First Communications Satellite Was a Huge Balloon
NASA's 135-foot rigidized inflatable balloon satellite undergoing tensile stress test in a dirigible hanger at Weekesville, North Carolina, in 1964.
The Program Begins
What do you do after you've been to the moon? NASA's grand plan was to build a space station and a fleet of reusable spaceships that could shuttle people and cargo back and forth like an airliner. Unable to afford both programs, NASA opted for the more technically challenging shuttle, a program formally launched by President Nixon on Jan. 5, 1972. The first orbiter built was Enterprise, pictured here, a prototype that never flew in space, but was used for critical atmospheric flight tests and practice landings.
A New Spaceship
The world's first reusable spaceship, Columbia, arrived at the Kennedy Space Center in March 1979. NASA assigned two astronauts for the first flight, Apollo veteran John Young and rookie Bob Crippen. At the time, NASA put the odds of them not surviving at about 1-in-100,000, but the risk actually was about 1-in-nine. Powered by three hydrogen-burning engines and a pair of solid-rocket boosters, the shuttle lifted off on April 12, 1981, the 20th anniversary of Yuri Gagarin's spaceflight. NASA stopped painting the shuttles' fuel tanks white after the second flight, saving money and about 600 pounds of weight. Between July 1982 and April 1985, three more space shuttles -- Challenger, Discovery and Atlantis -- arrived at the Florida spaceport.
Image: Sally Ride on board shuttle Challenger
NASA steadily increased the size of its shuttle crews, as the missions grew in duration and complexity. The original crews of two astronauts were doubled to four, and by the time the seventh mission was launched on June 18, 1983, there were five people aboard, including, for the first time, an American woman. Less than three months after Sally Ride’s historic flight, NASA broke cultural boundaries again, with the launch of the first African American to fly in space, Guion Bluford.
NASA realized its original projections to fly the shuttles once or twice a month were unrealistic, as the between-flight servicing turned out to be complicated, time-consuming and labor-intensive. It did, however, consider the ships safe enough for non-professionals to fly. The guest list included politicians, a Saudi prince and a teacher. These so-called "payload specialists" underwent minimal training, including parabolic flights on a NASA airplane which offers passengers a taste of weightlessness. Bill Nelson, photographed here (center), now a Florida senator, was in the House of Representatives when he flew in January 1986, less than a month before New Hampshire schoolteacher Christa McAuliffe (holding hands with Nelson in this photo) launched aboard the doomed shuttle Challenger. NASA ended its guest flyer programs after the fatal accident.
Image: Wreckage from the Challenger disaster
NASA had known the shuttle booster rockets had a nasty habit of burning their rubber seals, known as O-rings, during the fiery climb to orbit, but managers failed to grasp the big picture until Jan. 28, 1986. On that cold winter morning, one of the booster's O-rings completely failed, leading to the horrid and widely televised destruction of Challenger 72 seconds after liftoff. The accident killed five NASA astronauts, a Hughes Aircraft engineer and schoolteacher Christa McAuliffe. NASA shut down the shuttle program for over two years while it redesigned the booster rockets, added safety features, such as a telescoping escape pole, and revamped its management practices. Wreckage and debris from the mid-air explosion were retrieved from the ocean and sealed inside an abandoned missile silo at Cape Canaveral Air Force Station.
Image: Discovery blasts Hubble into orbit as
A sobered and more safety-conscious NASA resumed flying the shuttle in Sept. 1988, steadily working through a backlog of science and military spacecraft needing rides into orbit. Magellan, a radar-mapper bound for Venus, was the first interplanetary probe launched on the shuttle. The capstone mission was the launch of the Hubble Space Telescope on April 24, 1990, which also marked the first time since before the Challenger accident that NASA resumed dual launch pad operations. As Discovery blasted off with Hubble, sistership Columbia was being prepared the Astro-1 astronomy mission.
Image: Endeavour's first job: in-orbit satell
Hands-On Satellite Repair
Endeavour, the replacement ship for Challenger, debuted on May 7, 1992, on what was to be a straightforward mission to capture a stranded communications satellite and outfit it with a new upper-stage rocket motor so that it could reach its proper orbit. When the special tool devised to snag the spacecraft didn't work, the astronauts took matter into their own hands, literally. They devised plans for an unprecedented (and unpracticed) three-man spacewalk and grabbed the satellite with their gloved fingers. It was a bellwether moment for NASA and good practice for the complicated repair mission to follow to fix the Hubble telescope, which, much to NASA's chagrin, had been launched with a flawed primary mirror that blurred its view of the universe.
Image: The shuttle crew, including Mark Lee a
With the shuttle program in full swing and well over 100 astronauts in the corps, it was probably only a matter of time for the inevitable to happen -- a married pair on the same crew. NASA had a policy against couples flying together, but Mark Lee and Jan Davis weren't married when they were assigned to the 50th shuttle mission, a Japanese-sponsored science research flight called Spacelab-J whose crew also included the first Japanese astronaut, Mamoru Mohri, and the first African-American woman, Mae Jemison. Lee and Davis, who worked on opposite shifts during the eight-day flight, said they'd be too busy to have sex in space and it’d be awfully tacky to boot, considering the shuttle's close quarters and the five other people aboard.
The fall of the Soviet Union transformed world politics and opened a new chapter in space. The former Cold War foes, once keen competitors in a race to the moon, began an astronaut-cosmonaut exchange program that not only saved Russia's cash-strapped Mir space station, but also breathed new life into the flagging U.S. space shuttle program. Between March 1995 and June 1998, seven U.S. astronauts lived on Mir, and cosmonauts were added to shuttle crews. A fire, and later a crash, on Mir threatened the budding partnership, but ultimately Mir proved an apt training ground for the International Space Station program. During the shuttle's first docking at Mir, two cosmonauts took a ride in the station's Soyuz capsule to take pictures.
Image: Columbia's final crew. Credit: NASA
Fuel Tank Insulation
NASA was about halfway through building the International Space Station when it launched shuttle Columbia on Jan. 16, 2003, on a free-flying research mission, the only other flight besides a final servicing call to the Hubble Space Telescope that wasn't going to the orbital outpost. The crew included Israel's first astronaut, Ilan Ramon, and security for launch, already heightened in the wake of the Sept. 11, 2001, terrorist attacks, grew even tighter. But terrorists weren't the reason why Ramon and his six NASA crewmates never made it home. A piece of foam insulation about the size of a briefcase fell off Columbia's fuel tank during liftoff and smashed into the ship's wing, damaging the heat shield. NASA didn't realize until after Columbia's demise how delicate the shuttle's wing panels were or how blind the agency had been to the dangers of the seemingly innocuous foam debris. Columbia broke apart as it headed toward Florida for landing on Feb. 1, 2003. It was the beginning of the end for the shuttle program.
Image: Endeavour blast off for the last time.
The Alpha Magnetic Spectrometer
On May 16, 2011, NASA launched space shuttle Endeavour and a crew of six to install the last major science experiment, $2 billion particle detector called the Alpha Magnetic Spectrometer, onto the International Space Station. The 134th shuttle mission was the next-to-last for the 30-year-old program. All the shuttles have been promised to museums.
They call themselves "The Final Four" -- the last of the 355 people who will have flown on the space shuttles. The 135th flight, slated to launch July 8, was added just last year to buy time for the commercial companies NASA has hired to take over cargo runs to the International Space Station. Atlantis will carry a year's worth of food, clothing, science gear and supplies to the station in case the new freighters encounter delays. Until private firms can develop space taxis, the United States will now depend on Russia to fly its astronauts to the station, as the agency devotes its limited budget toward building spacecraft that can travel beyond the station's orbit. "There is not an American who doesn't look upon an ascending shuttle with a certain sense of American pride," says Atlantis commander Chris Ferguson. "It's just been great and I think it will be fantastic to the very end."
We depend on communications satellites. These space-based relay stations are more active than we realize, receiving signals from the ground, filtering them, changing their frequencies, and amplifying them before sending them back to specific spots on Earth. But the first communications satellites were passive, simply reflecting signals back to a specific point Earth. They were the “Echo satellites” — the first launched in 1960 and the second launched just over 50 years ago on January 25, 1964.
The Echo program began in 1956 as a National Advisory Committee for Aeronautics experiment. The large, balloon-inspired satellites were designed primarily to test the effects the upper atmosphere on large lightweight orbital structures. But a second use for a reflective body in space soon occurred to John Robinson Pierce and Rudolf Kompfner, two researchers with AT&T’s Bell Telephone Laboratories. Already interested in using satellites for communications, they realized the Echo was a perfect passive communications test bed. The satellite couldn’t do much, but it would be a great body off which to bounce signals, sending them from one point on Earth to another. When the NACA was dissolved and replaced by NASA, Echo became a NASA project.
The first Echo satellites were designed and built by engineers at NASA’s Langley Research Center. The first version called Echo 1 (properly Echo 1A after Echo 1 was destroyed during a failed launch attempt) was a 100-foot-diameter balloon with a mylar polyester skin just 0.0127 millimeters thick. And though it weighed just 150 pounds, in space it needed just a few pounds of gas to stay inflated. On board was a set of beacon transmitters for telemetry data that were powered by five nickel-cadmium batteries. The batteries were in turn charged by 70 solar cells mounted on the balloon.
Echo 1 launched on Aug. 12, 1960, and enabled some important firsts in satellite communications. It saw the first live satellite-based voice communication; a radio message delivered by President Eisenhower; the first satellite-transferred image; an image of the President; and the first transcontinental satellite phone call was made between two researchers. It was also one among the first satellites to feel the effects of solar wind. Like a solar sail, Echo 1 responded to the pressure of photons that pushed it around and distorted the satellite’s orbit.
Echo 2 followed four years later, another passive communications satellite larger than its predecessor. Although it had a similar battery-powered beacon telemetry system on board to provide a tracking signal, monitored the balloon’s skin temperature, and managed its internal pressure to keep it inflated, Echo 2 was more advanced than its predecessor in a few ways. For one, it was larger with a nearly 135-foot diameter. It featured a better inflation system, which meant that once it was inflated in orbit the balloon’s skin was smoother and its overall shape more spherical. As a secondary aim, Echo 2 helped scientists gather more data about the dynamics of large spacecraft in orbit and about the shape and size of large areas of the Earth.
Echo 2 marked the end of NASA’s investigation into passive communications satellites. These balloons were massive compared to the active communications satellites and far less sophisticated. At the same time that Echo 1 was scoring firsts for the nascent world of space-based communications, AT&T was developing the active communications satellite called Telstar. Echo 1A reentered on May 24, 1968. Echo 2 followed on June 7, 1969.