Misja rozpoczęła się z 3-letnim opóźnieniem, spowodowanym katastrofą Challengera.
Sonda znalazła się w magazynie, co z kolei wpłynęło na pogorszenie właściwości smarów w elementach anteny HGA (High-Gain Antenna).
Dodatkowe pogorszenie parametrów smarów miało miejsce z powodu wibracji w czasie transportu drogowego na Cape Canaveral (tak było taniej, niż użycie transportu powietrznego).
Antena o dużym zysku nigdy nie została rozwinięta.
Antena HGA miała zapewnić transmisję danych z szybkością 134 400 bitów/sek. z orbity wokół Jowisza.
Jej rolę przejęła antena o małym zysku LGA 1 (Low-Gain Antenna).
Modyfikacje anten Deep Space Network oraz łączenie ich w sieć pozwoliło zapewnić szybkość transmisji danych do 160 bitów/sek.
Mimo problemów misja okazała się wielkim sukcesem.Visit to a Large, Hot Planet: Galileo Heads for JupiterBy John Noble Wilford Oct. 17, 1989 [NYT]
Scientists hope the Galileo spacecraft's planned explorations of Jupiter, probing deep into the planet's hot, dense hydrogen atmosphere, will yield important clues to primordial conditions in the solar system and also insights about the ''big bang'' that may have created the universe.
With expectations like these, the $1.4 billion Galileo mission scheduled to begin Tuesday afternoon is the most ambitious interplanetary undertaking yet in the history of space flight. The 2.5-ton spacecraft, described by some exuberant scientists as the ''Rolls-Royce'' of planetary vehicles, will be the first to orbit Jupiter and conduct a sustained investigation of the four major Jovian moons, which Voyager photography disclosed as diverse and puzzling worlds unto themselves. Galileo will also be the first mission to probe the atmosphere of one of the giant outer planets. 'The Grandest Mission'
''It's the grandest mission we've attempted,'' said William J. O'Neil, science and mission design manager for Galileo at the Jet Propulsion Laboratory in Pasadena, Calif. ''Jupiter is most important to us in trying to understand how the solar system evolved.''
Galileo's six-year journey to Jupiter will begin in the cargo bay of the space shuttle Atlantis, now scheduled for liftoff at 12:57 P.M. Once in orbit, the crew of five astronauts are to release the spacecraft. Then an attached rocket should fire the spacecraft on a roundabout trajectory to Jupiter by way of Venus and two passes by Earth. At each of these encounters Galileo will pick up momentum from the force of the planets' gravity.
The launching, originally set for last Thursday, was delayed five days while technicians replaced a faulty electronic control unit in one of the shuttle's three main engines.
Officials of the National Aeronautics and Space Administration said the newly installed controller had been tested and was ''functioning flawlessly.'' Weather is predicted to be favorable.
Potential legal obstacles were swept awa today when a three-judge panel of the United States Court of Appeals for the District of Columbia ruled against anti-nuclear organizations attempting to obtain a temporary restraining order to halt the launching. The groups complained that Galileo's plutonium electric-generator posed a public hazard in case of an accident during liftoff. NASA insists that its studies show the risks of radioactivity escaping in a launching disaster are virtually nil.
About 40 demonstrators marched this morning on the gate to the Kennedy Space Center headquarters. Gary L. Wistrand, deputy director of the security office, said seven were arrested when they tried to enter the restricted area and charged with illegal trespass. He said additional security patrols would be on duty until the launching to prevent intruders from getting near the shuttle. Launching Chances 'Excellent'
At a news conference today, Richard H. Truly, the NASA administrator, said the chances for launching Tuesday were ''excellent.'' Noting the many scheduling problems that have beset Galileo, and he said, ''It's been a long haul for this marvelous science mission.'' This delay was nothing, Mr. O'Neil said, ''when you consider how long we've waited already.'' Authorized in 1978, the project was almost canceled in 1981, the first year of the Reagan Administration, for budget reasons. A planned launching in 1982 was deferred because the shuttle was not ready. Galileo was set for a shuttle launching in April 1986,but after the Challenger blew up that January everything was delayed indefinitely.
So by the time Galileo does reach Jupiter, in December 1995, it will be 10 years behind the original arrival plan.
On the way, Galileo will be transmitting pictures of and data about Venus, Earth's Moon and an asteroid, but scientists will have to wait patiently until the summer of 1995 for the main events to begin. That is when the lower segment of the spacecraft, a 745-pound capsule encased in an oval heat shield, will separate and spin away on a trajectory aimed at a spot just above Jupiter's equator.
Jupiter, the largest planet, contains more mass than all the other planets combined. Its Great Red Spot, a raging storm system in the southern hemisphere, is itself twice the size of Earth. The gravity of such a massive object is a powerful force, more than 350 times Earth's gravity, and this will draw the instrument-laden capsule in at increasingly accelerating speeds.
On Dec. 7, 1995, the spacecraft will slam into the high white ammonia clouds of Jupiter's atmosphere at 115,000 miles an hour. Friction between the plunging craft and the thickening Jovian atmosphere will create a fiery shock wave reaching temperatures of 28,000 degrees Fahrenheit. But the friction's braking action will slow the craft to 100 miles an hour in only a few minutes.
By this time, the capsule will deploy a parachute and drift slowly through the brilliantly colored clouds and violent winds into the hot, dense atmosphere below. It is expected to survive for at least 75 minutes and reach a depth in the Jovian atmosphere of about 400 miles before being crushed into silence by the tremendous heat and pressure, according to predictions by designers at the Ames Research Center in Mountain View, Calif. The craft was built by Hughes Aircraft Company. Range of Instruments
Instruments on the probe will gather data on temperature, pressure and density of the Jovian atmosphere; the location and thickness of cloud layers; the identity and intensity of electrons, protons and other energetic particles, and the chemical composition of the atmosphere. Voyager identified some of the atmosphere's composition with remote sensors, but many materials, including nitrogen, cannot be measured remotely.
Hydrogen and helium are known to be the principal components of Jupiter, and the probe is equipped to determine the ratio of hydrogen to helium. Richard Young, a project scientist at the Ames Research Center, said that for theoretical astrophysicists these could be the most critical measurements of the mission.
Jupiter is believed to have a small rocky core surrounded mostly by hydrogen in various states, depending on pressures. Near the core is a layer of liquid hydrogen that is so compressed that it behaves like a metal, and its motions are presumably the source of the planet's enormous magnetic field. Above that is a layer of liquid hydrogen. As pressures diminish with distance from the core the hydrogen changes gradually from a liquid to gaseous state.
Scientists want to check on their estimates that about 88 percent of Jupiter is hydrogen, with 11 percent helium and small amounts of methane, ammonia and water. Since Jupiter has apparently undergone little change from its beginnings, the planet's composition is thought to resemble the cloud of gas and dust from which the Sun and planets formed. Galileo's first direct observations of that atmosphere thus are expected to give scientists a better idea of what the early solar system was like.
Similarly, the hydrogen-to-helium ratio promises to be a vital clue in checking the validity of the Big Bang theory of how the universe was created in a single explosive moment. The helium found at Jupiter is assumed to be in roughly the same proportion as that created in the brief interval after the Big Bang. The planet is presumably uncontaminated by helium that has been produced subsequently in stellar nuclear reactions.
For the main segment of the Galileo spacecraft, the orbiting vehicle, the mission will be only beginning in December 1995. After it acts as a radio relay station for the atmospheric probe, the main vehicle will swing into an orbit of Jupiter for a planned 22-month mission. In that time, Galileo is expected to make 10 complete circuits and multiple passes of the four large moons, which were discovered in 1610 by Galileo with the first astronomical telescope. Of particular interest will be sustained observations of Io, the moon on which Voyager found erupting sulfur volcanoes. Advanced Camera
The Galileo spacecraft is equipped with a more advanced television camera, including a highly sensitive electronic imaging system, that is at least 10 times more sensitive than the vidicon tube used on the Voyager spacecraft.
''Galileo will go so close to some of the moons, as close as 200 kilometers, that we should achieve images 100 to 1,000 times better than Voyager got,'' Mr. O'Neil said.
Astronomers who have been studying Jupiter through ground-based telescopes reported last week that the planet seems to be putting on a slightly different face these days. ''It's changing and doing wild things on a huge scale,'' said Dr. Reta Beebe, an astronomer at New Mexico State University.
Since July one of the many multicolored bands in the Jovian atmosphere, the Southern Equitorial Belt, has changed from brown to white. And the Great Red Spot is getting redder. Scientists said the planet's atmosphere is so turbulent that there will undoubtedly be many more changes before Galileo arrives in 1995.https://www.nytimes.com/1989/10/17/science/visit-to-a-large-hot-planet-galileo-heads-for-jupiter.htmlShuttle Launched After Delay And Galileo Is Sent to JupiterBy John Noble Wilford, Special To the New York Times Oct. 19, 1989
The space shuttle Atlantis rocketed into orbit today to send the Galileo spacecraft on its planned six-year, 2.5-billion-mile journey to Jupiter.
After two postponements in a week, one caused by technical problems and the other by weather, the Atlantis and its crew of five astronauts lifted off the launching pad at 12:54 P.M. Eastern time, only four minutes late. The countdown had been briefly interrupted because of threatening clouds, but it was resumed as they drifted away.
The sky was so clear by then that the shuttle could be followed in flight with the unaided eye for at least five minutes. It was last seen a hundred miles out over the Atlantic as a tiny sparkling crystal vanishing in the blue.
''We're off to a great start,'' said Robert B. Sieck, the launching director at the Kennedy Space Center, at a news conference.
On the fifth orbit, the crew of Atlantis released the 2.5-ton Galileo from the cargo bay at 7:15 P.M. The astronauts maneuvered the shuttle out of the way, and an hour later, the rocket attached to Galileo fired to boost the spacecraft out of Earth orbit.
Minutes later, the second stage of the solid-fuel rocket was fired, sending the spacecraft on its interplanetary trajectory. Control Center Felt Quake
Operations of the Galileo rocket were controlled by an Air Force center in Sunnyvale, Calif., 37 miles south of San Francisco. The center suffered some minor damage in the earthquake but was restored to normal service early today.
Mission Control at the Johnson Space Center in Houston reported no serious problems on the spaceship. It was the 31st launching of a shuttle since the first test flights in 1981.
''Everything is going really well,'' said Ron Dittemore, a flight director.
The five astronauts on Atlantis are Capt. Donald E. Williams and Comdr. Michael J. McCulley of the Navy; Dr. Shannon W. Lucid, a biochemist; Dr. Franklin R. Chang-Diaz, a physicist, and Dr. Ellen S. Baker, a physician. It is the first trip in space for Commander McCulley and Dr. Baker. Galileo Launching Hailed
Jubilant scientists hailed the launching of the long-delayed Galileo mission to orbit Jupiter, the largest planet. During the mission, an instrumented probe will be fired into the Jovian atmosphere.
Lennard A. Fisk, the space agency's associate administrator for science, called this the beginning of ''the second golden age in the exploration of the solar system.''
After the initial reconnaissance of all the planets, except Pluto, and an 11-year hiatus in new planetary missions, the National Aeronautics and Space Administration began the second age in April by dispatching the Magellan spacecraft to map Venus with radar. Galileo marks the first ambitious attempt to follow up in detail on the spectacular discoveries of the two Voyagers that flew by Jupiter in 1979.
Galileo suffered several delays primarily because of the shuttle's development problems and then the Challenger accident in 1986. It was originally scheduled for launching in 1982. Now scheduled to arrive at Jupiter in December 1995, the spacecraft would be the first to orbit one of the giant outer planets and the first to obtain direct observations of the atmosphere of the gaseous bodies.
Scientists believe that Galileo's 745-pound probe, which is to penetrate deep into the dense hydrogen atmosphere, could give them important clues about primordial conditions in the solar system and perhaps insights into the validity of the ''big bang'' theories of the creation of the universe. Approaches to 4 Satellites
The main spacecraft is to orbit Jupiter for at least 22 months of planned reconnaissance, making 10 close approaches to the four largest Jovian satellites, Io, Europa, Callisto and Ganymede. Photographs of the moons are expected to be as much as 1,000 times as detailed as those returned by the Voyager spacecraft.
To get there, Galileo will take the scenic route, going first to Venus and then looping by Earth twice before speeding off toward Jupiter. The roundabout route was dictated by a decision in 1986 to use a smaller but safer rocket, the Air Force-developed inertial upper stage rocket, for the initial boost out of Earth orbit. In making its loops, the spacecraft will pick up additional momentum from the gravity of Venus and Earth.
Galileo's journey began with a ride in the shuttle's 60-foot-long cargo bay into an orbit 185 miles over Earth.
The original launching date of Oct. 12 was missed because ground tests uncovered a possible malfunction in an electronic control unit in one of the shuttle's three main rocket engines. The unit had to be replaced. Although countdown preparations this morning were virtually flawless, Mr. Sieck said, launching officials kept a wary eye on the weather all morning. Dark rain clouds had halted the countdown in the final minutes Tuesday.
If anything, the forecast for today was even more ominous: thunderstorms and rain and a 40 percent chance that weather would be unacceptable for launching.
Liftoff was planned for 12:50, with 29 minutes in which to get under way before Earth would move out of position for a spacecraft to make it out of orbit and on the way to Jupiter. Launching opportunities would recur daily until Nov. 21.
As the scheduled launching time approached, reports showed that clouds were threatening not only the Kennedy center but also the three emergency landing sites across the Atlantic, two in Spain and one in Morocco. Countdown Is Halted Briefly
The countdown was halted with nine minutes to go because of conditions on both sides of the Atlantic. Then the weather cleared here. The countdown was resumed and then halted again, with five minutes to go. Officials waited for word from the emergency landing sites. Finally, one base in Spain reported clearing skies.
Quickly, the countdown was started again, and it moved without further interruption until the fiery liftoff, which sent claps of thunder through the humid air.
The planned five-day mission is scheduled to end with a landing Monday afternoon at Edwards Air Force Base in the Mojave Desert of California.https://www.nytimes.com/1989/10/19/us/shuttle-launched-after-delay-and-galileo-is-sent-to-jupiter.html