Memorandum 92
Submission from Professor Colin R McInnes,
Department of Mechanical Engineering, University of Strathclyde
SPACE POLICY INQUIRY
1. INTRODUCTION
1.1 This invited submission provides a short
discussion of future visionary space activities and the opportunities
which they may present. The submission does not focus on near-term
policy issues but attempts to provide the committee with an overview
of speculative, but plausible long-term space developments. The
author has contributed to numerous industry and space agency studies
of future space mission concepts and technologies.
2. FUTURE VISIONS
2.1 Predicting future trends in science
and engineering is a notoriously difficult exercise. The best
which can be expected is to identify plausible futures and to
highlight any common themes which arise. There is an extensive
list of technologies which were confidently predicted at the beginning
of the 20th century but never arrived, and an equally long list
of totally unsuspected technologies which are now commonplace.
2.2 Future visions for space exploration and
exploitation abound. Most centre on large-scale industrialisation
of space for resource exploitation. Such visions consider space
exploration as a precursor activity. Examples of such visions
include the extraction of Helium-3 from the lunar regolith for
terrestrial fusion reactors, processing lunar material to fabricate
large solar power satellites and extracting rare metals from near
Earth asteroids. Many of these visions foresee private capital
driving future space exploitation rather than government programmes.
3. SPACE ACCESS
3.1 A key theme for the future exploration
and exploitation of space is low cost access. The current high
cost of delivering payloads to Earth orbit is widely recognised
as the main impediment to future large-scale space development.
Future options include lowering the cost and increasing the performance
of expendable launchers (such as the Ariane series) or developing
advanced re-useable vehicles (such as single-stage-to-orbit space
planes).
3.2 More visionary concepts include so-called
space elevators (orbital towers) which offer the possibility of
extremely low cost space access. Orbital towers require the deployment
of a long tether from geostationary orbit downwards to a fixed
point near the Earth's equator. Payloads then ascend the tether
from the surface of the Earth to geostationary orbit or beyond.
While tether materials of adequate strength do not yet exist,
the orbital tower concept in principle offers a means of rapidly
accelerating space development by lowering costs.
4. RESOURCE EXPLOITATION
4.1 Space-based solar power has been discussed
for many years, with a range of studies performed by government
agencies and industry. Extremely large collectors in Earth orbit
convert sunlight to electrical energy and then transmit power
to the surface of the Earth for collection. These schemes provide
almost limitless power without emissions. However, the scale of
engineering required would likely necessitate manufacture using
lunar derived materials rather than direct launch from Earth.
4.2 The extraction of Helium-3 from the
lunar regolith has been proposed as a commercial venture to provide
fuel for terrestrial nuclear fusion reactors, when such devices
become operational. Almost absent naturally on Earth, Helium-3
extracted from the moon could conceivably be a catalyst for large-scale
industrial space activities. While only a modest mass of material
would be returned to Earth, large volumes of regolith would be
processed to extract the isotope. Helium-3 has several key advantages
over the conventional fusion cycle.
4.3 As the cost of some rare metals grow
due to recovery from increasing difficult geological conditions,
metal-rich near Earth asteroids are considered to be a potential
resource for future exploitation. While direct return of material
for terrestrial use can be envisaged, it is perhaps more likely
that such resources would be used for other large-scale space
activities, such as the fabrication of solar power satellites.
5. CLIMATE ENGINEERING
5.1 A range of large-scale engineering ventures
have been proposed as a means of mitigating the effect of climate
variability. One such venture proposes the deployment of reflectors
along the Sun-Earth line in order to reduce the flux of heat from
the Sun by a modest amount to offset the predicted effects of
climate change. Again, industrial-scale space activity would likely
be required in order to fabricate and deploy a sufficient total
area of reflectors. It is interesting to note that the estimated
cost of such ventures could be considerably less than that of
the net economic impact of climate change on global GDP.
5.2 An even more ambitious concept envisages
the manipulation of planetary climates in order to render them
more suitable for human activity. So-called terraforming schemes
are envisaged as a means of engineering the climate of Mars by
increasing the density of the atmosphere and hence raising the
surface temperature in a positive feedback process.
6. FUTURE POSSIBILITIES
6.1 While the concepts discussed above are clearly
speculative, it is of interest to note the recent convergence
of commercial space tourism, a renewed interest in human space
exploration in the US and growing space ambitions in Asia. One
can envisage an increasing human presence in space driven by political
considerations, with the initial government investment in new
exploration technologies being utilised by private capital for
future space exploitation.
6.2 Aside from economic considerations,
it also possible to speculate as to future geopolitical issues.
Orbital towers delivering space-derived energy and material resources
to anchor points near the Earth's equator would represent a quite
different future to the present day oil economy centred on the
Middle East. Similarly, large-scale private capital investment,
wealth creation and a growing human population in space would
bring new challenges to the concept of the nation state and the
reach of government.
7. CONCLUSIONS
7.1 Future space exploration will likely
continue to be driven by government programmes. However, future
space exploitation is likely to be driven by private capital.
In order for such commercial exploitation to succeed, tradable
commodities of high market value are required. While it is clear
that space offers essentially limitless energy and material resources,
it is not clear at present how such commodities can be accessed
within the usual timescale of commercial returns. Rising terrestrial
energy and resource prices may drive future space exploitation
by increasing resource market value, while reduction in space
access costs may lower the threshold for investment.
7.2 The scenarios discussed above provide
a speculative view of possible futures where space exploitation
follows from present day space exploration. Given the long-term
nature of the space development, but the vast potential returns,
the UK would be advised to ensure a strong presence in international
space activities. In addition, the UK must broaden national space
interests from pure space science to include long-term space infrastructure
and human spaceflight. A true national space agency to ensure
continued UK excellence in space science, while developing a longer
term view of space development, would be a useful step.
February 2007
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