Author Topic: Space Station and Moon Flights  (Read 11278 times)

Offline Stormlordalpha

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Space Station and Moon Flights
« on: 11/29/2006 02:00 pm »
Hello!
On some papers related to the ESA ACTS, you can see the ISS as staging ground for a moon trip.
http://en.wikipedia.org/wiki/ACTS  please look at the "external links" the pdf.
The ACTS woulf fly to the Station, dock on and wait for the EDS to be launched. Than the ACTS would undock and dock to EDS and proceed to the moon.
This brings me to some Questions for the experts on this forum.

1st Because the ISS is in an Orbit that is not suitabel for Lunar missions, is it technically possible to change the plane   of the ISS so much to bring it to an near Lunar plane?

2nd If yes, what kind of space tug could be used? I tried his manouver in Orbiter with an Progress ship, but was not able to do such big plane change.

3rd If not, would it be economical to make an off plane intercept of the moon outside of the L1 Lagange point?

I like the idea of a waiting manned spacecraft at an space station. Not only you would have a save haven possibility at the station, the manned craft could throughoutly being tested. Also you could store fuel and small equipment there. If COTS became possible, the cost of bringing, for example Spacesuits and experiment racks, could be cheaper than have to lift it with Ares V.
Also the use of an Space Station would solve the problem with the fuel boiloff, because the CEV would wait for the EDS and not vice versa.
Thank you for your answers.

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Offline hektor

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Re: Space Station and Moon Flights
« Reply #2 on: 11/29/2006 02:59 pm »
I fear you are forgetting that the Moon rotates around the Earth.

The orbit of the ISS is suitable for a Lunar mission, provided you accept to wait for the Moon to be in the orbital plane of the ISS, which happens twice a month if I am not mistaken. This create an operational constraint on the date when you perform the TLI, but I think this is acceptable.

I am not even sure that the delta-V penalty not to launch precisely when the Moon is in the ISS plane is that large, maybe somebody here knows ?

Offline outward

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Re: Space Station and Moon Flights
« Reply #3 on: 11/29/2006 06:46 pm »
Quote
hektor - 29/11/2006  11:42 AM

I fear you are forgetting that the Moon rotates around the Earth.

The orbit of the ISS is suitable for a Lunar mission, provided you accept to wait for the Moon to be in the orbital plane of the ISS, which happens twice a month if I am not mistaken. This create an operational constraint on the date when you perform the TLI, but I think this is acceptable.

I am not even sure that the delta-V penalty not to launch precisely when the Moon is in the ISS plane is that large, maybe somebody here knows ?

The orbit of the ISS and the Orbit of the Moon are different in inclination by over 20 degrees. Although you can time a burn from the ISS orbit in such away that you could intercept the Moon's sphere of influence, the delta v required to enter an orbit around the moon is greater in this case than if the ISS and moon had co-planer orbits. This, in turn, does make the ISS orbit some what less energetically practical as a stepping stone to the Moon. (put only less practically, by no means useless).

The Moon first; she's right there, made of stuff we need, and it moves us to a two planet species.

Offline hektor

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Re: Space Station and Moon Flights
« Reply #4 on: 11/29/2006 06:53 pm »
Absolutely not, you are reasoning in 2-D. Think  3D take a ball and a piece of cardboard if you want to check, but when the Moon is in the ISS plane there is no extra Delta V to provide

Offline outward

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Re: Space Station and Moon Flights
« Reply #5 on: 11/29/2006 07:54 pm »
Quote
hektor - 29/11/2006  3:36 PM

Absolutely not, you are reasoning in 2-D. Think  3D take a ball and a piece of cardboard if you want to check, but when the Moon is in the ISS plane there is no extra Delta V to provide

.....but orbits are 2-D...both objects are in orbit around the earth, both with a different inclination relative to the earth's equator, therefore, by definition, their orbits are not in the same plane (but the two planes do cross at an imaginary intersection).....but maybe I'm being thick (I'll review my orbital mech).  :)
The Moon first; she's right there, made of stuff we need, and it moves us to a two planet species.

Offline Jim

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Re: Space Station and Moon Flights
« Reply #6 on: 11/29/2006 08:05 pm »
Quote
hektor - 29/11/2006  2:36 PM

Absolutely not, you are reasoning in 2-D. Think  3D take a ball and a piece of cardboard if you want to check, but when the Moon is in the ISS plane there is no extra Delta V to provide

You aren't thinking in 3D neither.  Even the planes 'align", there still is an out of plane velocity component in the ISS orbit that has to be dealt with

Offline hektor

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RE: Space Station and Moon Flights
« Reply #7 on: 11/29/2006 08:18 pm »
Please check "Human Spaceflight Mission Analysis and Design" - Wiley J. Larson - McGraw-Hill Ed.
Chapter 9.3.2 Lunar trajectories Page 247

Offline tom nackid

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Re: Space Station and Moon Flights
« Reply #8 on: 11/29/2006 08:42 pm »
What would be the point of using ISS as a "staging area" even if it was in a more suitable orbit? After all its not like ISS is an island where a passing ship can pick up fresh water and a couple of goats! Anything a CEV could get from ISS would still have to have been lifted their in the first place. Going to the moon is not like crossing a desert where you can go part way and leave a supply cache. Its more like crossing a canyon. You can't so it by taking two small jumps!

Offline wingod

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Re: Space Station and Moon Flights
« Reply #9 on: 11/29/2006 09:07 pm »
Quote
tom nackid - 29/11/2006  3:25 PM

What would be the point of using ISS as a "staging area" even if it was in a more suitable orbit? After all its not like ISS is an island where a passing ship can pick up fresh water and a couple of goats! Anything a CEV could get from ISS would still have to have been lifted their in the first place. Going to the moon is not like crossing a desert where you can go part way and leave a supply cache. Its more like crossing a canyon. You can't so it by taking two small jumps!

Its called a supply depot.  This concept has been used since before Roman times to aggregate supplies before heading off into the wild blue yonder.  It also makes a very nice assembly point for very large spacecraft that cannot be lifted no matter how spiffy your HLV is.  


Offline tom nackid

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Re: Space Station and Moon Flights
« Reply #10 on: 11/29/2006 09:20 pm »
What's the point of a supply depot in orbit? Everything has to be lifted there to begin with! One big launch is more efficient and lots safer than 10 small launches--at least with the current state of the art. Von Braun was big on orbital assembly back in the 50's because no one knew how to make large rocket engines and clustering can only take you so far--hence smaller, lower powered  boosters were the rule. Constellation will not need anything big enough to require orbital assembly beyond docking the Orion to the lunar insertion stage/LM. No doubt in the future extremely large vehicles for Mars and beyond will need to be asembled in orbit, but again why do it at a space station?

Offline jongoff

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Re: Space Station and Moon Flights
« Reply #11 on: 11/29/2006 11:22 pm »
Tom,
Quote
What's the point of a supply depot in orbit? Everything has to be lifted there to begin with! One big launch is more efficient and lots safer than 10 small launches--at least with the current state of the art.

"Efficient" can be a misleading term.  What you really care about is what allows you to do the most exploration (or whatever you're trying to do) with the resources you have.  And it isn't clear that one big launcher is the way to go when you look at the problem from a standpoint of economics.  Launching payloads, crew, and propellant to a staging site using existing off-the-shelf (or near derivatives) boosters would likely be much less expensive than developing and operating entirely new vehicles.  You can't just writeoff as "sunk costs" costs you haven't sunk yet!

Supply depots or staging points in orbit:
1-Act similar to a capacitor, accumulator, or grocery store.  Basically it gives you a place to store on-orbit "buffer stock", that allows you to deal with both varying supply and demand situations more smoothly.  
2-Make on-orbit propellant storage and transfer easier.  Now instead of having to do multiple rendezvous and dockings/berthings, your "EDS" only needs to rendezvous and berth once--with the station itself.  3-Can have much more sophisticated and robust berthing/docking equipment so you're less likely to damage anything if you have a docking mishap
4-Makes it easy to have people in the loop for the rendezvous and docking (which makes it cheaper and easier)
5-Allows you to reuse your EDS hardware
Etc, I could probably (and should probably) write a whole blog post about it.

~Jon

Offline josh_simonson

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Re: Space Station and Moon Flights
« Reply #12 on: 11/29/2006 11:44 pm »
The ISS has sufficient power available for reliquification of LH2 and LO2, preventing boiloff and allowing departure stages to remain on standby indefinitely.

Offline stargazer777

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Re: Space Station and Moon Flights
« Reply #13 on: 11/30/2006 02:04 am »
I don't have enough of a background in orbital mechanics to address the question of the suitability of the ISS to serve as a jumping off point for lunar or other mission so I will offer no opinion on that issue.  I believe, however, that the concept of a orbital or space based (L-1, L-2, etc.) staging point/supply depot for manned and unmanned exploratory missions is important and that such a facility will have to be established.  What's the point?  Because sooner rather than later we will be sending up parts, equipment, personnel, and fuel by a variety of different means.  The various nations with space capabilities, plus the companies that are developing launch capabilities, will have access to many different types of boosters -- some of which may be military surplus -- with a range of cargo costs and payload capabilities.  Which is only a long way of saying that there will be many paths to orbit and the economics will dictate that we will choose the cheapest way to send cargo -- and eventually people -- into space.  An orbital staging point at the optimal location (whatever that is) will allow us to accumulate the necessary fuel, supplies, personnel in orbit in preparation for missions to the Moon and beyond.  It will also be an essential step when we move to using reusable space craft that do not enter Earth's atmosphere or land on another planet or moon.   In this regard it will enable us to assemble spacecraft and to repair and resupply spacecraft between missions.  I would suggest that such craft will be far more capable than the disposable vehicles we contemplate today and will be able to offer far better protection for astronauts from the range of space hazards simply because the weight penalty of lifting shielding and other elaborate equipment off the Earth's surface will only have to be dealt with once.

Offline stargazer777

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Re: Space Station and Moon Flights
« Reply #14 on: 11/30/2006 02:07 am »
We are on the same page.  Different words, same ideas.

Offline wingod

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Re: Space Station and Moon Flights
« Reply #15 on: 11/30/2006 02:59 am »
Quote
tom nackid - 29/11/2006  4:03 PM

What's the point of a supply depot in orbit? Everything has to be lifted there to begin with! One big launch is more efficient and lots safer than 10 small launches--at least with the current state of the art. Von Braun was big on orbital assembly back in the 50's because no one knew how to make large rocket engines and clustering can only take you so far--hence smaller, lower powered  boosters were the rule. Constellation will not need anything big enough to require orbital assembly beyond docking the Orion to the lunar insertion stage/LM. No doubt in the future extremely large vehicles for Mars and beyond will need to be asembled in orbit, but again why do it at a space station?

Two assumptions here.

1. More Efficient
2. Safer

There is no empirical evidence for either of these theses.  I point out again that efficiency by your implied metric would have 747's delivering toys from China to Walmart in Huntsville Alabama (or anywhere else).  Yet they use an extremely complex shipping system were a cargo goes through several transportation systems and it is MORE efficient than sending things in one really big load.

Safer is an emphemeral concept in this context.  It is a value judgement. I could just as easily and with just as much logical support state that a single launch is less safe to the success of the mission due to the ramifications related to a failure of the large launcher.  Von Braun, with more experience in multiple launches of payloads than everyone else on the planet combined, stood on firm ground when calling for a lot of launches.

"Doing" it at a space station has many advantages even beyond what Jon has posited.

The first and foremost is that the station has its own attitude control system that is independent of the payloads delivered there.  This means that the station can be a platform where these payloads can be passively stored and or assembled in between flights and would require a much less complicated set of hardware than just trying to aggregate payloads at a virtual spot in a random orbit.  Second is that if there are any problems in the assembly process there are both humans and robots available to recover from the anomaly/failure.  

Another feature is that you can build a vehicle for cislunar transportation that has much better volumetric efficiency than the current LSAM.  I have already demolished the myth of the much lower payload to orbit to the station in another thread.

This is just for starters.

Offline Bill White

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Re: Space Station and Moon Flights
« Reply #16 on: 11/30/2006 04:44 am »
Dennis, if you are correct (and I will assume you are) then the Direct architecture suggested elsewhere at this site would allow us the opportunity to both sustain ISS and begin Moon, Mars and Beyond within the same overall budgetary envelope.

For those unfamilar with Direct, a link:

http://www.directlauncher.com/

The plan proposes to launch CEV on a booster capable of lofting 70.9 mT to LEO. From the FAQ:

Quote
Question: Isn't 70.9mT a little excessive for Crew Launch flights?

Answer:

No. It is certainly more than enough to lift the 22mT Orion CEV. But, having the ability to also bring up a further 48.9mT of payload creates the option to bring useful cargo up to space with every crew. This is an ability we completely lose otherwise after Shuttle retires.

This extra performance is utilized by the Lunar missions, where the Crew Launch brings up a 48mT Lunar Surface Access Module (LSAM).

For ISS flights, the Crew Launch can bring up large quantities of spares & supplies, for no extra cost. It could even bring up sections of the ISS which have been cancelled due to the Shuttle's retirement, such as:
Centrifuge Accommodations Module
Habitation Module
ISS Propulsion Module
Science Power Platform

I would propose a combination of Direct with a lighter smaller non-CEV crew taxi chosen via competition between RpK, SpaceX and Atlas V.

EML architectures should be seen as ratchet opportunities

Offline wingod

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Re: Space Station and Moon Flights
« Reply #17 on: 11/30/2006 06:17 am »
Quote
Bill White - 29/11/2006  11:27 PM

Dennis, if you are correct (and I will assume you are) then the Direct architecture suggested elsewhere at this site would allow us the opportunity to both sustain ISS and begin Moon, Mars and Beyond within the same overall budgetary envelope.

For those unfamilar with Direct, a link:

http://www.directlauncher.com/

The plan proposes to launch CEV on a booster capable of lofting 70.9 mT to LEO. From the FAQ:

Quote
Question: Isn't 70.9mT a little excessive for Crew Launch flights?

Answer:

No. It is certainly more than enough to lift the 22mT Orion CEV. But, having the ability to also bring up a further 48.9mT of payload creates the option to bring useful cargo up to space with every crew. This is an ability we completely lose otherwise after Shuttle retires.

This extra performance is utilized by the Lunar missions, where the Crew Launch brings up a 48mT Lunar Surface Access Module (LSAM).

For ISS flights, the Crew Launch can bring up large quantities of spares & supplies, for no extra cost. It could even bring up sections of the ISS which have been cancelled due to the Shuttle's retirement, such as:
Centrifuge Accommodations Module
Habitation Module
ISS Propulsion Module
Science Power Platform

I would propose a combination of Direct with a lighter smaller non-CEV crew taxi chosen via competition between RpK, SpaceX and Atlas V.


I like Dave Christensen's MAX design better.  Much quicker to flight and less costly than direct.

2 Standard 4 segment RSRM's

Replace the RS68's with RD-180's

Upper Stage is a two engined RL-10A-4

CEV on top.

That is for ISS.

Add two more RSRM's for a lunar mission.  Add J2x upper stage.

Add four for heavy payloads and for MARS.

The big problem right now Bill is that the J2X is not slated to be on the test stand till 2010.  The MAX launcher provides a much quicker path and then allows for the evolution of the MAX-1-ISS mission to a lunar mission design.  The launcher is no longer in the critical path for ISS, the Moon, or for Mars.

Dennis

Offline Stormlordalpha

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Re: Space Station and Moon Flights
« Reply #18 on: 11/30/2006 07:10 am »
Thanks for your replies so far!

At another view, I believe it should be possible to go from ISS inclination to the moon. Because the Sovjets had their Zond programm. And their spacecrafts was launched from Baikonur. The question is, 'cause Zond was just circumlunar, if you could go with a Orion or another CEV in a LLO economically.

Offline MKremer

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Re: Space Station and Moon Flights
« Reply #19 on: 11/30/2006 07:43 am »
Quote
Stormlordalpha - 30/11/2006  1:53 AM

Thanks for your replies so far!

At another view, I believe it should be possible to go from ISS inclination to the moon. Because the Sovjets had their Zond programm. And their spacecrafts was launched from Baikonur. The question is, 'cause Zond was just circumlunar, if you could go with a Orion or another CEV in a LLO economically.

Actually, any LEO inclination can do a TLI, it just depends on time/mass/orbital parameters/booster used.
Don't forget the saying "once you're in Earth orbit, you're halfway to anywhere".

Offline simonbp

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Re: Space Station and Moon Flights
« Reply #20 on: 11/30/2006 01:14 pm »
Quote
MKremer - 30/11/2006  2:26 AM

Actually, any LEO inclination can do a TLI, it just depends on time/mass/orbital parameters/booster used.
Don't forget the saying "once you're in Earth orbit, you're halfway to anywhere".

Or, rather, "once you're in Earth orbit and in the right inclination, you're halfway to anywhere"...

Dennis: The main thing that you'd store at a LEO "supply depot" would be cryogenic fuel. How is Fuel Tank A, Large Cryo System A, Fuel for Tank A, Spacecraft B, and empty Fuel Tank B a lower total LEO mass than Spacecraft B, Small Cryo system B, and full Fuel Tank B? By my math, you've lost the not insignificant mass of the depot fuel tank and the larger cryo system...

The major difference is that the depot approach allows you to use smaller boosters, but at the cost much higher recurring costs that won't go away over time. A large launch vehicle (like Ares V) has a high initial cost in development, but if they are made at a production level (like Deltas, as opposed to Saturns) the cost per kilogram to orbit would be lower than the smaller boosters, while still having lower total launch an on-orbit operations cost.

And speaking of Von Braun, what he really advocated during the Apollo design phase was two Saturn C-3's with on orbit rendezvous and docking (and direct landing), similar both to Direct and ESAS...

Simon ;)

Offline MKremer

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Re: Space Station and Moon Flights
« Reply #21 on: 11/30/2006 01:29 pm »
You can do a TLI burn from any inclination (even a polar orbit) as long as it's timed correctly.

Offline Jim

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Re: Space Station and Moon Flights
« Reply #22 on: 11/30/2006 01:36 pm »
Quote
wingod - 30/11/2006  2:00 AM


Add four "SRB's" for heavy payloads and for MARS.


This makes the vehicle unsuitable for the LC-39 complex.  none of the current infrastructure could be used.

Offline tom nackid

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Re: Space Station and Moon Flights
« Reply #23 on: 11/30/2006 01:59 pm »
Quote
wingod - 29/11/2006  9:42 PM

Quote
tom nackid - 29/11/2006  4:03 PM

What's the point of a supply depot in orbit? Everything has to be lifted there to begin with! One big launch is more efficient and lots safer than 10 small launches--at least with the current state of the art. Von Braun was big on orbital assembly back in the 50's because no one knew how to make large rocket engines and clustering can only take you so far--hence smaller, lower powered  boosters were the rule. Constellation will not need anything big enough to require orbital assembly beyond docking the Orion to the lunar insertion stage/LM. No doubt in the future extremely large vehicles for Mars and beyond will need to be asembled in orbit, but again why do it at a space station?

Two assumptions here.

1. More Efficient
2. Safer

There is no empirical evidence for either of these theses.  I point out again that efficiency by your implied metric would have 747's delivering toys from China to Walmart in Huntsville Alabama (or anywhere else).  Yet they use an extremely complex shipping system were a cargo goes through several transportation systems and it is MORE efficient than sending things in one really big load.

Safer is an emphemeral concept in this context.  It is a value judgement. I could just as easily and with just as much logical support state that a single launch is less safe to the success of the mission due to the ramifications related to a failure of the large launcher.  Von Braun, with more experience in multiple launches of payloads than everyone else on the planet combined, stood on firm ground when calling for a lot of launches.

"Doing" it at a space station has many advantages even beyond what Jon has posited.

The first and foremost is that the station has its own attitude control system that is independent of the payloads delivered there.  This means that the station can be a platform where these payloads can be passively stored and or assembled in between flights and would require a much less complicated set of hardware than just trying to aggregate payloads at a virtual spot in a random orbit.  Second is that if there are any problems in the assembly process there are both humans and robots available to recover from the anomaly/failure.  

Another feature is that you can build a vehicle for cislunar transportation that has much better volumetric efficiency than the current LSAM.  I have already demolished the myth of the much lower payload to orbit to the station in another thread.

This is just for starters.

Wingod, one shipborn cargo container of toys from China holds more than any 747 can handle! That is WHY we send everything but extremely high value goods by ship. Ships can carry an immense amount of cargo per trip compared to planes.

As I said I have no doubt that orbital assembly facilities will be important in the coming decades, but for the purposes of Project Constellation building one is more trouble than it is worth. Would you have told Lewis and Clark to put off their exploration until roads had been built into the Louisiana territory? Also the ISS is not designed to be an assembly facility or a supply depot and as has been pointed out is in a poor orbit to act as a staging area for lunar missions.

Safety is definitely NOT an "ephemeral concept"! Try getting a shipping insurance policy from Loyds without some hard numbers concerning failure rates!

Once again I have to point out that putting things into space is not like traveling along level ground where you can stop at any convenient point to rest. Going into space is quite literally taking a leap. You can't cross a canyon by taking two small jumps. or, to paraphrase Heinlien: "Once you are in LEO your are ONLY half way to anywhere." Halfway across a canyon doesn't do you much good!

The economics of spaceflight have to take this into account. The only economical reason for space-based assembly and or staging is if--for whatever reason--you can't build a big enough launch vehicle to send your spacecraft to its destination in one go, or there is some resource ALREADY in orbit that you can get without having to lug it up from Earth in the first place. An example of this might be a space-based tether or perhaps supplies launched into orbit by some ultra-cheap method like laser launch or mass-driver that is unsuitable for larger more fragile cargo.   This WILL come, but again this goes far beyond the scope of Project Constellation which can put everything it needs on its way to the moon with one small crew launch and one big cargo launch.

Offline wingod

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Re: Space Station and Moon Flights
« Reply #24 on: 11/30/2006 03:00 pm »
Quote
tom nackid - 30/11/2006  8:42 AM

Quote
wingod - 29/11/2006  9:42 PM

Quote
tom nackid - 29/11/2006  4:03 PM

What's the point of a supply depot in orbit? Everything has to be lifted there to begin with! One big launch is more efficient and lots safer than 10 small launches--at least with the current state of the art. Von Braun was big on orbital assembly back in the 50's because no one knew how to make large rocket engines and clustering can only take you so far--hence smaller, lower powered  boosters were the rule. Constellation will not need anything big enough to require orbital assembly beyond docking the Orion to the lunar insertion stage/LM. No doubt in the future extremely large vehicles for Mars and beyond will need to be asembled in orbit, but again why do it at a space station?

Two assumptions here.

1. More Efficient
2. Safer

There is no empirical evidence for either of these theses.  I point out again that efficiency by your implied metric would have 747's delivering toys from China to Walmart in Huntsville Alabama (or anywhere else).  Yet they use an extremely complex shipping system were a cargo goes through several transportation systems and it is MORE efficient than sending things in one really big load.

Safer is an emphemeral concept in this context.  It is a value judgement. I could just as easily and with just as much logical support state that a single launch is less safe to the success of the mission due to the ramifications related to a failure of the large launcher.  Von Braun, with more experience in multiple launches of payloads than everyone else on the planet combined, stood on firm ground when calling for a lot of launches.

"Doing" it at a space station has many advantages even beyond what Jon has posited.

The first and foremost is that the station has its own attitude control system that is independent of the payloads delivered there.  This means that the station can be a platform where these payloads can be passively stored and or assembled in between flights and would require a much less complicated set of hardware than just trying to aggregate payloads at a virtual spot in a random orbit.  Second is that if there are any problems in the assembly process there are both humans and robots available to recover from the anomaly/failure.  

Another feature is that you can build a vehicle for cislunar transportation that has much better volumetric efficiency than the current LSAM.  I have already demolished the myth of the much lower payload to orbit to the station in another thread.

This is just for starters.

Wingod, one shipborn cargo container of toys from China holds more than any 747 can handle! That is WHY we send everything but extremely high value goods by ship. Ships can carry an immense amount of cargo per trip compared to planes.

As I said I have no doubt that orbital assembly facilities will be important in the coming decades, but for the purposes of Project Constellation building one is more trouble than it is worth. Would you have told Lewis and Clark to put off their exploration until roads had been built into the Louisiana territory? Also the ISS is not designed to be an assembly facility or a supply depot and as has been pointed out is in a poor orbit to act as a staging area for lunar missions.

Safety is definitely NOT an "ephemeral concept"! Try getting a shipping insurance policy from Loyds without some hard numbers concerning failure rates!

Once again I have to point out that putting things into space is not like traveling along level ground where you can stop at any convenient point to rest. Going into space is quite literally taking a leap. You can't cross a canyon by taking two small jumps. or, to paraphrase Heinlien: "Once you are in LEO your are ONLY half way to anywhere." Halfway across a canyon doesn't do you much good!

The economics of spaceflight have to take this into account. The only economical reason for space-based assembly and or staging is if--for whatever reason--you can't build a big enough launch vehicle to send your spacecraft to its destination in one go, or there is some resource ALREADY in orbit that you can get without having to lug it up from Earth in the first place. An example of this might be a space-based tether or perhaps supplies launched into orbit by some ultra-cheap method like laser launch or mass-driver that is unsuitable for larger more fragile cargo.   This WILL come, but again this goes far beyond the scope of Project Constellation which can put everything it needs on its way to the moon with one small crew launch and one big cargo launch.

Tom

Have you ever done an architecture in each case, taken it down to a sufficient level of detail to do a comparative cost analysis?  If you have not, then you have little basis for the above.  ISS "is" that first place of rest in space.  The canyon analogy has no place here.

I have done these analysis under contract and in the case we studied there which was a telescope, orbital assembly wins hands down.  JWST is showing how much extra a system costs when you try and launch something too big for the fairing.  I did the same in 2004 for my book for a lunar architecture.

Here is a rejoinder.  If sending everything in one package is less expensive, why does NASA not just build a booster big enough to send everything they want to the Moon in one launch rather than two as the baseline is now?  For Mars it will take three launches minimum.

Have you taken into account DDT&E costs?  For the same $44 billion that the Ares ! and V cost TO DEVELOP. I can buy several hundred EELV's.  The flight rate on the Ares V is never going to be more than 3 per year.  At that rate it will take until 2035 to equal the throw mass of the several hundred EELV's and that does not include the cost of supporting the A-V infrastructure.

Also, what is the big deal with safety and lots of launches.  Please explain in detail why multiple launches are less safe than a single launch.  Please define safety within that context.  I work orbital rendevous and docking development all the time and in LEO it is pretty much a breeze.

Sorry, your figures just do not compute.

Offline wingod

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Re: Space Station and Moon Flights
« Reply #25 on: 11/30/2006 03:02 pm »
Quote
Jim - 30/11/2006  8:19 AM

Quote
wingod - 30/11/2006  2:00 AM


Add four "SRB's" for heavy payloads and for MARS.


This makes the vehicle unsuitable for the LC-39 complex.  none of the current infrastructure could be used.

Hmmm... Not unsuitable for LC-39 C or D.

A launch pad is going to cost more than what they are doing now?


Offline Jim

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Re: Space Station and Moon Flights
« Reply #26 on: 11/30/2006 03:10 pm »
Quote
wingod - 30/11/2006  10:45 AM

Quote
Jim - 30/11/2006  8:19 AM

Quote
wingod - 30/11/2006  2:00 AM


Add four "SRB's" for heavy payloads and for MARS.


This makes the vehicle unsuitable for the LC-39 complex.  none of the current infrastructure could be used.

Hmmm... Not unsuitable for LC-39 C or D.

A launch pad is going to cost more than what they are doing now?


I meant LC-39 complex area, VAB included.   Nothing other than the SRB facilities would be applicable

LC-39 C or D are just landmarks

Offline wingod

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Re: Space Station and Moon Flights
« Reply #27 on: 11/30/2006 03:36 pm »
Quote
Jim - 30/11/2006  9:53 AM

Quote
wingod - 30/11/2006  10:45 AM

Quote
Jim - 30/11/2006  8:19 AM

Quote
wingod - 30/11/2006  2:00 AM


Add four "SRB's" for heavy payloads and for MARS.


This makes the vehicle unsuitable for the LC-39 complex.  none of the current infrastructure could be used.

Hmmm... Not unsuitable for LC-39 C or D.

A launch pad is going to cost more than what they are doing now?


I meant LC-39 complex area, VAB included.   Nothing other than the SRB facilities would be applicable

LC-39 C or D are just landmarks

If you look at the history you wil find that the initial grading for LC-39 C and D was completed and they are on a direct path from A and B.  This is at the heart of the original Apollo program and why the VAB has four bays rather than two.  LC 39 C and D were designed from the beginning to be supported from the VAB.


Offline Jim

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Re: Space Station and Moon Flights
« Reply #28 on: 11/30/2006 06:07 pm »
I was referring to that there are no infrastructure out there to modify.  It would be a new start.  And could be called SLC-50

4 bays does not equate to 4 pads.  Apollo used 3 bays (4th bay was never outfitted)  and 1 pad (except for Apollo 10).  It was 2-3 bays per pad.  Pads C and D were associated with 6 and 8 bays VAB and nuke upperstages

Offline wingod

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Re: Space Station and Moon Flights
« Reply #29 on: 11/30/2006 06:47 pm »
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Jim - 30/11/2006  12:50 PM

I was referring to that there are no infrastructure out there to modify.  It would be a new start.  And could be called SLC-50

4 bays does not equate to 4 pads.  Apollo used 3 bays (4th bay was never outfitted)  and 1 pad (except for Apollo 10).  It was 2-3 bays per pad.  Pads C and D were associated with 6 and 8 bays VAB and nuke upperstages

Yep

It is my understanding that with the 33 ft diameter Ares V first stage that they have to basically tear down LC39 anyway so why not just start with a clean sheet?


Offline Bill White

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Re: Space Station and Moon Flights
« Reply #30 on: 12/01/2006 03:03 am »
If the destination is EML-1 or EML-2 then are all LEO inclinations are essentially equal?

What about launch windows to EML-1 or EML-2 from various LEO inclinations?
EML architectures should be seen as ratchet opportunities

Offline wingod

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Re: Space Station and Moon Flights
« Reply #31 on: 12/01/2006 02:47 pm »
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Bill White - 30/11/2006  9:46 PM

If the destination is EML-1 or EML-2 then are all LEO inclinations are essentially equal?

What about launch windows to EML-1 or EML-2 from various LEO inclinations?

If you are using solar electric propulsion launch windows are irrelevant.

:)+

Offline Norm Hartnett

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Re: Space Station and Moon Flights
« Reply #32 on: 12/01/2006 04:46 pm »
If I might broaden the original question somewhat. What about the station and Mars and Beyond? Would utilizing the station for assembly of Mars craft impose prohibitive fuel overhead for TMI? Would using the station for lunar staging provide experience for Mars and Beyond?
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline RedSky

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Re: Space Station and Moon Flights
« Reply #33 on: 12/02/2006 02:08 am »
Quote
Norm Hartnett - 1/12/2006  11:29 AM

If I might broaden the original question somewhat. What about the station and Mars and Beyond? Would utilizing the station for assembly of Mars craft impose prohibitive fuel overhead for TMI? Would using the station for lunar staging provide experience for Mars and Beyond?

Sad to say, but ISS will most likely be long gone by the time of any manned Mars voyage.  Even if it is somehow extended by Russia and ESA after NASA leaves in 2016... I doubt it'll last till the 2030s... probably the earliest date for any Mars trip.  Any potential new station, if built by the US (though unlikely) would probably be in a much more favorable orbital inclination, anyway.

From the scale and nature of what a Mars vehicle would have to be...  (Surface Habitat, living quarters, food and water stores, etc) it would almost be like assembling a small station in LEO by itself.  Therefore, it would act as its own assembly base in LEO.

Offline wingod

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Re: Space Station and Moon Flights
« Reply #34 on: 12/02/2006 03:35 am »
Quote
RedSky - 1/12/2006  8:51 PM

Quote
Norm Hartnett - 1/12/2006  11:29 AM

If I might broaden the original question somewhat. What about the station and Mars and Beyond? Would utilizing the station for assembly of Mars craft impose prohibitive fuel overhead for TMI? Would using the station for lunar staging provide experience for Mars and Beyond?

Sad to say, but ISS will most likely be long gone by the time of any manned Mars voyage.  Even if it is somehow extended by Russia and ESA after NASA leaves in 2016... I doubt it'll last till the 2030s... probably the earliest date for any Mars trip.  Any potential new station, if built by the US (though unlikely) would probably be in a much more favorable orbital inclination, anyway.

From the scale and nature of what a Mars vehicle would have to be...  (Surface Habitat, living quarters, food and water stores, etc) it would almost be like assembling a small station in LEO by itself.  Therefore, it would act as its own assembly base in LEO.

If you are using solar electric propulsion ISS is in a BETTER orbit than 28.5 degrees.

Extra points if you know why.


Offline hmh33

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Re: Space Station and Moon Flights
« Reply #35 on: 12/02/2006 10:50 am »
More sun for the solar panels (a vehicle with 0 inclination in LEO must be in night for almost half of each orbit, a polar orbit in the right plane can provide continuous illumination)

Offline wingod

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Re: Space Station and Moon Flights
« Reply #36 on: 12/03/2006 04:07 am »
Quote
hmh33 - 2/12/2006  5:33 AM

More sun for the solar panels (a vehicle with 0 inclination in LEO must be in night for almost half of each orbit, a polar orbit in the right plane can provide continuous illumination)

Bingo!

There are certain periods during the year where ISS is in full sun and you leave right before the opening of that window and you can "climb out" all the way to the Moon in full sun.  Cuts 10-30% off the trip time.  A really big help!


Offline Norm Hartnett

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Re: Space Station and Moon Flights
« Reply #37 on: 12/03/2006 02:29 pm »
wingod, please understand that I am a big proponet of solar electric propulsion but... As I remember it took SMART-1 6 months to get to the moon. We are going to need major funding to develop any usable SEP.
“You can’t take a traditional approach and expect anything but the traditional results, which has been broken budgets and not fielding any flight hardware.” Mike Gold - Apollo, STS, CxP; those that don't learn from history are condemned to repeat it: SLS.

Offline josh_simonson

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Re: Space Station and Moon Flights
« Reply #38 on: 12/03/2006 10:03 pm »
The main limitation in spaceflight right now is the cost of spacecraft, not of the launch vehicles.  A supply depot allows the use of re-useable spacecraft - which can reduce costs dramatically.  As it is, the Aries V will be capable of orbiting around 800t per year of spacecraft, but NASA will only be able to afford to build about 250t of spacecraft, leaving a large amount of expensive spare capacity on the Aries V.

Offline khallow

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Re: Space Station and Moon Flights
« Reply #39 on: 12/04/2006 12:16 am »
Quote
josh_simonson - 3/12/2006  2:46 PM

The main limitation in spaceflight right now is the cost of spacecraft, not of the launch vehicles.  A supply depot allows the use of re-useable spacecraft - which can reduce costs dramatically.  As it is, the Aries V will be capable of orbiting around 800t per year of spacecraft, but NASA will only be able to afford to build about 250t of spacecraft, leaving a large amount of expensive spare capacity on the Aries V.

I'm not sure I disagree, but I think I do. Even if the vehicles aren't reusable, manufacturing multiple mostly identical vehicles will lower costs. Even when NASA makes two instead of one copy of a space probe [not "vehicle"], they see substantial savings (eg, the marginal cost of building the second MER is stated as costing half as much as the first including development costs). Second, it doesn't make sense to launch an unreliable vehicle that costs $1000 per ton, if you will pay say $5000 per ton for launch costs. Currently, the ante for a space mission is huge. The remainder of the bet must be pretty good to justify it.
Karl Hallowell

Offline Jim

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Re: Space Station and Moon Flights
« Reply #40 on: 12/04/2006 12:30 am »
Quote
khallow - 3/12/2006  7:59 PM

I'm not sure I disagree, but I think I do. Even if the vehicles aren't reusable, manufacturing multiple mostly identical vehicles will lower costs. Even when NASA makes two instead of one copy of a vehicle, they see substantial savings (eg, the marginal cost of building the second MER is stated as costing half as much as the first including development costs). Second, it doesn't make sense to launch an unreliable vehicle that costs $1000 per ton, if you will pay say $5000 per ton for launch costs. Currently, the ante for a space mission is huge. The remainder of the bet must be pretty good to justify it.

Still have to launch the second vehicle and not on the launch vehicle

Offline khallow

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Re: Space Station and Moon Flights
« Reply #41 on: 12/04/2006 03:29 am »
Quote
Jim - 3/12/2006  5:13 PM

Quote
khallow - 3/12/2006  7:59 PM

I'm not sure I disagree, but I think I do. Even if the vehicles aren't reusable, manufacturing multiple mostly identical vehicles will lower costs. Even when NASA makes two instead of one copy of a vehicle, they see substantial savings (eg, the marginal cost of building the second MER is stated as costing half as much as the first including development costs). Second, it doesn't make sense to launch an unreliable vehicle that costs $1000 per ton, if you will pay say $5000 per ton for launch costs. Currently, the ante for a space mission is huge. The remainder of the bet must be pretty good to justify it.

Still have to launch the second vehicle and not on the launch vehicle

By "vehicle" I meant cargo not a launch vehicle. Bad choice of words, I'll correct it.

There's a bunch of numbers out there. I think the total mission for MER was just over $800 million through the end of the first year after landing on Mars including $100 million for launch costs and $75 million for mission control. The $600+ million remainder is the cost of the two probes. Only a third of that was the marginal cost of adding a second rover.

The original poster was claiming, if I understand correctly, that NASA couldn't afford to make more than 250 tons of stuff. I don't know where that claim comes from. But I was pointing out an example that shows substantial decrease in cost for the second item.
Karl Hallowell

Offline Jim

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Re: Space Station and Moon Flights
« Reply #42 on: 12/04/2006 11:57 am »
Quote
khallow - 3/12/2006  11:12 PM

Quote
Jim - 3/12/2006  5:13 PM

Quote
khallow - 3/12/2006  7:59 PM

I'm not sure I disagree, but I think I do. Even if the vehicles aren't reusable, manufacturing multiple mostly identical vehicles will lower costs. Even when NASA makes two instead of one copy of a vehicle, they see substantial savings (eg, the marginal cost of building the second MER is stated as costing half as much as the first including development costs). Second, it doesn't make sense to launch an unreliable vehicle that costs $1000 per ton, if you will pay say $5000 per ton for launch costs. Currently, the ante for a space mission is huge. The remainder of the bet must be pretty good to justify it.

Still have to launch the second vehicle and not on the launch vehicle

By "vehicle" I meant cargo not a launch vehicle. Bad choice of words, I'll correct it.

There's a bunch of numbers out there. I think the total mission for MER was just over $800 million through the end of the first year after landing on Mars including $100 million for launch costs and $75 million for mission control. The $600+ million remainder is the cost of the two probes. Only a third of that was the marginal cost of adding a second rover.

The original poster was claiming, if I understand correctly, that NASA couldn't afford to make more than 250 tons of stuff. I don't know where that claim comes from. But I was pointing out an example that shows substantial decrease in cost for the second item.

I meant to say "Still have to launch the second PAYLOAD and not on the SAME launch vehicle"

MER launch costs were much higher, closer to 2 times your number

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