"is a small planet inhabited by intelligent life." "Earthlings have always been curious creatures." "Even as we discovered our own world, we dreamed of exploring others." "Perhaps other beings inhabit planets around distant stars." "If they are sending signals we could detect them with this powerful radio telescope and maybe send a signal back across the cosmos." "But might we ourselves leave our home on Earth to explore new worlds?" "We have already taken the first small steps outside our planet." "We designed this shuttlecraft to carry people and cargo up into orbit." "Here, far above the Earth's atmosphere we're learning how to live and work in space." "You 've got go to maneuver the orbiter." "It's doing a nose sweep, going towards the starboard side." "The exterior shows just a little of the expected wear and tear of many trips back and forth." "The shuttle is equipped with a robotic arm to move large payloads ferried up from Earth." "It has lifted from the cargo bay a spacecraft which carries a German telescope named ORFEUS and a remotely operated lMAX camera." "Through its lens, we are seeing as never before the exterior of the shuttle as it orbits the Earth." "Now the ORFEUS telescope has been released into orbit." "We are riding with it, floating free in space." "Beneath us the shuttle pulls away, its cargo bay empty." "ORFEUS will spend several days observing the hottest and coldest gases in our galaxy." "Then the shuttle will take it back to Earth." "Over three decades, we've learned how to travel back and forth to space and live in low Earth orbit." "Now that we have taken these first steps, are we ready to cross the great black void to explore our solar system?" "The journey will be hundreds of times farther than any we have undertaken." "First, we need to understand how we adapt to weightlessness." "Connected by tunnel to the crew cabin, a laboratory known as SPACELAB is carried in the cargo bay on certain flights." "Inside it, scientists are performing experiments developed by 13 different countries." "Two medical doctors, Norm Thagard and Roberta Bondar, a Canadian, study how our sensory systems behave when introduced to microgravity." "More than half the astronauts have space motion sickness at first." "German payload specialist Ulf Merbold is conducting an experiment to find out more about how it happens." "The subject sees one thing, but he feels another." "His brain is confused by these conflicting messages and he becomes disoriented." "Is the spacecraft rotating or are we?" "While Roberta spins, a tiny camera inside her helmet is recording the movements of her eye as it reacts to the motion." "Data are collected at mid-flight, then again near its end." "When results are compared it's clear that the more time people spend in space the more they rely on the visual sense alone for orientation." "But these results tell us only about how we adapt in the short-term." "To find out how we're affected by longer stays people must live continuously in a space station." "There we could learn how to maintain a closed life-support system for months or years at a time." "Recycling is a must." "Future astronauts will be accomplished gardeners." "They will tend small farms in space like this hydroponic garden at the Kennedy Space Center that uses recycled water and oxygen to grow food." "The plants must be kept free of contamination." "Halfway to another planet, a crop failure would be a disaster." "Keeping fit is another challenge." "With no body weight to support, our muscles get weaker." "Bones become brittle." "The longer we stay, the worse the problems become." "People traveling to other planets will spend years in a very confined space." "What kinds of emotional stress will we face?" "Will we get homesick, so far from everything we know isolated from family and friends and the familiar comforts of home?" "Our first journeys to another world were to our nearby moon." "But those roundtrips took barely a week." "Today on the MIR station Russian cosmonauts live in space for many months." "From time to time, new crews arrive from Earth in the Soyuz craft." "Now, after almost a year in orbit the cosmonauts will return home in Soyuz." "Even though they've spent up to six hours exercising each day when re-exposed to Earth's gravity, they're temporarily unable to stand." "Imagine arriving on an alien planet in this condition." "But what if we could produce an artificial gravity as we travel to our destination?" "In 1968, Stanley Kubrick's classic film 2001, A Space Odyssey featured spaceship designs which would allow us to do this." "As the ship spins around, anyone inside feels an outward or centrifugal force that acts like gravity." "In another design, parts of the ship spin around a stationary hub." "But the rotation of a small spacecraft could make occupants disoriented or sick." "We could avoid this if we built a spacecraft large enough and with a slower spin." "But it would have to be about as long as the Golden Gate Bridge." "How could we build such a large ship in space?" "To get to Mars, for instance, we might design a spacecraft with two modules." "One attached to each end of a very long cable, or tether." "Once underway, the tether would be extended to separate the two modules." "The whole assembly, rotating about once per minute could provide the synthetic gravity needed." "But until recently, tethers were merely an elegant idea." "The concept would have to be tested." "So an experiment was flown on the space shuttle." "An Italian satellite was deployed on a very long tether." "The crew was then to retrieve it." "At first, the tether behaved exactly as predicted." "But then the reel jammed and the tether went slack." "By firing jets on both the orbiter and the satellite the crew learned that they could tighten it once again showing that we can control tethers in space." "Unexpected snags are bound to arise." "But we learn from them and keep moving forward." "To build more reliable spacecraft, we need light but tough materials." "To test them, in 1984 we launched a satellite with dozens of materials attached to its surface exposing them to the wear and tear of space." "We left it in orbit for 6 years, long enough for an interplanetary trip." "The shuttle retrieved it and took it back to Earth." "We found a wealth of information embedded in these panels." "As the microscopes reveal the vacuum of space is anything but empty." "A continuous bombardment of micrometeorites pitted the surfaces with craters." "But the most serious hazard in space is radiation." "The shuttle is suspended over the Earth's horizon." "We see only the lights of its cargo bay in the darkness." "But we can't see the harmful cosmic radiation that is everywhere here." "High-energy-charged particles stream out from the sun and other stars." "On Earth, we're protected by the atmosphere and the surrounding magnetic field." "In space, the radiation can penetrate the walls of our craft." "A Japanese x-ray satellite reveals vast clouds of radiation erupting from the sun." "On interplanetary trips we'll retreat to heavily shielded onboard shelters when solar storms are sighted." "Most planets are too hostile for people to visit." "But that doesn't stop us from exploring them." "Where humans cannot safely go we send remotely-controlled robot explorers." "Commanding them from Earth we use their electronic eyes and sensors to explore alien landscape." "In 1989, the Galileo spacecraft began a five-year journey to Jupiter the largest planet in our solar system." "Galileo dissolves out into nothingness as it goes into the darkness of space." "And that's the last we saw of it." "Early images of Jupiter were sent back to Earth in 1979 by two robot probes named Voyager." "This was our first opportunity to marvel at its Great Red Spot three times the size of Earth." "Life's molecular building blocks may be swirling within Jupiter's turbulent atmosphere." "If Galileo 's probe confirms this we should gain new insights into the origins of life." "Though it is our nearest planetary neighbor, Venus was always a mystery." "Thick cloud layers blocked our view of its surface." "Then we sent a spacecraft named Magellan to orbit the planet." "Its radar eyes could see through the clouds." "Magellan collected so much data that we can now explore the surface as if we were actually there." "We begin 60,000 feet up." "To help scientists recognize its features a computer exaggerated the height of the terrain ten times." "Perhaps these pancake domes were caused by lava pushing through weak spots in the surface." "These craters, some the size of Connecticut were made by collisions with comets and asteroids." "On Earth, ancient craters like these have been eroded by wind and water." "But there is little wind and no water here." "Venus swelters beneath a thick atmosphere of carbon dioxide which acts like a greenhouse:" "It allows sunlight to filter in, but then traps the heat inside." "The surface temperature is hot enough to melt lead." "In the distance, the great Gula Mons volcano." "We are now soaring more than 250,000 feet above the surface." "The long, smooth strips that now and then cross our path are small portions of the surface that Magellan 's radar did not scan." "Magellan has shown us the fantastic surface of an alien planet where no human could ever hope to land." "But there is another world in our solar system that people can visit." "Future generations of explorers will walk upon Mars." "To prepare the way for them, we could send a robot like this to scout a landing site." "We might dispatch a whole flock of these helpers to explore the terrain." "Unlike us, they are almost immune to radiation and need no air or water." "And they never get homesick." "Robots, like this Russian Mars rover being tested in Death Valley, California have been programmed for difficult tasks like negotiating rugged terrain." "More elaborate versions could help us construct a Mars base." "But operating them will be a challenge." "At the speed of light, a single command takes up to 20 minutes to travel from Earth to Mars." "If there is or has been life somewhere else in the solar system Mars is a good place to look for traces." "A great rift valley splits open the Martian plain." "It is as long as the entire United States." "We are now descending from 40,000 feet into a part of the valley known as Candor Chasma." "It is five times deeper than the Earth's Grand Canyon." "The height of the terrain has not been exaggerated." "This is how it really looks." "Life as we know it must have liquid water to develop." "Water may have flowed through these canyons long ago." "Perhaps it nourished life." "Fossil life forms may lie exposed on the floor of these canyons." "If we find any, it would be our first proof that life has existed beyond Earth." "It would mean that life probably is abundant in our galaxy and awaiting discovery in the universe beyond." "Today, Mars is a frozen world." "The average temperature here is lower than at the South Pole." "But long ago, when water may have flowed here it must have been warmer." "We don't know why Mars turned so cold but perhaps it could be made to change once again." "Could future generations somehow transform Mars into an Earth-like world where people could live?" "To do it, we might imagine somehow raising the temperature to build up the atmosphere and melt the ice caps." "This would create lakes and rivers." "Then we could introduce plants to fill the air with oxygen." "Animals and people could now breathe the air." "A new world might be ready for us to colonize." "What would life be like on Mars?" "Perhaps we could build farms and cities." "Or perhaps we will leave Mars as we found it." "Those decisions will be made by our descendants." "If terraforming is possible, it would take thousands of years." "By then, we may have left our solar system to explore the stars beyond." "Though it would take 100,000 years to reach them with present technology future generations may travel faster." "For the present, we must use telescopes to explore the stars." "Now, we are about to launch into space an instrument that will allow us to look far into the universe and back in time, almost to its birth." "This is the Hubble Space Telescope." "Once in orbit above the shimmer of the atmosphere it will see 10 times farther than telescopes on the ground." "Astronauts Kathy Sullivan, Loren Shriver and Bruce McCandless have come here to the Lockheed Vehicle Assembly facility for a final inspection." "Loved ones gather for the launch at the Kennedy Space Center." "Among them is Dr. Lyman Spitzer who first proposed the idea for a space telescope in 1946." "This is a tremendous milestone today for me." "Very exciting, very exciting." "I suggested a telescope of this nature would be very helpful to astronomy." "The idea finally took hold among astronomers and then among other people." "Finally, even in Congress." "Off it goes." "T-minus 10, go for main engine start." "We are go for main engine start." "Five, four, three, two, one...." "And liftoff of the space shuttle Discovery." "Once Hubble is deployed astronomers will be able to direct its eye to any region of the universe they wish to observe." "While pilot Charlie Bolden, at left, maintains the shuttle's position astronomer Steve Hawley prepares for the deployment." "Discovery, go for Hubble release." "Hawley releases the telescope." "Then very slowly and carefully retracts the arm." "The sky and sea of Earth, reflected in its door the Hubble Space T elescope the creation of 10,000 people, is launched at last." "It will remain here for many years, sending images back to Earth." "Shuttle crews will visit Hubble on regular service calls to replace and upgrade its parts." "Yeah, it looks good." "I don't see any motion at all in there." "Hubble is open for business." "I wish you guys had been here." "You'll never believe it." "Superb is an understatement." "The telescope would reveal objects in detail never before seen." "But there was a problem." "A flaw was found in the shape of the telescope's primary mirror." "A repair would be necessary." "As part of the regular service another crew would make the repairs three years later." "First, the crew would have to recapture the telescope." "Houston, Endeavour, the right solar array, as we can see one side of it is bent way over." "Clearly we have a dynamic situation." "There's a problem with one of the solar panels that provide power to the telescope." "Looks like the outer bi-stem has a kink in it and is twisted 90-plus degrees clockwise there at the kink." "Once the telescope is secured in the cargo bay the astronauts will move outside for a close inspection." "So begins the most ambitious and difficult service mission ever attempted." "Story Musgrave and astronomer Jeff Hoffman are both veteran spacewalkers." "They'll depressurize here in the airlock then go to work." "The crew planned to replace the solar panels as part of the regular service." "But now, the twisted panel cannot be safely stowed in the cargo bay." "They have no choice but to throw it overboard." "Mission Specialist Kathy Thornton will do it." "A large object floating in space can pose a hazard to other spacecrafts." "So bursts from the jets are fired directly at the panel to make it spin." "Motion will speed its descent to the atmosphere where it will burn up." "Now, work on the telescope can resume." "Okay, coming straight on up." "Looking good." "I'm gonna let go." "Okay, take me away." "Come right on up easy, just like that." "Bring the forward up a little." "It's difficult to maneuver bodies and equipment unassisted." "The repair of the telescope would be impossible without the shuttle's arm." "It is controlled by Swiss astronaut, Claude Nicollier while Ken Bowersox, the pilot, acts as lookout." "The wide-field planetary camera will tell us about the size of the universe and how rapidly it is expanding." "The crew lifts it up with great care." "The tiniest bump could damage its delicate parts." "The astronaut teams alternate each day spending up to six hours in the cold vacuum outside." "All their tools must be tethered to keep them from floating into space." "After five days of intensive work and dazzling accomplishments the astronauts will install the corrective optics package." "It's a kind of contact lens designed to bring Hubble's giant eye into focus." "If it succeeds we will be able to look back to the edge of time." "The service and repair are now complete." "The mission drew upon skills we've learned throughout three decades of work in space." "Whether repairing a telescope, assembling a space station or building a base on a far planet we must rely upon the teamwork of humans and machines if we are to succeed in this new environment away from Earth." "You 've got a go for release." "The Cape of Good Hope beneath it the space telescope is now poised to begin a new era of exploration." "One astonishing discovery is a first look at an enormous and very unstable star we call Eta Carinae." "Four-million times more luminous than our sun its last outburst was seen in 1841." "Now Hubble reveals that it has blown two massive clouds into space." "The clouds contain the heavy elements essential for the creation of life." "In the heart of the Orion Nebula Hubble reveals a stellar nursery." "Gas and dust are condensing here to create new stars." "And even more astounding new planets are being born." "Never before seen, the dark material appears to be a new solar system forming around a young sun." "Hubble has now provided evidence that planets are common in the universe." "Life may be widespread among them." "Perhaps we will hear a signal." "Our curiosity and our need to progress to explore our solar system our galaxy, and the universe beyond." "The distances are vast, the voyage hazardous the destination daunting." "Still, we choose to explore." "What we discover..."