Author Topic: ISS Commercial Resupply Services 2 (CRS2) 2017-2024  (Read 418556 times)

Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #620 on: 03/14/2015 06:19 pm »
... So my per-year guess, assuming the Dragon/Cygnus bids are pretty close to what they are in CRS-1, would be ...

So what if Cygnus adds unpressurized up/disposal capability?  Or Dragon or CST-100 adds a trunk module for pressurized up/disposal?  If sufficient additional pressurized up and disposal capability were available with Dragon or CST-100, that could significantly change the equation, and Dragon or CST-100 might satisfy all CRS-2 requirements with four CRS flights/year.  Which would leave Cygnus and Jupiter in the dust.

Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #621 on: 03/14/2015 06:31 pm »
They are how the bids will be judged, but not how logistics will be planned and operated. It's in that sense that they are fiction.
I hope and expect that logistics planning and operation was involved in developing the CRS-2 requirements, and that those requirements are not simply pro-forma.  Or maybe I'm being overly optimistic.

Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #622 on: 03/14/2015 06:36 pm »
Now that people have looked at Jupiter what chance do you see of it at least getting a piece of the CRS2 contract such as 1 -2 flights?

This probably belongs back in the main CRS II thread, but I see three possible scenarios:

1. 3-4 Dragon + 1-2 Cygnus per year. [80% likelihood]

2. 4 Dragon + 1 "Jupiter-Exoliner" every year. [12%]

3. ~3 Dragon + 1-2 Cygnus + 1 cargo CST-100 per year [8%]

I think NASA is looking for more cargo per year now than in CRS-1, and they are looking for 4-5 cargo flights per year.  To many flights taxes the astronauts too much, and too few doesn't give enough opportunities to get supplies that aren't expected ahead of time (e.g.: something breaks and needs to be replaced).  That implies that they're looking for more capable cargo systems than in CRS-1.  On the other hand, having already-developed and proven cargo systems is a big advantage.  Who knows how long it will take to develop a new system?  NASA won't want to count on a new one.  So my per-year guess, assuming the Dragon/Cygnus bids are pretty close to what they are in CRS-1, would be:

~2-3 Dragon
~2 Cygnus
~1 "something else on Atlas V"

In later years as it proves itself the "something else" might get a bigger cut.

For the "something else", CST-100 has the advantage that the crew version is being developed already.  However, Jupiter/Exoliner seem to meet NASA's needs more (getting the mass/volume NASA wants in, or closer to, that 4/5 flight per year box).
Agreed.

The Jupiter/Exoliner fits better the constraint on having as few cargo flights as reasonable (it has the most volume and payload of any of the proposals so far, by a significant margin) while being capable of both pressurized and unpressurized upmass and disposal and all that at a (presumably) quite reasonable cost since the spacecraft part is reused each time.

It also has a list of fairly unique attributes that would no doubt prove valuable to NASA operationally or to NASA's mission:
1) Should have capability to send up (and dispose of) multiple full ISS racks. Not as critical as it once was, but currently only HTV can do this.
2) Can transfer fluids. This makes water logistics more efficient and allows fuller use of the launch vehicle's capacity to launch water (or whatever).
3) Large unpressurized volume.
4) Tug capability with an arm would allow adding new modules to Station or some future station or outpost or interplanetary transfer vehicle at EML1/2 or lunar DRO.
5) Makes in-orbit rendezvous and docking/berthing fairly simple. The tug and the upperstage do all the work. So if you need, say, two SLS or two Delta IV Heavy or two Falcon Heavy launches in order to launch something big (like a Mars surface rendezvous or something), you don't have to add rendezvous capability to each piece, you can just off-load that to the tug. This is useful for more than just human spaceflight missions, of course. If you use this with less expensive launch vehicles (like Falcon Heavy), it would be cheap enough for unma'ammed missions, too.
6) It makes propellant transfer a US-native TRL-9 (i.e. not just tech demo but operational) technology and provides a template for a propellant tanker. This could end up being pretty useful if NASA decides to keep ISS running after the Russians leave.
7) In combination with propellant transfer, it gives the US options for controlled deorbit of ISS, if for whatever reason Progress isn't an option.
8) As a solar-electric tug (a later version of Jupiter), it'd also allow the ability to move payloads to different orbits. Launch stuff on ISS, move it to higher orbit. Launch stuff to LEO on a reusable launch vehicle, move it up to GTO or lunar orbit or whatever.
9) Is an obvious platform for robotic servicing.

I don't know exactly how the rest of these things would factor into the CRS-2 bid decision (if at all), but they certainly can't hurt. (Although for whatever reason, it seems that a lot of people dislike something if it's genuinely useful for more than a single thing... This is irrational, but I've seen it more than once, especially as related to space architectures.)
« Last Edit: 03/14/2015 06:43 pm by Robotbeat »
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Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #623 on: 03/14/2015 06:41 pm »
... So my per-year guess, assuming the Dragon/Cygnus bids are pretty close to what they are in CRS-1, would be ...

So what if Cygnus adds unpressurized up/disposal capability?  Or Dragon or CST-100 adds a trunk module for pressurized up/disposal?  If sufficient additional pressurized up and disposal capability were available with Dragon or CST-100, that could significantly change the equation, and Dragon or CST-100 might satisfy all CRS-2 requirements with four CRS flights/year.  Which would leave Cygnus and Jupiter in the dust.
I doubt that. The CRS-2 requirements seem written to favor the much larger volume of Cygnus and Exoliner (Jupiter). Recoverable down-mass capability is necessarily fairly volume-limited (inflatable heatshield would help change that trade-off, but is too low-TRL for this sort of thing), so I am confident that both reentry craft bid(s) and big-tin-can bid(s) will be chosen. And no, I don't think Dragon or CST-100 will include a separate tin can.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #624 on: 03/14/2015 06:50 pm »
I don't know exactly how the rest of these things would factor into the CRS-2 bid decision (if at all), but they certainly can't hurt. (Although for whatever reason, it seems that a lot of people dislike something if it's genuinely useful for more than a single thing... This is irrational, but I've seen it more than once, especially as related to space architectures.)

If they come at no additional risk or cost, then they are irrelevant.  If they come with additional risk and cost, then they are relevant.  The rationality of the decision, and like or dislike, has nothing to do with whether the solution is "useful for more than a single thing", but its risk and cost.

Offline jongoff

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #625 on: 03/14/2015 06:51 pm »
How long can centaur be in orbit and still be able to do a deorbit burn?

Assuming the reattachment can be done. How long would it all take from rendezvous after takeoff to swap of the cargo modules completed? The centaur will have to be active for that period and the period will not be too short.

Just in general, I believe it quite possible that Lockheed Martin has considered the requirements and has a plan how to achieve the goal. ;)

If IVF is flying in time, Centaur will have no problem hanging around long enough for this mission. Even without IVF, Centaur has done half-day missions, and could probably be "kitted" to support a reasonable duration for a mission like this, especially if they do a fast rendezvous like Soyuz has been doing lately.

~Jon

Offline Space Ghost 1962

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #626 on: 03/14/2015 07:02 pm »
Items to add to the list above:
 * leverages the assets of the ISS - including human interaction and return
 * works with hazardous (i.e. non-ISS bound) applications
 * can function as a "repurposable" sat
 * can host sensor / imaging platforms (note coverage of 52 degrees inclination)
 * CRS-2 payloads can "ride share" with non-insignificant secondary payloads
 * non CRS-2 missions can make use of same capabilities
 * "frequent flyer" usage can reduce parasitic payload loss by substituting Jupiter on-orbit "services"

As to the "irrational" above, its because you mess with certain peoples "perfect world" vision / hallucination.
« Last Edit: 03/14/2015 07:12 pm by Space Ghost 1962 »

Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #627 on: 03/14/2015 07:12 pm »
I doubt that. The CRS-2 requirements seem written to favor the much larger volume of Cygnus and Exoliner (Jupiter). Recoverable down-mass capability is necessarily fairly volume-limited (inflatable heatshield would help change that trade-off, but is too low-TRL for this sort of thing), so I am confident that both reentry craft bid(s) and big-tin-can bid(s) will be chosen. And no, I don't think Dragon or CST-100 will include a separate tin can.

Not necessarily.  At an optimal four flights/year with a total desired pressurized up-mass of 15000kg/yr over four flights = 3750kg/flight.  Again, Cygnus in its present form, and Jupiter as we know it today, cannot alone meet CRS-2 requirements.

Therefore there will be other providers.  Therefore the higher mass/volume capability of Jupiter (or Cygnus or whatever) for up-mass is a less significant benefit, and thus likely to be awarded a marginal number of flights ("gap filler" if you will, which increases cost/flight).

As to whether SpaceX or Boeing proposes an additional/optional pressurized tin can, we will have to see.  But, if proposed, I have to believe the cost and risk for such is significantly lower than what LM is proposing.

Offline ChrisWilson68

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #628 on: 03/14/2015 07:50 pm »
About disposal, if I understand correctly Hohmann transfer orbits, in order to go from ISS orbit to delivery orbit you need (simplifying it) a deorbit backburn to lower orbit and a new burn to stabilize on the rendevouz orbit. If the discarded PCM would be jettisoned before the last burn, wouldn't it safely deorbit and burn up even before you reach the Centaur? On the other hand, swapping PCMs would indeed allow for a more controlled deorbit.

No, the transfer orbit is an eliptical orbit with its low point at the intended low altitude and its high point at the original higher altitude.  If you discarded the PCM before the last burn, it would stay in the eliptical orbit, going back and forth between the low altitude and the high altitude.  It would eventually deorbit, just as anything in any low Earth orbit would, but more slowly than if it were in the Centaur's orbit even without the Centaur's de-orbit burn.

Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #629 on: 03/14/2015 08:53 pm »
I don't know exactly how the rest of these things would factor into the CRS-2 bid decision (if at all), but they certainly can't hurt. (Although for whatever reason, it seems that a lot of people dislike something if it's genuinely useful for more than a single thing... This is irrational, but I've seen it more than once, especially as related to space architectures.)

If they come at no additional risk or cost, then they are irrelevant.  If they come with additional risk and cost, then they are relevant.  The rationality of the decision, and like or dislike, has nothing to do with whether the solution is "useful for more than a single thing", but its risk and cost.
Cost also matters. This solution allows an Atlas V-based solution to be cost-competitive with the cheaper-launch Antares-based Cygnus.

Atlas V (especially 501) is a very, very reliable launch vehicle, so much so that it likely would easily overwhelm the tiny added perceived risk of doing things a little differently with rendezvous. And once Jupiter is in orbit, there's a lot less deployment risk. Once a spacecraft is functioning and in orbit, it's unlikely to just randomly breakdown (infant mortality tends to dominate). So past the initial mission, it could easily have a much, much lower per-launch risk overall than something like Cygnus.
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Offline jtrame

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #630 on: 03/14/2015 09:04 pm »
Looks like something that is needed long term and the short term use will satisfy the tenants of CRS2.

We can't dismiss the forward-looking component of this proposal as a non starter simply due to the written requirements of CRS2.  A computer is not making the decision; humans will make the call.  The seed has been planted.  Human nature will play a role. 


Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #631 on: 03/14/2015 09:21 pm »
Atlas V (especially 501) is a very, very reliable launch vehicle, so much so that it likely would easily overwhelm the tiny added perceived risk of doing things a little differently with rendezvous.
Yes, cost matters, which is partly a reflection of risk, which has been my point (sorry if that has not been clear).  The LV risk is, IMHO, a relatively minor part of this equation.

Quote
And once Jupiter is in orbit, there's a lot less deployment risk. Once a spacecraft is functioning and in orbit, it's unlikely to just randomly breakdown (infant mortality tends to dominate). So past the initial mission, it could easily have a much, much lower per-launch risk overall than something like Cygnus.
Yes... "once Jupiter is in orbit"... once DDT&E is complete... once the bugs have been worked out... I agree that it could have a lower risk.  It is getting to that point, and specifically in the context of CRS-2, which is the question.  Can LM do the development, deploy it, and make it work reliably on a day-to-day basis, and be competitive given the competition?  I have doubts.

Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #632 on: 03/14/2015 09:30 pm »
We can't dismiss the forward-looking component of this proposal as a non starter simply due to the written requirements of CRS2.

The CRS-2 requirements and evaluation criteria are cold and uncaring, and do not give a whit about any possibilities not otherwise called for in those requirements and evaluation criteria.

edit: If you want to talk about possibilities independent of CRS-2, I think Jupiter has potential (in which case this is not the proper thread for that discussion).  In the context of CRS-2--which is what this thread is about--the CRS-2 requirements cannot be dismissed.
« Last Edit: 03/14/2015 09:38 pm by joek »

Offline ChrisWilson68

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #633 on: 03/14/2015 09:39 pm »
Atlas V (especially 501) is a very, very reliable launch vehicle, so much so that it likely would easily overwhelm the tiny added perceived risk of doing things a little differently with rendezvous.
Yes, cost matters, which is partly a reflection of risk, which has been my point (sorry if that has not been clear).  The LV risk is, IMHO, a relatively minor part of this equation.

Quote
And once Jupiter is in orbit, there's a lot less deployment risk. Once a spacecraft is functioning and in orbit, it's unlikely to just randomly breakdown (infant mortality tends to dominate). So past the initial mission, it could easily have a much, much lower per-launch risk overall than something like Cygnus.
Yes... "once Jupiter is in orbit"... once DDT&E is complete... once the bugs have been worked out... I agree that it could have a lower risk.  It is getting to that point, and specifically in the context of CRS-2, which is the question.  Can LM do the development, deploy it, and make it work reliably on a day-to-day basis, and be competitive given the competition?  I have doubts.

I think the risk of the first Jupiter failing is comparable to the risk of a new interstellar probe built on an existing, proven bus failing.  The U.S. has a very good record with such probes, especially in recent decades.  LM is involved with a lot of that -- the very bus that Jupiter is planned to use is also on MAVEN.  So I think the chances of the first Jupiter working as planned are very good.

And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.

Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #634 on: 03/14/2015 10:01 pm »
And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.

If it is not that big a deal, then why go there?  Again, how much are you willing to pay for reliable ISS supply as a system (i.e., independent of individual providers)?  At best, I see Jupiter as a marginal addition, which makes it less attractive.

Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #635 on: 03/14/2015 10:07 pm »
Atlas V (especially 501) is a very, very reliable launch vehicle, so much so that it likely would easily overwhelm the tiny added perceived risk of doing things a little differently with rendezvous.
Yes, cost matters, which is partly a reflection of risk, which has been my point (sorry if that has not been clear).  The LV risk is, IMHO, a relatively minor part of this equation.

Quote
And once Jupiter is in orbit, there's a lot less deployment risk. Once a spacecraft is functioning and in orbit, it's unlikely to just randomly breakdown (infant mortality tends to dominate). So past the initial mission, it could easily have a much, much lower per-launch risk overall than something like Cygnus.
Yes... "once Jupiter is in orbit"... once DDT&E is complete... once the bugs have been worked out... I agree that it could have a lower risk.  It is getting to that point, and specifically in the context of CRS-2, which is the question.  Can LM do the development, deploy it, and make it work reliably on a day-to-day basis, and be competitive given the competition?  I have doubts.

I think the risk of the first Jupiter failing is comparable to the risk of a new interstellar probe built on an existing, proven bus failing.  The U.S. has a very good record with such probes, especially in recent decades.  LM is involved with a lot of that -- the very bus that Jupiter is planned to use is also on MAVEN.  So I think the chances of the first Jupiter working as planned are very good.

And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.
I agree with your point. Failure is not likely. And by using the most reliable launch vehicle around (Atlas V), they're buying down the risk so much that I'd probably score it just as high as Cygnus-on-Antares.

...but I would like to see where you're finding these interstellar probes. ;)
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Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #636 on: 03/14/2015 10:11 pm »
And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.

If it is not that big a deal, then why go there?  Again, how much are you willing to pay for reliable ISS supply as a system (i.e., independent of individual providers)?  At best, I see Jupiter as a marginal addition, which makes it less attractive.
You see wrong, then. It's the most volume-capable of any of the options and the only one capable of full racks like HTV. It's an attractive option. No guarantee of being picked, but it's certainly a good showing by Lockheed.

Also, CRS was never about extreme risk aversion as you seem to imply (and the latest round, CRS-2, is no different). Toilet paper, tang, and t-shirts are cheap to replace and ISS has plenty of margin for a failure or two without drastically affecting anything.

This is NOT the same as some unique, multi-billion-dollar national security payload. This is why NASA was ever willing to put station supply on totally new launch vehicles to start. A strong bid by an experienced player using an existing satellite bus on the most reliable launch vehicle available is not worth considering "too risk-averse to be viable," and so there must be some other reason. I don't get what the REAL reason you don't like the Jupiter/Exoliner concept is.
« Last Edit: 03/14/2015 10:14 pm by Robotbeat »
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Offline Avron

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #637 on: 03/14/2015 10:13 pm »
And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.

If it is not that big a deal, then why go there?  Again, how much are you willing to pay for reliable ISS supply as a system (i.e., independent of individual providers)?  At best, I see Jupiter as a marginal addition, which makes it less attractive.

Looking at the benefits the Tug in ISS context brings, I fail to see many over the status quo. I see increased costs, with increased risks. 
The first question that comes to mind is what does it really replace, or for that matter where is the reuse to the existing proven means?
What is the increased fuel use in orbit to make use of a tug?
How to safely use the tug to  de-orbit spacecraft?
What will it cost to maintain a tug in orbit?

Each of these are covered to the extent of the tug gets reused. but does to show any benefit /risk or cost reduction

 

Offline Robotbeat

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #638 on: 03/14/2015 10:38 pm »
And even if the first Jupiter fails, it's not that big a deal as far as CRS-2 is concerned because they can fly another one soon after if the first fails, and in the meantime there are other providers.  The Cygnus failure shows NASA isn't affected much by one provider being down for a year.

If it is not that big a deal, then why go there?  Again, how much are you willing to pay for reliable ISS supply as a system (i.e., independent of individual providers)?  At best, I see Jupiter as a marginal addition, which makes it less attractive.

Looking at the benefits the Tug in ISS context brings, I fail to see many over the status quo. I see increased costs, with increased risks. 
The costs are decreased significantly. Exoliner has roughly twice Cygnus's volume, and not having to build a new bus each time (which is usually the majority of the cost!) means they save enough to use a more powerful and much more reliable launch vehicle. (Cygnus/Antares is the status quo).

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The first question that comes to mind is what does it really replace, or for that matter where is the reuse to the existing proven means?
Unclear question, but the arm has some heritage from Shuttle and ISS, the bus is a typical Lockheed bus used for spacecraft in the past, and the Exoliner is made on ATV, Cygnus, and ISS module heritage.
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What is the increased fuel use in orbit to make use of a tug?
Not really any. Remember, using a tug means you don't have to launch a new spacecraft bus each time, so that saves significant mass.
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How to safely use the tug to  de-orbit spacecraft?
Addressed up-thread.
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What will it cost to maintain a tug in orbit?
Nothing significant, really. The tug just sits there like any other bird until another Exoliner is launched. It is refueled once it docks/berths to the new Exoliner. That's the nice thing: it can be reused without having to withstand the rigors (and subsequent refurbishment) of reentry and another launch. There's nothing magically complicated about refueling, either. Salyut 6 (in orbit 5 years), Salyut 7 (9 years), Mir (15 years for the first module and had several such modules), and ISS's Zvezda and Zarya (in orbit 14 & 15 years respectively and will be 25+ years by the time ISS is EOL) all had/have such capability.

Quote
Each of these are covered to the extent of the tug gets reused. but does to show any benefit /risk or cost reduction
The cost reduction is you can just build a dumb container, not a super-expensive spacecraft every mission. It also means there's more room for payload (as mentioned above) per-launch and less risk of infant mortality. And the fact that you're also doing much more payload per launch (both volume and mass) also contributes to the savings.
« Last Edit: 03/14/2015 10:49 pm by Robotbeat »
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Offline joek

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Re: ISS Commercial Resupply Services 2 (CRS2) 2017-2024
« Reply #639 on: 03/14/2015 11:12 pm »
You see wrong, then. It's the most volume-capable of any of the options and the only one capable of full racks like HTV. It's an attractive option. No guarantee of being picked, but it's certainly a good showing by Lockheed.

This may be a case of missing the forest for the trees.  If it was a matter of this one vehicle capable of satisfying the requirements against all others, then yes, it might be at the top of the list.  But it is not.  It is one vehicle among others which will be required to satisfy the system requirements.  That it may be the most volume-capable as a single vehicle is irrelevant alone.  The question is what is the relevance of that large volume in the context of the overall ISS supply requirements and competition?

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