NASA teams evaluating ISS-built Exploration Platform roadmap

[spectre9]

1. So the Russians learned that treadmills can shake a station first?

2. I will not remind you about all the USSR space firsts. You're not ignorant just glazing over for the sake of this argument.

3. How are you not putting down MIR? Shuttle lasted 10 days on orbit and the USA had no space station of their own. Sure NASA might have had the technology for long stays on orbit but this was not demonstrated past the 84 days of Skylab.

4. I use "can" to mean shape but I can call them rigid pressurised modules if you like. I know they're advanced but you can launch a lot more at once if done with bigger modules. Even NASA themselves says that a station will never be built this small chunk way again.

I'm not making this an East vs West argument and dragging it into the gutter you've done that with your arrogance and bias. You clearly are intelligent and know heaps about space but you need to take a step back here and just acknowledge that the Russians have made huge advances in space station technology while the USA could've but has not until very recently with the ISS.

[Robert Thompson]

@ FF , @ NSF

2 cents and 3 rationales for KSC LEO 28 degrees:

1. Maintain the fiscal moral high ground of not impairing the stated intention of getting hard microgravity science from the ISS, but leverage it as a logistical and safety backup to a 28 degree site. Scientists will be pleased to help out in dire need, and will be even more pleased to be left to their work in the absence of dire need. Their best results are crucial to how effectively we open up deep space.

2. Provide a nearby playpen for the commercial cubs. Whatever helps them grow well the fastest is best. LEO is tough enough; see "China", a nation of 1b. The precocious will escape the playpen on their own.

3. Construction at EML2 is tantamount to a human NEO mission in terms of unnecessary opportunity cost lost in logistics and travel time. LEO is tough enough. Maximize the learning cycle by proximity in an optimally, but not maximally, extreme environment. Sharpen axe more, chop less. Construction at EML2 is also politically inscrutable until China duplicates the order of magnitude of ISS. Construction at 28 degrees can be immediately leveraged as soft power. A thin sliver of soft power is increased public awareness in the visible flyovers of multiple U.S. assets and craft.

4. The risk: Construction of a cart must not outpace development or readiness of a sufficient horse. For both cart and horse, always have fallback configurations or capabilities leveraging modularity and proximity in the event of fiscal hard landing. If we cannot build a horse sufficient to this task in a timely manner, the nation (species?) should hang it up and order a Fermi Daiquiri. It is a sound risk to start work on the cart with every expectation of a good enough horse.

[spectre9]

http://www.nasaspaceflight.com/2007/07/oxygen-generating-system-activated-onboard-iss/

NASA generating oxygen since way back in 2007. 

Thanks for the article once again Chris.

Just goes to show that much of the stuff the gets written retains it's relevance many years later.

The propulsion module was cancelled. Seems like it was just a backup if Russia didn't come through with a service module.

Here's what this mission requires.

Launch Mission Kit
Core Module - 11mt
Utility Module - 8mt
Habitation Module - 13mt
International Module - 20mt
400kw SEP Tug

3x Atlas 5 launches
1x Proton/Ariane 5 ?
1x SLS

That's quite a bit of hardware and launches. Schedule of all that before 2020 seems a little optimistic.

How much can SLS throw to EML2 with a CPS?

I guess that depends on which version is available.

Build an all in one module of around 50mt. Size is no issue. Big and wide with expandable docking ports and fold out solar panels/radiators. Build it all on the ground and take as long as it takes. 2021 launch. Make sure everything is state of the art as much as is possible.

First manned Orion to visit the station in 2022.

SLS to launch beefy moon landers to the station for lunar surface sorties. 

[Space Pete]

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?

Why would science be compromised by using ISS as a construction platform?

The only real thing required from the ISS side would be crew time - and we could simply send additional crewmembers up on commercial vehicles for short periods to help with that.

And then, once the exploration platform departs ISS, it can go back to exclusive science ops again.

[baldusi]

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?

Why would science be compromised by using ISS as a construction platform?

The only real thing required from the ISS side would be crew time - and we could simply send additional crewmembers up on commercial vehicles for short periods to help with that.

And then, once the exploration platform departs ISS, it can go back to exclusive science ops again.

Not to mention that the core module might work as a Node 4 for a while, which might in fact reduce the time the crew needs for VV ops, thus, actually increasing the science output. One piece of the station per year, vs no less than six VV, possibly eight with crew. I think it might well be a good tradeoff. Once you integrate the Hab module, if the Commercial Crew can take three or four extra crew for a couple of weeks, you could send one or two dedicated to do station assembly and checkout, and EVA crew, thus, again maximizing the science output.

[Drkskywxlt]

Nice article.

Is there any prayer of having room in the HEOMD funding wedge for some of this hardware before 2020?  As far as I can see, it looks like SLS, Orion, and ISS eat all available dollars up until that date.  I realize this concept would at least partially reuse existing hardware, but it's still not free.  Not to mention the development of the SEP. 

[Jorge]

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?

Why would science be compromised by using ISS as a construction platform?

Microgravity environment.

[A_M_Swallow]

If the LEO spaceship yard has to be a different spacestation from the ISS then what functions it need to support need determining.  From which we can decide what modules need building.  These modules is likely to include living quarters as well as control rooms for the arms.

I suspect that is off topic for ISS-built.

[Robotbeat]

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?

Why would science be compromised by using ISS as a construction platform?

Microgravity environment.

I find that a pretty poor reason to avoid using ISS in another very important role. ISS has over a dozen or so dockings/berthings every year, plus reboosts. Another couple gentle berthings a year isn't going to make a significant difference to the platform's microgravity utility.

[Robotbeat]

And the Russians plan on still adding and removing modules from their section (and they do it more violently than the gentle USOS berthings), so it's not like the center of mass of ISS is going to stay exactly the same, either. ISS has been under construction since day 1 and still is, what with all the spacecraft docking and undocking and berthing and unberthing and all the new modules planned.

EDIT: And even with the "International module" (which I'm not sure will survive either the US House of Representatives or the Russian Federal Assembly), the total mass of the Exploration gateway should still be a lot less than a full Shuttle orbiter, which many were supporting for continual ISS logistics use, equivalent to a full Exploration gateway docking and undocking with ISS several times a year.

[Robert Thompson]

And the Russians plan on still adding and removing modules from their section (and they do it more violently than the gentle USOS berthings), so it's not like the center of mass of ISS is going to stay exactly the same, either. ISS has been under construction since day 1 and still is, what with all the spacecraft docking and undocking and berthing and unberthing and all the new modules planned.

EDIT: And even with the "International module" (which I'm not sure will survive either the US House of Representatives or the Russian Federal Assembly), the total mass of the Exploration gateway should still be a lot less than a full Shuttle orbiter, which many were supporting for continual ISS logistics use, equivalent to a full Exploration gateway docking and undocking with ISS several times a year.

Can you identify any advantages to 28 degrees not retained at ISS? (other than upmass and dv)

[Robotbeat]

And the Russians plan on still adding and removing modules from their section (and they do it more violently than the gentle USOS berthings), so it's not like the center of mass of ISS is going to stay exactly the same, either. ISS has been under construction since day 1 and still is, what with all the spacecraft docking and undocking and berthing and unberthing and all the new modules planned.

EDIT: And even with the "International module" (which I'm not sure will survive either the US House of Representatives or the Russian Federal Assembly), the total mass of the Exploration gateway should still be a lot less than a full Shuttle orbiter, which many were supporting for continual ISS logistics use, equivalent to a full Exploration gateway docking and undocking with ISS several times a year.

Can you identify any advantages to 28 degrees not retained at ISS? (other than upmass and dv)

I don't think there are any, other than a slight decrease in radiation dose. Did I somehow give the impression I thought we should build it at 28 degrees? I'm in favor of building at ISS.

[Robert Thompson]

I don't think there are any, other than a slight decrease in radiation dose. Did I somehow give the impression I thought we should build it at 28 degrees? I'm in favor of building at ISS.

Mea culpa. With respect to the ISS orbit, are there any advantages to a 28 degrees orbit for construction purposes *other than* upmass and dv? What causes the difference in radiation doses?

[psychocandy007]

Microgravity environment.

I find that a pretty poor reason to avoid using ISS in another very important role. ISS has over a dozen or so dockings/berthings every year, plus reboosts. Another couple gentle berthings a year isn't going to make a significant difference to the platform's microgravity utility.

IIRC, one of the original concepts for Space Station Freedom included a free floating experiment lab.  I think they've known from the start that the IIS would not be a perfect zero-gravity (or micro-gravity) research lab.

[Robotbeat]

I don't think there are any, other than a slight decrease in radiation dose. Did I somehow give the impression I thought we should build it at 28 degrees? I'm in favor of building at ISS.

Mea culpa. With respect to the ISS orbit, are there any advantages to a 28 degrees orbit for construction purposes *other than* upmass and dv? What causes the difference in radiation doses?

Radiation is trapped by the Earth's magnetic field in the Van Allen belt(s). The Earth's magnetic field changes in direction (and intensity) depending on your latitude (and altitude and time of day at the point directly below your spacecraft in orbit... and also a little on longitude because of the South Atlantic Anomaly and magnetic declination... this all also depends on space weather, i.e. the state of the solar wind and the Solar Cycle).

[pathfinder_01]

Mea culpa. With respect to the ISS orbit, are there any advantages to a 28 degrees orbit for construction purposes *other than* upmass and dv? What causes the difference in radiation doses?

There is one disadvantage, I don't think Russia can launch into that orbit from thier current launch site.  The ISS's orbit takes them near the van allen belt on certian orbits.

[A_M_Swallow]

I don't think there are any, other than a slight decrease in radiation dose. Did I somehow give the impression I thought we should build it at 28 degrees? I'm in favor of building at ISS.

Mea culpa. With respect to the ISS orbit, are there any advantages to a 28 degrees orbit for construction purposes *other than* upmass and dv? What causes the difference in radiation doses?

If you are not going to the ISS then it is a waste to go to the ISS.

If the spaceship yard is not attached to the ISS then there is no need for it to be in the same orbit.  Pick an orbit that is near the launch pad.

We already have to delay launches due to congestion at the launch pad and congestion at the ISS.  A second spacestation would result in three causes of congestion - ISS, launch pad and spaceship yard.  If the two spacestations are in significantly different orbits then they no longer interfere with launches to the other one.

edit:spelling

[QuantumG]

If you are not going to the ISS then it is a waste to go to the ISS.

This has been discussed a thousand times already.

The benefits of having access to the ISS beats any of the disadvantages.

[pathfinder_01]

If you are not going to the ISS then it is a waste to go to the ISS.

This has been discussed a thousand times already.

The benefits of having access to the ISS beats any of the disadvantages.

Yeap, Crew and Cargo can be shared.  The commercial crew craft will have seats for 7, and the ISS only needs 4. You can use the extra seats for construction crew. You can also use and trade cargo space amoung the international partners.

[CitabriaFlyer]

I really like this concept but I am concerned about funding.  Maybe they will go with a scaled down version to begin with consisting just of Node4 with an airlock and an FGB.

In a worse case scenario just buy an FGB and throw it out to EML2 with SLS.  At least you have a docking target for Orion flight tests and a life boat for the crew if there is a problem with Orion.  You also have a starting point for additional modules and landers.

I don't know that an EML 2 Gateway necessarily needs to be manned all the time.