《美国空间6.5米望远镜完成了声学和振动试验》

  • 来源专题:天文仪器与技术信息
  • 编译者: zwg@niaot.ac.cn
  • 发布时间:2017-04-05
  • At NASA's Goddard Space Flight Center in Greenbelt, Maryland the James Webb Space Telescope team completed the acoustic and vibration portions of environmental testing on the telescope. These tests are merely two of the many that spacecraft and instruments endure to ensure they are fit for spaceflight.

    For the acoustic test, the telescope was wrapped in a clean tent, and engineers and technicians pushed it through a large pair of insulated steel doors nearly a foot thick into the Acoustic Test Chamber. In the chamber the telescope was exposed to the earsplitting noise and resulting vibration of launch.

    A new vibration test system also known as a shaker table, was built specifically for testing the Webb. The Webb was mounted on the shaker table and experienced the simulated forces the telescope will feel during the launch by vibrating it from 5 to 100 times per second. The test ensures a spacecraft like Webb can withstand the vibrations that occur as a result of the ride into space on a rocket.

    This spring, after other environmental tests are completed, the Webb telescope will be shipped to NASA's Johnson Space Center in Houston, Texas, for end-to-end optical testing in a vacuum at its extremely cold operating temperatures, before it goes to Northrop Grumman Aerospace Systems in Redondo Beach, California, for final assembly and testing prior to launch.

    By performing these tests, scientists and engineers can ensure that the spacecraft and all of its instruments will endure the launch and maintain functionality when it is launched from French Guiana in 2018.

    The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

  • 原文来源:https://www.nasa.gov/feature/goddard/2017/nasas-james-webb-space-telescope-completes-acoustic-and-vibration-tests
相关报告
  • 《美国NASA对空间6.5米望远镜(JWST)进行新的振动试验》

    • 来源专题:天文仪器与技术信息
    • 编译者:zwg@niaot.ac.cn
    • 发布时间:2017-02-23
    • Scientists and engineers had many challenges in designing the components of NASA's James Webb Space Telescope and then had to custom design and build ways to test it. Because of the sheer size and scale of the assembled Webb telescope, some of the equipment typically used to test spacecraft simply doesn’t measure up. One of those is a "shaker table" that is used to shake satellites to ensure a spacecraft like Webb can withstand the shaking that comes with a ride into space on a rocket. So, engineers at Team Corporation in Burlington, Washington built a new, large and advanced shaker table system at NASA's Goddard Space Flight Center in Greenbelt, Maryland, especially for testing Webb. "The new “Vibration Test Systems” simulates the forces the telescope will feel during the launch by vibrating it from 5 to 100 times per second" said Jon Lawrence, Webb telescope mechanical systems lead and launch vehicle liaison at NASA's Goddard Space Flight Center. For Webb, the need for a new shaker system was a combination of things, including shaker force magnitude, the shaker table’s ability to handle the telescope’s highly offset center of gravity, and the need for a precision “smart” shaker control system—one that will automatically adjust shaker input levels based on test article responses, including an automatic ‘soft shutdown’ capability. "No matter what facility anomaly might be experienced during testing (loss of power, loss of coolant, etc.), the Vibration Test System or VTS is designed to shut down 'softly' so as to avoid imparting potentially damaging loads," Lawrence said. After vibration testing of the telescope is completed soon, the new VTS can be used to test other future large spacecraft. To make sure it works properly before using it to test the flight telescope, engineers put the new shaker system though its paces with many practice runs over months, using a dummy mass to represent the telescope. In November, Webb was moved from the Spacecraft Systems Development and Integration Facility ‘cleanroom’ and onto the new neighboring Vibration Test System (VTS), where testing is ongoing. While in the shirtsleeve environment of the VTS, a large 3-story tall cover enshrouds the telescope, acting as a portable ‘cleanroom’ that protects it from dust and dirt. This spring, after vibration testing is complete, the Webb telescope will be shipped to NASA's Johnson Space Center in Houston, Texas, for end-to-end optical tests in a vacuum at extremely cold temperatures, before it goes to Northrop Grumman Aerospace Systems in Redondo Beach, California, for final assembly and testing prior to launch.
  • 《美国6.5米空间望远镜进入测试仓》

    • 来源专题:天文仪器与技术信息
    • 编译者:zwg@niaot.ac.cn
    • 发布时间:2017-09-07
    • NASA's Johnson Space Center’s "Chamber A" in Houston is an enormous thermal vacuum testing chamber and now appears to be opening it's "mouth" to take in NASA's James Webb Space Telescope for testing. The telescope and the Integrated Science Instrument Module (ISIM) are two of the three major elements that comprise the Webb telescope Observatory flight system and are being lifted into the chamber in this photo. The other is the Spacecraft Element (spacecraft bus and sunshield), which is currently under construction at Northrop Grumman Aerospace Systems (NGAS) in Redondo Beach, California. The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.