Launch from Cape Canaveral (KSC) and landing on the Edwards AFB, Runway 23.

The launch was originally targeted for October 12, 1989. Liftoff was rescheduled for October 17, 1989 to replace a faulty main engine controller for Space Shuttle Main Engine No. 2. It was postponed again until October 18, 1989 because of rain showers at Cape Canaveral (Return To Launch Site (RTLS)). At this day the countdown was delayed at T-minus 5 minutes for 3 minutes and 40 seconds to update the onboard computer for a change in the Transoceanic Abort Landing (TAL) site. The TAL site was changed from Ben Guerir Air Base, Morocco, to Zaragoza Air Base, Spain, because of heavy rain at Ben Guerir.

Primary payload was the Galileo/Jupiter spacecraft (start of a very successful Galileo mission). STS-34 was only the second shuttle flight to deploy a planetary spacecraft, the first being STS-30, which deployed the Magellan spacecraft.
Galileo was a NASA spacecraft mission to Jupiter to study the planet's atmosphere, satellites and surrounding magnetosphere. It was named for the Italian renaissance scientist who discovered Jupiter's major moons by using the first astronomical telescope.
This mission was the first to make direct measurements from an instrumented probe within Jupiter's atmosphere and the first to conduct long-term observations of the planet and its magnetosphere and satellites from orbit around Jupiter. It was the first orbiter and atmospheric probe for any of the outer planets. On the way to Jupiter, Galileo also observed Venus, the Earth-moon system, one or two asteroids and various phenomena in interplanetary space.
Galileo was boosted into low-Earth orbit by the Shuttle Atlantis and then boosted out of Earth orbit by a solid rocket Inertial Upper Stage. The spacecraft flew past Venus and twice by the Earth, using gravity assists from the planets to pick up enough speed to reach Jupiter. Travel time from launch to Jupiter was a little more than 6 years.
In December 1995, the Galileo atmospheric probe conducted a brief, direct examination of Jupiter's atmosphere, while the larger part of the craft, the orbiter, began a 22-month, 10-orbit tour of major satellites and the magnetosphere, including long-term observations of Jupiter throughout this phase.
The 2-ton Galileo orbiter spacecraft carried 9 scientific instruments. There were another six experiments on the 750-pound (340 kg) probe. The spacecraft radio link to Earth served as an additional instrument for scientific measurements. The probe's scientific data were relayed to Earth by the orbiter during the 75-minute period while the probe was descending into Jupiter's atmosphere. Galileo communicated with its controllers and scientists through NASA's Deep Space Network, using tracking stations in California, Spain and Australia.
Galileo made three planetary encounters in the course of its gravity-assisted flight to Jupiter. These provided opportunities for scientific observation and measurement of Venus and the Earth-moon system. The mission also had a chance to fly close to one or two asteroids, bodies which have never been observed close up, and obtain data on other phenomena of interplanetary space.
The Galileo spacecraft approached Venus early in 1990 from the night side and passed across the sunlit hemisphere, allowing observation of the clouds and atmosphere. Both infrared and ultraviolet spectral observations were planned, as well as several camera images and other remote measurements. The search for deep cloud patterns and for lightning storms was limited by the fact that all the Venus data must be tape-recorded on the spacecraft for playback 8 months later.
Approaching Earth for the first time about 14 months after launch, the Galileo spacecraft observed, from a distance, the nightside of Earth and parts of both the sunlit and unlit sides of the moon. After passing Earth, Galileo observed Earth's sunlit side. At this short range, scientific data were transmitted at the high rate using only the spacecraft's low-gain antennas. The high-gain antenna was to be unfurled like an umbrella, and its high-power transmitter turned on and checked out, about 5 months after the first Earth encounter.
Nine months after the Earth passage and still in an elliptical solar orbit, Galileo entered the asteroid belt, and two months later, had its first asteroid encounter. Gaspra was believed to be a fairly representative main-belt asteroid, about 10 miles (16 km) across and probably similar in composition to stony meteorites. The spacecraft passed within about 600 miles (965 km) at a relative speed of about 18,000 miles (28,968 km) per hour. It collected several pictures of Gaspra and made spectral measurements to indicate its composition and physical properties.
Thirteen months after the Gaspra encounter, the spacecraft had completed its 2-year elliptical orbit around the Sun and arrived back at Earth. It needed a much larger ellipse (with a 6-year period) to reach as far as Jupiter. The second flyby of Earth pumped the orbit up to that size, acting as a natural apogee kick motor for the Galileo spacecraft. Each gravity-assist flyby required about three rocket-thrusting sessions, using Galileo's onboard retropropulsion module, to fine-tune the flight path. The asteroid encounters required similar maneuvers to obtain the best observing conditions.
Nine months after the final Earth flyby, Galileo had a second asteroid-observing opportunity. Ida is about 20 miles (32 km) across. Like Gaspra, Ida is believed to represent the majority of main-belt asteroids in composition, though there are believed to be differences between the two. Relative velocity for this flyby was nearly 28,000 miles (45,061 km) per hour, with a planned closest approach of about 600 miles (965 km).
Some 2 years after leaving Earth for the third time and 5 months before reaching Jupiter, Galileo's probe separated from the orbiter. The spacecraft turned to aim the probe precisely for its entry point in the Jupiter atmosphere, spinned up to 10 revolutions per minute and released the spin-stabilized probe. Then the Galileo orbiter maneuvered again to aim for its own Jupiter encounter and resumed its scientific measurements of the interplanetary environment underway since the launch more than 5 years before. While the probe was still approaching Jupiter, the orbiter had its first two satellite encounters. After passing within 20,000 miles (32,186 km) of Europa, it flew about 600 miles (965 km) above Io's volcano-torn surface, twenty times closer than the closest flyby altitude of Voyager in 1979.
The probe mission had four phases: launch, cruise, coast and entry-descent. During launch and cruise, the probe carried by the orbiter and serviced by a common umbilical. The probe was dormant during cruise except for annual checkouts of spacecraft systems and instruments. During this period, the orbiter provided the probe with electric power, commands, data transmission and some thermal control.
Six hours before entering the atmosphere, the probe was shooting through space at about 40,000 mph (64,363 km/h). At this time, its command unit signals "wake up" and instruments began collecting data on lightning, radio emissions and energetic particles.
A few hours later, the probe slammed into Jupiter's atmosphere at 115,000 mph (185,074 km/h), fast enough to jet from Los Angeles to New York in 90 seconds. Deceleration to about Mach 1 - the speed of sound - took just a few minutes. At maximum deceleration as the craft slowed from 115,000 mph (185,074 km/h) to 100 mph (160.9 km/h), it was hurtling against a force 350 times Earth's gravity. The incandescent shock wave ahead of the probe was as bright as the sun and reached searing temperatures of up to 28,000 degrees Fahrenheit. After the aerodynamic braking has slowed the probe, it dropped its heat shields and deployed its parachute. This allowed the probe to float down about 125 miles (201 km) through the clouds, passing from a pressure of 1/10^th that on Earth's surface to about 25 Earth atmospheres.
The probe passed through the white cirrus clouds of ammonia crystals - the highest cloud deck. Beneath this ammonia layer probably lie reddish-brown clouds of ammonium hydrosulfides. Once past this layer, the probe reached thick water clouds. This lowest cloud layer may act as a buffer between the uniformly mixed regions below and the turbulent swirl of gases above.
A set of six scientific instruments on the probe measured, among other things, the radiation field near Jupiter, the temperature, pressure, density and composition of the planet's atmosphere from its first faint outer traces to the hot, murky hydrogen atmosphere 100 miles (160 km) below the cloud tops. All of the information was gathered during the probe's descent on an 8-foot (2.44 meters) parachute. Probe data were sent to the Galileo Orbiter 133,000 miles (214,043 km) overhead then relayed across the half billion miles to Deep Space Network stations on Earth.
Space Shuttle mission STS-34 deployed the Galileo planetary exploration spacecraft into low-Earth orbit starting Galileo on its journey to explore Jupiter by command of Shannon Lucid.
Forward payload restraints were released and the aft frame of the airborne-support equipment was tilt the Galileo/IUS to 29 degrees. This extended the payload into space just outside the orbiter payload bay, allowing direct communication with Earth during systems checkout. The orbiter then was maneuvered to the deployment attitude.
The belly of the orbiter already was oriented towards the IUS/Galileo to protect orbiter windows from the IUS's plume.
Following deployment about 6 hours after launch, Galileo was propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist (VEEGA) by an Air Force-developed, inertial upper stage (IUS).

Several anomalies occurred during the flight, but none had a major impact on the mission. On October 22, 1989, an alarm woke the shuttle crew when the gas generator fuel pump system A heaters on Auxiliary Power Unit (APU) 2 failed to recycle at the upper limits of the system. There were also some minor problems with the Flash Evaporator System for cooling the orbiter, and the cryogenic oxygen manifold valve 2, which was left closed for the rest of the mission. A Hasselblad camera jammed twice, and a spare camera had to be used.

Besides the Galileo spacecraft, Atlantis' payload bay held two canisters containing the Shuttle Solar Backscatter Ultraviolet (SSBUV) experiment. SSBUV, which made its first flight on STS-34, was developed by NASA to check the calibration of the ozone sounders on free-flying satellites, and to verify the accuracy of atmospheric ozone and solar irradiance data.
The SSBUV should help scientists solve the problem of data reliability caused by calibration drift of solar backscatter ultraviolet (SBUV) instruments on orbiting spacecraft. The SSBUV used the Space Shuttle's orbital flight path to assess instrument performance by directly comparing data from identical instruments aboard the TIROS spacecraft, as the Shuttle and the satellite pass over the same Earth location within a 1-hour window. These orbital coincidences could occur 17 times per day.
The SBUV measured the amount and height distribution of ozone in the upper atmosphere. It did this by measuring incident solar ultraviolet radiation and ultraviolet radiation backscattered from the Earth's atmosphere. The SBUV measured these parameters in 12 discrete wavelength channels in the ultraviolet. Because ozone absorbs in the ultraviolet, an ozone measurement can be derived from the ratio of backscatter radiation at different wavelengths, providing an index of the vertical distribution of ozone in the atmosphere.
The SSBUV instrument and its dedicated electronics, power, data and command systems were mounted in the Shuttle's payload bay in two Get Away Special canisters, an instrument canister and a support canister. Together, they weighed approximately 1200 lb. (544.3 kg). The instrument canister holds the SSBUV, its specially designed aspect sensors and in-flight calibration system. A motorized door assembly opened the canister to allow the SSBUV to view the sun and Earth and closes during the in-flight calibration sequence.
The experiment operated successfully.

The Growth Hormone Concentration and Distribution in Plants (GHCD) experiment was designed to determine the effects of microgravity on the concentration, turnover properties, and behavior of the plant growth hormone, Auxin, in corn shoot tissue (Zea Mays).
Mounted in foam blocks inside two standard middeck lockers, the equipment consisted of four plant canisters, two gaseous nitrogen freezers and two temperature recorders. Equipment for the experiment, excluding the lockers, weighed 97.5 pounds.
A total of 228 specimens (Zea Mays seeds) were "planted" in special filter, paper-Teflon tube holders no more than 56 hours prior to flight. The seeds remained in total darkness throughout the mission. Mission specialist Ellen Baker placed two of the plant canisters into the gaseous nitrogen freezers to arrest the plant growth and preserve the specimens. The payload was restowed in the lockers for the remainder of the mission.
STS-34 carried a further five mid-deck experiments, all of which were deemed successful, including the Polymer Morphology (PM) experiment, sponsored by the 3M Company under a joint endeavor agreement with NASA. The PM experiment was designed to observe the melting and resolidifying of different types of polymers while in orbit. The Mesoscale Lightning Experiment, which had been flown on previous shuttle missions, observed the visual characteristics of large-scale lightning in the upper atmosphere.
On October 22, 1989, Shannon Lucid and Ellen Baker completed the Growth Hormone Concentration and Distribution in Plants experiment by freezing samples of corn seedlings grown in orbit during the mission.

The Polymer Morphology (PM) experiment was a 3M-developed organic materials processing experiment designed to explore the effects of microgravity on polymeric materials as they are processed in space. The apparatus for the experiment included a Fournier transform infrared (FTIR) spectrometer, an automatic sample manipulating system and a process control and data acquisition computer known as the Generic Electronics Module (GEM). The experiment was contained in two separate, hermetically sealed containers that were mounted in the middeck of the orbiter. Each container included an integral heat exchanger that transfers heat from the interior of the containers to the orbiter's environment. All sample materials were kept in triple containers for the safety of the astronauts.
Mission specialists Franklin Chang-Diaz and Shannon Lucid were responsible for the operation of them PM experiment on orbit. Their interface with the PM experiment was through a small, NASA-supplied laptop computer that was used as an input and output device for the main PM computer. This interface has been programmed by 3M engineers to manage and display the large quantity of data that was available to the crew. The astronauts had an active role in the operation of the experiment.
In the PM experiment, infrared spectra (400 to 5000 cm^-1) was acquired from the FTIR by the GEM computer once every 3.2 seconds as the materials are processed on orbit. During the 100 hours of processing time, approximately 2 gigabytes of data were collected.
The samples of polymeric materials being studied in the PM experiment were thin films (25 microns or less) approximately 25 mm in diameter. The samples were mounted between two infrared transparent windows in a specially designed infrared cell that provided the capability of thermally processing the samples to 200 degrees Celsius with a high degree of thermal control. The samples were mounted on a carousel that allowed them to be positioned, one at a time, in the infrared beam where spectra may be acquired. The GEM provided all carousel and sample cell control. The first flight of PM contained 17 samples.

The Space Shuttle again carried the Mesoscale Lightning Experiment (MLE), designed to obtain nighttime images of lightning in order to better understand the global distribution of lightning, the interrelationships between lightning events in nearby storms, and relationships between lightning, convective storms and precipitation.
In this experiment, Atlantis' payload bay camera was pointed directly below the orbiter to observe nighttime lightning in large, or mesoscale, storm systems to gather global estimates of lightning as observed from Shuttle altitudes. Scientists on the ground analyzed the imagery for the frequency of lightning flashes in active storm clouds within the camera's field of view, the length of lightning discharges, and cloud brightness when illuminated by the lightning discharge within the cloud.

The IMAX project is a collaboration between NASA and the Smithsonian Institution's National Air and Space Museum to document significant space activities using the IMAX film medium. This system, developed by the IMAX Systems Corp., Toronto, Canada, uses specially designed 70mm film cameras and projectors to record and display very high definition large-screen color motion pictures.
IMAX cameras previously have flown on Space Shuttle missions STS-41C, STS-41D and STS-41G to document crew operations in the payload bay and the orbiter's middeck and flight deck along with spectacular views of space and Earth.
The IMAX camera, most recently carried aboard STS-29, was used on this mission to cover the deployment of the Galileo spacecraft and to gather material on the use of observations of the Earth from space for future IMAX films. The next IMAX movie was "The Wild Blue Yonder".

The Air Force Maui Optical Site (AMOS) tests allowed ground- based electro-optical sensors located on Mt. Haleakala, Maui, Hawaii, to collect imagery and signature data of the orbiter during cooperative overflights. The scientific observations made of the orbiter, while performing reaction control system thruster firings, water dumps or payload bay light activation, and were used to support the calibration of the AMOS sensors and the validation of spacecraft contamination models. The AMOS tests had no payload unique flight hardware and only required that the orbiter be in predefined attitude operations and lighting conditions.

The Sensor Technology Experiment (STEX) was a radiation detection experiment designed to measure the natural radiation background. The STEX was a self-contained experiment with its own power, sensor, computer control and data storage. A calibration pack, composed of a small number of passive threshold reaction monitors, was attached to the outside of the STEX package.
Sponsored by the Strategic Defense Initiative (SDI) Organization, the STEX package weighed approximately 50 pounds (22.68 kg) and was stowed in a standard middeck locker throughout the flight.

The crew successfully troubleshooted a student experiment on ice crystal growth. The experiment's first activation did not produce crystals because the supercooled water formed an ice slag on the cooling plate. The crew turned the experiment off, allowing the ice to thaw, and then redispersed the liquid. Several crystals were formed.

Franklin Chang-Diaz and Ellen Baker, a medical doctor, performed a detailed supplementary objective by photographing and videotaping the veins and arteries in the retinal wall of Ellen Baker's eyeball to provide detailed measurements which might give clues about a possible relationship between cranial pressure and motion sickness. Ellen Baker also tested the effectiveness of anti-motion sickness medication in space.

Because of high winds predicted at the nominal landing time, the landing was moved two orbits earlier.