NASA teams evaluating ISS-built Exploration Platform roadmap

[Chris Bergin]

The Gateway leaked out in "Press reports". FFS Space.com.

Merged into the Gateway thread.

[cro-magnon gramps]

Used this opportunity with Gaia to mention the Gateway again (not that there's been any notable movement on it):

http://www.nasaspaceflight.com/2014/01/eml2-gaia-destination-future-possibilities/

Chris, that was a great article, and I'm glad you took the opportunity to bump the Gateway concept; while I don't expect to see it in my lifetime, before 2040, I do think that it is the logical progression from the ISS / LEO / Cis-Lunar Stations on a road map to Mars and the Outer Planets. These are early days, so not surprised there is no movement. Just give it time. Man-kind is still taking baby steps.

Cheers

Gramps

[Rocket Science]

Used this opportunity with Gaia to mention the Gateway again (not that there's been any notable movement on it):

http://www.nasaspaceflight.com/2014/01/eml2-gaia-destination-future-possibilities/

Chris, that was a great article, and I'm glad you took the opportunity to bump the Gateway concept; while I don't expect to see it in my lifetime, before 2040, I do think that it is the logical progression from the ISS / LEO / Cis-Lunar Stations on a road map to Mars and the Outer Planets. These are early days, so not surprised there is no movement. Just give it time. Man-kind is still taking baby steps.

Cheers

Gramps

Keep drinking the “pickle juice” Gramps, it’ll preserve ya...  I’ll add my kudos as well to Chris for another fine article!

[HappyMartian]

Thank you for a great article about something that may be useful in 2050 or 2060 after Lunar ISRU propellant is in full production.

"L2 also provides a moderate radiation environment, which helps extend the life of the instrument detectors in space" is the part I don't understand.

Low Lunar orbit would allow some GCR protection by the large nearby Moon.

"L2" is deep space and is a GCR rich environment.

Without effective and cheap GCR shielding, it is extremely difficult to justify humans spending any significant amounts of time at L2.

A stable low Lunar polar orbit is the lowest risk, lowest cost, and shortest mission flight time staging orbit for human Lunar missions.

Put a gateway station in a stable low polar Lunar orbit and it could be quite useful.


Edited

[Lars_J]

Thank you for a great article about something that may be useful in 2050 or 2060 after Lunar ISRU propellant is in full production.



A stable low Lunar polar orbit is the lowest risk, lowest cost, and shortest mission flight time staging orbit for human Lunar missions.

Put a gateway station in a stable low polar Lunar orbit and it could be quite useful.

Not really. You would only have two launch windows from Earth (surface or LEO) every month. And as a gateway to Mars and beyond it would be disastrous, with years or more between efficient launch windows at times.

[HappyMartian]

Thank you for a great article about something that may be useful in 2050 or 2060 after Lunar ISRU propellant is in full production.



A stable low Lunar polar orbit is the lowest risk, lowest cost, and shortest mission flight time staging orbit for human Lunar missions.

Put a gateway station in a stable low polar Lunar orbit and it could be quite useful.

Not really. You would only have two launch windows from Earth (surface or LEO) every month. And as a gateway to Mars and beyond it would be disastrous, with years or more between efficient launch windows at times.

Do you have any evidence that the Apollo and Orion mission planners were wrong? Perhaps the burden of proof rests heavily on the shoulders of anyone proposing an alternative Lunar exploration architecture.

"Recent studies performed by NASA mission designers concluded that equivalent landing site access and 'anytime abort' conditions could be met by rendezvous missions in LLO with less propulsive delta-V and lower overall Initial Mass in Low Earth Orbit (IMLEO). If used only as a node for lunar missions, the L1 Earth-Moon LPR is inferior to the LOR mission mode."

From: National Exploration Systems Architecture Study 1. Executive Summary 2005  Page 15
At: http://www.nss.org/resources/library/spacepolicy/2005Architecture-01-ExecutiveSummary.pdf

[Coastal Ron]

I like the idea of using existing & proven ISS elements to build other exploration systems, since it keeps development costs down to a minimum.  And considering that what has been holding us back from leaving LEO has been a lack of money, and not any technical reasons, low cost exploration systems are more likely to be funded.  Plus they would show results much faster too.

Back in 2010 before the Boeing Gateway study was released I had been working on my own estimate of how much an EML station would cost.  Since I am not an engineer I chose existing hardware systems for my "design", and it was not too different in concept from what Boeing came up with.

Using public figures for costs from the ISS and other programs, and a few educated guesses for near-term technology needs like space tugs and fuel tankers, I came up with a total hardware cost of about $5B, which covered the initial construction and two six-month crew rotations (3 people/crew).  That assumed using Falcon Heavy for the non-crew payloads, but substituting Delta IV Heavy only increased the total cost by $1B, so using a mix of both would still result in an overall hardware cost below $6B.

I'm sure there are a lot of holes that can be poked in my assumptions, especially the transportation and logistics costs, but since I assumed using ISS hardware for the station itself I feel pretty good about that part.  My assumptions also included in-space refueling and in-space docking of crew vehicles to tugs, which eliminates the need for an HLV, but if we can't get competent at doing things like that we're not going far in space anyways.

Were there any cost estimates for the Boeing proposal?

[HappyMartian]

I like the idea of using existing & proven ISS elements to build other exploration systems, since it keeps development costs down to a minimum.  And considering that what has been holding us back from leaving LEO has been a lack of money, and not any technical reasons, low cost exploration systems are more likely to be funded.  Plus they would show results much faster too.

Back in 2010 before the Boeing Gateway study was released I had been working on my own estimate of how much an EML station would cost.  Since I am not an engineer I chose existing hardware systems for my "design", and it was not too different in concept from what Boeing came up with.

Using public figures for costs from the ISS and other programs, and a few educated guesses for near-term technology needs like space tugs and fuel tankers, I came up with a total hardware cost of about $5B, which covered the initial construction and two six-month crew rotations (3 people/crew).  That assumed using Falcon Heavy for the non-crew payloads, but substituting Delta IV Heavy only increased the total cost by $1B, so using a mix of both would still result in an overall hardware cost below $6B.

I'm sure there are a lot of holes that can be poked in my assumptions, especially the transportation and logistics costs, but since I assumed using ISS hardware for the station itself I feel pretty good about that part.  My assumptions also included in-space refueling and in-space docking of crew vehicles to tugs, which eliminates the need for an HLV, but if we can't get competent at doing things like that we're not going far in space anyways.

Were there any cost estimates for the Boeing proposal?

Were there any Loss of Mission and Loss of Crew numbers for Boeing's complex mission proposal?

Perhaps another issue would be GCR exposure for American and international astronauts on "six-month crew rotations".

Getting Congress and our international space exploration partners to buy into using astronauts as long-term GCR test subjects might be hard.

And getting astronauts to appreciate the value of such "six-month" crew rotation testing on the deep space EML station in a GCR rich environment that nearly maxes out their lifetime radiation exposure limits and greatly reduces their potential for doing future long-term space missions could be difficult.

Astronauts tend to like being astronauts and maybe many of them don't want to prematurely end their interesting careers.

Last time I read about it, affordable GCR shielding was NASA's number one technical problem for human long duration deep space missions.

Astronauts tend to be pretty smart folks and keeping them busy doing some useful "exploration" for six months at EML and claiming that such risky and costly "exploration" couldn't be done in some other lower cost and lower risk manner might also be a problem.

If we want to go to the Moon to do exploration and ISRU for propellant to help reduce cislunar mission risks and transportation costs, we humans and our robots just need to go to there in the least complex and lowest risk manner that we can devise.

[Archibald]

Aaaaand... here we go again with the GCR-rich fallacy... after the LLO fallacy that conveniently ignored Lars_J answer...

[HappyMartian]

Concerning GCRs:

""Describing some of the Curiosity mission’s discoveries in the rover’s first year on Mars during a lecture commemorating its anniversary, Deputy Project Scientist Dr. Ashwin Vasavada explained that the high levels of radiation measured by the spacecraft indicate that a Mars-bound human mission would exceed NASA’s lifetime exposure limit for astronauts. 'It is a problem, but NASA has to solve it,' said Vasavada."

From: Vasavada: Radiation is Problem NASA Needs to Solve for Human Missions   By Laura M. Delgado  Aug 17, 2013
At: http://www.spacepolicyonline.com/news/vasavada-radiation-is-problem-nasa-needs-to-solve-for-human-missions


Thick Galactic Cosmic Radiation Shielding Using Atmospheric Data  By Youngquist, Robert C., Nurge, Mark A., Starr, Stanley O., and Koontz, Steven L.       Jan 1, 2013
At: http://ntrs.nasa.gov/search.jsp?R=20130014272&qs=N%3D0%26No%3D120

"Abstract:  NASA is concerned with protecting astronauts from the effects of galactic cosmic radiation and has expended substantial effort in the development of computer models to predict the shielding obtained from various materials. However, these models were only developed for shields up to about 120 g!cm2 in thickness and have predicted that shields of this thickness are insufficient to provide adequate protection for extended deep space flights. Consequently, effort is underway to extend the range of these models to thicker shields and experimental data is required to help confirm the resulting code. In this paper empirically obtained effective dose measurements from aircraft flights in the atmosphere are used to obtain the radiation shielding function of the earth's atmosphere, a very thick shield."


Perhaps most folks in Congress and taxpayers everywhere would prefer to see some research that indicates NASA, or some other space agency, has solved the deep space GCR issue prior to spending many billions of dollars on a space exploration architecture and an EML station that the use of which would entail American and international astronauts having career limiting "six-month crew rotations" in the naturally GCR rich environment of deep space. 

The burden of proof for the cost effectiveness, utility, benefits, and risk minimization of any alternative space missions and space exploration architecture other than relatively direct four day flights to the Moon is on the shoulders of those who propose such alternatives.

Congress and the international community seem to want success optimized missions to the Lunar surface.

Note:

"It was only through the concerted efforts of specific individuals within Congress, NASA, and aerospace contractors that the Orion capsule was saved and the Ares V went through a design reboot to emerge with the rather uninspiring SLS moniker."

And, "To be specific, NASA is interested in discovering the means to potentially extract water and oxygen from processing lunar material in close proximity to Earth in order to be able to mount exploratory missions beyond the Moon."

From: Why not return to the Moon? (part 2)      By Anthony Young     February 10, 2014 
At: http://www.thespacereview.com/article/2449/1


By paying close attention to what Congress and our international partners expect and are willing to allocate funds for we should be able to extract the Lunar resources needed to minimize space transportation risks and costs while expanding our human and robotic presence in LEO and beyond LEO environments.

[Robert Thompson]

http://www.thespaceshow.com/detail.asp?q=2189
Update on developing RLIP 76 as a radiation countermeasure drug. Dr. Curt Bilby.

[Robotbeat]

http://www.thespaceshow.com/detail.asp?q=2189
Update on developing RLIP 76 as a radiation countermeasure drug. Dr. Curt Bilby.

That is a critical development. I'm of the opinion that the current perspective on GCR and the linear-no-threshold model are both over-conservative (in other words, focus should be on reducing bursty sources like Solar Energetic Particle events rather than long-term doses like GCR, since the body is able to adapt to longer term doses), and that the current way of thinking of radiation as somehow a separate risk other than other risky parts of the mission are counter-productive to a safe, capable Mars architecture.

However, a drug treatment that improves radiation resistance with only a tiny amount of mass would be an enormous benefit. The issue, however, is that it doesn't solve the problem of irrational risk averseness to any kind of radiation. By merely deciding to set the radiation limits yet /more/ conservative, any advocacy group with influence could in one fell swoop double the IMLEO of any Mars mission while doing essentially nothing to reduce risk.

[Robert Thompson]

RLIP76 is certainly transhuman. The guest speaker telescoped about ten years (so I'll guess 15) before it can be leveraged for space. Do you have sources for the claim that the human body adapts to prolonged low dose radiation? I see only speculative medical articles for functional adaptation. High altitude populations adapt to higher UV, which I don't think counts for GCR/CME/flare.

I would quietly say that HSF is quantum entangled with nationalist patriotism along a dialectic of practically or functionally divine infallibility ('failure is not an option'), that is buttressed by the irreducible residue of 'assured launch' geopolitical defense asset requirements, extending down to/against the secular fallibility of prior Cold War political systems. A four-year politician cannot risk a national hero, even if they could risk a worker in a dangerous de-nationalized, de-politicized, de-partisan field of labor, such as, say, rail. Of course, there is no field of labor until there is taxable income from that activity. The only way to break this degeneracy, between astronaut as priceless national treasure and 'space worker', is lower launch cost. From where I sit.

[Robotbeat]

Ramsar, Iran has far greater than normal background radiation levels, but the population has no more increase in mutations or cancer than anyone else.

Also, there have been many studies that have shown that cell cultures acclimated to long-term doses have much better survival rates for acute doses than ones without previous long-term exposure.

The model which has only questionable support (at low dose /rates/) due to only having data extrapolated down from the highest dose rates is the linear, no-threshold model. But that gets repeated endlessly seemingly without question.

[baldusi]

The lineal model simply doesn't makes any biological sense. There are many factors that damage DNA. That's why there are four copies for each base. Each side of a strand, and the other strand of the dual helix. RNA not only copies but permanently repairs DNA because no only radiation but many molecules damage it.
So, since we have an ongoing DNA cleaning and repair system, it would only make sense that there's a maximum threshold of damage rate that the system can handle. Under that level, is business as usual and no damage is permanent. Above it, the probability of permanent damage increases significantly. Thus, if you are going to integrate the damage function, at the very least you should only consider doses above the threshold. Which haven't been studied because that stupid lineal doasage model.