NASA Probe Sees Solar Wind Decline
The 33-year odyssey of NASA's Voyager 1 spacecraft has reached a distant point at the edge of our solar system where there is no outward motion of solar wind. Now hurtling toward interstellar space some 17.4 billion...
A team of astronomers, including two NASA Sagan Fellows, has made the first characterizations of a super-Earth's atmosphere, by using a ground-based telescope...
NASA's Kepler spacecraft has discovered the first confirmed planetary system with more than one planet crossing in front of, or transiting, the same star...
Tight double-star systems might not be the best places for life to spring up, according to a new study using data from NASA's Spitzer Space Telescope....
Archive for 2010
- Technology Demonstration Missions Program
- Edison Small Satellite Demonstration Missions Program
- Flight Opportunities Program.
On Dec. 16, 2010, NASA's Mars Exploration Rover Opportunity reached a crater about the size of a football field—some 90 meters (295 feet) in diameter. The rover team plans to use cameras and spectrometers during the next several weeks to examine rocks exposed at the crater, informally named "Santa Maria."
It was as big as it may have shattered old ideas about solar activity. "The August 1st event really opened our eyes," says Karel Schrijver of Lockheed Martin’s Solar and Astrophysics Lab in Palo Alto, CA. "We see that solar storms can be global events, playing out on scales we scarcely imagined before."
For the past three months, Schrijver has been working with fellow Lockheed-Martin solar physicist Alan Title to understand what happened during the "Great Eruption." They had plenty of data: The event was recorded in unprecedented detail by NASA's Solar Dynamics Observatory and twin STEREO spacecraft. With several colleagues present to offer commentary, they outlined their findings at a press conference today at the American Geophysical Union meeting in San Francisco.
Explosions on the sun are not localized or isolated events, they announced. Instead, solar activity is interconnected by magnetism over breathtaking distances. Solar flares, tsunamis, coronal mass ejections--they can go off all at once, hundreds of thousands of miles apart, in a dizzyingly-complex concert of violence.
"To predict eruptions we can no longer focus on the magnetic fields of isolated active regions," says Title, "we have to know the surface magnetic field of practically the entire sun." This revelation increases the work load for space weather forecasters, but it also increases the potential accuracy of their forecasts.
"The whole-sun approach could lead to breakthroughs in predicting solar activity," commented Rodney Viereck of NOAA's Space Weather Prediction Center in Boulder, CO. "This in turn would provide improved forecasts to our customers such as electric power grid operators and commercial airlines, who could take action to protect their systems and ensure the safety of passengers and crew."
In a paper they prepared for the Journal of Geophysical Research (JGR), Schrijver and Title broke down the Great Eruption into more than a dozen significant shock waves, flares, filament eruptions, and CMEs spanning 180 degrees of solar longitude and 28 hours of time. At first it seemed to be a cacophony of disorder until they plotted the events on a map of the sun's magnetic field.
Title describes the Eureka! Moment: "We saw that all the events of substantial coronal activity were connected by a wide-ranging system of separatrices, separators, and quasi-separatrix layers." A "separatrix" is a magnetic fault zone where small changes in surrounding plasma currents can set off big electromagnetic storms.
Researchers have long suspected this kind of magnetic connection was possible. "The notion of 'sympathetic' flares goes back at least three quarters of a century," they wrote in their JGR paper. Sometimes observers would see flares going off one after another--like popcorn--but it was impossible to prove a link between them. Arguments in favor of cause and effect were statistical and often full of doubt.
"For this kind of work, SDO and STEREO are game-changers," says Lika Guhathakurta, NASA's Living with a Star Program Scientist. "Together, the three spacecraft monitor 97% of the sun, allowing researchers to see connections that they could only guess at in the past."
To wit, barely two-thirds of the August event was visible from Earth, yet all of it could be seen by the SDO-STEREO fleet. Moreover, SDO's measurements of the sun's magnetic field revealed direct connections between the various components of the Great Eruption—no statistics required.
Much remains to be done. "We're still sorting out cause and effect," says Schrijver. "Was the event one big chain reaction, in which one eruption triggered another--bang, bang, bang!--in sequence? Or did everything go off together as a consequence of some greater change in the sun's global magnetic field?"
Further analysis may yet reveal the underlying trigger; for now, the team is still wrapping their minds around the global character of solar activity. One commentator recalled the old adage of three blind men describing an elephant--one by feeling the trunk, one by holding the tail, and another by sniffing a toenail. Studying the sun one sunspot at a time may be just as limiting.
"Not all eruptions are going to be global," notes Guhathakurta. "But the global character of solar activity can no longer be ignored."
As if the sun wasn't big enough already….
The meeting runs from Monday, Dec. 13, through Friday, Dec. 17, at San Francisco's Moscone Convention Center. They are all open to registered media representatives.
This NASA AGU media Web site contains detailed information about how media can participate in the press briefings, both on-site and remotely. The site will be updated throughout the week with additional information about NASA presentations.
When massive stars die, they explode in tremendous blasts, called supernovae, which send out shock waves. The shock waves sweep up and heat surrounding gas and dust, creating supernova remnants like the one pictured here. The supernova in IC 443 happened somewhere between 5,000 and 10,000 years ago.
In this WISE image, infrared light has been color-coded to reveal what our eyes cannot see. The colors differ primarily because materials surrounding the supernova remnant vary in density. When the shock waves hit these materials, different gases were triggered to release a mix of infrared wavelengths.
The supernova remnant's northeastern shell, seen here as the violet-colored semi-circle at top left, is composed of sheet-like filaments that are emitting light from iron, neon, silicon and oxygen gas atoms and dust particles heated by a fast shock wave traveling at about 100 kilometers per second, or 223,700 mph.
The smaller southern shell, seen in bright bluish colors, is constructed of clumps and knots primarily emitting light from hydrogen gas and dust heated by a slower shock wave traveling at about 30 kilometers per second, or 67,100 miles per hour. In the case of the southern shell, the shock wave is interacting with a nearby dense cloud. This cloud can be seen in the image as the greenish dust cutting across IC 443 from the northwest to southeast.
The Falcon 9 lofted the Dragon capsule into orbit this morning at 10:43 a.m. EST, lifting off from Launch Complex 40 at Cape Canaveral Air Force Station in Florida, a few miles south of the space shuttle launch pads. The Dragon returned to Earth at about 2:02 p.m., safely splashing down in the Pacific Ocean following two orbits. It marked the first time a commercial company has recovered a spacecraft from orbit.
NASA officials also were very pleased with the mission's results.
"This is really an amazing accomplishment for SpaceX," said Alan Lindenmoyer, NASA's Commercial Crew and Cargo Program Manager. "Thank you for the early Christmas present."
The mission was a demonstration flight under NASA's Commercial Orbital Transportation Services, or COTS, contract.
During a routine inspection this week, SpaceX engineers observed two small cracks in the rocket's second stage engine nozzle. SpaceX completed repairs to the cracked nozzle Tuesday.
The successful ejection of NanoSail-D demonstrates the operational capability of FASTSAT as a cost-effective independent means of placing cubesat payloads into orbit safely.
The producers of "NASA 360" have reached agreement with Airline Media Productions (AMP) International to air the half-hour magazine-style TV show through AMP's entertainment outlets around the world.
"We're excited to work with AMP International to bring 'NASA 360' to hundreds of thousands of the 760 million people who fly each year," said Mike Bibbo, the program's producer.
AMP International provides in-flight entertainment for airlines in the U.S., Middle East and Asia, including US Airways, Virgin America, Singapore Airlines, Philippine Airlines, Middle East Airlines, Flydubai and Tunisair. The company also supplies video products to cruise ships and other users of entertainment services.
"We thought travelers would be interested in learning more about how NASA technology makes planes safer, quieter and more efficient and other contributions to their daily lives," said "NASA 360" co-producer Kevin Krigsvold.
The nanotech-based material now being developed by a team of 10 technologists at the NASA Goddard Space Flight Center in Greenbelt, Md., is a thin coating of multi-walled carbon nanotubes — tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair. Nanotubes have a multitude of potential uses, particularly in electronics and advanced materials due to their unique electrical properties and extraordinary strength. But in this application, NASA is interested in using the technology to help suppress errant light that has a funny way of ricocheting off instrument components and contaminating measurements.
NASA's Mars Science Laboratory, also known as the Curiosity rover, is being tested and assembled in a clean room at the agency's Jet Propulsion Laboratory in Pasadena, Calif. The webcam, affectionately dubbed "Curiosity Cam," shows engineers and technicians clad in head-to-toe white smocks working on the rover.
Metrics from the webcam's hosting platform, Ustream, showed more than one million unique viewers spent more than 400,000 hours watching Curiosity Cam between Oct. 21 and Nov. 23. There have been more than 2.3 million viewer sessions.
The camera is mounted in the viewing gallery of the Spacecraft Assembly Facility at JPL. While the gallery is a regular stop on JPL's public tour, Curiosity Cam allows visitors from around the world to see NASA engineers at work without traveling to Pasadena
The news conference will be held at the NASA Headquarters auditorium at 300 E St. SW, in Washington. It will be broadcast live on NASA Television.
- Mary Voytek, director, Astrobiology Program, NASA Headquarters, Washington
- Felisa Wolfe-Simon, NASA astrobiology research fellow, U.S. Geological Survey, Menlo Park, Calif.
- Pamela Conrad, Astrobiologist, NASA's Goddard Space Flight Center, Greenbelt, Md.
- Steven Benner, distinguished fellow, Foundation for Applied Molecular Evolution, Gainesville, Fla.
- James Elser, professor, Arizona State University, Tempe.
NASA's Cassini spacecraft resumed normal operations today, Nov. 24. All science instruments have been turned back on, the spacecraft is properly configured and Cassini is in good health. Mission managers expect to get a full stream of data during next week's flyby of the Saturnian moon Enceladus.
Cassini went into safe mode on Nov. 2, when one bit flipped in the onboard command and data subsystem computer. The bit flip prevented the computer from registering an important instruction, and the spacecraft, as programmed, went into the standby mode. Engineers have traced the steps taken by the computer during that time and have determined that all spacecraft responses were proper, but still do not know why the bit flipped.
The flyby on will bring Cassini to within about 48 kilometers of the surface of Enceladus. At 61 degrees north latitude, this encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission.
During the closest part of the 30th November flyby, Cassini's radio science subsystem will make gravity measurements. The results will be compared with those from an earlier flyby of the Enceladus South Pole to understand the moon's interior structure better. Cassini's fields and particles instruments will sample the charged particle environment around Enceladus. Other instruments will capture images in visible light and other parts of the light spectrum after Cassini makes its closest approach.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C.
These "sandbars," or filaments, are known to span vast distances between galaxy clusters and form a lattice-like structure known as the cosmic web. Two years ago, Spitzer's infrared eyes revealed that one such intergalactic filament containing star forming galaxies ran between the galaxy clusters called Abell 1763 and Abell 1770.
Now these observations have been bolstered by the discovery, inside this same filament, of a galaxy that has a rare boomerang shape and unusual light emissions. Hot gas is sweeping the wandering galaxy into this shape as it passes through the filament, presenting a new way to gauge the filament's particle density. Researchers hope that other such galaxies with oddly curved profiles could serve as signposts for the faint threads, which in turn signify regions ripe for forming stars.
- A system that lets the engines be incrementally throttled up and down depending on the needs of the mission
- A hydrogen turbo pump spins 567 times a second with each 2” tall turbine blade generating 700 horsepower.
- A computer that runs 50 health checks on the engine every second using data from 200 sensors
- A system of pipes, or ducts, those withstand pressures as high as 7,000 pounds per square inch
- A main combustion chamber strong enough to contain the explosion of 970 pounds of oxygen and 162 pounds of hydrogen fuel every second, continuously for 8 1/2 minutes
- The only heavy-lift booster engine that continuously performs all the way from launch pad to orbit
- Engineering and materials that allow the engine to be reused multiple times
- A compact, efficient design that produces 8 times the thrust of a modern high performance jet engine per each pound of weight.
The Glory mission's scientific objectives are met by implementing two separate science instruments, one with the ability to collect polarimetric measurements along the satellite ground track within the solar reflective spectral region (0.4 to 2.4 micrometers) and one with the ability to monitor changes in sunlight incident on the Earth's atmosphere by collecting high accuracy, high precision measurements of total solar irradiance.
Glory accomplishes these objectives by deploying two instruments aboard a low earth orbit satellite, the Aerosol Polarimetry Sensor (APS) and the Total Irradiance Monitor (TIM). Additionally, a cloud camera system will provide images that allow the APS scans along the spacecraft ground track to be put into spatial context and to facilitate determination of cloud occurrence within the APS instantaneous field of view.
The Glory mission will respond to the U.S. Climate Change Science Program (CCSP) by continuing and improving upon NASA's research of the forcings influencing climate change in the atmosphere. As summarized below, measurements produced by this mission and the scientific knowledge such observations will provide are essential to predicting future climate change, and to making sound, scientifically based economic and policy decisions related to environmental change.
The science objectives of the Glory mission include:
1. The determination of the global distribution, microphysical properties, and chemical composition of natural and anthropogenic aerosols and clouds with accuracy and coverage sufficient for a reliable quantification of the aerosol direct and indirect effects on climate.
2. The continued measurement of the total solar irradiance to determine the Sun's direct and indirect effect on the Earth's climate.
For more Info: http://glory.giss.nasa.gov/
"She responded with links to two different blogs that compared it to older aircraft contrail pictures, and indicated that the blog authors thought it was an aircraft contrail," Minnis recalls. "I had not really thought about that aspect previously and, at first glance, the video showed what looked like a missile launch. Once the idea that it was an aircraft contrail entered my head, I had to pay closer attention, because aircraft contrails are part of my job description."
Minnis usually studies contrails to determine their effect on Earth's climate. He and others have discovered that airplane contrails create cirrus clouds on days they wouldn't usually exist. Because of this, he calculates, the cirrus-cloud cover over the United States is increasing by one percent each decade and contributing to global warming by blocking the release of heat from the planet.
Another team of technicians is working on repairing cracks on the tops of two, 21-foot-long support beams, called stringers, on the exterior of the external tank in an area known as the intertank. The team includes personnel from the external tank manufacturing plant in Louisiana, the Michoud Assembly Facility.
Over the weekend, technicians removed a section of one of the stringers that had two, 9-inch cracks in it. Last Friday, during foam removal and inspection of adjacent stringers to the one with the 9-inch cracks, technicians identified a crack about 3-inches long on the left-hand adjacent stringer. Further foam removal revealed one additional corresponding crack on the same left-hand adjacent stringer. Technicians plan to remove that section of the stringer Monday night. They’ll also install a new section of metal, called a doubler because it’s twice as thick as the original stringer metal, on the stringer that had the 9-inch cracks.
Engineers continue evaluating the intertank for any potential issues, but so far no other cracks have been found beyond the ones on the two previously identified stringers. There are a total of 108 stringers on the intertank. Senior managers plan to meet on Nov. 22 at NASA’s Johnson Space Center and via video conference for a launch status briefing to assess and review the repair work and launch preparations. Although managers have not set a new target launch date for Discovery’s STS-133 mission to the International Space Station, the repair work and planning still are aimed at supporting an attempt in the upcoming launch window that opens November 30.
The services provided are primarily under the management of Johnson's Information Resources Directorate with participation by the Office of External Relations. The services include operation and maintenance of primary information technology services; graphics; library management; imagery acquisition, processing and cataloguing; television systems support for human spaceflight missions; public affairs services including creative content for NASA Television, live mission television, multimedia and the public Internet; and education program support.
The three-year base performance period is valued at $150.5 million. Two one-year options are valued at $50.5 million each. The base period extends from Jan. 18, 2011 through Jan. 17, 2014. If both options are exercised, the contract would extend to Jan. 17, 2017. It is a cost-plus-incentive, indefinite-delivery, indefinite-quantity contract.
Teams performed an initial inspection of the flight seal and quick disconnect prior to sending them to labs for a thorough inspection. Data collected from the initial inspections will be evaluated today by the investigation team. Engineering saw some areas of interest that are being further evaluated. Based on this evaluation, crews could be ready to install a new GUCA on Friday.
Also, technicians have removed external tank foam insulation that cracked during initial loading operations for space shuttle Discovery’s launch attempt on Nov. 5. After foam removal, two cracks were found on a section of the tank’s metal exterior. The cracks were found on the stringer, which is the aluminum strip that forms the section between the Liquid Oxygen tank and the Liquid Hydrogen tank.
Stringers provide structural integrity to the intertank. The cracks are approximately nine inches long and were found at the top of one of the stringers beneath the area of foam that cracked during tanking. The cracks in the stringer moved the metal outward sufficiently to dislocate the foam. Engineers are reviewing images of the cracks to determine the best possible repair method, which would be done at Launch Pad 39A.
The stringers are manufactured using a lighter weight, stronger material of Aluminum Lithium, which was initially incorporated with the Super Light Weight Tank on ET-96 and first flown on STS-91. While the material is stronger and lighter in weight, it is more brittle and has resulted in increased cases of cracked stringers in the areas noted.
The cracked stringer section matches well with the area of foam that cracked, which indicates the stringer crack was the root cause of the foam crack. Analysis shows the intertank has sufficient structural capability for the launch and ascent environments with the cracks in a single stringer. Although the foam was firmly attached to the damaged structure, it is undesirable to launch in this configuration. This area is clearly visible during the pre-launch inspections and would have been detected by the final inspection team.
Crews have repaired similar cracks during external tank production by installing a second piece of aluminum for reinforcement on top of the cracked area before replacing the foam insulation. This piece frequently is referred to as a "doubler." The repair plan being put into effect is a known one consisting of cutting out the cracked section and replacing it with an available piece that matches its size. A doubler will be inserted before the mounting rivets to complete the repair.
BX foam then will be formed over the newly repaired stringer and will require about four days to cure.Exact schedules and repair options still are being evaluated. Engineers will meet Friday to discuss the status of the three repair activities underway, the external tank stringer and foam repair, the ground umbilical carrier plate and the cockpit panel L4 removal and replacement.
The news conference will start off from NASA Headquarters' TV studio, 300 E St. SW in Washington and going to live on NASA TV.
Reporters wishing to be present at the conference in-person must have a valid press credential for access. Non-U.S. media people must bring passports.
Scientists involved answering questions.
- Jon Morse - Director, Astrophysics Division, NASA Headquarters in Washington
- Kimberly Weaver - Astrophysicist, NASA's Goddard Space Flight Center, Greenbelt, Md.
- Alex Filippenko - Astrophysicist, University of California, Berkeley
Radiation from the flare created a wave of ionization in Earth's upper atmosphere that altered the propagation of low-frequency radio waves. There was, however, no bright CME hurled in our direction, so the event is unlikely to produce auroras in the nights ahead.
The video clip of the flyby is comprised of 40 frames taken from the spacecraft's Medium-Resolution Instrument during the encounter. The first image was taken at about 37 minutes before the time of closest approach at a distance of about 27,350 kilometers (17,000 miles). The last image was taken 30 minutes after closest approach at a distance of 22,200 kilometers (13,800 miles). The spacecraft was able to image nearly 50 percent of the comet's illuminated surface in detail.
The EPOXI mission's flyby of comet Hartley 2 was only the fifth time in history that a comet nucleus has been imaged, and the first time in history that two comets have been imaged with the same instruments and same spatial resolution.
EPOXI is an extended mission that utilizes the already "in flight" Deep Impact spacecraft to explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). The spacecraft will continue to be referred to as "Deep Impact."
Observations by NASA's Mars Reconnaissance Orbiter enabled researchers to identify the mineral as hydrated silica and to see its volcanic context. The mounds' composition and their location on the flanks of a volcanic cone provide the best evidence yet found on Mars for an intact deposit from a hydrothermal environment -a steam fumarole, or hot spring. Such environments may have provided habitats for some of Earth's earliest life forms.
"The heat and water required to create this deposit probably made this a habitable zone," said J.R. Skok of Brown University, Providence, R.I., lead author of a paper about these findings published online today by Nature Geoscience. "If life did exist there, this would be a promising type of deposit to entomb evidence of it - a microbial mortuary."
No studies have yet determined whether Mars has ever supported life. The new results add to accumulating evidence that, at some times and in some places, Mars has had favorable environments for microbial life. This specific place would have been habitable when most of Mars was already dry and cold. Concentrations of hydrated silica have been identified on Mars previously, including a nearly pure patch found by NASA's Mars Exploration Rover Spirit in 2007. However, none of those earlier findings were in such an intact setting as this one, and the setting adds evidence about the origin.
This is the fifth time humans will see a comet close-up, and the Deep Impact spacecraft flew by Earth for its fifth time on Sunday, June 27, 2010.
Eco-friendly Spacecraft: Recycle, Reuse, Record:
The EPOXI mission is recycling the Deep Impact spacecraft, whose probe intentionally collided with comet Tempel 1 on July 4, 2005, revealing, for the first time, the inner material of a comet. The spacecraft is now approaching a second comet rendezvous, a close encounter with Hartley 2 on Nov. 4. The spacecraft is reusing the same trio of instruments used during Deep Impact: two telescopes with digital imagers to record the encounter, and an infrared spectrometer.
Small, Mighty and Square-Dancing in Space:
Although comet Hartley 2 is smaller than Tempel 1, the previous comet visited by Deep Impact, it is much more active. In fact, amateur skywatchers may be able to see Hartley 2 in a dark sky with binoculars or a small telescope. Engineers specifically designed the mighty Deep Impact spacecraft to point a camera at Tempel 1 while its antenna was directed at Earth. This flyby of comet Hartley 2 does not provide the same luxury. It cannot both photograph the comet and talk with mission controllers on Earth. Engineers have instead programmed Deep Impact to dance the do-si-do. The spacecraft will spend the week leading up to closest approach swinging back and forth between imaging the comet and beaming images back to Earth.
Comets are an important aspect of studying how the solar system formed and Earth evolved. Comets are leftover building blocks of solar system formation, and are believed to have seeded an early Earth with water and organic compounds. The more we know about these celestial bodies, the more we can learn about Earth and the solar system.
What's in a Name?:
EPOXI is a hybrid acronym binding two science investigations: the Extrasolar Planet Observation and Characterization and Deep Impact extended Investigation. The spacecraft keeps its original name of Deep Impact, while the mission is called EPOXI.
“Acceleration, Reconnection, Turbulence and Electrodynamics” are the acronym for ARTEMIS of the Moon’s Interaction with the Sun”. The mission uses two of the five in-orbit spacecraft from another NASA Heliophysics constellation of satellites THEMIS that were launched in 2007 and successfully completed their mission earlier in 2010.
The mission allowed NASA to repurpose two in-orbit spacecraft to expand their useful science mission. ARTEMIS mission will use real-time measurements of particles and electric and magnetic fields from two locations to provide the first three-dimensional perspective of how energetic particle acceleration occurs near the Moon's orbit, in the distant magnetosphere, and in the solar wind.
However, there was still a chance that water might be found in special places on the Moon. Due to the Moon's orientation to the Sun, scientists theorized that deep craters at the lunar poles would be in permanent shadow and thus extremely cold and able to trap volatile material like water as ice perhaps delivered there by comet impacts or chemical reactions with hydrogen carried by the solar wind.
For more details:http://www.nasa.gov/mission_pages/LRO/news/lro-lcross-impact.html
Although all five vehicles that have comprised NASA's space shuttle fleet are unmatched in achievements, space shuttle Discovery is unique among the extraordinary. In 38 trips to space, Discovery has spent 351 days in orbit, almost a full year. Discovery has circled Earth 5,628 times, all the while speeding along at 17,400 miles per hour. It has traveled almost 143 million miles. That equals 288 round trips to the moon or about one and a half trips to the sun.
Discovery has carried more crew members -246- than any space vehicle. Those have included the first female to ever pilot a spacecraft, the oldest person to fly in space, the first African-American to perform a spacewalk, the first cosmonaut to fly on an American spacecraft and the first sitting member of Congress to fly in space.
It took four years to build Discovery, the third shuttle orbiter built. Named for past sailing ships of exploration, it rolled out of its Palmdale, Calif. assembly plant in October 1993 and was delivered via piggyback airplane flight to NASA’s Kennedy Space Center the next month. Discovery's first launch was Aug. 30, 1984 on mission STS-41D. That flight launched three communications satellites and tested an experimental solar array wing. The mission was commanded by astronaut Henry W. Hartsfield.
For details : http://www.nasa.gov/mission_pages/shuttle/flyout/discovery.html