Student 5: Low Achieved
3.8 Powered Space Exploration: Space Shuttle
1 Being human means looking to extend your horizons. From earliest time human
beings have been restricted by individual diversity and broadly characteristic physical
limitations which influence their ability to move beyond their immediate
environment. Our sun, moon and stars have always attracted attention and the
invention of the telescope extended the ability of humans to see far distance and to
study and understand the movement of celestial objects. Being human is to look to
understand our immediate environment and to extend this understanding beyond
existing physical limitations. The development of powered flight machines provided a
massive leap forward in satisfying the natural desire to explore – but the power of
gravity remained a limiting factor. The quest for flight beyond the influence of gravity
remained a seemingly impossible dream.
2 Powered space exploration, as opposed to sub orbital jet flight , had its origin in the
development of rocket-based weaponry used during World War 2. In the final years of
this war the Germans launched over 3000 of their V-2 long range combat ballistic
missiles against enemy cities and it was this rocket that became the first man-made
object to be launched into space. It was an event that starting human beings on a
route that would see them finally escape the confines of the earth’s gravitational field
and have the capability of controlled powered travel into our solar system.
3 Following the end of the war the race was on amongst the victorious allied countries
to further develop the German rocket technology by gaining access to not only both
the technology and the full design plans, but also to the key scientific and
technological personnel involved in the German development process. Werner Von
Braun, one of the most influential of the German scientist-engineers, and some of his
select rocket team ended up moving to USA to work on the US military intermediate
range ballistic missile programme. Von Braun moved to NASA to become director of
the Marshal Flight Centre where he was responsible for developing the Saturn V
rocket that would eventually propel the Apollo spacecraft towards planet Earth’s
closest neighbour in our solar system - the Moon, and to the landing promised by
United States president John F. Kennedy before the end of the 1960s decade Over
the course of the Apollo moon landing program, Saturn V rockets enabled six teams
of astronauts to reach the Moon’s surface.
4 Following the US success in winning the political race to put the first man on the
moon the drive to set new exploratory goals turned away from the moon towards
more distant and what were perceived as being more interesting and challenging parts
of the solar system. So attention moved away from further Moon exploration towards
more distant space travel with the development of what became known as the Space
Shuttle - a launch system and orbital spacecraft that could take humans into earth
orbit and return them to earth again – with the crucial added benefit of actually being
able to be reused time and time again.
5 Although the actual design and construction of the Space Shuttle began in the early
1970s, the conceptualization of a spacecraft which could be launched into space and
then return to the earth’s surface through a horizontal landing began much earlier - in
fact even before the Apollo programme of the 1960s. By the middle of that decade the
US Air Force was conducting a series of classified studies on next-generation space
transportation systems and concluded that semi-reusable designs would be the most
economic option and in 1968 work began on an integrated launch and re-entry vehicle
and a Space Shuttle main engine – leading towards the construction a spacecraft that
could not only deliver a payload into stable earth orbit but also re-enter the
atmosphere and fly back down to Earth again
6 The cutting short of the Apollo program was the result of waning public interest in
further astronaut activity on the moon and what was seen as a rather dull and boringly
routine return journey. There was also significant political reluctance to continue to
commit the huge level of funding required to maintain its ongoing development.
7 The Space Shuttle program was formally launched three years after the moon
landing, in January 1972, when President Nixon announced that NASA would
proceed with the development of a reusable Space Shuttle system. During early
shuttle development there was a lot of debate about the optimal shuttle design to best
balance capability, development costs and also ongoing operating costs. However, the
final design was chosen from the available options because it was less costly to build
and less technically ambitious than alternative fully reusable designs. The system
combines rocket launch, orbital spacecraft, and re-entry vehicle with modular addons.
8 The first complete orbiter vehicle was rolled out in September 1976, and a
successful series of glide-approach and landing tests were carried out to validate the
chosen design. The first of four orbital test flights occurred in 1981 leading to
operational flights beginning in 1982, Five space-worthy orbiters were built, two were
destroyed during missions and three retired from duty - with the last operational flight
occurring in 2011. Many important goals were achieved over the course of the
programme – both military and non-military – with major missions including a long
series of satellite and interplanetary probe launches and the construction and
servicing of AN orbiting space station.
9 Usually, five to seven crew members rode in the orbiter. A typical payload capacity
was about 20,000 kilograms, but could be raised depending on the choice of launch
configuration. The orbiter was unique in that it carried its payload in a large cargo bay
with doors that open along the length of its top. It was this feature that made possible
the deployment of large satellites such as the Hubble Space Telescope (HTS) and
allowed the capture and return of large payloads back to Earth.
10 The long term programme of satellite launches carried out over the lifespan of the
Shuttle directly changed our world. The satellites orbiting the Earth allow us to
communicate instantaneously with people on different sides of the world, and to
broadcast high quality television pictures to people all over the globe. The Global
Positioning System now established allows us to pinpoint our location anywhere in
the world. And the comprehensive network of weather satellites saves lives by giving
advance warning of likely or potential catastrophic events, and together with other
scientific instruments in orbit allow vast amounts of data to be gathered to expand our
understanding of the physical world
11 The Space Shuttle played a key role in the construction of the International Space
Station (ISS) - a large artificial satellite established as a habitable low earth orbit
microgravity and space environment research laboratory , also suited for the testing of
spacecraft systems and equipment required for future space missions to the Moon and
Mars. It is a modular structure whose first component was launched in 1998.
Additional components and support crew have been able to be ferryed up to the ISS
during progressive Space Shuttle missions. The ISS project involves joint
collaboration between five international space agencies with the station divided into
two orbital segments shared by many countries. It is funded until 2020, and expected
to be able to function for a significant additional period if funding is extended.
12 Other Shuttle successes included the mission of the spacecraft Ulysses to study the
Sun at all latitudes. Originally scheduled for launch in May 1986 aboard the Space
Shuttle Challenger, its untimely destruction meant that the launch was delayed until
October 1990 aboard the Shuttle Discovery. The end of mission was scheduled for
July 2008, being determined by the inability to prevent attitude control fuel from
freezing. However clever improvisation by the mission technologists extended the last
mission operations until the end of June 2009.
13 The 2.4 metre Hubble Space Telescope was carried into orbit by a Space Shuttle in
1990 and remains in operation in low Earth orbit today. Hubble's orbit outside the
distortion of the Earth’s atmosphere allows it to take extremely sharp images of the
universe's most distant objects. Although not the first space telescope, Hubble is one
of the largest and most versatile, and is well known as both a vital research and public
relations tool for astronomy. Many Hubble observations have led to fundamental
breakthroughs in the science of astrophysics such as the accurate determination of the
rate of expansion of the universe. Hubble is the only telescope designed to be serviced
in space by astronauts and between 1993 and 2002, four missions repaired, upgraded,
and replaced systems on the telescope. A fifth mission was cancelled on safety
grounds following the shuttle Columbia disaster, however public support for the
project resulted in the approval of one final mission to the telescope in 2009 to
hopefully extend its life until 2014.
14 The Shuttle programme enjoyed considerable success as a platform for scientific
research and resulted in many commercially successful technological spin-offs in
fields as diverse as gas detection systems, medical instrumentation, automotive
insulation, rescue equipment and video stabilisation software. When government
expenditure on the Shuttle programme was being questioned supporters often cited
the many scientific investigations and commercial spin-offs as important
contributions that justified the high cost of the programme.
15 However despite these ongoing programme successes, by January 1986 there had
only been 24 Shuttle flights, although in the 1970s NASA had projected more flights
than that for every year of operation. The complexity of the reusable system, coupled
with the rigors of flight, meant that the time needed to prepare the Shuttle for another
flight turned into several months instead of the expected several days. In addition, a
wide range of problems associated with ensuring the safety and performance of the
complex Shuttle system resulted in delays in the planned mission schedule resulting
in less flights and far fewer scientific experiments than had been publicly predicted.
16 NASA responsibilities during the design, development and Shuttle operation
phases centred on balancing the ongoing safety considerations within an environment
of strict budget constraints. However, to the casual observer at the beginning of 1986
all appeared to be on track and going well. That all changed at the end of January of
that year when a catastrophic systems failure resulted in the Challenger disaster,
very shortly after mission launch with the loss of all seven crew members .
17 Disintegration of the entire vehicle began after a seal in one of the solid rocket
boosters failed at liftoff. The O-ring failure caused a breach in the joint it sealed,
allowing pressurized hot gas from within the solid rocket motor to reach the outside
and led to the structural failure of the external tank and the break up of the orbiter.
Although several crew members are known to have survived the initial breakup of the
spacecraft the shuttle had no escape system and the impact of the crew compartment
with the ocean surface was not survivable.
18 The disaster resulted in a 32 month break in the shuttle program and the formation
of a special presidential commission to investigate the accident. The Rogers
Commission found that NASA’s organisational culture and decision-making
processes had been key contributing factors to the accident with managers having
known of the design flaw in the O-rings since 1977, but failing to address it properly.
Warnings from engineers on the launch day about the dangers posed by the low
temperatures of that morning and had also not been acted on. The graphic television
coverage of the actual explosion and the follow-up events had a dramatic influence on
the level of public support for the Shuttle programme both in terms of its risk to
human life and the level of public investment required for the continuation of the
programme.
19 NASA policy regarding safety was to ensure that risk assessment and risk
management systems were in place to avoid loss of life , injury of personnel, damage
and property loss. The need for safety awareness was instilled in all NASA
employees and contractors to ensure that an organised and systematic approach was
able to be utilised to identify safety hazards and ensure that safety could be fully
considered from conception to completion of all agency activities.
20 Right from the start of the Shuttle programme there had been a tension between
performance requirements and budgetary constraints which influenced both design
and operational considerations, and eventually contributing to the initial Space Shuttle
Challenger disaster. Eighteen years after the Challenger disaster a second Space
Shuttle, Columbia, disintegrated on re-entry at the end of its 16 day mission. Both
disasters were intensively investigated and disturbingly the report of the Columbia
Accident Investigation Board showed that risk assessment, risk management and
communication systems within NASA were again found to be wanting and that
recommendations made after the first disaster had proved inadequate in the prevention
of the second catastrophic failure. The focus for the NASA management and
engineering teams was firmly directed towards ensuring the safety of mission
personnel and over optimistic projections within NASA management of the lifespan
of the Shuttle programme questioned.
21 The end of the Space Shuttle programme in 2011 may have resulted in another
forced break in the human exploration of space, but it will certainly not dim the age
old human characteristic of looking to push our boundaries for travel and exploration
further away from the Earth’s surface, beyond our solar system and into deep space.
Our advancing technological capability will undoubtedly play a critical role in
increasing human capability to push these boundaries far beyond present limits.
The film Blade Runner, released over 30 years ago, depicts a world where the sun no
longer shines - an energy shortage has crippled life in the future. The earth is decayed,
and millions of people have been forced to colonize other planets. Genetic
engineering has become one of the earth's major industries, with humans now
assuming the role of "maker" and "creator." and artificial humans called "replicants"
have been created to do the difficult, hazardous jobs
Defining what it means to be human, provides most of Blade Runner's philosophical
focus, and in an online article in the Huffington Post John W. Whitehead contends
that this is increasingly the dilemma faced by contemporary society – “that is, the
most vital question confronting us is how to maintain our humanity in the face of
overwhelming technologies that tend to dehumanize us”.
The article contends that although the film was a box office flop its ultimate relevance
its challenge of what it must mean to be human.
At the moment travelling times stretching to many years confined in an alien
spacecraft environment is limiting human capability to reach distant planets – so the
focus for powered space exploration is on robotic missions. However technological
intervention is speedily chipping away at these constraints with the development of an
increasingly sophisticated range of robotic ‘replicants’, capable of carrying out set
tasks without associated ‘human’ constraints.
A key question being faced is what degree of being of ‘flesh and blood’ is a defining
characteristic of being human. Technology is already being implemented in the
human body to address physical disability and also boost ‘normal’ performance
beyond existing levels of human expectation. The increasing availability of this type
of ‘modification technology’ will further fuel ethical and moral debate about what it
means to be human and also influence our capability to successfully extend human
experience further into space.