Stargazer Paul Murdin finds the perfect guide for satellite-spotters everywhere.
Since the space age began with the launch of Sputnik in 1957, more than 8,000 satellites and spacecraft have been launched by more than 30 countries, and more than 350 people have travelled in space. This is the scope of The Cambridge Encyclopedia of Space , translated and updated to 2002 from a French work published in 1997.
It is organised by Fernand Verger, a professor of geography, and gives a global perspective on our use of space - scientific, industrial, commercial, technical and military. It displays its information through not only words and illustrations of what spacecraft have found, but through diagrams, maps and charts. Its original French title can be translated as "atlas of the geography of space" and the word atlas has been interpreted as a geographer would. Masses of information have been presented in fresh and digestible ways.
The book starts by describing the space environment; we learn what a hostile place the solar system is for man and machine. And in future, interstellar travel may be even more dangerous: " Apollo to Mission Control./ We are almost within reach of our goal,/ but our readings of G / seem excessive to me,/ so we may be inside a black hoI..." (G. J. S. Ross, 1984) The encyclopedia goes on to chart orbits and ground tracks. Considering how little there is to play with, it is remarkable how much variety is to be found in the orbits of spacecraft. Depending on the inclination of the orbit, its eccentricity and how far the satellite is from Earth and so what its orbital period is, satellites can systematically scan the globe, or hover and leap from place to place.
Not all orbits are equal, however. One diagram shows how crowded the orbits are above the equator at a height of 40,000km, where a satellite revolves within the same period as the rotation of the Earth and appears to hang stationary above a given point. "Geostationary" orbits are much prized for communications purposes - you can beam a message or a TV broadcast up to such a satellite and it will relay it down into a "footprint" region below.
As a result of its useful continuity, this orbit is now almost full.
A major chapter in the encyclopedia is on space policy and budgets. At the beginning of the 21st century, the US spends more per capita than any other country on its space budget. The visible face of the US expenditure is the Hubble space telescope and the international space station, but a second diagram shows that the largest space agency in the world is the US department of defense, not Nasa, although this may change with the recently announced Mars exploration programme.
We see how the red dots representing Soviet and then Russian satellites have dominated satellite launches, while in later illustrations we see their uses. The red and blue squares of Russian and US military telecommunications and reconnaissance satellites form massive blocks (or blocs) on the diagrams. Green squares represent western Europe's satellites - mostly civilian research and technology satellites procured through the European Space Agency and the agencies of individual European nations, but also a number of civilian telecommunication satellites and the UK's eight Skynet satellites for military telecommunications. A map of Europe's space industries underplays Britain's space ability by omitting the highly successful microsatellite manufacturer spun off from the University of Surrey; some of its score or so of satellites are illustrated elsewhere.
What we are not shown is that they are controlled from the university campus in Guildford, from a room in which anyone from a university science department would feel at home. Europe's and Britain's emphasis on the civilian use of space shows that it does not have to be supported by huge military activity.
The map of launch sites shows how few there are. To get to equatorial orbit it is best to be on the equator and to pick up free speed from the Earth's rotation.Rockets taking off from Russia, with its lack of equatorially located land, have to supply at least 500km an hour more speed than rockets taking off from the European Space Port at Kourou in Guyana.
It is safest if the rockets take off and head east with the Earth's rotation over uninhabited areas. Cape Kennedy and Kourou are ideal: rockets take off over the sea. At the Russian Baikonur cosmodrome, rockets take off over the steppes - not entirely uninhabited, but the concerns of the nomads and farmers do not count for much. There are no uninhabited regions of China so the regions east of the launch sites of Jiuquan and Xichang are not the safest in the world, as recent launch disasters there show.
Launches of converted Russian intercontinental ballistic missiles (ICBM) are available from the Odyssey floating platform, which is loaded up in San Diego and towed to its launch site near Christmas Island bang on the equator and in the middle of the virtually uninhabited Pacific Ocean.
This encyclopedia puts hard-to-find maps and satellite images of the major space ports into wide circulation. There are, however, no even harder-to-find photographs of the launch sites, so we do not see the post-industrial decay of much of the Russian Baikonur site, now that the Russian military has largely pulled out; the ICBMs are decommissioned and have left behind flaking concrete bunkers. Buran , the huge Russian space shuttle that flew only one unmanned test flight and helped bankrupt the Soviet Union, lies gutted and imprisoned in one gigantic, broken-windowed, leaking, fire-damaged building - a mummy in a mausoleum.
Verger and his fellow authors describe space telecommunications, space navigation, Earth observation, science missions, planetary exploration and space stations. There is a tendency among space enthusiasts to over-egg the pudding, augmenting reality with dreams. These authors describe the pudding as it is, rich enough without exaggeration. The most significant peaceful achievement of the space age is that satellite observation has mapped the world so we can begin to understand it as a planet and can begin, even more tentatively, to manage it; satellite telecommunications have accomplished Marshall McLuhan's vision of a "global village" of information exchange and gossip; satellite navigation systems locate you instantly anywhere in the world within a few metres, millimetres if you work hard (you can measure continental drift); satellite telescopes have opened up a vision of the universe otherwise clouded by the Earth's atmosphere; and satellite exploration has shown us other worlds with which we can compare our own Earth and better understand it.
This book is highly accessible and affordable, setting out the big picture in a factual and comprehensible way. It is the perfect reference book for students, because it will keep their feet on the ground while raising their sights and filling their heads with notions.
Paul Murdin is a senior fellow of the Institute of Astronomy, University of Cambridge, and was formerly director of science at the British National Space Centre.
The Cambridge Encyclopedia of Space: Missions, Applications and Exploration
Author - Fernand Verger, Isabelle Sourb s-Verger, Raymond Ghirardi and Xavier Pasco
Publisher - Cambridge University Press
Pages - 418
Price - £35.00
ISBN - 0 521 77300 8