress, so everything would fit as usual, except reversed. After the Progress on Pirs nadir departs, the station arm could translate Pirs to Rassvet nadir (assuming the Soyuz on Rassvet nadir magically disappears, which does happen under certain circumstances), and the male adapter on Pirs nadir would mate with the female adapter on Rassvet nadir. This would leave a male hybrid adapter exposed at the bottom of Pirs.
In both scenarios, Pirs would be temporarily stowed at ports that are planned to be occupied by other vehicles, so a more permanent location is required; in this case, the quasi-permanent location would be the radial MLM hybrid port. The station RMS would translate Pirs a second time and dock the male hybrid adapter with MLM's lateral port. Pirs would remain on MLM until the Node module were in place, after which Pirs would be moved down by ERA to an axial hybrid port on the Node Module.
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#192
by
manboy
on 02 Sep, 2011 17:58
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OK, although my initial post in this thread was pretty clear in stating that return of Pirs in the Shuttle would only be possible IF the Shuttle program were extended, just about everyone told me that it was impossible to return Pirs in the Shuttle program since the Shuttle program was ending. So, let me address the issue of saving Pirs in the current environment where there is no Shuttle.
I am not going to address at the moment WHY saving Pirs is a good idea, we can assume for the moment that throwing away perfectly good space hardware is not an optimal solution.
There are 2 different approaches to saving Pirs that I can think of, but I am sure there are more. Both approaches require that a grapple fixture be attached to Pirs, either at a Strela base point, or at one of the hard points used to transport Pirs on the ground. Whatever adapter is developed for the grapple fixture should also support cabling to an external power port on Pirs, so that the module has power while being moved by the station RMS. And, in all cases, the station SSRMS will use the newly installed PGDF on FGB as a base, and, of course, the Progress docked with Pirs nadir would have to depart prior to the operation.
Scenario 1: around the time of launch of MLM, the station crew would replace the forward hybrid docking adapter on Pirs with APAS. Field replacement of hybrid with APAS is indeed a feature of the system.
After APAS is installed, the station arm would remove Pirs from the Service Module, and translate it to a PMA located at Node 3 nadir. During this time, Pirs would be powered via SSRMS. The arm would berth Pirs to the PMA.
I believe the two open PMAs are being used for Commercial Crew.
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#193
by
Jim
on 02 Sep, 2011 18:03
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So you reopen this thread so you can once again ignore facts provided to you and slander people in the process?
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#194
by
Danderman
on 02 Sep, 2011 18:09
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So you reopen this thread so you can once again ignore facts provided to you and slander people in the process?
You bet!
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#195
by
arkaska
on 02 Sep, 2011 19:57
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I believe the two open PMAs are being used for Commercial Crew.
Re-read Danderman's post
