[AS] The Romance of Adventure: Remembering Galileo's Ride on STS-34

[Orionid]

The Romance of Adventure: Remembering Galileo's Ride on STS-34 (Part 1)
By Ben Evans, on October 15th, 2016


Atlantis roars into orbit on 18 October 1989 to deploy the Galileo spacecraft on its mission to Jupiter. Photo Credit: NASA

When the Galileo spacecraft drifted out of Shuttle Atlantis’ payload bay on the evening of 18 October 1989, on the first leg of its voyage to Jupiter, the sight was a moving one for Shannon Lucid. As STS-34’s lead mission specialist, she was primarily responsible for the deployment of one of the most important payloads ever launched by NASA. For almost a dozen years, Lucid had lived and worked with the reality that her job was an overwhelmingly technical one, drawing from its roots in engineering and pure science … but on this day, as Galileo and its Inertial Upper Stage (IUS) booster floated silently into the inky void, she beheld a new reality: the romance of adventure. Emblazoned across the base of the spacecraft which would one day circle Jupiter and deposit an instrumented probe into its atmosphere were two names: “Galileo” in script and “NASA” in worm-like block capitals.

To Lucid, those two words symbolized exactly what the mission stood for: The script represented the romance of adventure and exploration, whilst the worm was indicative of the outstanding engineering and scientific talent which had brought this awesome project from the drawing board to fruition. Yet Galileo’s journey to the launch pad had been a long and tortured one, and its voyage to Jupiter would be longer and harder still.

The mission traced its genesis back to the mid-1970s. Named in honor of the great Italian scientist, Galileo Galilei, whose endeavors in the early 17th century included the discovery of Jupiter’s four large moons—Ganymede, Callisto, Europa, and Io—but which also assured him a retirement under house arrest, courtesy of the Roman Inquisition.

Originally known as “Jupiter Orbiter and Probe” (JOP), the name “Galileo” seemed an obvious one and the project received Congressional approval on 1 October 1977, with a planned launch four years later. However, delays to the first flight of the shuttle and the limited capability of Boeing’s IUS to boost Galileo on its way to Jupiter raised concerns. In 1979, Washington Post journalist Thomas O’Toole highlighted that problems with certifying the three Space Shuttle Main Engines (SSMEs) to operate at the 109 percent performance threshold needed to lift Galileo posed additional obstacles.


Galileo’s target was Jupiter, the largest planet in the Solar System. Photo Credit: NASA, ESA and E. Karkoschka (University of Arizona)

By now, the launch had slipped until 1982 at the earliest. O’Toole noted that if the 109-percent-capable SSMEs were not ready for this date, Galileo could slip even further. Timing was critical, since a 1982 launch depended upon a Mars gravity assist and if it was delayed much further, the potential existed to halve the scientific mission at Jupiter, from 11 to just five orbits of the giant planet. At length, in late 1980, under pressure from Rep. Edward Boland, a Democrat from Mass., NASA was obliged to abandon the IUS plan and initiate planning for a launch on General Dynamics’ liquid-propeled Centaur-G Prime, which Administrator Robert Frosch had earlier opposed.

The situation for Galileo’s future dimmed substantially for much of 1981, with Congressional mutterings of closing down the California Institute of Technology’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., which managed many of NASA’s planetary projects. A massive letter-writing campaign to George Keyworth, head of the White House’s Office of Science and Technology Policy, was spearheaded by Galileo investigator and famed physicist James van Allen. In a speech to the National Academy of Sciences, van Allen identified Galileo as one of the most exciting missions of exploration ever undertaken and that its cancellation would prove devastating.

Thankfully, in December 1981 the Office of Management and Budget relented, reinstated Galileo and it was rescheduled for 1983. There was a caveat, however: Galileo would not use the powerful Centaur-G Prime. In January 1982, NASA rescoped the mission and returned to the less powerful IUS fitted with a third, “injection stage” to provide increased propulsion. As a consequence, Galileo’s launch was rescheduled for August 1985, but the absence of the powerful Centaur meant that it would take five years, instead of two, and the spacecraft would be injected into a two-year-long elliptical solar orbit, would require a gravity assisted boost from Earth in June 1987, and would finally reach Jupiter in January 1990.

By the summer of 1982, some members of Congress—led by New Mexico Sen. Harrison “Jack” Schmitt, a former Moonwalker and chairman of the Senate Space Subcommittee of the Science, Commerce and Transportation Committee—were pushing vigorously for a return to the Centaur and a reduced journey time. Despite worries about additional expense in changing boosters again, coupled with concerns about further delays to the mission, in July President Reagan approved the move and NASA was forced to replan. The Centaur would be used to boost Galileo, but launch would be unavoidably postponed until May 1986, with a two-year flight time to the giant planet.


Artist’s impression of Galileo, attached to the giant Centaur-G Prime upper stage, shortly before deployment from the Shuttle in May 1986. The Challenger disaster sounded the death knell for the highly dangerous human-rated Centaur. Image Credit: NASA

At this stage, the mission truly entered the phase of equipment testing. In the early summer of 1983, the parachute for the instrumented probe, which would descend into Jupiter’s atmosphere, successfully passed full-scale tests, and by September of that year the main spacecraft and probe were integrated. A model of the Centaur passed its own tests in September 1984, and the actual flight model was rolled out of General Dynamics’ plant in San Diego, Calif., in August of the following year. By this time, NASA Administrator Jim Beggs had endorsed other possible tasks for Galileo, most notably a flyby of the asteroid Amphitrite, which it was hoped might unlock secrets of the primordial solar nebula from which the Sun and planets formed. An Amphitrite flyby would delay the Jupiter arrival from August to December 1988, however, and it was decided to make a final decision after launch. In December 1985, only weeks before the loss of Challenger, Galileo was transported, cross-country by truck, guarded by police, state troopers, and other guards, and arrived safely at the Kennedy Space Center (KSC) for launch the following May.

When Challenger exploded in the skies above Florida on 28 January 1986, Galileo was undergoing final checkout and preparation for attachment to its Centaur-G Prime booster. In the weeks after the accident, NASA Acting Administrator William Graham spoke of the possibility of a return to flight in the spring of 1987, which kept alive the option to launch Galileo in the next Jovian “window” in June of that year. Eventually, the modifications to the shuttle’s Solid Rocket Boosters (SRBs) and the orbiters themselves inevitably pushed the return to flight further to the right.

On 19 June 1986, newly-reappointed NASA Administrator Jim Fletcher formally canceled Centaur-G Prime and new options had to be found. One of these was an “enlargement” of the IUS, possibly coupled with an additional booster, such as a Special Payload Assist Module (PAM-S). However, as already noted, the IUS was insufficient to send Galileo directly to Jupiter and alternate trajectories, involving planetary gravity assists, were explored. Even before NASA settled on October-November 1989 as the most appropriate “window” for Jupiter, Galileo’s planners were already working toward this date, creating a complex flight profile, known as the Venus-Earth-Earth Gravity Assist (VEEGA), in which the spacecraft would perform a flyby of Venus in February 1990, return to Earth in December, and be placed into a two-year elliptical solar orbit. Returning a second time to Earth in December 1992, it would pick up sufficient energy to reach Jupiter in December 1995.

The VEEGA technique was highly conservative of Galileo’s on-board propellant, with predictions indicating that up to 176 pounds (80 kg) would remain, even after the arrival at Jupiter and completion of its primary mission. The trajectory also permitted possible rendezvous with up to three asteroids—Ausonia, Gaspra, and Ida—and eventually the latter two were selected. However, since the spacecraft would fly much closer to the Sun than had been planned, additional thermal shielding was added in the three-year down time after Challenger. It is interesting that Galileo also “leapfrogged” Ulysses in the launch pecking order. “NASA based its decision on optimising data return from the two missions,” wrote Michael Meltzer in Mission to Jupiter. “Launching Ulysses first would have resulted in too long a wait before Galileo reached Jupiter and began transmitting prime data from the Jovian system.”


Jupiter and Galileo adorn the official crew patch for STS-34, together with the names of the five-member crew: Commander Don Williams, Pilot Mike McCulley and Mission Specialists Shannon Lucid, Franklin Chang-Diaz, and Ellen Baker. Image Credit: NASA

As launch neared, with an opening of the Jupiter window at 1:29 p.m. EST on 12 October 1989, there were still last-minute concerns about Galileo … although these were not focused upon its mission, but upon its power system. Since the spacecraft would be traveling so far from the Sun, the use of solar cells for electrical provision was impractical. Therefore, General Electric supplied a pair of Radioisotope Thermoelectric Generators (RTGs), fueled by fracture-resistant pellets of plutonium-238, whose decay produced heat which was in turn converted into electricity. To keep them at a safe distance from the sensitive scientific instruments, the RTGs were mounted on a boom, which extended them 16 feet (5 meters) away from the main body of the spacecraft.

Both power plants produced 570 watts of electricity at launch, which steadily decreased by around half a watt per month and reached around 493 watts by the time Galileo reached Jupiter. Shuttle Atlantis also required modification to incorporate an RTG coolant line and purging system in her payload bay. In the late 1980s, of course, “nuclear” was a dirty word—a word which conjured images of military superpowers, the faceless Department of Defense and Department of Energy, and greedy power corporations. Peace marches were undertaken and representatives of several anti-nuclear groups gathered at the gates of KSC to express their disgust and fear that a Challenger-like explosion could spread radioactive plutonium across much of the United States’ eastern seaboard.

The allegation that NASA was playing “ecological roulette” with the lives of Floridians was not groundless. Memories of the “messy” crash of the Soviet Union’s nuclear-fueled Cosmos 954 satellite in Canada, a decade earlier, were fresh in many minds, and even the noted physicist Carl Sagan remarked that “there is nothing absurd about either side of this argument.” Final approval to proceed with the Galileo launch came from President George H.W. Bush himself in September 1989. Three days before the scheduled launch, on 9 October, outraged protestors staged a mock “death scene” at the Cape and even threatened to sit on Pad 39B itself to prevent Atlantis from launching into orbit.

STS-34 astronaut Franklin Chang-Díaz was astonished by the controversy surrounding a mission which was not a military one, but a scientific odyssey. “It was striking to drive through the gates…and see all these demonstrators, trying to stop the launch,” he told a Smithsonian interviewer, years later. “The topic of nuclear power is going to come up over and over again as we move into space. It’s a key issue we are going to have to resolve, because the survival of people in space, far away from Earth, will totally depend on the use of nuclear power.”

The launch window for Jupiter would close on 21 November 1989, after which the next opportunity would not arise until 1991, so there existed a very real risk that the mission might be canceled. Security was increased at KSC, as guards armed with M-16 assault rifles and 9 mm semi-automatic pistols patrolled the perimeter of the launch site. A faulty main engine controller put paid to the 12 October attempt and launch was rescheduled for the 17th, then the 18th when rain showers drifted within 18 miles (30 km) of the Shuttle Landing Facility (SLF). During these few days, final efforts to stop the launch were rejected by the Circuit Court of Appeals in Washington, D.C. In her summary, Chief Justice Patricia Wald declared that she could find no evidence that NASA had improperly compiled its environmental assessment reports for Galileo, and on 16 October a number of activists were arrested at the Cape for trespassing.

With this final clearance, the last hurdle was removed before Galileo’s long-awaited mission to the King of the Planets.

Source: https://www.americaspace.com/2016/10/15/the-romance-of-adventure-remembering-galileos-ride-on-sts-34-part-1/

[Orionid]

The Romance of Adventure: Remembering Galileo’s Ride on STS-34 (Part 2)
By Ben Evans, on October 16th, 2016


Jupiter and its volcanic moon Io were key focuses for the Galileo mission. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Goddard Space Flight Center

Almost three decades ago, shuttle mission STS-34 and the crew of Atlantis rocketed into orbit to launch NASA’s Galileo spacecraft on a lengthy odyssey to Jupiter. As described in yesterday’s AmericaSpace history article, the mission was extensively delayed, by political and technical issues—including the Challenger tragedy—and almost met with outright cancellation, when anti-nuclear protesters campaigned against the use of its plutonium-powered Radioisotope Thermoelectric Generator (RTG). However, after considerable rain, on the wet morning of 18 October 1989, the five astronauts departed their crew quarters at the Kennedy Space Center (KSC), bound for Pad 39B and Atlantis.

In command of STS-34 was Don Williams, who had previously flown as pilot of Mission 51D in the spring of 1985. He was joined by pilot Mike McCulley and mission specialists Shannon Lucid—a veteran of the multi-national Mission 51G—Franklin Chang-Díaz, and Ellen Baker. The quintet had been training since November 1988. Their launch on 18 October was postponed by 3.5 minutes, in order to update the shuttle’s computers for a change in the Transoceanic Abort Landing (TAL) site, which had been moved to Zaragoza in Spain, due to heavy rain at Ben Guerir in Morocco. Finally, at 12:53 p.m. EST, Atlantis thundered into clear Florida skies, bound for low-Earth orbit.

Despite all of his training, the dynamic nature of the launch surprised Mike McCulley, who described much of its effect as “acoustic,” which “shakes your body and your soul.” At one stage, a few seconds after liftoff, as the tower disappeared faster than his simulator experience had taught him to expect, he turned to Williams and jokingly remarked: “You didn’t prepare me for this!” Another thing which came as unexpected was the separation of the twin Solid Rocket Boosters (SRBs), about two minutes into the ascent. “In the simulator, there’s a flashbulb that goes off when you get to SRB sep,” McCulley , “and in real life there’s an explosion that goes off, right in front of your face. It was wonderful … but it was surprising!”


Atlantis roars into orbit on 18 October 1989 to deploy the Galileo spacecraft on its mission to Jupiter. Photo Credit: NASA

To be fair to Williams, his position in command of STS-34 was quite distinct to his previous stint as a shuttle pilot. “There’s some amount of loneliness at the top,” he told the NASA oral historian, “and having that authority and with it comes the responsibility for accomplishing the mission. With those first two comes the most important one, in my mind, which I learned early on as a midshipman at Purdue … is with the authority and responsibility comes the accountability and if something goes wrong, it’s not somebody else’s fault, it’s the person in command’s fault! The same thing is true when you command a mission. You’re accountable for the performance of the crew, for the accomplishment of the mission, for getting the objectives completed successfully, and for getting the spacecraft back so somebody else can use it again. That’s the name of the game.” Command was important to Williams. In fact, by his own admission, it was his primary goal as a pilot: to command the shuttle. “Okay, this is what you came here for,” he told himself. “Let’s go do it.”

Six hours into the mission, at 7:15 p.m., under the watchful eye of Shannon Lucid, Galileo and its Boeing-built Inertial Upper Stage (IUS) booster were tilted to their deployment position and set free. “Galileo is on its way to another world,” exulted Williams. “It’s in the hands of the best flight controllers in the world. Fly safely!” Franklin Chang-Díaz felt a very personal affinity with Galileo. To him, it was a memorable occasion, because it represented his childhood desire to leave Earth and travel to other planets. Shortly thereafter, Williams and McCulley maneuvered Atlantis to a safe separation distance, and the IUS fired to boost Galileo onto a course for Venus, which it would reach in a little over three months’ time.

“Both Ellen and I sighed a great sigh of relief,” recalled Lucid, “because we figured Galileo was not our concern at that point, because we’d gotten rid of it. Happiness was an empty payload bay and we got happier and happier as the IUS and Galileo went further away from us.” An hour after deployment, the IUS fired to commence Galileo’s six-year journey to the King of the Planets.

As circumstances transpired, it would prove a remarkable example of the triumph of human ingenuity over adversity. Eighteen months into its cruise, and several months after its first flyby of Earth, Galileo’s high-gain antenna only partially unfurled, threatening to ruin the mission. “Workaround” techniques were devised to use the low-gain antenna instead, and the spacecraft returned remarkable images from the asteroids Gaspra (in October 1991) and Ida (in August 1993) and, far from conducting two years of scientific exploration at Jupiter, Galileo spent almost eight years in operation. During that period, it measured the chemical composition of the giant planet’s atmosphere, directly observed its ammonia clouds and mysterious Great Red Spot, analyzed the causes and effects of volcanism on Io, and yielded tantalizing clues for liquid oceans beneath the frozen surfaces of Europa and Ganymede, and the extent of Jupiter’s gigantic magnetosphere was mapped and modeled for the first time. On its way to the planet, in July 1994, Galileo also observed the impact of Comet Shoemaker-Levy 9 into the Jovian clouds.


By the time Galileo eventually left Earth in October 1989, it was boosted towards Jupiter by a less powerful Inertial Upper Stage (IUS). Photo Credit: NASA

Having set Galileo on its way, for all intents and purposes, the primary mission of STS-34 was over. Several secondary experiments were performed, including the first flight of the Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument in the payload bay. This was part of an ongoing NASA effort to calibrate ozone sounders on free-flying satellites and verify the accuracy of atmospheric ozone and solar irradiance data. A polymer solidification study was conducted on the middeck, and observations were made of lightning events in the high atmosphere.

Living in space, even for just five days, was quite different to anything the astronauts had experienced before. Williams described it as akin to a camping trip, with the exception that none of them departed their camper van, at all, for the entire five days. “What’s it like to be in space?” he rhetorically asked his audience at the STS-34 post-flight press conference. “Unfortunately, this is one of the most difficult questions to answer, since the word ‘like’ implies a comparison, and it’s not ‘like’ anything you’ve ever done before. So most of us are stuck with describing the differences. Weightlessness. How do you describe weightlessness, when we live in a world where everything weighs something? The ability to move about, almost be thinking about it. No up or down. Behavior and misbehavior of common, ordinary things, such as liquids, elastic, food, objects.

“Watch the video with us,” Williams invited his audience. “Compare it to things you do on Earth. Look for the differences. Perhaps you can describe ’em to us!”

Betwixt this wonderland of weightlessness, the crew was periodically called away to tend to minor issues with Atlantis herself. A problem with one of the shuttle’s Auxiliary Power Units (APUs) triggered an alarm on 22 October, together with a glitch with the Flash Evaporator System (FES) and cryogenic oxygen manifolds. Predicted high winds at Edwards Air Force Base, Calif., on the 23rd prompted a decision to bring the shuttle home two orbits earlier than planned, and Williams and McCulley guided the shuttle to a smooth touchdown at 6:33 a.m. PST (12:33 p.m. EST), just 20 minutes short of five full days after launch.

Don Williams regarded STS-34 and having accomplished something quite remarkable for science. “We knew that Galileo was going to be a lasting program,” he said, “as opposed to the first flight, where we deployed the two satellites. The Galileo mission, we knew, if it was successful, the spacecraft was going to end up in orbit around Jupiter several years later and then there were going to be several years of data and images sent back. It was going to be a living, ongoing program and we got to be a part of it.”

Source: https://www.americaspace.com/2016/10/16/the-romance-of-adventure-remembering-galileos-ride-on-sts-34-part-2/


GALILEO SPACE MISSION EXTENDED
UPI Jan. 23, 1982

The space agency announced today that it would continue development of the Galileo space mission to explore Jupiter and its moons but that the new plan would lengthen the voyage by 30 months and add $170 million to the project's cost.

The National Aeronautics and Space Administration said its $5.94 billion revised operating plan had been approved by the White House budget office and by Congress.

Although the budget for the fiscal year 1983 will not be disclosed until next month, White House approval means the nation's planetary exploration program will not be eliminated, as had been feared.

The operating plan, however, does eliminate funds for a proposed mission to map the planet Venus with a radar satellite. In addition, NASA will not develop a powerful hydrogen-fueled upper-stage rocket called Centaur for use with the space shuttle. The plan was to use the Centaur to propel t he Galileo from Earth orbit to Jupiter. Instead, a less powerful ro cket will be used along with another rocket ''kick'' motor. The chang e was made to eliminate the high cost of developing the Centaur but w ill increase the length of the trip and the cost of the mission,

The plan now is to launch the Galileo spacecraft in the summer of 1985. It would reach Jupiter in 1989.
https://www.nytimes.com/1982/01/23/us/galileo-space-mission-extended.html

[Orionid]

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 Jupiter
By 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.html


Shuttle Launched After Delay And Galileo Is Sent to Jupiter
By 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