Author Topic: OSC COTS I Proposal Discussion  (Read 167519 times)

Offline marsavian

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Re: OSC COTS I Proposal Discussion
« Reply #20 on: 02/23/2008 12:28 PM »
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simpl simon - 23/2/2008  6:00 AM

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marsavian - 23/2/2008  11:54 AM

The manned spaceflight gap is the biggest public crisis facing NASA, I would say the liklihood of NASA *not* funding COTS part D for both companies is very small. If so Antonio and Orbital then need to see how many people they can send up on Taurus II on a $200m development budget.

But the 2009 Budget Request includes funds for Soyuz missions.

and so will the 2010 and 2011 ones too.

Offline Frediiiie

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Re: OSC COTS I Proposal Discussion
« Reply #21 on: 02/23/2008 01:34 PM »
COTS part D as it stands in the SpaceX agreement would not be completed till 2012

Offline antonioe

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RE: OSC COTS I Proposal Discussion
« Reply #22 on: 02/23/2008 03:47 PM »

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SIIAlum - 21/2/2008 11:09 PM Is your berthing box (box for capture and grapple by the SSRMS) the same for both the UCM and PCM versions?

I believe so, but I will have to check.

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 If so, based on your figures it looks to be a bit of a stretch for the SSRMS to reach both a Node 2 Nadir CBM position and either of the truss (I think S3 or P3) positions. Maybe there's intermediate hand off positions so the SSRMS can reposition? If not, does that require a different rendezvous profile and targeting for the final closure to ISS?

I don't think so - as far as I understand it (and, again, this is NOT my area of specialy) the arm is capable of positioning the Shuttle-carried ELC's into any of the six (6) CAS positions, and the same is probably true from the SM+UCM berthing box.  What I don't know is if getting to the outmost CAS positions requires the arm "hopscotching".  The enclosed sketch illustrates en ECL and a SM+UCM in two CAS positions on one of the trusses (Starboard?)

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 Also, you mentioned METEOR in an early post, this brings back good memories of a spacecraft which was originally called ComET. I might differ with you on the details of the work CTA did as although they might have done the final assembly, the detailed design and development of the cargo recovery module was all done inhouse at Space Industries. Although I had a minor part on ComET , it was a thrill to be working on trying to commercial low earth orbit some 15 years ago by providing a platform for microgravity processing. Unfortunately things didn't pan out for us. Maybe it just wasn't the right time as our Industrial Space Facility (ISF) effort to commercialize LEO in the late '80s didn't work out as well. Hopefully between Orbital and SpaceX maybe the timing is right and we can now see commercialized manned and unmanned operations in LEO and get NASA focused on exploration.

Of course!!! Space Industries!!! I'm sorry, I'm getting senile.  I knew Joe Allen, Max Faget and C. C. Johnson about the time they merged with Calspan.  I believe I posted in my "Q&A" thread a picture of Max, CC, Joe, Burt, DWT and me in front of one of the early Pegasi at Dryden in 199something.  Giants, all of them.  Giants.

I'm unsure what were the CTA/SI relations during Comet - that was before our acquiring CTA - but here's a picture of Ray Crough in front of the spacecraft, atop the ill-fated Conestoga.  Note the reentry capsule on top.  I met Ray when he was the PM for the Pegasus F2 payload (six microsats built by DRI).  Of course, he became an Orbitaleer when we acquired CTA, and up to two days ago headed Systems Engineesing at Dulles.  Yesterday he was appointed Gregg Burgess' deputy (Gregg head Special Programs within APG).  He's a great guy, even if he bikes 30 miles from his home in the rain and snow...

ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #23 on: 02/23/2008 04:06 PM »

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CFE - 23/2/2008 1:41 AM Is it confirmed that Taurus II will launch from LC-0B? It would seem that the existing Minotaur pad would need a lot of mods to support a liquid vehicle. Not to mention the fact that T-II has roughly twice the thrust of a Minotaur IV.

That is currently the plan.  Yes, 0B will require a lot of mods, but so will any pad at CCASF or VAFB... we checked them all!  Liquid propellant sotrage tanks being the simgle biggest mod everywhere.

While, yes, Taurus II has more thrust than anything that has been launched from it (by the way, the Ray Crough picture I posted in the posting above is precisely at pad 0B!!!) the mods are less violent that the ones that would have been required had we gone with the original T II "single NK-33/at least two SRB's" configuration due to a) the wider "stance" of the 2-SRB configuration and b) the more energetic and damaging plume of the solids.  However, adapting the transporter-erector to the 01B geometry is actually harder than is the case for the CCAFS and VAFB pads.  You can't win everything...

ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #24 on: 02/23/2008 04:15 PM »

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hop - 22/2/2008 7:23 PM Note that progress M1 (listed above) is not currently in normal use. M1 carries more fuel and less cargo than M.

Here's a corrected (and hopefully more readable) version of the table including Danderman's Soyuz-M data.  I guess we are all still a bit confused on the issue of HTV's capability envelope.  By the way, in case you haven't already figured it out, my "Payload Ratio" is based on the combined payload of each vehicle.  Before we compare too many apples and oranges, I must point out some notes:

  1. Soyuz if handicapped by its heritage (derived from a manned capsule) and technology base.  It also has capabilities (e.g., ISS reboost) that only ATV, AFAIK, has.
  2. ATV is also handicapped by its extensive gas and liquid tankage, and its reboost capabilities.
  3. Dragon is taxed by its reentry capabilities (but still has a higher payload fraction than our SM+RCM combo).
  4. Orbital's PCM is a dumb can with the minimum MMOD shielding, ECS, etc. to pass ISS muster, hence its relatively high payload fraction.  the SM+Mission Module concept is optimized for this combination, at the expense of the others.
  5. Orbital's RCM is also quite dumb.

If somebody is curious as to why Orbital's UCM has less cargo capacity than the PCM, it's because of the FRAMs, ECA, and other accoutrements the ORU's need.  In the PCM case, the containers are included in the "cargo" figure and also are usually very lightweight (e.g. the "soft bags").  In the UCM, the FRAMs are not included in the cargo figure.  If my memory serves me right, the UCM can hold up to six FRAMs, and they are comparatively heavy

ARS LONGA, VITA BREVIS...

Offline simpl simon

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Re: OSC COTS I Proposal Discussion
« Reply #25 on: 02/23/2008 05:47 PM »
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antonioe - 23/2/2008  6:15 PM

..............

Orbital's PCM is a dumb can with the minimum MMOD shielding, ECS, etc. to pass ISS muster, hence its relatively high payload fraction.  the SM+Mission Module concept is optimized for this combination, at the expense of the others.
..................

 

Antonioe, can you tell us anything about the stowage system in the PCM? Will it have an internal cargo accommodation/support structure like ATV has? Do you plan for sequential cargo transfer to the ISS combined with trash transfer to the PCM?


Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #26 on: 02/23/2008 06:24 PM »

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simpl simon - 23/2/2008 12:47 PM Antonioe, can you tell us anything about the stowage system in the PCM? Will it have an internal cargo accommodation/support structure like ATV has?

No, I can't, because I don't know.  I overheard Jim Duffy (Cygnus Chief Engineer) talk to the JSC guys about "Seat tracks" and "CTB tie-down straps" but it's all greek to me.  Correction, if it were classical greek, I could understand it a bit.  It's Cantonese to me.

Please understand, I know very little about ISS operations.  I'm learning.

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 Do you plan for sequential cargo transfer to the ISS combined with trash transfer to the PCM?

Yes, that is the plan; the SM can survive autonomously for a very long time attached to ISS, even with the ISS sun shielding.  After dumping the trash in the PCM, closing the hatch, re-grapple by the arm, unlatching the CBM, release form the arm, it separates from ISS, lowers its orbit, and, once away from the ISS prox volume, and at the right arg of p, it deorbits destructively.

ARS LONGA, VITA BREVIS...

Offline simpl simon

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Re: OSC COTS I Proposal Discussion
« Reply #27 on: 02/23/2008 07:22 PM »
Thanks for that, Antonioe,

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antonioe - 23/2/2008  8:24 PM

I overheard Jim Duffy (Cygnus Chief Engineer) talk to the JSC guys about "Seat tracks" and "CTB tie-down straps".....

Why I asked, was that I understand the cargo in Progress is just packed in lose, and compressed until the module is full. You might get away with that for 1.8 MT, but that approach won't work with 5.5 MT.

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Do you plan for sequential cargo transfer to the ISS combined with trash transfer to the PCM?

Yes, that is the plan; the SM can survive autonomously for a very long time attached to ISS, even with the ISS sun shielding.  After dumping the trash in the PCM, closing the hatch, re-grapple by the arm, unlatching the CBM, release form the arm, it separates from ISS, lowers its orbit, and, once away from the ISS prox volume, and at the right arg of p, it deorbits destructively.


What I was really wondering was how you propose to manage cargo transfer while the PCM is berthed. You can't wait until all the 5.5 tons has been unloaded before you start repacking the PCM with trash (can you?) So that presumes some kind of acommodation system to let the crew access the cargo in the order in which it is needed, and refill the vacated space with trash.
 
Just wondering. I appreciate this isn't your field.

Offline Jim

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Re: OSC COTS I Proposal Discussion
« Reply #28 on: 02/23/2008 07:34 PM »
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marsavian - 23/2/2008  5:54 AM

The manned spaceflight gap is the biggest public crisis facing NASA, I would say the liklihood of NASA *not* funding COTS part D for both companies is very small. If so Antonio and Orbital then need to see how many people they can send up on Taurus II on a $200m development budget.

Actually, just the opposite.  It is very small

Offline simpl simon

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Re: OSC COTS I Proposal Discussion
« Reply #29 on: 02/23/2008 07:54 PM »
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antonioe - 23/2/2008  6:15 PM

Thanks for your review of the various logistics vehicles and their cargo performance. I notice in your table you make the remark that the actual capability of HTV is not well understood. I fully share your doubt. I have seen various figures quoted for HTV pressurised cargo, and cannot understand how it is proposed to accommodate 6000 kg in a volume less than that of ATV. I have seen a figure of 4500 kg reported for HTV pressurized cargo, and that makes more sense to me (see: http://iss.jaxa.jp/en/htv/overview/)
Part of the problem is the assumption one has to make about overall cargo density. It is known that ESA's first assumption was too low, so theoretically the ATV could carry more pressurized cargo if you apply the higher density factor. Before you go and pack it all in, however, you need to consider whether the structure is qualified for a higher load, and as you have noted in your previous post, you must take account of the fuel, gas and air cargo elements in order to stay within launch limits.

In that respect the COTS winners have an easier life than ESA had: they can specialise on, say, dry pressurized cargo, knowing that ATV and Progress will truck all the messy stuff. In addition, NASA can likely provide more specific itemised cargo lists than were available when the ATV and HTV designs were frozen.
And before I forget: congratulations on the award, and thanks for your great posts.

Made a mess of the Quote function. The above text is mine, not antonioe's.

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #30 on: 02/23/2008 08:27 PM »

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simpl simon What I was really wondering was how you propose to manage cargo transfer while the PCM is berthed. You can't wait until all the 5.5 tons has been unloaded before you start repacking the PCM with trash (can you?) So that presumes some kind of acommodation system to let the crew access the cargo in the order in which it is needed, and refill the vacated space with trash. Just wondering. I appreciate this isn't your field.

Sorry, I missed something important in your question: the SM+PCM cargo capacity is not 5.5 mt (that's slightly over the entire launch mass of 5,400 Kg) but only 2,300 Kg.  On the other hand, the PCM has about 23m3 of volume for 2,300 Kg (100 Km/m3) vs. 225 Kg/m3 for Progress-M, 175 Kg/m3 for Dragon, and 115 Kg/m3 for ATV.  So the job of unloading/reloading with trash it is a bit easier than for Progess.

Also, one must take into account that

  1. The astronaut's can't spend a lot of time packing the trash neatly, which lowers its density with respecto to the neatly packed upcargo,
  2. SM+PCM could theoretically dispose of a lot more than 2,300 Kg of trash (we haven't figure out the practical limit yet), and
  3. Unlike the up cargo, the "trash" does not have to be stacked in a way that makes its removal easier, logical or orderly, which actually tends to increase its density with respect to the upcargo.
ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #31 on: 02/23/2008 08:29 PM »

Hey, I just realized that the TV table we've been putting together is missing the pressurized cargo volume data.  Here's yet one more version with that data added.  Please post any additions/corrections/comment, please:

ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #32 on: 02/23/2008 09:12 PM »

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simpl simon - 23/2/2008 2:54 PM ... cannot understand how it is proposed to accommodate 6000 kg in a volume less than that of ATV.

Do you have a reputable source for that volume?  I could not find squat.

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 I have seen a figure of 4500 kg reported for HTV pressurized cargo, and that makes more sense to me (see: http://iss.jaxa.jp/en/htv/overview/)

Any suggestions from anybody else for what figure we should carry on the table?

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 Part of the problem is the assumption one has to make about overall cargo density. It is known that ESA's first assumption was too low, so theoretically the ATV could carry more pressurized cargo if you apply the higher density factor. Before you go and pack it all in, however, you need to consider whether the structure is qualified for a higher load

Right on the mark.  But, also, the LV has to be able to accomodate the extra mass.  Anybody know what the Ariane 5 margin is?  In the case of the SM+PCM, the super-low density value allow us to eventually take advantage of the extra Taurus II performance with the liquid second stage (if we ever get to develop it...)

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, and as you have noted in your previous post, you must take account of the fuel, gas and air cargo elements in order to stay within launch limits. In that respect the COTS winners have an easier life than ESA had: they can specialise on, say, dry pressurized cargo, knowing that ATV and Progress will truck all the messy stuff. In addition, NASA can likely provide more specific itemised cargo lists than were available when the ATV and HTV designs were frozen.

Yes, no doubt at all, especially not having to re-boost ISS with the Transfer Vehicle's own thrust!!!

ARS LONGA, VITA BREVIS...

Offline hop

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Re: OSC COTS I Proposal Discussion
« Reply #33 on: 02/23/2008 11:26 PM »
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antonioe - 23/2/2008  1:27 PM
  1. The astronaut's can't spend a lot of time packing the trash neatly, which lowers its density with respecto to the neatly packed upcargo,
  2. SM+PCM could theoretically dispose of a lot more than 2,300 Kg of trash (we haven't figure out the practical limit yet), and
  3. Unlike the up cargo, the "trash" does not have to be stacked in a way that makes its removal easier, logical or orderly, which actually tends to increase its density with respect to the upcargo.
I recall that quite a bit of attention is paid to keeping packing the trash to keep the CG in the expected location for Progress... I recall reading one ISS crew account describing  this "Progress packing" as a rather unpleasant task.

edit:
Looking at the illustration of HTV and judging that the pressurized compartment is somewhere around 1/4 and 1/3 the total length, I'd guess the pressurized volume is around ~25-35 m3

A couple more HTV pages without a lot of information:
http://www.jaxa.jp/projects/rockets/htv/index_e.html
http://www.jaxa.jp/projects/rockets/htv/topicslist_e.html
The second does have some nice pictures of the prototype hardware.

Offline SIIAlum

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RE: OSC COTS I Proposal Discussion
« Reply #34 on: 02/24/2008 03:53 AM »
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I don't think so - as far as I understand it (and, again, this is NOT my area of specialy) the arm is capable of positioning the Shuttle-carried ELC's into any of the six (6) CAS positions, and the same is probably true from the SM+UCM berthing box.  What I don't know is if getting to the outmost CAS positions requires the arm "hopscotching".  The enclosed sketch illustrates en ECL and a SM+UCM in two CAS positions on one of the trusses (Starboard?)

Thanks! That brings up another question: After looking at the Shuttle manifest, it appears that all six CAS locations will be full at Shuttle retirement (5 ELCs and AMS-02 if it goes). What is the plan for this issue. Maybe I'm misinterpreting the manifest and/or ISS assembly sequence and maybe one fo the NASA folks on the forum can clarify?

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I'm unsure what were the CTA/SI relations during Comet - that was before our acquiring CTA - but here's a picture of Ray Crough in front of the spacecraft, atop the ill-fated Conestoga.  Note the reentry capsule on top.  ...

Thanks for the pic. Ahhhh.....the memories. Too bad we never had the chance to see if the SM and recovery module could do their thing. I'm still nervous about new launch vehicles to this day. Well, at least putting my one and only spacecraft on a launch vehicle's maiden flight. A lot of hard lessons learned from that one. :frown:


Offline antonioe

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RE: OSC COTS I Proposal Discussion
« Reply #35 on: 02/24/2008 04:03 AM »

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SIIAlum - 23/2/2008 10:53 PM That brings up another question: After looking at the Shuttle manifest, it appears that all six CAS locations will be full at Shuttle retirement (5 ELCs and AMS-02 if it goes). What is the plan for this issue. Maybe I'm misinterpreting the manifest and/or ISS assembly sequence and maybe one fo the NASA folks on the forum can clarify?

Excelent question, and I certainly do not have an answer; maybe it is related to the issue of what happens if the last two - currenlty unmanifested - Shuttle flights are available to carry unpressurized cargo?  Maybe that's where all those ELCs come from... in which case, COTS has little use for unpressurized cargo, as I described in one of my previous posts (and then we only get to fly PCMs).

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Thanks for the pic. Ahhhh.....the memories. Too bad we never had the chance to see if the SM and recovery module could do their thing. I'm still nervous about new launch vehicles to this day. Well, at least putting my one and only spacecraft on a launch vehicle's maiden flight. A lot of hard lessons learned from that one. :frown:

Glad I could bring you some memories... I, too, have lost spacecraft (OrbView II was a particularly painful one) but not on an LV first flight, thank God.  But I know how it feels to loose a bird.  I remember very vividly the Pegasus F6 failure... seeing it start to corkscrew on the long-range camera... thinking "no, no it can't be true..." after five flights, we thought we were invincible...

ARS LONGA, VITA BREVIS...

Offline SIIAlum

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Re: OSC COTS I Proposal Discussion
« Reply #36 on: 02/24/2008 06:24 AM »
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antonioe - 23/2/2008 3:29 PM

Hey, I just realized that the TV table we've been putting together is missing the pressurized cargo volume data.  Here's yet one more version with that data added.  Please post any additions/corrections/comment, please:

Wow!  At 23 m3, the PCM is quite a bit larger than I expected and nearly 3x larger than Progress or SpaceX.  That should definitely be advantageous when considering crew transfer operations.  Also, based on that size, my guess is that you should be able to fit roughly 175 Middeck Locker Equivalent (MLE) of cargo in there.  Assuming this type of number (maybe Antonio can confirm?), that would put the cargo density at about 13.5 kg per MLE which is very close to the historical NASA packing density (based on Shuttle middeck, MPLM and Spacehab cargo flights).  Maybe other NASA cargo type folks can confirm.  We all wish the NASA cargo could be more densely packed (capability is up to 27 kg per MLE) but history shows otherwise.


Offline Jim

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Re: OSC COTS I Proposal Discussion
« Reply #37 on: 02/24/2008 08:17 AM »
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SIIAlum - 24/2/2008  2:24 AM

 Maybe other NASA cargo type folks can confirm.  We all wish the NASA cargo could be more densely packed (capability is up to 27 kg per MLE) but history shows otherwise

Very hard to do.   Some foam is needed and also the items need to be user accessible and which is not optimal for packing efficiency

Offline antonioe

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Re: OSC COTS I Proposal Discussion
« Reply #38 on: 02/24/2008 12:15 PM »

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SIIAlum - 24/2/2008 1:24 AM  Also, based on that size, my guess is that you should be able to fit roughly 175 Middeck Locker Equivalent (MLE) of cargo in there. 

Looking at our presentation material, I did not find an MLE equivalent, but I found the sentence "148 CTBs-Single Equivalent".  I don't know what that means, frankly.  I know there's a lot of empty space in the axis, and in the "corners" below the "Seat Tracks" - that's where the (flexible?) water tanks would be located, if flown in a flight.

Oh, it also sez "Dry cargo volume 9.84m3"  I don't know how that correlates with the pressurized vessel internal volume of 23m3.

ARS LONGA, VITA BREVIS...

Offline Jim

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Re: OSC COTS I Proposal Discussion
« Reply #39 on: 02/24/2008 01:33 PM »
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antonioe - 24/2/2008  8:15 AM

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SIIAlum - 24/2/2008 1:24 AM  Also, based on that size, my guess is that you should be able to fit roughly 175 Middeck Locker Equivalent (MLE) of cargo in there.

Looking at our presentation material, I did not find an MLE equivalent, but I found the sentence "148 CTBs-Single Equivalent".  I don't know what that means, frankly.  


A single CTB was designed to fit in a Middeck Locker.   I had a longer discussion here, but moved it to a separate thread, so not to derail the thread.

Evolution of Stowage in US spacecraft

http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=12018&mid=248598#M248598

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