NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Galaxy Evolution Explorer Launch Press Kit April 2003 Media Contacts Nancy Neal Policy/Program Management 202/358-2369 Headquarters [email protected] Washington, D.C. Jane Platt Galaxy Evolution Explorer Mission 818/354-0880 Jet Propulsion Laboratory, [email protected] Pasadena, Calif. Mark Hess Explorers Program 301/286-8982 Goddard Space Flight Center, [email protected] Greenbelt, Md. Robert Tindol Science Operations 626/395-3631 California Institute of Technology, [email protected] Pasadena, Calif. George Diller Launch 321/867-2468 Kennedy Space Center, Fla. [email protected] Contents General Release ……………………………….........................................………………………..... 3 Media Services Information ……………………….........................................…………………...… 5 Quick Facts …………………………………………...……........................................…………...…. 6 Mission Overview ……………………………...................……….....................…………….……. 7 Why Study How Galaxies Form? .…...………..…..………….......................................……….….12 How Ultra is the Ultraviolet? …………………………………………….........………………13 Science Objectives ………..……………………………….......................……………….…14 Science Team ………..……………………..…………………….......................……….…. 15 Spacecraft ………..……..………………...........………..…...….……………….................………. 18 The Telescope……………………………………………………..……………………...............…. 23 NASA's Explorers Program ……………...…………..……………………….…….……................. 26 Program/Project Management …………………………...........…...…………................…........ 27 1 2 GENERAL RELEASE: GALAXY EVOLUTION EXPLORER LOOKS BACK IN TIME NASA's Galaxy Evolution Explorer will carry a telescope into Earth orbit that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars we see today had their origins. Galaxy Evolution Explorer is set to launch no earlier than April 28, 2003, from Cape Canaveral Air Force Station, Fla. A Pegasus XL rocket, released by an L-1011 jet air- craft, will launch the satellite. The aircraft will climb to approximately 39,000 feet and release the launch vehicle and payload. The science mission will start after an initial month of in-orbit testing. From its orbit high above Earth, the spacecraft will sweep the skies for up to 28 months using state-of-the-art ultraviolet detectors. Looking in the ultraviolet will single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, therefore provid- ing a window into the history and causes of galactic star formation. "The Galaxy Evolution Explorer is crucial to understanding how galaxies, the basic structures of our universe, form and function," said Dr. Anne Kinney, director of astron- omy and physics in the Office of Space Science at NASA Headquarters, Washington. "Its ultraviolet observations will round out the knowledge we gain from observations in infrared and other wavelengths." Astronomers believe the universe originated approximately 13.7 billion years ago in a cataclysmic event called the Big Bang. Galaxies, the basic building blocks of the uni- verse, began to appear as the fireball of hydrogen and helium gas expanded and cooled. Recent observations suggest star formation peaked some eight to 10 billion years ago. This mission is specifically designed to investigate whether this occurred and why. The centerpiece of the satellite is a 50-centimeter-diameter (19.7-inch) telescope equipped with sensors that will gather continuous images of galaxies in the ultraviolet to study their shape, brightness and size. Ultraviolet light -- the type of invisible energy responsible for sunburn -- is at the higher end of the electromagnetic spectrum, just above visible light in frequency, but below X-rays and gamma rays. A device called a spectrometer will break down the light into its component colors, just as a prism separates white light into a rainbow. These measurements will enable sci- entists to determine the distances of galaxies, and thus, their places in cosmic history. Combined with precise measurements of the ultraviolet brightness of galaxies, astronomers will be able to determine the rate at which stars are forming within those galaxies. 3 "This mission will provide the first comprehensive map of a universe of galaxies under construction and bring us closer to understanding how they, and our own Milky Way, were built," said Dr. Christopher Martin, the mission's principal investigator and an astrophysics professor at the California Institute of Technology in Pasadena. Scientists will use data from the mission to learn when carbon, oxygen and other chemical elements were created inside blazing stars. Most of the elements found in the human body originated in stars. We are literally made of stardust. The mission will also conduct the first ultraviolet surveys of the entire sky beyond our own galaxy, including the first wide-area spectroscopic surveys. Rich in objects from galaxies to quasars to white dwarf stars, this vast data archive will serve as a resource for the entire astronomical community. The Galaxy Evolution Explorer mission is led by the California Institute of Technology, which is also responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of Caltech, manages the mission and built the science instrument. Orbital Sciences Corp., Germantown, Md., is respon- sible for the spacecraft, integration and testing, ground data system and mission oper- ations, and the launch vehicle. Other partners include the University of California, Berkeley; and Johns Hopkins University, Baltimore, Md., and its Space Telescope Science Institute. The mission was developed under NASA's Explorers program, man- aged by the Goddard Space Flight Center, Greenbelt, Md. Key flight optics compo- nents were developed and contributed by France’s Laboratoire d’Astrophysique de Marseille. Important test equipment and science operations software was developed and contributed by Yonsei University in Seoul, South Korea. More information about the mission is available on the project web site at: http://www.galex.caltech.edu Information on NASA's Explorers Program is available at: http://explorers.gsfc.nasa.gov The launch will be broadcast live on NASA Television on the GE-2 satellite, transpon- der 9C, located at 85 degrees west longitude, vertical polarization, frequency 3880.0 megahertz, audio 6.8 megahertz. The launch will be carried on a live webcast at: http://www.jpl.nasa.gov/webcast/galexlaunch.html - end - 4 Media Services Information NASA Television Transmission NASA Television is broadcast on satellite GE-2, transponder 9C, C band, 85 degrees west longitude, frequency 3880.0 MHz, vertical polarization, audio monaural at 6.8 MHz. The tentative schedule for television transmissions of mission activities is described below; updates will be available from the Jet Propulsion Laboratory, Pasadena, Calif.; the Goddard Space Flight Center, Greenbelt, Md.; and NASA Headquarters, Washington. Briefings and Television Feed Pre-launch mission and science briefings will air on NASA Television at 1 p.m. EDT April 25, 2003. The news conference will originate from NASA Kennedy Space Center, Fla. NASA plans to broadcast the launch live on NASA Television. The broadcast will be accessible via webcast at http://www.jpl.nasa.gov/webcast/galexlaunch.html . Status Reports NASA will issue status reports on mission activities. They may be accessed online as noted below. Launch Media Credentialing News media representatives who wish to cover the launch in person must be accredit- ed through the NASA Kennedy Space Center newsroom. Journalists may contact the newsroom at 321/867-2468 for more information. Internet Information Information on the mission, including an electronic copy of this press kit, press releas- es, fact sheets, status reports and images, is available from a variety of sources. The Galaxy Evolution Explorer web site is operated by Caltech at http://www.srl.caltech.edu/galex/ . Information is also available on the Jet Propulsion Laboratory home page at http://www.jpl.nasa.gov , the Goddard Space Flight Center home page at http://www.gsfc.nasa.gov , and the NASA Explorers Program web page at http://explorers.gsfc.nasa.gov . 5 Quick Facts Spacecraft Size: 1 meter (3 feet) wide, 2.5 meters (6.4 feet) high Mass: 277 kilograms (609 pounds) Power: 290 watts from two solar wings totaling 3 square meters (32 square feet) Batteries: 15-amp-hour nickel-hydrogen battery providing up to 250 watts at 28 volts Science instrument: 50-centimeter-diameter (19.7-inch) telescope with two ultraviolet detectors (near- and far-ultraviolet) Launch Vehicle Type: Pegasus XL Length: 16.9 meters (55.6 feet) Diameter: 1.3 meters (4.2 feet) Weight: 23,130 kilograms (50,900 pounds) Stages: Three Fuel: Solid Mission Launch: No earlier than April 28, 2003 from Kennedy Space Center, Florida Primary mission: One year plus 1-month in-orbit checkout, with possible extension to 28 months Orbit altitude: 690 kilometers (about 429 miles) Orbit inclination to Earth's equator: 29 degrees Orbital period: 96 minutes 6 Mission Overview The Galaxy Evolution Explorer is an orbiting telescope that will observe a million galax- ies across 10 billion years of cosmic history using state-of-the-art ultraviolet detectors. The satellite will be launched into a circular orbit around Earth at an altitude