Those who know me, know that I have been a fan of space exploration since boyhood. Long ago, I even worked professionally in the satellite launch business.
Remaining connected to that dream, I have come to believe that such exploration is important to us now, for the same reason that it was important to the empires of old. The most effective explorers and colonizers were also those with the greatest wealth, power, and longevity.
Those most effective explorers and colonizers understood the proper roles of government and enterprise in that joint effort. Unfortunately, our space program has never used that model, although the Augustine Commission has recommended something similar.
Back then, government provided exploration and new technology developments, because business would not invest in them. Business would utilize those results to create colonies, organize trading networks, and develop other profitable activities, something government (almost by definition) does not know how to do.
Space exploration, particularly manned exploration, requires certain things to be successful. For the transition to commercial exploitation, these things must be not just feasible, but economically practical. We have not been able to achieve that in 53 years of flying chemical rockets into space, so clearly, something new must be tried.
One of the most important things is reliable access to Earth orbit, and it has to be inexpensive to be commercially practical. We are losing the ability to launch big payloads with the retirement of the space shuttle, although some commercial rockets appear almost ready to take up that role.
We have never, ever had an inexpensive launch method, and we have had no way to reach the moon (much less beyond) since the last of the big Saturn-5 boosters flew long ago. It takes a government program to create a booster that big, because there is no commercial need for it until long after it already exists.
A technology I would suggest is the integral rocket-ramjet (a 1970’s missile technology), as a strap-on booster capable of separate fly-back and landing. The higher performance of the ramjet can be traded both for more throw weight, and for the extra structural “beef” necessary for effective re-usability.
To go anywhere beyond the moon is a voyage measured in months or years, not days. That raises the issue of providing effective crew survivability: protection from medical damage from zero-gravity exposures beyond about 400 days, protection from lethal solar and cosmic radiation, sufficient habitat volume, long-term life support, and much more powerful deep space propulsion (if for no other reason than just to cut down flight times).
Devotees of science fiction already know that spinning can substitute for gravity. The unanswered technical questions are how fast a spin can new tolerate, how much gravity is enough, and how much head-to-toe variation in “gravity” can we tolerate?
Sounds like a worthy government project to me. After 49 years of manned spaceflight, I have to ask why we have not already answered these questions. Doing these experiments is certainly long overdue.
Protection from radiation requires heavy shielding, and perhaps shorter flight times to reduce exposure risks. Both point to a need for vastly more powerful deep-space propulsion capabilities.
A much larger habitat space, and a self-sustaining long-term life support capability, are things we can do right now, but they are bigger and heavier than anything we have ever flown before. This also points toward a need for very powerful deep space propulsion.
Powerful propulsion is not just higher efficiency, it is also a very high acceleration capability. Ion and plasma devices typically have the efficiency, but not the thrust. The rockets we have built up to now have the thrust, but not the efficiency.
Something new and different is obviously required, and I would suggest a couple of nuclear approaches. One is the nuclear thermal rocket for shorter interplanetary voyages with smaller payloads, and the other is nuclear explosion propulsion for the really long-range and heavy-payload stuff.
We actually pursued nuclear rockets under NASA/AEC Project “Rover” from about 1959-1972, but gave it up when President Nixon killed the Apollo moon program (and by extension the Mars mission planned for the 1980’s). USAF actually pursued the explosion drive under Project “Orion” 1959-1965, but it died for lack of funding when all space program activities were transferred to NASA in 1965.
Both would have worked then, and still could today. The safest place to “play” with stuff like this is the airless, waterless, uninhabited moon so very near; almost as if God put it there for that very purpose. Sounds like a good government project to me, and it is long overdue.
Doing significant things in space will require at least two additional capabilities. These are the ability to refuel in space from one vehicle to another, and the capability to do fine assembly and repair work in vacuum and zero-gee, something prevented by the clumsy Michelin-man space suits available to us now.
Refueling looks to me like relatively straightforward component and procedure development work. Doing fine work while space-suited is going to require a major, fundamental change.
Perhaps the initial form of the breakthrough already exists in the form of the mechanical counter-pressure suit. This is an update of the old USAF “partial pressure” suits of the 1950’s with better design criteria and far better materials. It has existed since the late 1960’s, but has been “forgotten to death”.
I found this technology on an internet site, complete with a video and four supporting documents. Two of those documents date from live-subject tests in the late 1960’s, including one in a hard vacuum. See for yourself at www.elasticspacesuit.com
The test subject was wearing an oxygen helmet and breathing bag, plus 3-4 layers of what amounted to nothing but porous pantyhose material. He cooled very effectively by sweating directly into vacuum. Exposure time appeared to be measured in hours, if not essentially unlimited.
This subject had great agility and freedom of movement, and his entire rig weighed only 85 pounds. His easily-removable gloves were less cumbersome than the cowhide work gloves I use in my shop. Data I found elsewhere indicated a man could doff these gloves and work barehanded in space for up to 10 minutes before re-donning them!
This is the sort of mobility and dexterity breakthrough we have needed in manned spaceflight for decades. And it existed decades ago, but was never used. Sounds like another good government project to me, and one long overdue.
Update 10-11-13: See also 1-21-11 "Fundamental Design Criteria for Alternative Spacesuit Approaches".
If significant progress were made on all the fronts I listed above, the effects could be as astounding as the original moon shot effort. This would include enabling the initial commercialization of some space travel.