Space Transportation System
en.wikipedia.org
en.wikipedia.org
As a hobbyist, I am trying to create a model of the "space tug" featured so frequently in the 1970's NASA studies.
Here is more information on the Space Tug than anyone could need including links to NASA documents/studies:
http://www.projectrho.com/public_html/rocket/spacetug.php
My progress on a model:
Let's hope Elon cools down, or someone else steps up to it.
I don't think that's the way causation flows. We got the dreamers because we did ambitious things. If our country put its mind to establishing a permanent colony on the Moon or on Mars, it would light a fire in us all.
Hell, the field of rocketry was itself started by dreamers. Tsiolkovsky and von Braun weren't inspired by ambitious things, they dreamed of ambitious things, and helped made them happen. Goddard reportedly credited Wells[0] as the initial source of inspiration; Tsiolkovsky was apparently moved by the works of Verne[1].
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What we need, really, is more dreamers in positions of money and influence. People with enough money and political clout to move the needle. Because at this point, what's stopping us is no longer science, just the bank account, and some engineering work of the kind which gets solved when you throw money at it.
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[0] - https://en.wikipedia.org/wiki/Robert_H._Goddard#Cherry_tree_...
[1] - https://en.wikipedia.org/wiki/Konstantin_Tsiolkovsky#Early_l...
Money magically “becomes” available when there is a profit to be made. Part of what we need to do as a community is finding ways to “monetize” the activities we want to see. Part of this is having the visionaries, but part of this is about “closing” business cases. Things are better now, but the old joke of “How do you make a million in space? Start with 10 million” still applies.
Specific example: law of gravity. If you don’t understand it, you still are impacted by it. So you can either learn it and use it (to make airplanes) or you can just try to jump into the sky and be upset why you can’t fly.
How this applies here: Why is there a lack of political will to “do” space? Well it comes down to kitchen table politics and budgeting. If push comes to shove, “we” as a country think that NASA is something “nice to have” and will budget it at the level of say a “nicer car” then is absolutely necessary to get from a to b safely. But if it will come in the way of safety/food on the table/etc, it will be the first to be cut.
Until there is a true “need”, space exploration will always be a “nice to have” rather than a core necessity.
The shuttle has flown some classified missions for the DoD but not as many as initially intended, because the platform didn't turn out as reliable as they had hoped. [0]
[0] https://en.wikipedia.org/wiki/Manned_Spaceflight_Engineer_Pr...
Then came the Challenger Disaster, which grounded the Shuttle fleet for three years and lead NASA to cancel all performance improvements, leading to the NRO giving up on the Shuttle as a launch vehicle. In the end the space shuttle was neither reliable enough nor powerfull enough for NRO missions. [1][2]
1: https://de.scribd.com/document/348134338/Declassifying-the-F...
Of course, the Soviets never shot down an American reconnaissance satellite and the Shuttle never launched into a polar orbit. Also the military and NRO figured out that you could just launch a reconnaissance satellite even into a polar orbit on an unmanned rocket anyway.
The Soviets, of course, were a lot more inclined towards unmanned solutions anyway, and concluded that the only thing the Shuttle would actually be useful for was orbital bombing, since it could launch nukes, do a burn to change its orbit, and repeat until empty to confound any kind of ASAT system. And then they panicked, invented their own space shuttle, and then collapsed as a major superpower and abandoned the project. I don't know of any clear evidence that the USAF even considered this, but if you evaluate the Shuttle design from a perspective of already having different and arguably better solutions for all of the stated requirements, it was probably safer for the Soviets to think, "this must be a secret orbital space bomber" than to think, "wow, the Americans made a lot of really weird and nonsensical design decisions". Among other things, they probably didn't account for the fact that the American space program held onto the mythos of the heroic astronaut even when manned missions weren't the best technical solution (e.g. satellite launches).
> When in 1979 President Jimmy Carter considered canceling the shuttle program because of its cost overruns, it was the national security uses of the shuttle, particularly in terms of launching the photo-reconnaissance satellites needed to verify arms control agreements, that convinced the presi- dent to continue the program. Once the Reagan administration took office in 1981, an early action was to confirm as national policy that the shuttle would be “the primary space launch system for both United States military and civilian government missions" (Logsdon, 291).
Maybe we'd have been better off had that happened, then or earlier. But there's little indication that NASA would have been able to successfully get approval for a less radical vehicle without the Shuttle's biggest selling point at the beginning: cheap, reusable, with a fast turnaround time. And in terms of mission capability, everything and the kitchen sink to boot.
As for the compromises, among other examples, in 1969 the Shuttle's payload bay was "...in fact sized to launch HEXAGON," or Keyhole-9, then in development, ten feet in diameter by 60 feet long and over 30,000 pounds (Logsdon, 167). Well and good, except for the fact that HEXAGON would be EOL when the Shuttle started flying and thus was never expected to be launched on it. But they figured any future satellites would be the same size and weight, so the Shuttle was likely designed around those parameters as a result. Oops.
For what it's worth, even if the national security community hadn't originally pushed for the cross-range single pass capability that helped lead to the delta wing design, it's likely that NASA would have wound up there anyhow:
> The need for high cross-range was throughout the shuttle debate a point of contention between NASA and the national security community. In reality, requirements for national security missions requiring high cross-range were never formalized and more or less evaporated during the 1970s. Well before that time, however, NASA had decided that a shuttle having significant maneuvering capability as it returned from orbit was needed to survive the heat of entry into the atmosphere. So while the national security cross-range requirement initially drove NASA to a particular shuttle orbiter design, one with delta-shaped wings and the thermal protection needed to resist high temperatures during a maneuvering entry, NASA likely would have adopted a similar design even if that requirement had not been levied in 1969. Whether NASA would have gone forward with a shuttle having a 15 × 60 foot payload bay and powerful enough to launch the most heavy national security payloads is not as clear; in the final days of the shuttle debate in December 1971, NASA put forward a somewhat smaller and less powerful shuttle as its proposed design (169).
I cannot recommend John Logsdon's After Apollo? Richard Nixon and the American Space Program[0] enough. It's a fascinating look into the politics and challenges NASA faced even in the heady days after Apollo 11. And, yes, the mistakes: by DOD, NASA, congress, and the White House starting with Nixon.
0. https://www.amazon.com/After-Apollo-American-Palgrave-Techno...
Part 1: http://thespacereview.com/article/3172/1
Part 2: http://thespacereview.com/article/3302/1
Part 3-1: http://thespacereview.com/article/3390/1
Part 3-2: http://thespacereview.com/article/3394/1
Not surprising, given that back then, a) patriotism seem to have mattered more, and b) that's how you got funding for ambitious - and thus expensive - projects.
It seems to me that the dreamers are going to come from the private sector a la Musk, Bezos, and gangs. This can allow deep pockets like governments to spend frugally on projects that the general public can get behind.
I think we would still hear a a cacophony of moral objections. A spirit of pessimism seems to be hanging over us these days:
I'm curious to what you are referring, exactly?
Probably worth reminding about it here:
http://www.lettersofnote.com/2012/08/why-explore-space.html
I think space exploration can create happiness.
And also what's your alternative? For the different parts of the global never to come into contact?
You could throw shade at pretty much all human exploration because most of it was done to get more resources of some kind.
Granted, the New World suffered grievously by contact - an estimate 100M dead from diseases they were unequipped to handle. So there's that.
You tend to have dreamers pushing and implementing ideas, but it is much easier to get funding for more immediate goals
Space Settlements: A Design Study, NASA, SP-413 https://settlement.arc.nasa.gov/75SummerStudy/Table_of_Conte...
The space shuttle was only the first step in a very ambitious program that culminated with a spinning cylindrical space community housing 10,000 people and growing its own food.
There are detailed discussions about construction (using moon rocks), shielding, what plants and animals to use for farming, etc. etc.
Also this sentence is fascinating to me: "Whether space colonization is a unilateral effort on the part of the United States or a cross-national enterprise, it will most likely be sponsored by a public or quasipublic organization with a bureaucratic structure which permeates the early settlement." I've always thought the Alien movies strike the most realistic tone in this regard, with the Weyland Corp lurking in the background.
Thats why a simple diagram is better.
To be sure, the rendering is top-notch today, less so when they first made the switch, but I dislike even the modern realistic CG renderings. I want palette-knife clouds on the Earth in the background, hues of cerulean blue and rust orange on the aluminum surfaces of the space craft.... You know, art!
At some point, we started to prioritize form over function.
E.g. https://www.youtube.com/watch?v=yYAw79386WI [Around The Corner - How Differential Steering Works (1937)]
Can you recommend any online resources with good examples of professionally handdrawn graphs?
https://en.wikipedia.org/wiki/NERVA#NERVA_rocket_stage_speci...
NERVA had a greater thrust than the weight of the rocket, so could at least theoretically be turned into a ground launch system (probably after a few more iterations).
Related:
https://en.wikipedia.org/wiki/Project_Pluto
Nuclear ramjets were viable just before they were cancelled out of environmental and nuclear proliferation concerns. I'm fairly certain that a denser working fluid like nitrogen/oxygen creates a higher thrust than hydrogen, at the cost of having a lower specific impulse (ISP). So it should have been straightforward to build a final rocket that could use either. Maybe someone knows for sure?
Even as a tree hugging hippie in spirit, I'm saddened that we have hundreds of nuclear reactors around the world that may very well begin spilling more and more radiation into the oceans and air as our scientific wisdom declines under pressure from (insert dystopian endgame here: late stage capitalism/communism, austerity, fascism, what have you), but don't use nuclear power for scientific pursuits.
Also I'm a bit saddened that we never had nuclear launch systems, because they might have been a stepping stone to a microwave or laser rocket that used power transmitted from a ground station to run as an electric ramjet and transition to hydrogen in the upper atmosphere. To me, that's probably the only feasible way to reduce launch costs to something comparable to a space elevator.
To really do harm with nuclear reactors or waste from nuclear reactors you actually need to do a lot of stuff and once you shoot one down, doing nothing is a reasonable policy.
Seems to me its highly unlikely that we will ever see significant radiation impact on humans from current nuclear.
Sadly the destruction of nuclear has essentially slowed our whole civilization, we have never really jumped from becoming a chemical to an atomic society. Had nuclear energy won out we would have lots more research in applications for these technologies.
Nuclear trains, ships and rockets. Nuclear batteries. Medical isotopes. Materials for medical diagnostic.
https://en.wikipedia.org/wiki/List_of_nuclear_power_systems_...
And even then, the communications package for Neptune or Pluto or for KBOs probably would share a lot of common parts. As would power and guidance.
Maybe could be useful for moving things between LEO and Lagrange. Then the tug could be used again quickly.