The Glory Days
From 1961 to 1973, a
period of 11 years, American space experience grew in leaps and bounds on every single flight, amazing even the people who
participated in it. In 1961, we barely launched Alan Shepard into space at all,
not even for a full orbit. In 1962, John Glenn was on orbit for 3 laps. In 1963 Gordo Cooper was on orbit for a day and a half. In 1965 we were walking in space and rendezvoused two manned spacecraft, one of which stayed up for 14
days, the duration of a typical shuttle flight. In 1966, we were docking ships
together, more specifically, a manned spacecraft with a propulsion stage, the commercial significance of which I will get
into later. In 1968 we were orbiting the Moon, and in 1969 we landed on it. In May 1973, in one shot, we launched Skylab, a space station as big as Mir was after
7 big launches. Before the month was out, we rescued it from potentially mortal
launch damage, possibly not too unlike STS-107, launched nearly 30 years later.
Backsliding and Blindness
On 16 January, 2003,
we launched STS-107. It lasted 16 days, comparable to the 18 days of Soyuz 9,
launched in 1970. It did not add anything to the space station. It did not attempt any significant new space travel technologies or techniques. STS-107 set no records at all, except perhaps the number of individual experiments carried out on a single human space flight. STS-107, from the perspective
of expanding our presence into space, simply ran 255 laps in well trodden Low Energy Orbit.
What a boring cause to give seven lives for! In AS-204, better known as
Apollo One, Ed White, Gus Grissom, and Roger Chaffee gave their lives to allow others to go to the moon. What vision were the fourteen since then given for?
The International Space
Station was derived originally from the dual-keel concept dating from 1986. This
old concept bragged of untried Solar Thermal Dynamic Generators (TDG), a bold new step in space power generation, with proven
photovoltaic wings as a fallback in case these didnt work. It had large hangars
for space tugs, reusable upper stages to make launching and servicing commercial satellites on geostationary orbit possible. It was designed as a stepping stone to Mars; to make an return to the moon economical. The development of ships to transfer satellites to GEO from this station gave the
space shuttles biggest upper stage the name Interim Upper Stage (IUS), a device to tide us over until this station
and its reusable tugs were ready.(Trento Prescription p 120)
The station we got is
for microgravity research. Its proponents argue that more experience is necessary
for studying the effects of long term exposure of humans to the microgravity environment.
These proponents either forget, or simply deny, that the 20 years experience our new friends the Russians have from
their Salyut 7 and Mir space stations is enough. Even with that argument, there
was no reason to deny the ISS the ability to stage a mission to the Moon or to Mars.
The backwards evolution of this station even changed the name of our stopgap space tug, Inertial Upper Stage
Im not going to go into
the ugly details of why the Space Shuttle is a backward step or why the ISS is a step to nowhere. Robert Zubrin has already done this in his book Entering Space (1999 Penguin Putnam), an excellent
forward looking dissertation on how to thrive in space. Im going to present specific
ideas and plans for expanding our space program from the failure of STS-107, as well as general rules for improving the safety
of future spacecraft. I would like to join the collaboration of the aerospace
community in this endeavor.
The Good News
The good news from the
Space Shuttle is that we now have 114 flights worth of experience with manned aerospace ships (counting VKK-1 Buran.) Even though it was at great expense: 14 lives and at least $60 billion, this is extremely
valuable operational experience and has given me several ideas for being able to improve safety on the next generation system. I would like to consolidate my ideas with those of others so that we can have the
widest range of options to chose from in developing critical systems for the next generation.
We now understand the vagaries of space station design, construction, and assembly.
With ISS we threaded the middle ground between the opinion that a proper space station, like Skylab or Option C, should
be built on the ground and launched in one piece, reducing the number of expensive and dangerous launches and spacewalks by
an order of magnitude, and the other opinion, that we dont need a space station at all.
Because of the pad-launched, mostly expended nature of the Space Shuttle stack and proposals for high-lift and high-energy
derivations, both of these routes offered a more economical next step than the ISS!
The big, single chunk station took the form of Shuttle-C/Option-C, while the latter took the form of Ares/Mars Direct.
The value of the Shuttle and ISS, therefore, is not in their efficiency, but in their demonstration. The Shuttle will be remembered in history as the technology demonstrator for fully
reusable aerodynamic orbital service vehicles, unless we continue to stagnate. The
Space Station has successfully demonstrated the feasibility of assembling multiple units on orbit. The advantage of this only comes if many small launch tickets are cheaper than one big launch ticket. Using current launch systems and those that can be quickly developed (i.e. Shuttle
Derived Vehicles), this is demonstrably false. In fact, I've figured it out from
cost data available at www.astronautix.com, that the Space Shuttle is, at current (or at least, recent) launch rates, the single most expensive launch vehicle
on a per pound to orbit basis in the entire history of spaceflight! If it can
be safely used a few more times until its replacement becomes operational, we still should, because the Shuttle is also the
most versatile launch vehicle in history, with an unprecedented return payload capacity (i.e. completed experiments), and
is currently the only orbital service vehicle capable of supporting a remote manipulator system (robotic arm or crane.)
The Best Case
STS-107 was hit by orbital
debris or similar, that caused damage to the thermal protection system or structure.
There was no way to detect it, and nothing could be done about it, and nothing can be done to significantly improve
the safety of future flights. I don't consider this likely, but if it is the
case, and comes to light quickly, we can continue the current shuttle manifest delayed by perhaps 4 to 6 months, while the
Shuttle's replacement is developed. In this case, we still need a replacement
for this aging system because it is too expensive to continue operating the Space Shuttle, even if it is safe. The difference is that we will not require interim vehicles for human spaceflight.
The Space Shuttles latest disaster was caused by a major flaw in the design or age of the Thermal
Protection System or structure, causing a stand-down so long (3-5 years) that it is not worth fixing the problem. The International Space Station can be assembled by Proton and Ariane 5 launches, with the robotic arm
and airlock on the Space Station doing the assembly work (if the overweight modules can be lighted up enough.) NASA develops semi-ballistic interim spacecraft to get back into manned spaceflight within 3 years, provide
a solid return capacity, and provide a backup to the now critical and non-redundant 11A511U launch vehicle, which launches
both Progress and Soyuz spacecraft. A heavy lift vehicle can be developed to
use existing shuttle hardware and perhaps launch several modules for the Station at once.
In this worst case, the SSMEs and OMS/RCS pods from the existing orbiters can be used in a Shuttle Derived Vehicle
(Shuttle-C, Shuttle-C2, Shuttle-Z, Ares, or my proposal, Shuttle-X.) Of Shuttle
hardware that is used, good mockups should replace those items removed from the orbiters so that they can serve as accurate
I am working with this worst case scenario, as you can probably guess from the names on the
title page of some of the spacecraft/launch systems. The STS replacement concepts,
Bluestar, Cyanstar, Greystar, and Greenstar are not affected by this. The Sprint
and Shuttle-X concepts were formed on assumption that the Space Shuttle will never fly again.