posted 11-20-2011 12:15 PM               

Landsat 5 Mission in Jeopardy

The U.S. Geological Survey (USGS) has stopped acquiring images from the 27-year-old Landsat 5 Earth observation satellite due to a rapidly degrading electronic component.

Landsat 5 was launched in 1984 and designed to last 3 years. The USGS assumed operation of Landsat 5 in 2001 and managed to bring the aging satellite back from the brink of total failure on several occasions following the malfunction of key subsystems. There is now an increasing likelihood that the Landsat 5 mission is nearing its end.

"This anticipated decline of Landsat 5 provides confirmation of the importance of the timely launch of the next Landsat mission and the need for an operational and reliable National Land Imaging System," stated Anne Castle, Assistant Secretary for Water and Science at the Department of the Interior. "The USGS is committed to maintaining the unique long term imaging database that the Landsat program provides."

For several months, the Landsat flight operations team has been closely tracking the fluctuating performance of an amplifier essential for transmitting land-surface images from the Landsat 5 satellite to ground receiving stations in the U.S. and around the world. Over the past 10 days, problems with the amplifier have led to drastically reduced image download capabilities, a sign of impending failure.

Numerous engineering and technical adjustments have been made to Landsat 5 in the past several days to sustain at least a limited imaging capability, but performance has continued to decline. Instead of continuing to operate until the amplifier fails completely, which could bring the mission to an end, USGS engineers have suspended imaging activities for an initial period of 90 days in order to explore every possible option for restoring satellite-to-ground transmissions.

The USGS-operated Landsat 7 remains in orbit collecting global imagery. Since its launch in 1999 with a 5-year design life, Landsat 7 has experienced an instrument anomaly which reduces the amount of data collected per image. Landsat 8, currently called the Landsat Data Continuity Mission, is now scheduled to be launched in January 2013.

posted 12-24-2012 08:40 AM               

Mission Accomplished for Landsat 5

Today (Dec. 21), the U.S. Geological Survey announced that Landsat 5 will be decommissioned over the coming months, bringing to a close the longest-operating Earth observing satellite mission in history. By any measure, the Landsat 5 mission has been an extraordinary success, providing unprecedented contributions to the global record of land change. The USGS has brought the aging satellite back from the brink of failure on several occasions, but the recent failure of a gyroscope has left no option but to end the mission.

Now in its 29th year of orbiting the planet, Landsat 5 has long outlived its original three-year design life. Developed by NASA and launched in 1984, Landsat 5 has orbited the planet over 150,000 times while transmitting over 2.5 million images of land surface conditions around the world.

"This is the end of an era for a remarkable satellite, and the fact that it flew for almost three decades is a testament to the NASA engineers and the USGS team who launched it and kept it flying well beyond its expected lifetime," stated Anne Castle, Department of the Interior Assistant Secretary for Water and Science. "The Landsat program is the 'gold standard" of satellite observation, providing an invaluable public record of our planet that helps us tackle critical land, water, and environmental issues."

"Any major event since 1984 that left a mark on this Earth larger than a football field was likely recorded by Landsat 5, whether it was a hurricane, a tsunami, a wildfire, deforestation, or an oil spill," said USGS Director Marcia McNutt. "We look forward to a long and productive continuation of the Landsat program, but it is unlikely there will ever be another satellite that matches the outstanding longevity of Landsat 5."

For more than a quarter of a century, Landsat 5 has observed our changing planet. It has recorded the impact of natural hazards, climate variability and change, land use practices, development and urbanization, ecosystem evolution, increasing demand for water and energy resources, and changing agricultural demands worldwide. Vital observations of the Mount Saint Helens eruption, Antarctica, the Kuwaiti oil fires, the Chernobyl disaster, rainforest depletion, major wildfires and floods, urban growth, global crop production, and ice shelf expansion and retreat have helped increase our understanding and awareness of the impact of humans on the land.

The USGS Flight Operations Team recently began the process required to safely lower Landsat 5 from its operational orbit. The first series of maneuvers is expected to occur next month.

With Landsat 5's decommissioning, Landsat 7, which was launched in 1999 and has also outlived its five-year design life, will continue to provide information, although an instrument anomaly reduces the amount of data it collects. The next mission, Landsat 8 — also called the Landsat Data Continuity Mission — is scheduled for launch by NASA in February 2013.

The natural resource management and development challenges that the Nation has faced since the beginning of the Landsat program have not diminished; they've only accelerated. Landsat, and the many applications that it has spawned, will be even more critical in the future to keep pace with these challenges. The Department of the Interior and NASA are working closely with the Administration on options for long-term continuity of the Landsat data stream.

Since 2008, when the USGS made the Landsat archive accessible to on-line users at no cost, nearly 10 million images, each covering over 12,000 square miles, have been downloaded in 190 countries.

posted 01-06-2013 02:09 PM               

1. The longevity of Landsat 5 and other show that the capability is not needed.
   
2. It was never cost effective. It is cheaper to launch a replacement spacecraft than an expensive shuttle launch with an expensive repair mission. This is even more true for a west coast mission.

posted 01-06-2013 04:35 PM               

Having a west coast shuttle capability would not make it any quicker or cheaper. The replacement hardware would not be sitting on the shelf. It would take just as long or even longer to procure replacement hardware and fly it. It isn't the MMS hardware that needs to replaced, but the mission specific instruments. This "replacement" hardware would have to compete with all of NASA's priorities for new missions.

And, no it couldn't be added to a later shuttle mission, Landsat is in a specific orbit and not shared with others. LDEF and the Solar Maximum Mission were manifested together for many years and the simplicity of LDEF allowed to be a partner and it was deployed near Solar Max. There are no equivalent on the west coast. The USAF was looking at Titan II's before Challenger because it didn't make sense to fly small weather sats (similar to Landsat) on the shuttle.

posted 02-11-2013 09:16 AM               

Landsat 5 Sets Guinness World Record For 'Longest Operating Earth Observation Satellite'

Landsat 5 successfully set the new Guinness World Records title for 'Longest-operating Earth observation satellite’ as stated in an e-mail from Guinness World Records sent to NASA Goddard Space Flight Center in Greenbelt, Md. Outliving its three-year design life, Landsat 5 delivered high-quality, global data of Earth's land surface for 28 years and 10 months.

NASA launched Landsat 5 from Vandenberg Air Force base in Lompoc, Calif. on March 1, 1984. Landsat 5 was designed and built at the same time as Landsat 4 and carried the same two instruments: the Multispectral Scanner System (MSS) and the Thematic Mapper (TM).

Managed by the U.S. Geological Survey (USGS) as part of the Landsat Program, it completed over 150,000 orbits and sent back more than 2.5 million images of Earth’s surface. On Dec. 21, 2012 the USGS announced Landsat 5 would be decommissioned in the coming months after the failure of a redundant gyroscope. The satellite carries three gyroscopes for attitude control and needs two to maintain control.

"This is the end of an era for a remarkable satellite, and the fact that it flew for almost three decades is a testament to the NASA engineers who launched it and the USGS team who kept it flying well beyond its expected lifetime," said Anne Castle, Department of the Interior Assistant Secretary for Water and Science in a press release.

Originally designed to be retrievable by the space shuttle, Landsat 5 was equipped with extra fuel. That extra fuel kept the satellite operating for much longer than anticipated after the space shuttle retrieval plan was thrown out.

Space is a harsh environment, and Landsat 5 faced more than twenty technical issues throughout its lifetime as parts gave in to wear and age. Landsat 5's USGS Flight Operations team found engineering and operational fixes to work around the problems, which included losing batteries, star trackers, and on-board data recording capability.

"The efforts of the Landsat team were heroic. Landsat 5 could not have lasted so long without the dedication and devotion of the USGS flight operations team that overcame a number of difficult technical challenges over the last 12 years," said Jim Irons, LDCM project scientist.

Not only did they keep the satellite going, said Irons, but in doing so, "Landsat 5 saved the Landsat program. This satellite's longevity preserved the Landsat program through the loss of Landsat 6 in 1993, preventing the specter of a data gap before the launch of Landsat 7 in 1999."

Today, the Landsat program continues to provide data used across the United States and the world for agricultural and forest monitoring and water resource management, among many other environmental applications.

NASA is launching its next successor to the still operational Landsat 7 satellite, the Landsat Data Continuity Mission (LDCM) on Feb. 11, 2013. LDCM carries two new instruments, the Operational Land Imager and the Thermal Infrared Sensor, which will collect data that are compatible with data from Landsat 5 and 7, and improve upon it with advanced instrument designs that are more sensitive to changes to the land surface, said Irons.

LDCM will continue the Landsat program's 40-year data record of monitoring Earth from space. Once the LDCM satellite is extensively tested and certified for its mission, it will be renamed Landsat 8 and be operated by the U.S. Geological Survey.