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Hubble Celebrates 30th Anniversary of Servicing Mission 1
Astronaut F. Story Musgrave works in the space shuttle Endeavour’s cargo bay while the solar array panels on the Hubble Space Telescope are deployed during the final Servicing Mission 1 spacewalk. NASA In the pre-dawn hours on Dec. 2, 1993, the space shuttle Endeavour launched from Kennedy Space Center in Florida on a critical mission to repair NASA’s Hubble Space Telescope.
Hubble was designed to be serviced in space with components that astronauts can slide in and out of place. But prior to launch, no one expected the first servicing mission to be of such urgency.
For three years, Hubble had been the punchline of late-night comics and editorial cartoons: the telescope that couldn’t see straight. Since its deployment in 1990, the telescope had been beaming blurry images back to Earth, the result of a flaw in the shape of its primary mirror. Though the mirror was off by only one-fiftieth the width of a human hair, the error had devastating consequences: the light from the mirror didn’t focus quite right. While the images were still better than those taken from Earth and science was still possible, their quality was not what the world expected.
The sense that you got was everybody was looking at the servicing and repair of the Hubble Space Telescope as the mission that could prove NASA’s worth … There was this overarching focus and pressure on the success of this mission.
Servicing Mission 1 Astronaut
Servicing Mission 1 was the solution. Aboard the shuttle were the Wide Field and Planetary Camera 2 (WFPC2) and Corrective Optics Space Telescope Axial Replacement (COSTAR), along with other critical components to upgrade the telescope. WFPC2, responsible for the telescope’s visually impactful images, had built-in corrective optics to compensate for the mirror flaw and would replace the Wide Field/Planetary Camera that Hubble launched with. COSTAR was a refrigerator-sized component containing a constellation of mirrors, some only the size of a U.S. nickel, intended to correct and redirect light to the telescope’s other cameras and spectrographs.
Astronaut Kathryn C. Thornton grips a tool to perform servicing mission tasks on the Hubble Space Telescope during the fourth spacewalk of Servicing Mission 1. NASA The shuttle’s crew of seven astronauts was aware that not only Hubble’s fate was on their shoulders, but the public perception of NASA and its space program as well.
“If the Hubble repair is a failure, we can write off space science for the foreseeable future,” John Bahcall, the late astrophysicist who advocated for the telescope and a member of its science working group, told the New York Times in 1993.
Credit: NASA’s Goddard Space Flight Center; Lead Producer: Grace Weikert On Dec. 2, 2023, NASA commemorates the 30th anniversary of Servicing Mission 1 and its success in transforming Hubble into one of NASA’s greatest triumphs: a shining example of human ingenuity in the face of adversity.
During one of the most complex spacewalking missions ever attempted, astronauts conducted five extravehicular activities, totaling over 35 hours. They removed the High Speed Photometer instrument to add COSTAR and swapped out the original Wide Field/Planetary Camera for the Wide Field and Planetary Camera 2. They also installed other critical components to upgrade the telescope.
The crew of Servicing Mission 1 poses for a portrait on the space shuttle. In the front row from left to right are Swiss scientist Claude Nicollier, mission specialist; Kenneth D. Bowersox, pilot; and Richard O. Covey, mission commander. In the back row are the spacewalkers on this flight: F. Story Musgrave, payload commander; Jeffrey A. Hoffman, mission specialist; Kathryn D. Thornton, mission specialist; and Thomas D. Akers, mission specialist. NASA At 1 a.m. on December 18, 1993, about a week after the mission had ended, astronomers gathered around computers at the Space Telescope Science Institute in Baltimore to witness the first new image from the telescope: a star, shining clear and pristine in the image without the hazy effects of Hubble’s flawed mirror. The new images were so dramatically different that even though the telescope needed around 13 weeks for adjustment to reach its full capabilities, NASA released them early. “It’s fixed beyond our wildest expectations,” said Ed Weiler, Hubble chief scientist during SM1, at a January 1994 press conference.
The look on people’s faces as this picture came up – this was an old [cathode ray] tube-type TV. It took a while for it to build up, but it got clearer and clearer and clearer. Everybody starts shouting.
Hubble chief scientist during SM1
Images of spiral galaxy M100 show the improvement in Hubble’s vision between Wide Field/Planetary Camera and its replacement instrument, the Wide Field and Planetary Camera 2. NASA, STScI Senator Barbara Mikulski of Maryland, who had advocated diligently for Hubble, was the first to show off the new images to the public at the Jan. 13 press conference. “I’m happy to announce today that after its launch in 1990 and some of its earlier disappointments, the trouble with Hubble is over,” she said.
Sen. Barbara Mikulski displays a picture showing the difference between a star image taken before COSTAR’s installation and the same star after Servicing Mission 1 during the Jan. 13, 1993 press conference announcing the success of the mission. NASA Though Servicing Mission 1 is best remembered for its resolution of Hubble’s blurry vision, it accomplished a host of additional tasks that helped transform the telescope into the astronomical powerhouse it remains today.
By the time Servicing Mission 1 launched, the telescope’s gyroscopes – delicate pieces of equipment required to steer and point Hubble – were already breaking down. Three of the six gyroscopes, or gyros, aboard Hubble had failed. The other three – typically kept as backups – were in operation, the minimum number needed to keep Hubble collecting science data. Astronauts replaced four gyroscopes, a fix that would help keep the telescope running smoothly for several years.
Early in Hubble’s time in orbit, NASA discovered that the telescope’s solar arrays would expand and contract excessively in the alternating heat and cold of space as the telescope traveled in and out of sunlight, causing them to vibrate. This forced engineers to use Hubble’s computing capacity to compensate for the “jitter” and reduced observation time. Astronauts replaced Hubble’s solar arrays with new versions that brought the natural jitter down to acceptable levels.
Astronauts also performed an augmentation whose vital importance would become clear a year later: upgrading Hubble’s flight computer with a co-processor and associated memory. Just weeks before the disintegrating comet Shoemaker-Levy 9 collided with Jupiter in 1994, Hubble went into a protective “safe mode” due to a memory unit problem in the main computer. Engineers were able to use that co-processor’s memory to fix the problem, capturing stunning images of the gas giant being pummeled by comet fragments.
Hubble Memorable Moments: Comet Impact
Find out more about Servicing Mission 1 and its accomplishments
Servicing Mission 1’s impact echoed far beyond Hubble. The mission was a showcase for tasks that could be done in space, proving humanity’s ability to perform highly complex work in orbit. The lessons learned from training for Hubble and from the servicing work itself would be built upon for other astronaut missions, including the four subsequent servicing visits to Hubble between 1997-2009. These additional missions to Hubble would enable the installation of new, cutting-edge instruments, repair of existing science instruments, and the replacement of key hardware, keeping Hubble at the forefront of astrophysics exploration.
Further, the lessons learned from Servicing Mission 1 were a guiding force for work on the International Space Station, and for missions yet to occur. “A lot of the knowledge that was developed there transferred directly to construction of the International Space Station and it’ll transfer to the things we do with [the future orbiting lunar space station] Gateway someday,” said Kenneth Bowersox, associate administrator for NASA’s Space Operations Mission Directorate, who was also astronaut on Servicing Mission 1. “And it’ll apply to things we do on the Moon and in deep space, going to Mars and beyond. It all links.”
To celebrate Servicing Mission 1, NASA is releasing a series of videos over the next two weeks featuring key players – astronauts, scientists, engineers, and more – as they reflect on the struggles and triumphs of that time, as well as the emotional and personal impact that Hubble and SM1 had on their lives. Follow @NASAHubble on X, Instagram, and Facebook, or go to nasa.gov/hubble to watch as the series kicks off this weekend.
Last Updated Dec 01, 2023 Editor Andrea Gianopoulos Contact Location Goddard Space Flight Center Related Terms
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NASA’s Dragonfly to Proceed with Final Mission Design Work
Artist’s Impression: Dragonfly Departs and heads off toward its next landing spot on Titan. Image credit: NASA/Johns Hopkins APL/Steve Gribben NASA’s Dragonfly mission has been authorized to proceed with work on final mission design and fabrication – known as Phase C – during fiscal year (FY) 2024. The agency is postponing formal confirmation of the mission (including its total cost and schedule) until mid-2024, following the release of the FY 2025 President’s Budget Request.
Earlier this year, Dragonfly – a mission to send a rotorcraft to explore Saturn’s moon Titan – passed all the success criteria of its Preliminary Design Review. The Dragonfly team conducted a re-plan of the mission based on expected funding available in FY 2024 and estimate a revised launch readiness date of July 2028. The Agency will officially assess the mission’s launch readiness date in mid-2024 at the Agency Program Management Council.
“The Dragonfly team has successfully overcome a number of technical and programmatic challenges in this daring endeavor to gather new science on Titan,” said Nicola Fox, associate administrator of NASA’s Science Mission Directorate at NASA headquarters in Washington. “I am proud of this team and their ability to keep all aspects of the mission moving toward confirmation.”
Dragonfly takes a novel approach to planetary exploration, for the first time employing a rotorcraft-lander to travel between and sample diverse sites on Titan. Dragonfly’s goal is to characterize the habitability of the moon’s environment, investigate the progression of prebiotic chemistry in an environment where carbon-rich material and liquid water may have mixed for an extended period, and even search for chemical indications of whether water-based or hydrocarbon-based life once existed on Titan.
Dragonfly is being designed and built under the direction of the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, which manages the mission for NASA. The team includes key partners at NASA’s Goddard Space Flight Center in Greenbelt, Maryland; Lockheed Martin Space in Littleton, Colorado; Sikorsky, a Lockheed Martin company; NASA’s Ames Research Center in Silicon Valley, California; NASA’s Langley Research Center in Hampton, Virginia; Penn State University in State College, Pennsylvania; Malin Space Science Systems in San Diego, California; Honeybee Robotics in Pasadena, California; NASA’s Jet Propulsion Laboratory in Southern California; CNES (Centre National d’Etudes Spatiales), the French space agency, in Paris, France; DLR (German Aerospace Center) in Cologne, Germany; and JAXA (Japan Aerospace Exploration Agency) in Tokyo, Japan. Dragonfly is the fourth mission in NASA’s New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate.
Last Updated Nov 28, 2023 Editor WILLIAM KEETER Related Terms
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