NASA teams evaluating ISS-built Exploration Platform roadmap

[Jorge]

The point about the arm is a good one, and needs to be carefully assessed. Look at the image in the article that shows the Launch Mission Kit. Note the forward end of the payload is equipped with a low impact docking system, not with a common berthing mechanism. Is there any evidence supporting the notion that -- without thrusters near the forward end of the payload -- the RCS on the LMK could provide the attitude control needed for capture by the arm? Or does the "build it as ISS" plan still require autonomous docking?

I would lay a bet that berthing would be prefered to docking if you are building at the ISS. Lower risk.

Cgynus, although smaller does not have thrusters in the Front.

Huh?

http://forum.nasaspaceflight.com/index.php?topic=25251.msg744835#msg744835

[A_M_Swallow]

Edit: to ask, can FH get Orion to EML1?

Not  in one launch but with two FH or even a Delta heavy could do.

Also if you could get orion's mass down some or increase FH performance just a bit you could do it in one launch.

Would having the Orion's return propellant at the EML spacestation be a sufficient saving in mass?

We will soon have tugs that can move fuel around.

[A_M_Swallow]

I would lay a bet that berthing would be prefered to docking if you are building at the ISS. Lower risk.

I suspect that a practical EML spacestation will have a mixture of docking ports and CBM berthing ports.  Same for a LEO ship yard.

Temporary docking locations used by capsules, landers and transfer vehicles are likely to use docking ports.  This means that they can undock.

Permanently connected modules are likely to use the Common Berthing Mechanism (CBM) because once connected they are unlikely to be undocked.

At least one of the CCiCap spacecraft may have the control authority to act as a short range tug simplifying the assembly of the spacestation.  A passive NDS connector can be attached to the modules.

[sdsds]

There are three places the space station could be made:

1. At EML using 6t chunks
2. At the ISS using 15-20t chunks
3. At 28 degree orbit using 15-20t chunks

There's yet another possibility. Belbruno recently presented[1] several SEP trajectories from circular Earth orbit to Lissajous orbit near EML-1 (and also from EML-1 to EML-2). He proposes starting from a 75000 km Earth orbit. That's already almost a quarter of the distance to the Moon! (Compare to GEO at 35786 km.)

From there, with reasonable assumptions[2] about thrust, Isp, etc. the assembly arrives in an EML-1 orbit after 55 days, with thrusting only required for the first 16 days or so. These trajectories use the ability to "coast in" to orbits around the Lagrange points with no arrival delta-v required.

Coming from Belbruno one can assume these transfer trajectories were carefully and correctly calculated. I wish there were an "apples to apples" comparison of  missions using these trajectories with those using the ~100 day entirely ballistic trajectories that don't require SEP. But if you're a fan of SEP, these trajectories look like great places to start integrating the technology into a human exploration architecture....

[1] January 4, 2012 FISO, "Transportation for Exploration: New Thoughts About Orbital Dynamics."

[2] SEP dry 10t, prop 37.6t, thrust 64N, Isp = 2200s. iHab 20t.

[MP99]

But the whole idea is to use the ISS because you can easily get 20tn chunks with stock LV AND you have an arm. Please note that nothing prevents the station from receiving an arm at the ISS and using it later on EML2. Incidentally, I can't think of other significant provision for the Canada share. So I suspect it will have a Canadarm 3.

I can understand the attraction of assembly at ISS. Can perform module checkout from a safe environment and use the station arm to berth the components together. Once they're berthed they're more solidly connected than docked modules for the push through TLI. And, of course, existing launchers if you add an ARDV capability.

However, it also requires a big stage to push that mass through TLI. If they're gonna go with a SEP stage, that will need to push beyond current state of the art, and I assume that would be quite a big project in it's own right.

That's understandable if this is first use of a SEP stage that will inject NEA and Mars missions outwards from EML. But is this stage in current plans and budgets? (I know the whole station isn't in current plans and budgets, but how much would this SEP stage cost? To design? Per launch?)



The point of my ~20t chunks with SLS block 1 / DCSS statement was that this uses the same stack as EM-1 (SLS block 1 and DCSS), just with a PLF (and LMK which would be required, anyway). It trades SLS build and launch against SEP-stage development, build and launch costs.

Mostly it is predicated on a distrust of the high costs of adding an SLS launch into an empty schedule. Given costs that have to be paid to sustain the system in a year with no launches, how much would it actually cost to add a launch into that year?

I did actually forget to include the mass of the LMK in the mass to be pushed through TLI, but that's still well within the capabilites of SLS / DCSS, without any SEP or CPS development required. Ed seems to have similar concerns:-

I'm not thrilled about the "existing launchers" bit.  It's fine to use them, but only if SLS is stopped right now.  Otherwise, what is the monster for?

cheers, Martin

[MP99]

Note that in December Chris posted a link to a ZIP file Hatfield_8-10-11 in this thread.

It includes a PPT with most of the article images at much higher resolution, and videos of the core module and an inflatable being delivered to ISS. Warning: 94MB file.

cheers, Martin

Edit: and a link to an MP3, presumably of the talk though I haven't listened to it yet.

[Space Pete]

I would lay a bet that berthing would be prefered to docking if you are building at the ISS. Lower risk.

Assuming the Node 4 concept is used as part of the exploration platform, then that was planned to dock to PMA-2 rather than berth to a CBM.

Yet NASA needs to decide what ISS is meant to be once and for all.  It is advertised right now as a world-class microgravity research labratory.

Why can't it do both - i.e. microgravity science up to 2020, then after that an exploration platform?

That of course is a bad example since only new modules would be used for the exploration platform, meaning ISS would still continue to be available for science after 2020.

So, the answer is that ISS is a science platform, which will be used to *construct* an exploration platform - not *become* an exploration platform.

[8900]

Updating what we have via L2. Again, planning only - nothing set in stone still.

http://www.nasaspaceflight.com/2012/06/nasa-teams-evaluating-iss-built-exploration-platform-roadmap/

But the above would be cool!

I'm not thrilled about the "existing launchers" bit.  It's fine to use them, but only if SLS is stopped right now.  Otherwise, what is the monster for?

 - Ed Kyle

Falcon-H can also be used o lift the hardware and send resupply vehicles to EML2
The LEO capability of 53mT seems sufficient for these missions, high energy upper stage will definitely make things better, after all it is the most powerful launch vehicle after the SLS

btw Ad Astra is not selected as solar electric propulsion candidate? Probably NASA has given up on the exotic VASIMR concept in favor of the more established but low thrust ion engine

[edkyle99]

Falcon-H can also be used o lift the hardware and send resupply vehicles to EML2
The LEO capability of 53mT seems sufficient for these missions, high energy upper stage will definitely make things better, after all it is the most powerful launch vehicle after the SLS

Falcon Heavy would be second most capable to LEO after SLS (I believe 40-ish tonnes is what the described rocket will actually be able to lift), but without a high energy upper stage it will only be roughly comparable to Delta 4 Heavy to escape velocity.

 - Ed Kyle

[Go4TLI]

Yet NASA needs to decide what ISS is meant to be once and for all.  It is advertised right now as a world-class microgravity research labratory.

Why can't it do both - i.e. microgravity science up to 2020, then after that an exploration platform?

That of course is a bad example since only new modules would be used for the exploration platform, meaning ISS would still continue to be available for science after 2020.

So, the answer is that ISS is a science platform, which will be used to *construct* an exploration platform - not *become* an exploration platform.

Because that is somewhat of what is referred to as a "bait and switch". 

We have no real way of getting up there routinely anymore.  We are pushing for commercial crew, and as a off-shoot of that it is at least suggested in passing that more customers and more utilization of the ISS will help both ISS, remember half of it is now a National Lab, and commercial crew.

2012 is now half over.  Commercial crew is 3 to 4 years away at best.  It is a lengthy process currently to get something on ISS.  So assuming all this comes together and then real experiments are ready to fly on ISS, you suggest we pull the rug out 8 years from now and say now the science may be compromised because ISS will serve part-time as a construction platform? 

That will likely keep people, groups, etc from even wanting to consider ISS in the near future, again taking into account logistical problems now and the time it takes to get something to fly. 

[Robotbeat]

Fear, uncertainty, and doubt?

[MP99]

Note that in December Chris posted a link to a ZIP file Hatfield_8-10-11 in this thread.

It includes a PPT with most of the article images at much higher resolution, and videos of the core module and an inflatable being delivered to ISS. Warning: 94MB file.

cheers, Martin

Going by slide 12 of that PPT, the four radial ports on the Core Module are CBMs.

However, slides 20 (attached), 21 & 22 (and pics in Chris' article) show Orion berthed to one of those CBMs. That doesn't seem right?

Also, why would an Orion be attached to the stack for it's trip from LEO to EML? I'd assume the trip would be made un-manned?

Would the EML gateway include a spare Orion as lifeboat?

cheers, Martin

[Jim]

Getting bogged down with medium lift launches is not the path forward.

The USA is very far behind on space station technology.

Both statements have no truth in them

[pathfinder_01]

Going by slide 12 of that PPT, the four radial ports on the Core Module are CBMs.

However, slides 20 (attached), 21 & 22 (and pics in Chris' article) show Orion berthed to one of those CBMs. That doesn't seem right?

Also, why would an Orion be attached to the stack for it's trip from LEO to EML? I'd assume the trip would be made un-manned?

Would the EML gateway include a spare Orion as lifeboat?

cheers, Martin

No from listining to the presentation Orion is just standing in for a visting vechile. Mission could be done via commercal crew if needed.

[spectre9]

Getting bogged down with medium lift launches is not the path forward.

The USA is very far behind on space station technology.

Both statements have no truth in them

The ISS relies heavily on Zvezda and Zarya. There is no ISS without them. The USA couldn't build these modules themself. If they can it will take time to catch up.

I don't know how far behind so perhaps "very" was offensive to you.

I've heard over and over again from NASA and others that medium lift launching is high risk and high cost compared to heavy lift especially when it comes to the schedule.

If there's no payloads for heavy lift it's going to be stillborn. No doubt about that.

No more building tin can stations after ISS. This is one of the lessons learned isn't it?

Possibly not?

What am I missing here Jim.

Less "you're wrong" and more "this is why you're wrong" or "go read this document to see why you're wrong".

[Jim]

1.  The ISS relies heavily on Zvezda and Zarya. There is no ISS without them. The USA couldn't build these modules themself. If they can it will take time to catch up.

I've heard over and over again from NASA and others that medium lift launching is high risk and high cost compared to heavy lift especially when it comes to the schedule.

1. See Prop module and ICM.  The US could build any modules it wants, but chose not to.  This has nothing to do with "being behind".  Outside of propulsion systems, the USOS has all the same systems and better versions of those systems.  The Prop Module and ICM were to replace the propulsion systems of the SM.

2.  Exact opposite.  Medium lift is low risk since most of the launches are propellant and there is less risk using a system that flies multiple times vs one that flies less than once a year.

[FinalFrontier]

Getting bogged down with medium lift launches is not the path forward.

The USA is very far behind on space station technology.

Both statements have no truth in them

The ISS relies heavily on Zvezda and Zarya. There is no ISS without them. The USA couldn't build these modules themself. If they can it will take time to catch up.

I don't know how far behind so perhaps "very" was offensive to you.

I've heard over and over again from NASA and others that medium lift launching is high risk and high cost compared to heavy lift especially when it comes to the schedule.

If there's no payloads for heavy lift it's going to be stillborn. No doubt about that.

No more building tin can stations after ISS. This is one of the lessons learned isn't it?

Possibly not?

What am I missing here Jim.

Less "you're wrong" and more "this is why you're wrong" or "go read this document to see why you're wrong".

1. Yes we can and did build our own control/prop modules just never flew/finished to completion.

2. If it ever becomes a serious issue, IE SM or FGB fail or need to be removed its likely we would fly one of our own to replace it, depending on the timing and nature of the failure.

3. We or ESA may end up doing that anyway if ISS is eventually extended beyond 2020,to say 2028.
 

4. There is nothing wrong with medium lift or HLV, it all depends on application and either will work for a BEO program. And given NASA's apparent lack of ability to self regulate size and cost a medium lift commercial program might well be the best option at this time.

5. Tin Can stations? Not sure what your talking about ISS modules have kevlar/ballistics insulation so even though its rigid shell its hardly "tin can"

6. Rigid structures will be needed for BEO stacks, inflatables are also as yet untested in actual application even in LEO.

7. There are payloads for heavy lift. See L2. If you don't have L2 don't complain to me about not knowing.

8. 

I've heard over and over again from NASA and others that medium lift launching is high risk and high cost compared to heavy lift especially when it comes to the schedule.

Aside from CXP related stuff: Documentation Please. Show me specifically where they say medium lift cannot work. I'll be glad to refute it in the unlikely event you can.  Note: CXP does not count because of administration derived bias.

9. We are the most advanced nation in terms of space and space based technologies, the Chinese are only just now learning how to dock and operate Salyut sized modules in LEO we have already been to the moon and back, have operated a re-usable space plane, have invented a plethora of advanced propulsion systems and flown them on deep space probes,  and have in large part built and operated the worlds first and only true space station intended for long term use and full research capability, have invented nuclear propulsion, ect list goes on.

We are not behind on space technology or station technology, we wrote the book on it. Get your facts straight.

[Patchouli]

I think it's good they're planning on using a station as a staging point as Von Braun originally planned to do and are considering using advanced propulsion.

[spectre9]

@ Jim. Thanks for that response.

1. Didn't know that. Interesting.

2. Thanks for your thoughts on medium vs heavy lift, obviously there's plenty of misinformation and confusion about this.

@FinalFrontier

Tin can was a reference to size not materials. Those modules are keeping people alive and don't look like having any problems.

I want to see big cans like Skylab not inflatables.

Your national pride is bordering on arrogance. "we wrote the book on space station tech".

You obviously know which nation launched Salyut since you've referenced it.

[FinalFrontier]

@ Jim. Thanks for that response.

1. Didn't know that. Interesting.

2. Thanks for your thoughts on medium vs heavy lift, obviously there's plenty of misinformation and confusion about this.

@FinalFrontier

Tin can was a reference to size not materials. Those modules are keeping people alive and don't look like having any problems.

I want to see big cans like Skylab not inflatables.

Your national pride is bordering on arrogance. "we wrote the book on space station tech".

You obviously know which nation launched Salyut since you've referenced it.

1. Yes I know who launched salyut. I also know they had problems out the wazoo and shook whenever someone used the treadmill.

2. We wrote the book on space based technology. That said, Russia made many contributions and, as many shortcomings as they had, their early space stations were ahead of the time.

3. We went to the moon. After that, we built the most complex flying machine mankind has ever constructed. After that, we designed and built many of the major components of mankind's most complex space station. No I am not putting down the Russians or MIR, but you cannot discount the fact that we literally designed many of the most advanced systems for Apollo and shuttle after it. So yes we did write the book on it, that said, I am not going to engage in an East West flame war with you no matter how much you so desire it.

4. Stop referring to it as "cans" as if that is somehow detrimental. Rigid structures are required for deep space travel until or unless inflatable systems can be proven to work. That is fact. ISS is not a can, in case you have not noticed each module has an *immense* amount of internal volume. While each module could have been bigger had it not been shuttle driven, that would not necessarily make it more capable. Bigger is not always better, particularly not if you destroy your budget in the process of going bigger. And building parts of something out of aluminium does not make it somehow a "can". If you seriously regard ISS as nothing but a bunch of  "spam in cans" modules your out of touch with reality.



All of that said since you decided to drag this conversation into the gutter I wash my hands of it.