大象传媒

How we know what we know - the real missions behind Pegasus' journey

The series-makers used facts collected by hundreds of robotic missions to the planets in order to construct the most accurate and realistic human experiences of walking on these exotic worlds.

Every detail of their atmospheres, rock formations and gravity fields has been gathered over the last 40 years.

The colours, sights, sounds and smells encountered by the astronaut explorers in the series are as predicted by planetary scientists who have already been there - experiencing these alien planets and moons through these robotic emissaries.

The information below provides summaries of the missions the astronauts in this series had to undertake and the accomplishments and discoveries of the real trail-blazing robots.

Venus

Today, 98 per cent of the surface of Venus has been mapped by radar from Earth and orbiting Russian and American spacecraft.

They revealed a world covered in volcanic features ranging from tiny craters to continent-sized features.

The Russian Venera landers took panorama images of their landing sites.

In this series, the crew's descent through the Venusian atmosphere and their experiences on the surface are based on the results of these missions.

Working with the Russian mission team who designed and built Venera 14, their robotic lander was rebuilt and aged in the way these scientists believe it would have been altered by decades sitting on one of the most extreme surfaces in the solar system.

Mars

There have been more robotic missions to Mars than to any other world and, today, there are more complete maps of its surface than Earth's.

Nasa's Mars Odyssey and Global Surveyor satellites and ESA's Mars Express orbiter provided detailed maps of the surface and subsurface, as well as detailed observations of its weather and climate.

Robotic landers and rovers have recorded the chemistry, mineralogy and microscopic textures of the ground and it has become clear that liquid water played a big part in shaping the contours of Mars.

To film the Mars scenes, the cast and crew went to the remote Atacama Desert of northern Chile, deemed "Mars-like" enough by Nasa to be a testing ground for its future missions to the red planet.

Sun

Solar science has progressed enormously in the last decade. There's now an armada of international robotic missions scrutinising it.

Nasa's TRACE mission, the Nasa/ESA Soho satellite and Japan's Yohkoh mission have been sending back stunning images of the tormented solar surface, twisted and gnarled by the potent magnetic forces emanating from deep within.

An ESA/Nasa mission - Ulysses - has made four giant, one billion mile-wide orbits of the Sun, providing the first-ever map of the heliosphere from the equator to the poles.

The views shown in the series are modelled entirely on the images from these missions.

To protect the crew from the lethal levels of radiation, they pass by the Sun during a period of quietness called Solar Minimum, with Pegasus shielded by an artificial, on-board magnetic field - a technology currently being researched at the University of Washington in Seattle for possible future propulsion.

Asteroid Belt

This 80 million kilometre thick band of debris is known to stretch out for 280 million kilometres.

Over 48,000 asteroids are catalogued but there are over a million more waiting to be found.

The Pegasus crew encounters one of these unknown asteroids. It is modelled on observations from a number of robotic missions that have flown past, orbited and even landed on these tiny worlds, in particular Nasa's Near Earth Asteroid Rendezvous (Near).

This spacecraft orbited and mapped the surface of an asteroid called Eros for a year then survived a crash landing onto it and continued to send back useful data and pictures.

Jupiter & Moons

The first probes to visit Jupiter - Nasa's Pioneer 10 and 11 missions - discovered that its magnetic field captures charged particles thrown out by the Sun and accelerates them to incredible speeds generating dangerous radiation amounting to over 1,000 times the lethal dose for a human.

A few years later, Nasa's famous Voyager 1 and 2 spacecraft sent back thousands of pictures and gigabytes of data, charting the planet's immense weather systems and imaging its moons.

In 1995, Nasa's Galileo mission dropped a probe into the planet's atmosphere which relayed data on temperatures, pressures, wind speed and cloud.

The orbiter spent eight years scrutinising the whole Jovian system and making multiple fly-bys of the four main moons.

In December 2001, Cassini also flew past Jupiter on its way to Saturn.

The details of Pegasus' encounter with Jupiter and the crew's exploration of the moons, Io and Europa, are taken entirely from the results of these missions.

Saturn & Moons

So far, three probes have gone to Saturn. In the Seventies, Pioneer 11 navigated across the ring plane and discovered its eleventh moon, two new rings and that it had a magnetic field a thousand times stronger than Earth's.

Voyagers 1 and 2 sped past in 1980 and 1981 studying the planet's vast weather patterns, the dynamics of the rings and the orbits of its moons.

In 2004, the joint ESA/Nasa mission, Cassini-Huygens, reached Saturn, going into orbit for a four-year study of the system.

In 2005, the Huygens probe will drop into the atmosphere of Titan, taking images and recording weather patterns as it falls towards the surface where, if it survives, it will conduct a series of further experiments designed to analyse the environment it finds.

The Saturn encounter in the series is based entirely on these missions.

Pluto-Charon

Pluto remains the only planet never to have been visited by a spacecraft but, since the Eighties, it has passed in front of numerous stars giving astronomers the chance to make precise measurements of its size and revealing a very thin atmosphere made mostly of nitrogen.

The best images of this planet come from the Hubble space telescope.

Through these observations, it is thought the surface resembles that of Neptune's moon, Triton.

Voyager 2 flew past Triton in 1989, so Pluto's landscape was recreated for this series using the detailed pictures it took.

A Nasa mission called New Horizons will head for Pluto in 2006.

Comet

Our first close-up look at a comet came in 1986 when ESA's Giotto mission made a spectacular flight to Halley's Comet.

Nasa's Stardust mission flew through the tail of comet Wild 2 in early 2004, catching a sample of debris which it will drop back to Earth in January 2006.

The latest comet exploration, mounted by ESA, is called Rosetta.

It was launched from Earth in March 2004 and, in 10 years, will land on comet Churyumov-Gerasimenko.

The comet lander in this series is modelled on Rosetta's designs.

The crew's exploration of the surface draws on all the robotic encounters with comets to date.