Since the pioneering superpower races of the 1950s and ’60s, when nations competed to be first in space and then first to journey to the moon, the spacecraft industry has been at the forefront of exploration and technological development. Into the ’90s, the emphasis has, to some extent, shifted away from such high-profile political objectives, towards a more pragmatic approach. The exploration of space has been superseded by its exploitation. Participation in space programs is no longer confined to a handful of richer nations: many smaller countries are also developing space industries to accelerate their technological development.

The applications of spacecraft technology are numerous. For example, use of spacecraft has been central to the growth of global communications. Large international organisations such as Intelsat, with 136 participating nations, provide high bandwidth data communications between countries and continents. More than half of all international telephone calls, and nearly all international television transmission, is carried by Intelsat alone. Direct broadcast satellites cover the globe, sometimes providing the only means with which to transmit television pictures over large distances or to scattered island populations. A constellation of satellites orbits the earth day and night, providing a precise means of fixing global position. Satellite phones communicating directly with orbiting transceivers form a mobile communications network increasingly utilised by a wide variety of clientele. Many more systems are planned for the next decade to meet the predicted explosion in global communications in the Asia Pacific Region and the advent of hand-held mobile satellite phone systems.

Earth observation is also a major application of spacecraft technology, now enjoying multi-national participation. Umbrella organisations, such as the European Space Agency and Eumetsat, combine efforts and share expense.

Countries still continue to develop spy satellites as a means of recording activities in other sovereign states without infringing on their territories or airspace, but the trend is towards collaboration and commercialisation. The French, Russian and US governments have recently removed their militaries’ exclusive right to high resolution satellite imagery, allowing the commercial sale of pictures with resolutions as high as 1 metre. High quality optical images taken by French SPOT, Indian IRS-1C, or forthcoming Israeli David spacecraft, as well as US and Russian systems, are now used for a wide variety of other purposes including urban planning, mineral exploration, agricultural monitoring and pollution detection.^,

Increasingly, spacecraft are employed, as the most efficient, cost effective means of making a discovery or observation.^, Weather forecasting—a problem not confined within national borders—is a highly co-ordinated commercial enterprise, with national organisations combining to monitor, process and communicate weather predictions to a wide variety of customers. Radar imaging of the ground and seabed provides a competitive way to survey for oil and other natural resources. Accurate, continuous measurements of global phenomena are often best made from space. Earth observation missions such as Envisat, conceived to monitor constantly climate change and ozone depletion are realised by multi-national collaboration for the benefit of all. Other programs provide detailed information about a wide variety of conditions, from sea-state to deforestation.

Manned exploration of space continues with such initiatives as the recent in-flight docking procedures between the Russian space station MIR and the American shuttle orbiter and the proposed international space station Alpha. The emphasis is now increasingly on such co-operative ventures.

The exploration of the surrounding solar system and its interaction with earth is a truly international venture requiring the participation and financial support of several organisations. The European space agencies SOHO mission will send a spacecraft to the L1 lagrangian point (a point of equal gravity between earth and sun) to monitor solar activity. It is hoped that the results will facilitate a greater understanding of how the sun’s activity affects the earth’s atmosphere and climate. The Voyager, Pioneer and Mariner programs have been followed by programs like Ulysses—the first spacecraft to venture outside the ecliptic plane in an effort to study the poles of the Sun. The Magellan spacecraft has sent back detailed radar imagery of the surface of Venus, for the first time examining the planet’s topography.

Hubble space telescope (built by multinational collaboration) has been operational now since 1990, observing distant stars and galaxies, confirming and confounding theories describing the evolution of the universe. The Hipparcos spacecraft (European Space Agency) has been used to map star positions and movement to sub-arcsec precision.

Many missions are planned to shed further insight on the formation of the solar system by visiting other celestial bodies. The Galileo spacecraft is currently carrying out an in-depth study of Jupiter and includes a lander. The Cassini mission proposes to examine Titan (a moon of Saturn), sending down a probe to examine the atmosphere. The Rosetta mission (expected launch 2003) will study a comet in detail, eventually deploying a lander to study the primitive surface of the comet in situ, carrying out spectral analysis of cometary material and transmitting the results back to earth. Another mission, Gravity Probe B, proposes to verify untested aspects of Einstein’s General Theory of Relativity using orbiting gyroscopes.

Today’s space industry designs instruments and spacecraft for all these types of application. Modern spacecraft are complex devices conceived and constructed to high specification by consortia of companies and nations working together.

Next: Mission Types

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