Space exploration – the final frontier?
04 March 2009
For over 50 years, space travel has fascinated, informed and challenged mankind. Yet some believe that the space programme – particularly manned missions – is a gamble, with outcomes of programmes difficult to predict and benefits that might not become clear long beyond the political cycle. But what is the real value of the space programme? Should we be investing more, not less? What practical and political challenges must we overcome to do so? Our team of globally renowned experts offer their insights.
Professor Marcello Coradini, FRAS, Coordinator, Solar System Missions, European Space Agency
Science is a luxury that no-one can afford in a world in perpetual crisis; we need to make investments in productive activities that improve everyday life and produce immediate financial returns.' How many times have we heard statements like that? Well, space science and exploration activities just do it!
First of all, spacecraft and instruments are mostly built in hi-tech non-polluting companies that employ a large number of young graduates. Needless to say, a large part of 'given for granted' technologies, which allow communications, environmental monitoring, miniaturisation of medical instruments, highly efficient fishing, etc. (the list would be endless), were first developed for deep space missions.
And if this is not enough, if we still want to dream, if our Earth gives us the impression to be too small and troubled, what's better than wandering on Martian or Titanian landscapes? What about the fundamental philosophical aspects triggered by the time voyage that we make when we observe breathtaking images of distant galaxies?
The first phase of exploration of the solar system bodies from an orbiting platform is over. Go to the surface and even under it: this is the new, overriding priority of space science and exploration. On the surface and the sub-surface, we can go looking for extant or extinct life; on the surface and underground, we need to look for resources that one day will sustain human settlements. But in order to do that, we need to make major technological efforts in robotics and autonomy, in high precision landing capability, and particularly, we need to develop reliable capability to take off from a planetary surface, eg. Mars.
Waiting for humans to be able to walk and live on another planet, a fundamental tool for science, with deep anthropological and sociological aspects, is the so-called virtual reality. We stay home and we have the 3D sensation of being present and moving on the surface of a celestial body. To achieve this, we need to augment dramatically the deep space communications bit-rate by constructing orbiting and on surface communications networks, signal amplification stations placed in the Lagrangian points, and powerful and innovative ground stations. Planetary geology would have a dramatic boost with such a technique, but the layman would be able to walk around Mars or the moon by simply going to a virtual reality space theatre.
Richard B Horne, Principal Investigator, Sun Earth Connections Programme, The British Antarctic Survey
While policy-makers discuss the benefits of manned spaceflight to the moon and beyond, scientists and engineers are considering how to protect astronauts from the harsh realities of space. During the Apollo era, when astronauts went to the moon, the sun emitted one of the largest bursts of energetic charged particles on record. Luckily, this occurred between the Apollo 16 and 17 missions, on 2nd August 1972; otherwise, if the astronauts had been on a moon walk, they would have received a life threatening dose of radiation. Today, solar energetic particle (SEP) events are recognised as one of a wide range of hazards affecting astronauts, spacecraft, aviation, and ground-based tech-nology that is referred to as space weather.
Radiation dose to astronauts is a major concern for spaceflight. Galactic cosmic rays, which originate from supernova shock waves, provide an ever present but variable radiation background. On the other hand, SEP events originate from shock waves near the sun and provide an intense burst of radiation that swamps cosmic rays, but only lasts for a few days. Large SEP events, such as the 1972 event, may occur once or twice over the 11 year solar cycle, but smaller events occur more often and the radiation dose can accumulate to hazardous levels unless protective measures are taken.
The geomagnetic field offers some measure of protection for astronauts on the International Space Station by deflecting the incoming particles, but this becomes less effective at higher energies. As a result, the hull of the space station is heavily shielded and the sun is continuously monitored so that if a SEP event occurs, astronauts outside can take cover inside. Some scientists have suggested creating a large magnetic field around the spacecraft to protect longer missions to the moon and Mars. Along with shielding, this may form part of the solution, but it poses a significant engineering challenge and higher launch costs due to weight.
SEP events are unpredictable at present, but a better understanding of how they are related to solar variability may help to plan missions for periods of low risk. Here the ice cores of Antarctica and Greenland may provide an important source of information to complement satellite data. Energetic charged particles penetrate the atmos-phere more easily in the Polar regions due to the orientation of the geomagnetic field. They deplete ozone and create special forms of nitrogen, which precipitate with the snow and accumulate over time to form a record of past climate. SEP events have been identified in ice cores, but there is considerable uncertainty over whether some of the nitrates could have been deposited with sea salts or through other processes not related to the sun. This may be resolved by a careful analysis of ice cores from several locations. The best timing of a mission to the moon or Mars may yet be deduced from a combination of solar observations, current space weather, and ice core records going back thousands of years.
Ian Crawford, Senior Lecturer in Planetary Science, Birkbeck College, London
The UK is the only major industrialised economy that has consistently declined to participate in human space exploration, largely because many scientists believe that the limited resources available for space exploration should be invested in robotic missions. On the other hand, while it may be expensive to send people into space, once there, they are uniquely qualified to undertake a range of scientific investigations in the space environment. In addition, there are a number of powerful economic, cultural and political arguments for human space activities that transcend the purely scientific. Partly as a result of these considerations, the government is now in the process of reviewing its current policy.The scientific case
The scientific case for humans in space consists of several inter-related strands, of which the most important are microgravity research and the exploration of planetary surfaces.
The microgravity environment of low Earth orbit provides unique opportunities for research in the life sciences, materials science, and fundamental physics. Further progress in these areas will rely on the unique capabilities of the International Space Station (ISS). Although the UK has so far opted out of microgravity research on the ISS, the potential scientific benefits are well documented, most recently in an independent review of the European Space Agency's microgravity research programme conducted by the European Science Foundation in 20081
. A large part of microgravity research concerns studies of human physiology in the space environment, much of it with potential medical benefits here on Earth, and this necessarily requires people in space as people are the experimental subjects. An earlier review2
commissioned by the British National Space Centre (BNSC) in 2003 concluded that 'without access to such facilities...the UK will be excluded from entire areas of scientific endeavour', although the government so far failed to act on this finding.
Turning to planetary exploration, the Apollo programme demonstrated the scientific value of astronauts as explorers of planetary surfaces 40 years ago, principally because they bring agility, versatility and intelligence to exploration in a way that robots cannot. Although it is true that humans will face many dangers and obstacles operating on other planets, the potential scientific returns are more than sufficient to justify employing astronauts as field scientists on other planets. Consider, for example, the relative efficiencies of the Apollo astronauts and the Spirit and Opportunity rovers currently on Mars – in terms of geological exploration, the former achieved more in a few days than the latter have achieved in four years.3
There is little doubt that if people return to the moon, and go on to explore Mars, there will be a comparable quantum leap in the pace of scientific discovery, and it is important that the UK planetary science community is able to participate in this activity.The social and economic case
As for the scientific arguments, the socio-economic case for human spaceflight also consists of a number of inter-related strands.
One of the most important is the inspiration of young people to take an interest in science and technology. The DIUS 'Science in Society' website4
lists as one of its objectives 'to increase the number of people who choose to study scientific subjects and work in research and scientific careers', and this is indeed crucial for a knowledge-based economy such as ours. Space exploration is inherently exciting, especially for young people, and UK participation in a highly visible, global human spaceflight programme could prove to be of significant benefit by inspiring more students to take an interest in the scientific and engineering disciplines.
Human spaceflight is also technically very demanding and, for this very reason, acts as a stimulus for employment, skill development, and technical innovation in the participating industries. This expansion of technical capabilities is in turn likely to find applications in other areas of the wider economy. Currently, UK industry is effectively ostracised from these potential benefits by government policy, and is thus at a disadvantage when compared with industries overseas. Note also that the money invested in space exploration does not itself leave the ground, but circulates in the economy where it helps stimulate additional economic benefits.
Last but not least, space exploration provides a natural focus for international co-operation, as demonstrated most recently by the Global Exploration Strategy5
agreed by 14 of the world's space agencies (including BNSC) in 2007. This strategy calls for a global effort of solar system exploration, with the ultimate aim of establishing a 'sustained and ultimately self-sufficient human presence beyond Earth', and it must be desirable that a major economy such as the UK is seen to be pulling its weight in this exciting global endeavour.Conclusions
Clear scientific benefits of human space exploration have been identified. Given that participation in human space activities would also be inspiring UK school children, supporting UK industry, and making a positive contribution to international co-operation, there appears to be a strong case for re-examining UK policy in this regard. This is especially so given the new international context provided by the Global Exploration Strategy, where UK participation would provide wide ranging scientific, industrial and educational benefits that cannot obviously be attained in any other way.
1 'Scientific Evaluation and Future Priorities of ESA's ELIPS Programme', European Science Foundation (2008)
2 See http://www.microgravity.org.uk/recommendations.pdf
3 Crawford I A (2005) 'Towards an Integrated Scientific and Social Case for Human Space Exploration', Earth, Moon and Planets, 94, 245-266. See http://www.springerlink.com/content/l8rh21128j3325ng/fulltext.pdf
4 See http://www.dius.gov.uk/policy/science_society.html
5 See http://www.scitech.ac.uk/Resources/PDF/gesframework.pdf
Vladimír Remek MEP, Member of the crew of the space shuttle Soyuz 28 and orbital complex Salyut 6
There is little doubt that space exploration through robotic exploration and manned space flights are mutually interconnected, and both have clear advantages and disadvantages. For robotic exploration, the attraction comes in the form of lower financial costs and without the protection of human life to worry about. But I am sure that it is not just robotic space exploration that we care about as human beings.
We have come far in a short time. We have been using space intensively in telecommunication, meteorology, navigation, orbital complex operation, use of the knowledge gained through the moon landings, and so forth. And we want to include space more and more in our lives – it is going to be a big part of our future.
There is much at stake. In meeting global challenges such as developing new energy sources, dealing with over population, achieving food and water security, and so on, we have to take space flight into account.
For instance, two experiments that I conducted during my space flight (I was ranked as only the 87th cosmonaut) were directly related to the endeavour to find new possibilities for food production and as yet unknown materials. In project CHLORELLA-1, we explored the speed of growth of algae in space flight conditions. Experiment MORAVA–SPLAV (invar) dealt with crystal systems and their formation while cooling down in conditions of zero gravity.
Russian scientist Konstantin Tsiolkovsky, considered to be the father of cosmonautics, stated a long time ago: "Earth is the cradle of humanity, but one cannot remain in the cradle forever." He predicted that it would be possible to colonise other planets in the future. Over time, Tsiolkovsky's predictions have proved right.
And I do not even need to explain the intrinsic desire of mankind to explore the unexplored, to discover the undiscovered. Beyond all reasonable doubt, space exploration is an undisputed part of it.
So let's get back to our basic question: Why should man fly into space? I am confident that this article thus far proves that the benefits of robotics are irreplaceable, both in space exploration and in understanding space.
But the human factor cannot be ignored. Neither computer, nor robot, nor automatic probe can describe the feelings or experience of discovery. Robotics are able to analyse and evaluate afterwards, but only according to the parameters set up by us, people.
It is not possible to substitute the human brain, with all its capability to improvise and react to unexpected signals and events. As a member of the space crew of the complex Salyut 6, I have realised that some experiments, like the ones I have mentioned, might only achieve success using the intellect of cosmonauts. I am certain that the maximum benefits of space exploration cannot be fully achieved without manned space missions.
Professor G Scott Hubbard, Department of Aeronautics and Astronautics, Stanford University, Former Director, NASA Ames Research Center
Three forces will determine the future of civilian space exploration: relevance to the taxpayer, return on investment, and relationships, especially between countries.
Of immediate relevance to every taxpayer is Earth science. Global climate change is now a scientific fact and we must not only maintain but also intensify our space-borne observations of the Earth's atmosphere, oceans and landscape. Regional climate change measurements that extend our knowledge to the local scale are needed to provide policy-makers with correct information as they consider billion dollar investments in infrastructure.
The world has spent more than $100bn on the International Space Station (ISS) but the return on investment has yet to be realised. A few tantalising experiments suggest that gene expression, plant growth and infectivity of microbes may all be influenced by weightlessness. Only an intensive use of the ISS as an international laboratory will determine whether these results are reproducible and might lead to new knowledge or products. To enable such research, frequent and reliable low earth orbit access is required. The entrepreneurial space sector is on the verge of establishing the business case for suborbital tourism. As with the airmail routes of the early 20th Century, it is time for government to transfer low earth orbit to the private sector.
Humanity is inspired by the exploration of Mars, the outer planets and the Universe. In many new proposed projects, the cost and complexity has expanded to such an extent that no single country can afford them. Such efforts include a robotic sample return from Mars, revisiting the moons Europa and Titan, and human missions to the Moon and Mars. New international relationships and collaborations that require interdependence must be forged to carry out these exciting endeavours.