What kind of death wish in NASA would cause them to choose 1919, the 50th anniversary of Apollo 11, as the date for this pathetic, ludicrous exercise in futility? Do they really want to see headlines saying "After wasting half a century, NASA takes a giant leap backward for mankind"? If this is the best NASA's human spaceflight program can do, let's put the poor thing out of its misery forthwith: flatline the budget.

It may be unfair, but the truth is that NASA cannot possibly win compared to SpaceX in this endeavor. If the NASA astronauts return safely, the mission will be dismissed as an embarrassing fiasco compared to Apollo 11. If they crash and burn, the mission will be depicted as definitive proof that NASA has become a totally worthless waste of money, killing astronauts for no good reason.

On the other hand, the SpaceX circumlunar mission will be seen as a giant leap for the fledgling extraterrestrial private enterprise -- and at a fraction of the cost of the NASA debacle. If the crew return safely, they can expect a ticker tape parade like the Apollo 11 crew; if they die, they will be remembered as heroes whose sacrifice helped open the high frontier.

Gerald Black's suggestion of a joint public-private mission would be a truly horrible mistake. For SpaceX, the bottom line is financial, while for NASA it is political, and these two do not mix. NASA must spend whatever it takes to avoid failure, while SpaceX can just fix whatever went wrong and launch again. A joint mission would almost certainly involve NASA micromanagement, including the agency's byzantine human-rating procedures, greatly increasing the cost while sucking SpaceX into the inevitable public relations disaster awaiting NASA.

The right answer is of course to cancel the SLS and the Orion and to remove NASA from the space launch business altogether. Force NASA to rent seats on private launch vehicles, with no more micromanagement of the development or operation of the vehicle than when a NASA employee flies on Delta Airlines..

Of course a sun-synchronous orbit can have a ground track a few hours before sunset (or any other time of day); the local time for the other half of the ground track will be 12 hours later. If the sun lies in the plane of the orbit, the ground track will be near noon on the dayside and near midnight on the night side.

A problem for space tourism is that direct observation of the Earth or the cosmos through a window (as in the cupola on the ISS) must be limited to a few hours total, in order to avoid radiation exposure above the 20 mSv limit proposed by Al Globus. It is of course possible to use some kind of periscope (with mirrors backed by shielding) to allow viewing, but a virtual window may be a preferable solution (i.e., a video screen displaying the external view as seen by a camera).

Note that this approach is used in some interior staterooms on the cruise ship Oasis of the Seas, which have "virtual balconies" – i.e., floor to ceiling video screens showing the view outside the ship.

Virtual windows on a tourist satellite have other advantages. Every stateroom can have one, and the screen can also be used for TV, onboard info such as entertainment schedules or restaurant menus, computer displays, artwork, realtime or canned views of other scenes (close-ups of the Moon, a street scene in Paris, a tropical beach, whatever). If this is accepted, however, there is no apparent reason not to locate the tourist facility in ELEO and to display the views seen by cameras on other small satellites in whatever orbits seem interesting. Indeed, why not just stay home on Earth and watch such scenes on TV? (Note that you can already watch realtime views from the ISS at https://eol.jsc.nasa.gov/ESRS/HDEV/ ).

I have no doubt that many tourist satellites will offer the transcendent experience of floating in free fall inside some kind of transparent bubble, with the cosmos all around you, where you can "put out your hand and touch the face of God." Time in such a facility will be limited, not only to avoid excessive radiation but to give other tourists their turn. Apart from that, I think most windows will be virtual in almost all tourist satellites, space settlements, deep space vehicles, lunar settlements, etc.

Three comments:
1. A major defect of ELEO for tourism is that the ground track is the same on every orbit, and >70% of it is over ocean, so there is not much to look at. Once cheap shielding is available (probably water or slag from an asteroid), inclined orbits will probably be preferred. The optimal tourism orbit may be sun-synchronous, a few hours before sunset, providing complete Earth coverage, optimal lighting for Earth-viewing, and simple articulation of solar arrays. While we should of course pursue all profitable markets for facilities in ELEO, I think assembling sunsats there (for subsequent transfer to GSO) is a better potential source for the throughput that is needed to reduce Earth launch prices.

2. The geomagnetic field seems to be disintegrating. It is highly probable that we are in the early stages of a geomagnetic excursion (a.k.a. a geomex), one of the periodic episodes, typically lasting one or two thousand years, in which the field becomes disorganized and collapses to a small fraction (<5%) of its normal strength. The last one of these occurred 40,000 years ago. This means that we are likely to lose the geomagnetic shielding in ELEO within a few decades, so we need to get moving if we want to take advantage of it to reduce the initial costs of space settlement. For more info, see my recent paper at http://www.nss.org/settlement/journal/NSS-JOURNAL...

3. A fundamental reason for space settlement is that we absolutely must establish a thriving interplanetary society before the end of the Holocene (the warm interglacial period that began 11,700 years ago and has encompassed the entire development of human civilization). The next global glaciation, which will last a thousand centuries (!!), is certainly coming, and it will be by far the worst catastrophe in recorded history. The only question is when. This is a current controversy among climatologists, but as far as I know nobody has yet considered seriously the possible impact of the new geomex. The ominous observation is that a geomex seems to have occurred at the end of every previous interglacial for which adequate records are available. It is thus conceivable but not proven that the descent into the long glacial nightmare could begin within a century or two. That is a very short time in which to develop an extraterrestrial civilization that can maintain human progress while the Earth descends into frigid chaos. See the paper for more discussion.

The original qualifications for pilot astronauts adopted by NASA included a technical undergraduate degree and experience as a jet test pilot. There were no women pilots meeting these requirements, so the question of their exclusion did not arise. In 1959, Jerrie Cobb had about 7000 hours of flight experience, but only one flight in a jet, and no bachelor’s degree. Jackie Cochran had quite a lot of time in jets (including being the first woman to exceed Mach 1), but she was too old (53) and also lacked a degree. NASA’s prejudice was not against women per se, but in favor of test pilots – and that was not unreasonable, given the uncertainties about spaceflight.

It is not clear what would have happened if an exceptionally qualified female had applied. Given the prudish standards of the time, it would have been difficult for NASA to assign her with males to the very cramped quarters of a Gemini or Apollo capsule. She might have had to wait until Skylab, where some privacy could have been arranged.

The test-pilot requirement was relaxed to 1000 hours of jet time by the 3rd intake of pilots in 1963. In 1965, when the first group of scientist astronauts were accepted, candidates needed a doctorate but no flight experience. It was however clear that everybody would be expected to complete standard USAF jet pilot training. The same was true when I joined the program in 1967 (I had a private pilot’s license, but only about 200 hours, mostly in Tiger Moths).

Plenty of women met the qualifications for scientist astronauts, and I expect NASA received many applications. If I remember correctly, there were 63 finalists who went through physicals, interviews and tests when I did -- and none of them were female. This might be evidence of prejudice in NASA – but it could also be the USAF’s fault, since women were not then accepted for jet pilot training.

Many of the mid-level managers in NASA had backgrounds in aircraft flight test, and they clearly preferred pilots to scientists. The basic problem was that they thought the purpose of spaceflight was to test spacecraft, while we thought the purpose of spacecraft was to permit spaceflight.

When my group reported to MSC, we were welcomed by Deke Slayton, who told us that he had been forced to accept us by the National Academy of Sciences, but that we might as well resign forthwith, since no scientist would get into space while he was in charge of crew selection. That’s why we called ourselves the Excess 11.

Deke kept his word, at least through Apollo. The only reason Jack Schmitt went to the Moon on the last mission was that several of us broke ranks and approached the Administrator directly, and he countermanded Deke. Our argument was that teaching pilots to do geology by following checklists was no substitute for the professional experience of the two geologists among the scientist astronauts (the other was Tony England).

Times have certainly changed, for scientists as well as women. The best example is biochemist Peggy Whitson, who accumulated 377 days in space in two tours aboard the ISS (the second as station commander), including nearly 40 hours EVA – and she was Chief Astronaut from 2009 to 2012. So much for the claim that only male test pilots have the Right Stuff.

Article 103 of the UN Charter says “In the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreement, their obligations under the present Charter shall prevail.”

Article 73 says “Members of the United Nations which have or assume responsibilities for the administration of territories whose peoples have not yet attained a full measure of self-government recognize the principle that the interests of the inhabitants of these territories are paramount, and accept as a sacred trust the obligation … to develop self-government, to take due account of the political aspirations of the peoples, and to assist them in the progressive development of their free political institutions…”

It is thus clear that future inhabitants of the Moon (and other celestial bodies) will have rights to self-government that trump the Moon Treaty (and all the space treaties). As a member of the UN, the US is required to recognize and encourage the exercise of those rights by insisting on modification of any treaties that support extra-terrestrial colonialism. In particular, we need a clear, equitable mechanism for establishing and protecting private property rights in space, and we must reject the international protection racket called the Common Heritage of Mankind Principle (CHOMP).

The giggle factor (i.e., incredulity) is the principal impediment to deployment of SBSP. Claiming (as in #3 in the statement) that we need extraterrestrial in situ resource utilization (ET ISRU) is counterproductive because it squares the giggle factor. The enthusiasm about lunar resources shown by Gerry O’Neill and the L5 Society in the early 1980s was one of the principal reasons for the lack of Congressional support after the original NASA/DOE study. I know about this, because I was President of L5 at the time.

Moreover, the claim is untrue. Unless it can be shown that the manufacturing cost of SPS hardware using space resources is somehow less than the cost of similar components fabricated on Earth, the only possible advantage of ET ISRU is that it may avoid the cost of launch from Earth. It doesn’t seem probable.

According to the DOE, the rising worldwide demand for electricity will require at least 110 GW/year of new generating capacity for the foreseeable future. That implies an annual capital investment of order $250 billion, depending on the technology employed. There should be plenty of money for SBSP, if we can overcome the giggle factor and show that it will be both reliable and cost-competitive with alternatives.

Justifying SBSP requires that it make a significant contribution to this market – i.e., at least 10 and perhaps 30 GW/year. Assuming a reasonable satellite specific mass of 7 kg per kW delivered to the grid (plus about 10% for orbital transfer propellants, using electric propulsion), this deployment schedule requires launching 200 to 600 MT per DAY. For comparison, worldwide launches now amount to less than 400 MT per YEAR!

This traffic is quite sufficient to justify building reusable LVs. We don’t need much new technology (except reusable reentry protection, such as hot structures): the economies of scale lead to launch costs to LEO below $400/kg, using quite conventional (but reusable) two-stage LVs. With the specific mass above, this means a launch cost of < $3080/kW. Amortizing this over 30 years @ 3.25% (the current prime rate), and assuming the SPS operates 95% of the time, launch costs then contribute < 2 cents/kWh to the cost of power. This is a quite competitive cost; it is in fact less than the cost of fuel in a coal or natural gas fired power plant.

It makes no sense to develop ET ISRU as a precursor to SBSP, because that means paying the present high cost (~$5000/kg to LEO) to launch the needed missions and equipment. Also the time needed to develop the ET infrastructure would make the SBSP business case harder to close by delaying revenues from selling electric power. In the unlikely event that this approach reduced SBSP costs, it would eliminate the high launch traffic to LEO that is needed to get costs down, and would therefore impede development of solar system resources. A much better path is to deploy ASAP a competitive SPS using terrestrial materials, and then take advantage of the resulting low launch costs to expand beyond Earth orbit.

Although the credit belongs to Leigh Ratiner and not to me, I am pleased that I was President of the L-5 Society in the early 'Eighties, when we persuaded the US Senate not to ratify the Moon Treaty.