
Space Transportation System - benbreen
https://en.wikipedia.org/wiki/Space_Transportation_System
======
JKCalhoun
Always fascinated by this — I suppose during my formative years, this was the
kind of stuff in space books I checked out from the library: space tugs, lunar
colonies....

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](http://www.projectrho.com/public_html/rocket/spacetug.php)

My progress on a model:

[https://www.therpf.com/showthread.php?t=294711](https://www.therpf.com/showthread.php?t=294711)

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ChuckMcM
That is a thing of beauty. I am in awe of your modelling skills.

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JKCalhoun
Wuh? I'm just a novice — figuring this all out (but enjoying the ride). Thank
you though.

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cecilpl2
The better you get, the worse you think you are.

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hef19898
I love how, despite things like the Cold War and the Vietnam War, projects for
the future have been so _optimistic_ and _ambitious_ back then. We really need
of these dreamers, people who's goal to land on Mars and build space stations,
instead of getting rich by selling adds over social media.

Let's hope Elon cools down, or someone else steps up to it.

~~~
wnkrshm
The project was intended as dual-use from the start, the shuttle was pitched
as a way for the USAF to get classified payloads into space and experience for
their military personnel.

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...](https://en.wikipedia.org/wiki/Manned_Spaceflight_Engineer_Program#Shuttle_missions_with_classified_payloads)

~~~
wongarsu
The originally envisioned Space Shuttle was much smaller, but NASA couldn't
get funding without USAF. In the process USAF and NRO demanded a much larger
shuttle, which required the boosters and the additional orange fuel tank, and
generally raised operating costs. You could argue that this significantly
contributed to the overall failure of the shuttle program (outside of narrow
use cases)

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...](https://de.scribd.com/document/348134338/Declassifying-the-Fact-of-
the-NRO-s-Use-of-the-Space-Shuttle-as-a-Launch-Vehicle)

2:
[https://nsarchive2.gwu.edu/NSAEBB/NSAEBB509/](https://nsarchive2.gwu.edu/NSAEBB/NSAEBB509/)

~~~
philwelch
The NRO requirements were a huge part of what sunk the shuttle. One
requirement was that the Shuttle should be able to launch into a polar orbit,
launch a reconnaissance satellite (to replace one that the Soviets shot down),
and then immediately land after coming once around (so the Soviets don't also
shoot down the Shuttle). This is why the Shuttle has that massive, heavy delta
wing--because you have to do a lot more controlled aerodynamic gliding to land
from a polar orbit.

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).

~~~
Bluestrike2
The compromises arising from NRO and other intel/military requirements may
very well have "sunk" the Shuttle (or helped do so); if so, it was only after
the same compromises likely helped it garner much of the political support
necessary to build it in the first place. DOD caused all sorts of headaches,
but the alternative probably would have been no launch system rather than a
better one. It certainly helped protect the program when it at risk:

> 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...](https://www.amazon.com/After-Apollo-American-Palgrave-Technology-
ebook/dp/B00VILIVCE/)

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rladd
This NASA publication shows the plans in much more detail.

Space Settlements: A Design Study, NASA, SP-413
[https://settlement.arc.nasa.gov/75SummerStudy/Table_of_Conte...](https://settlement.arc.nasa.gov/75SummerStudy/Table_of_Contents1.html)

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.

~~~
benbreen
Thanks for posting, that's an interesting resource. Table 3.2, laying out
projections of community space usage in outer space (including churches!),
could be good fodder for future historians writing about the mid-20th century
cultural assumptions that structured early space travel.

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.

~~~
WorldMaker
I'm mostly finished with the "Lady Astronaut" duology (The Calculating
Stars/The Fated Sky) from Mary Robinette Kowal. Highly recommended. She
started with predecessor works to these Shuttle-era dreams (such as Wernher
von Braun's original treatise on colonizing Mars, most of which the science
still holds up today, and was written prior to NASA's moon work) and posits a
timeline to make that happen in the 50s/60s to eventually push humanity to
Mars colonies by present day. (Via international cooperation in that case,
sparked in large part by a meteorite hit that caused massively sped up global
greenhouse effect/climate change on Earth.) The bibliography for the books has
some other interesting early space travel reading that's worth revisiting with
present day eyes.

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iscrewyou
Something about that image in Wikipedia makes it very easy to understand. Why
are vintage graphics so good? Is it the nostalgia or the limited amount of
color usage? Or is it the use of arrows and and telling the user exactly what
they need to know from the image? I can’t quite put my finger on it.

~~~
codeulike
If they released it now there would be a glossy video animation and a press
kit, and then fifty different websites would add clickbait titles like 'You
won't believe what NASA's new Robot Tug can do with its arms' and then make
you wade through paragraphs of blurb before letting you get to the bit that
actually explains whats going on. And you'd also have to click no to a pop-up
subscribe window and turn off the sound of an unrelated autoplay video, by
which time you would have forgotten why you even came to look at that page.

Thats why a simple diagram is better.

~~~
duxup
And somehow I still wouldn't understand it...

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zackmorris
A little easter egg as part of the usual Wikipedia crawl:

[https://en.wikipedia.org/wiki/NERVA#NERVA_rocket_stage_speci...](https://en.wikipedia.org/wiki/NERVA#NERVA_rocket_stage_specifications)

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](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.

~~~
nickik
> 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

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.

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rbanffy
I just love the concept of modular spacecraft. Even if we can get better
performance out of custom designs for space probes, there is a compelling case
for building more probes sharing the cost of a common architecture with
mission-optimized sensor and communication packs riding commodity boosters.

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.

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mundu_wa_hinya
Nerva sounds very interesting. Hmm, I wonder if spacex would have use for a
Nerva LEO to anywhere tug.... So launch a geosynchronous payload with a
minimal upper stage to get to LEO, get a tug to dock with the payload and
boost it to wherever.... Every so often an f9 or FH would put up a fuel tanker
into orbit to refuel the tug... Are there any other options to nuclear
propulsion for the tug? Solar? Lasers?

~~~
7952
For longer distances like earth to mars I don't think it really makes sense.
The tug will be out orbiting the sun for quite a while before it is useful
again. So you might as well leave it attached to the cargo and use it for a
return journey. But then isn't really a tug any more.

Maybe could be useful for moving things between LEO and Lagrange. Then the tug
could be used again quickly.

