A Unique test for Hubble's new Solar Arrays
19 October 2000
A World Class Test in a World Class Facility for a World Class Observatory.In mid-October, a team from the European Space Agency (ESA) and NASA will perform a difficult, never-before-done test on one of the Hubble Space Telescopes new solar array panels. Two of these panels, or arrays, will be installed by astronauts in November 2001, when the Space Shuttle Columbia visits Hubble on a routine service mission. The test will ensure that the new arrays are solid and vibration free before they are installed on orbit.The test will be conducted at ESAs European Space Research and Technology Center (ESTEC) in Noordwijk, The Netherlands. Because of the arrays size, the facilitys special features, and ESAs longstanding experience with Hubbles solar arrays, ESTEC is the only place in the world the test can be performed. This test is the latest chapter in a longstanding partnership between ESA and NASA on the Hubble Space Telescope.
The Large Space Simulator at ESTEC, ESAs world-class test facility, features a huge vacuum chamber containing a bank of extremely bright lights that simulate the Suns intensity including sunrise and sunset. By exposing the solar wing to the light and temperature extremes of Hubbles orbit, engineers can verify how the new set of arrays will act in space.
Hubble orbits the Earth once every 90 minutes. During each orbit, the telescope experiences 45 minutes of searing sunlight and 45 minutes of frigid darkness. This test will detect any tiny vibrations, or jitters, caused by these dramatic, repeated changes. Even a small amount of jitter can affect Hubbles sensitive instruments and interfere with observations.
Hubbles first set of solar arrays experienced mild jitter and was replaced in 1993 with a much more stable pair. Since that time, advances in solar cell technology have led to the development of even more efficient arrays. In 2001, NASA will take advantage of these improvements, by fitting Hubble with a third-generation set of arrays. Though smaller, this new set generates more power than the previous pairs. The arrays use high efficiency solar cells and an advanced structural system to support the solar panels. Unlike the earlier sets, which roll up like window shades, the new arrays are rigid.
ESA provided Hubbles first two sets of solar arrays, and built and tested the motors and electronics of the new set provided by NASA Goddard Space Flight Center. Now, this NASA/ESA test has benefits that extend beyond Hubble to the world-wide aerospace community. It will greatly expand basic knowledge of the jitter phenomenon. Engineers across the globe can apply these findings to other spacecraft that are subjected to regular, dramatic changes in sunlight and temperature.
Note to editors
The Hubble Project
The Hubble Space Telescope is a project of international co-operation between the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The partnership agreement between ESA and NASA was signed on 7 October 1977.
ESA has provided two pairs of solar panels and one of Hubbles scientific instruments (the Faint Object Camera), as well as a number of other components and supports NASA during routine Servicing Missions to the telescope. In addition, 15 European scientists are working at the Space Telescope Science Institute in Baltimore (STScI), which is responsible for the scientific operation of the Hubble Observatory and is managed by the Association of Universities for Research in Astronomy (AURA) for NASA. In return, European astronomers have guaranteed access to 15% of Hubbles observing time.
The Space Telescope European Coordinating Facility (ST-ECF) hosted at the European Southern Observatory (ESO) in Garching bei M|nchen, Germany, supports European Hubble users. ESA and ESO jointly operate the ST-ECF.
For more information, please contact :
ESA Communication Department
Media Relations Office
Tel: +33(0)1.53.69.7155
Fax: +33(0)1.53.69.7690
Ton Linssen, ESA Science Head of Management Support Office
Estec, Noordwijk The Netherlands
Tel: +31 71 565 3477
Email: Antonius.Linssen
esa.int
The Hubble Space Telescope arrays test preparation and proceedings can be watched by webcam at http://sci.esa.int/webcam as from 18 October, 2000. The actual test will start on 26 October.
For more information on the Hubble Space Telscope visit the ESA Science Website at: http://hubble.esa.int.
More information on the ESA Science Programme can be found at: http://sci.esa.int. Info on ESA in general can be found at http://www.esa.int.
