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80's style Stations Modules...
wrote in message ... On Feb 16, 12:32 pm, Brian Thorn wrote: On Sat, 16 Feb 2008 09:39:48 -0600, "Joseph S. Powell, III" wrote: With all the excitement experienced during the past few days with the attachment of the Columbus module to the ISS, I was reminded of the types of Space Station modules proposed back in the 1980's.... These tended to have a longer design, filling up the entire payload bay of the Shuttle. Does anyone know why these longer modules were rejected in favor of the shorter ones now used on the ISS? The Kibo Lab is the same dimensions it has always been planned to be. The U.S. modules shrank in a cost-cutting move during one of the redesigns in the early 1990s (this happened before the Russians came aboard and the inclination changed, so it wasn't because of that.) Columbus uses the MPLM spaceframe, probably as another cost-saving move. The MPLM was sized that way to leave room in the payload bay for non-pressurized cargo, if necessary. Brian The first "M" in MPLM used to be for Mini. It was another cost saving measure. The original PLM were bigger Wikipedia doesn't agree (but it's obviously not the best source): The MPLM was originally designed for Space Station Freedom. Initially, it was to be built by Boeing, but in 1992, the Italians announced that they would build a "Mini-Pressurized Logistics Module," able to carry 4500 kg of cargo. After the 1993 redesign, the length was doubled and it was renamed the "Multi-Purpose Logistics Module." Each empty MPLM is approximately 21 feet (6.4 m) long, 15 feet (4.6 m) in diameter, weighs 4.5 tons, and can deliver up to 10 tons of cargo to the ISS. Spaceref seems to agree with you: Note: the acronym "MPLM" used to stand for "Mini-Pressurized Logistics Module". During the various space station redesigns in 1992/1994 various modules were reduced in size to save weight. The Space Station Freedom program's larger PLM (Pressurized Logistics Module) was reduced in size and dubbed the "mini" PLM. The acronym stuck, but as the program evolved, the original name did not. Astronautix.com (article by Marcus Lindroos) doesn't agree: When the International Space Station (ISS) was redesigned again in 1993, it was decided to expand the original Mini-Pressurized Logistics Module design. The new Multi-Purpose Logistics Module was twice as long and could carry 9000 kg of cargo to ISS. It almost seems like there was a Pressurized Logistics Module which got shortened to a Mini-Pressurized Logistics Module, but the Mini-Pressurized Logistics Module was then doubled in size to the Multi-Pressurized Logistics Module. If true, this begs the question, is the current MPLM bigger, smaller, or the essentially the same size as the original PLM? Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
#22
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80's style Stations Modules...
Jeff Findley wrote:
From the "interactive" bit on the webpage, it looks like Destiny has room for a total of 24 racks, so launching with only 5 racks installed is launching the module mostly empty, at least in my book. Destiny is the "brains" of the ISS. IT is the core for command and control, communications, the US ECLSS etc. The "science" racks came later, and remember that in the plans, the MPLMs would continually bring new racks and return scientific racks that are no longer needed. The priority was to outfit Destiny with the ISS core systems first. Science came later. And with the shuttle soon to be grounded, it is doubtful that Destiny will ever be outfitted with 24 racks unless they decide to leave one or more MPLMs at the station as storage bins, and those would be launched with empty racks. They could then install empty racks in Destiny and elsewhere, and later on use progress/atv to send components small enough to fit through the small russian hatches to populate those empty racks. |
#23
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80's style Stations Modules...
"John Doe" wrote in message ... And with the shuttle soon to be grounded, it is doubtful that Destiny will ever be outfitted with 24 racks unless they decide to leave one or more MPLMs at the station as storage bins, and those would be launched with empty racks. They could then install empty racks in Destiny and elsewhere, and later on use progress/atv to send components small enough to fit through the small russian hatches to populate those empty racks. If the Japanese HTV flies, it has a CBM at one end and has room for 8 racks inside its pressurized compartment. If the COTS program is successful, we may very well see NASA launching racks to ISS using whatever vehicle wins. ATV uses Russian docking hardware, so entire racks are too big to fit through the hatch. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
#24
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80's style Stations Modules...
On Tue, 19 Feb 2008 13:03:04 -0500, "Jeff Findley"
wrote: If the Japanese HTV flies, it has a CBM at one end and has room for 8 racks inside its pressurized compartment. If the COTS program is successful, we may very well see NASA launching racks to ISS using whatever vehicle wins. Such is the case with Orbital's Cygnus, which was awarded a NASA contract today. It also will use the MPLM design. Brian |
#25
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80's style Stations Modules...
"Brian Thorn" wrote in message ... On Tue, 19 Feb 2008 13:03:04 -0500, "Jeff Findley" wrote: If the Japanese HTV flies, it has a CBM at one end and has room for 8 racks inside its pressurized compartment. If the COTS program is successful, we may very well see NASA launching racks to ISS using whatever vehicle wins. Such is the case with Orbital's Cygnus, which was awarded a NASA contract today. It also will use the MPLM design. I've been sick with a nasty cold for more than a week, so I'm not as up to date on these developments as I'd like to be. I'm going to have to play catch up here... http://www.orbital.com/AdvancedSpace/COTS/index.shtml There isn't a whole lot of information here. In particular, is this system entirely throw-away, or is there a reentry vehicle? If there is a reentry vehicle, is any returned component reused? From the "artist's rendering" this thing looks like it's completely disposable. How disappointing. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
#26
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80's style Stations Modules...
"Jeff Findley" wrote in message ... "Brian Thorn" wrote in message ... On Tue, 19 Feb 2008 13:03:04 -0500, "Jeff Findley" wrote: If the Japanese HTV flies, it has a CBM at one end and has room for 8 racks inside its pressurized compartment. If the COTS program is successful, we may very well see NASA launching racks to ISS using whatever vehicle wins. Such is the case with Orbital's Cygnus, which was awarded a NASA contract today. It also will use the MPLM design. I've been sick with a nasty cold for more than a week, so I'm not as up to date on these developments as I'd like to be. I'm going to have to play catch up here... http://www.orbital.com/AdvancedSpace/COTS/index.shtml There isn't a whole lot of information here. In particular, is this system entirely throw-away, or is there a reentry vehicle? If there is a reentry vehicle, is any returned component reused? From the "artist's rendering" this thing looks like it's completely disposable. How disappointing. Actually, an article at NASASpaceflight.com says that it "will be able to return 1,200 kg of cargo from the ISS to Earth". That's encouraging, but it doesn't sound like a whole lot of down mass per mission. Personally I'd like to see SpaceX's Dragon pan out and start flying. The "growth option" to a manned capsule is very appealing. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
#27
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80's style Stations Modules...
On Feb 20, 1:02 pm, "Jeff Findley"
wrote: "Jeff Findley" wrote in message ... "Brian Thorn" wrote in message .. . On Tue, 19 Feb 2008 13:03:04 -0500, "Jeff Findley" wrote: If the Japanese HTV flies, it has a CBM at one end and has room for 8 racks inside its pressurized compartment. If the COTS program is successful, we may very well see NASA launching racks to ISS using whatever vehicle wins. Such is the case with Orbital's Cygnus, which was awarded a NASA contract today. It also will use the MPLM design. I've been sick with a nasty cold for more than a week, so I'm not as up to date on these developments as I'd like to be. I'm going to have to play catch up here... http://www.orbital.com/AdvancedSpace/COTS/index.shtml There isn't a whole lot of information here. In particular, is this system entirely throw-away, or is there a reentry vehicle? If there is a reentry vehicle, is any returned component reused? From the "artist's rendering" this thing looks like it's completely disposable. How disappointing. Actually, an article at NASASpaceflight.com says that it "will be able to return 1,200 kg of cargo from the ISS to Earth". That's encouraging, but it doesn't sound like a whole lot of down mass per mission. Personally I'd like to see SpaceX's Dragon pan out and start flying. The "growth option" to a manned capsule is very appealing. Jeff -- It isn't "per" mission. The return vehicle is different from the MPLM carrier and has less up mass. Down mass is for experiment samples and not ORU's/racks |
#28
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80's style Stations Modules...
Personally I'd like to see SpaceX's Dragon pan out and start flying. The
"growth option" to a manned capsule is very appealing. Well, yeah, if they manage to achieve what they've been talking about, yes it is more ambitious. But I'm also glad to see Orbital's COTS contract. I thought maybe the whole idea of having two vendors was going to fall to the wayside, and it seemed to me like it would make the whole thing more vulnerable to problems/overruns/etc. Of course, the program still may have other problems (like whether the funding is sufficient, what will happen if there turns out not to be a return on the private investment, etc), but we'll see... |
#29
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80's style Stations Modules...
On Feb 20, 10:19 pm, Jim Kingdon wrote:
Personally I'd like to see SpaceX's Dragon pan out and start flying. The "growth option" to a manned capsule is very appealing. Well, yeah, if they manage to achieve what they've been talking about, yes it is more ambitious. But I'm also glad to see Orbital's COTS contract. I thought maybe the whole idea of having two vendors was going to fall to the wayside, and it seemed to me like it would make the whole thing more vulnerable to problems/overruns/etc. Of course, the program still may have other problems (like whether the funding is sufficient, what will happen if there turns out not to be a return on the private investment, etc), but we'll see... COTS I is not about ISS resupply, COTS II is. COTS II will be competed soon (even before the demos fly) and any contractor can go for it |
#30
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80's style Stations Modules...
"Jim Kingdon" wrote in message news Personally I'd like to see SpaceX's Dragon pan out and start flying. The "growth option" to a manned capsule is very appealing. Well, yeah, if they manage to achieve what they've been talking about, yes it is more ambitious. But I'm also glad to see Orbital's COTS contract. I thought maybe the whole idea of having two vendors was going to fall to the wayside, and it seemed to me like it would make the whole thing more vulnerable to problems/overruns/etc. Of course, the program still may have other problems (like whether the funding is sufficient, what will happen if there turns out not to be a return on the private investment, etc), but we'll see... Orbital certainly isn't in this to lose money. They've got a good track record doing quite a few different things in the aerospace field, so I think they're a pretty safe bet. Certainly there is development and funding risks though, so nothing is 100%. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
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