登录
 机构网站
  1. 首页
  2. 情报产品
  3. 快讯详情

《USGS Release: Landsat 5 Mission in Jeopardy 》

  • 来源专题：湿地遥感信息动态监测
  • 编译者： shengchunlei
  • 发布时间：2016-03-25

  • 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 U.S. 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 image 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.

    For further details and the latest information about the status of Landsat 5, visit the USGS Landsat Missions website.

    USGS provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels. Subscribe to our news releases via e-mail, RSS or Twitter.

    Links and contacts within this release are valid at the time of publication.

50浏览量
原文链接
相关报告

  • 《USGS Release: USGS Completes Decommissioning of Landsat 5 》
    • 来源专题：湿地遥感信息动态监测
    • 编译者：shengchunlei
    • 发布时间：2016-03-15
    • On June 5, 2013, the U.S. Geological Survey Flight Operations Team transmitted the last command to the Landsat 5 satellite, effectively terminating the mission 29 years, 3 months and 4 days after its launch by NASA from Vandenberg Air Force Base on March 1, 1984. The Landsat program is a joint effort between USGS and NASA. Landsat 5 had orbited the planet over 150,000 times while transmitting over 2.5 million images of land surface conditions around the world, long outliving its original three-year design life. In December 2012, USGS announced that Landsat 5 would be decommissioned. The durable satellite is recognized by the Guinness Book of Records as the longest-operating Earth-observing satellite mission in history. Landsat 5 beamed its last image down to the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD, on January 6, 2013. Nine days later, Mission Operations began the methodical process of maneuvering the satellite from its 438 mile-high operational orbit into a lower disposal orbit. With Landsat 5's fuel reserve completely depleted, the Operations team issued commands on June 5 to shut off all moving mechanisms and hobble the spacecraft’s ability to generate and store power from its solar arrays. The final command shut down Landsat 5’s transmitter, silencing the mission permanently. For nearly a year the USGS team methodically planned a complex series of steps that were necessary to ensure that the satellite's decommissioning would meet the requirements set under international agreements. When the planning began, a date for decommissioning had not yet been set, but the failure of a critical component last November forced USGS managers to direct that the mission be ended as soon as practicable. Landsat 5 recorded many significant events. It was the first satellite to image the nuclear accident at Chernobyl in 1986; it documented the massive rainforest deforestation occurring in tropical regions; and it captured the devastating tsunami in southeast Asia in 2004. Seemingly right on cue, the newest remote sensing mission, Landsat 8 — launched by NASA on February 11 and then checked out in orbit — was transferred to the USGS on May 30 to begin operations in the orbital slot previously held by Landsat 5. Landsat 8 orbits Earth once every 99 minutes at an average altitude of 438 miles, repeating the same ground track every 16 days. As Landsat 8 joins Landsat 7 in imaging the Earth, researchers and natural resource managers will once again be able to receive Landsat data every eight days for any given location. Many Landsat users depend on a short repeat cycle for prompt data on resources such as agricultural crops, forests, and water. Current and historical data from the entire series of Landsat satellites (since 1972) is available from the USGS-EROS Earth observation archive free of charge. Additional information USGS Landsat Missions (latest satellite status, how to obtain data). NASA Landsat information (selected imagery, feature articles). What is the Economic Value of Satellite Imagery? (USGS Professional Paper). NASA-USGS 40th Anniversary of Landsat. USGS provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels. Subscribe to our news releases via e-mail, RSS or Twitter.
    46浏览量
    原文链接

  • 《USGS Release: Aging Landsat 5 Changes Glasses 》
    • 来源专题：湿地遥感信息动态监测
    • 编译者：shengchunlei
    • 发布时间：2016-03-15
    • Landsat 5 has orbited Earth over 150,000 times since it was launched in 1984, making it the longest-operating Earth observing satellite of its kind. During this time, two data collection instruments onboard Landsat 5 — the thematic mapper (TM) and the multi-spectral scanner (MSS) — have transmitted over five million images of land conditions to U.S. and international ground stations. In November 2011 an electronic malfunction in the TM transmitter forced a suspension of routine imaging. Now, after months of trying without success to restore daily TM image transmissions, USGS flight engineers will attempt only a few additional image acquisitions over specific sensor-calibration sites as the TM transmitter nears complete failure. On a positive note, the MSS instrument onboard Landsat 5 was recently powered back on in a test mode after more than a decade of silence. "The resurrection of the MSS a decade after it was last powered up and 25 years beyond its nominal lifespan is welcome news indeed," said USGS Director Marcia McNutt. "While not a complete replacement for the loss of the Thematic Mapper, it does provide some insurance for ensuring Landsat data continuity should Landsat 7 fail prior to Landsat 8 achieving orbit next year." The MSS sensor, the forerunner of TM, gathers data in fewer spectral bands than TM, has lower pixel resolution, and does not acquire thermal data. However, each MSS scene covers the same area as a TM scene, approximately 12,000 square miles. The USGS is currently acquiring MSS data only over the United States. Landsat International Cooperator stations may begin downlinking data from other parts of the globe, depending on their intentions and ability to establish MSS data processing capabilities. It will take some months for MSS data to be integrated into current production systems and be made publically available. Landsat 5 has sufficient fuel to operate through 2013. Landsat 7, the other active Landsat spacecraft operated by the USGS, continues to collect images worldwide, as it has done since 1999. In 2003, Landsat 7 experienced a hardware failure that causes a 22% loss of data in every image. In the intervening nine years, many techniques have been developed to partially compensate for the data loss and leverage the remaining data for scientific analysis and resource monitoring. The next Landsat, the Landsat Data Continuity Mission (LDCM or Landsat 8), is scheduled for launch in January 2013. Following launch, it will become Landsat 8 and is expected to extend the Landsat record for at least another five years. Once Landsat 8 is fully operational, the collection of MMS data from Landsat 5 will be re-evaluated. For further details and the latest information about the status of Landsat 5, visit the USGS Landsat Missions website. The Landsat Program is a series of Earth observing satellite missions jointly managed by the U.S. Geological Survey and NASA. Landsat satellites have been consistently gathering data about our planet since 1972. They continue to improve and expand this unparalleled record of Earth's changing landscapes for the benefit of all. USGS provides science for a changing world. Visit USGS.gov, and follow us on Twitter @USGS and our other social media channels. Subscribe to our news releases via e-mail, RSS or Twitter.
    51浏览量
    原文链接