DOCSLIB.ORG

High Stakes for Japan's Space Probe

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
High Stakes for Japan's Space Probe NEWS IN FOCUS is also a member of ASTRO-H’s ESA team. Spectra carry information about the veloc- SPECTRA IN SPACE ity and turbulence of the plasma that per- The Japanese space observatory X-RAY TELESCOPES vades galaxy clusters, which in turn can reveal SOURCE: JAXA ASTRO-H will detect an Soft X-ray Telescopes unusually broad range of whether, and how, a cluster resulted from a wavelengths, from low-energy, Hard X-ray Telescope merger of two smaller ones, says Christine ‘soft’ X-rays to high-energy, Forman, a high-energy astrophysicist at Har- ‘hard’ X-rays and soft γ - rays. The S oft X-ray S pectrometer vard University in Cambridge, Massachusetts. (SXS) will be able to produce X-ray pictures of clusters, when combined with high-resolution spectra for wide visible-light images, have also previously pro- objects such as galaxy clusters. vided striking — although indirect — evidence for the existence of dark matter. ASTRO-H should be able to help settle whether a 3.5-kilo- electronvolt X-ray signal seen in certain galax- ies is a signature of dark matter decaying into photons — or something else, says Alexey Boyarsky, an astrophysicist at Leiden Univer- sity in the Netherlands who co-discovered the X-RAY DETECTORS signal (see Nature 517, 422–423; 2015). ASTRO-H will also cover a broader range of Soft X-ray Imager Extendable boom (6.4 metres) wavelengths than most other missions, from SXS ‘soft’, low-energy photons starting at 300 eV, Soft γ-ray Detector through hard X-rays and right up to soft Hard X-ray Imager γ-rays of 600 keV. But only the soft X-rays will have their spectra imaged to high resolution. At the heart of the instrument responsible for this — the Soft X-ray Spectrometer (SXS) — is LENGTH Approx. 14 m | MASS 2.7 tonnes | POWER 3,500 watts | LIFE 3 years an array of 36-pixel elements that must be kept at 0.05 degrees above absolute zero, well inside the main body of the craft. When a photon ASTRONOMY strikes one of the sensors, the temperature of the sensor rises slightly, causing its electrical conductivity to increase. The resulting change in voltage can be used to measure the energy High stakes for of the original photon — and therefore its wavelength — with a precision of nearly one part in 1,000. Japan’s space probe The technology first took shape in 1984, when Richard Kelley, an astrophysicist at NASA’s Goddard Space Flight Center in Green- ASTRO-H will carry a technology that two earlier, ill-fated belt, Maryland, started designing sensors for space telescopes failed to put into action. Chandra. After NASA scaled back its ambitions for the observatory and scrapped that plan, Kelley and his team provided the spectrometer BY DAVIDE CASTELVECCHI also major participation from NASA, as well for a Japanese X-ray telescope called ASTRO-E. as institutions in six other nations and the But in 2000, the rocket that was supposed to stronomers around the world are European Space Agency (ESA). put it into orbit crashed shortly after take-off. hoping that the third time will be the Studying X-ray emissions is the best way JAXA prepared a replacement mission, charm as Japan prepares to launch its to observe a wide range of cosmic phenom- Suzaku, which reached orbit in July 2005 — Alargest space observatory ever. The telescope ena, from galaxy clusters to the super-heated only for disaster to strike again. The liquid will use X-rays to study phenomena from black accretion disks around black holes. But Earth’s helium used to keep a spectrometer’s sensors holes to dark matter and carries cryogenic atmosphere is mostly opaque to radiation out- cold has to be slowly released, or outgassed. But imaging technology that flew on two previous side the visible spectrum, and particularly to in Suzaku, a tiny amount of that helium accu- missions — but met disaster both times. X-rays and γ-rays, meaning that most X-ray mulated inside the craft. This was enough to Weather permitting, a Japanese-built H-IIA astronomy requires a satellite. ruin the vacuum that was supposed to insulate rocket is scheduled to launch the probe, provi- The major existing X-ray satellites are the helium tank from the rest of the craft. The sionally named ASTRO-H, from Tanegashima NASA’s Chandra X-ray Observatory and ESA’s tank heated up faster than expected, causing Space Center at 17:45 local time on 12 Febru- XMM-Newton, which both launched in 1999. the helium to boil off and vent into space within ary. Once in orbit, the 2.7-tonne probe will These can analyse the constituent wavelengths four weeks of launch. Unable to stay super- stretch out to its maximum length of 14 metres, of X-rays — the spectra — emitted by point- chilled, the spectrometer was crippled before including a 6.4-metre boom that will host an like objects such as stars. But ASTRO-H will it could start making observations, although imager capable of collecting high-energy, or be the first to provide high-resolution spectra Suzaku’s other instruments continued to oper- ‘hard’ X-ray photons (see ‘Spectra in space’). for much more spread-out X-ray sources such ate until the craft was decommissioned in 2015. The Japan Aerospace Exploration Agency as galaxy clusters, says Norbert Schartel, project For ASTRO-H, JAXA redesigned the tank (JAXA) leads the mission with an investment scientist for XMM-Newton at ESA’s European with plumbing to outgas the helium straight of ¥31 billion (US$265 million), but there is Space Astronomy Centre outside Madrid, who into space. And to further guard against glitches, 140 | NATURE | VO L 530 | 11 FEBRUA RY 2 016 | CORRECTED ONLINE 1 0 FEBRUARY 2016 © 2016 Macmillan Publishers Limited. All rights reserved IN FOCUS NEWS ASTRO-H project manager Tadayuki REPLICATION Takahashi, an astrophysicist at the Uni- versity of Tokyo and ASTRO-H’s project manager, pushed his collaboration to work without borders. “Usually, international Biotech giant posts co alitions have clearly defined interfaces,” with different laboratories providing isolated components of a spacecraft and its payload, negative results says Takahashi. But ASTRO-H researchers regularly visited each other’s labs, sometimes for months at a time. Amgen papers seed channel for discussing reproducibility. Kelley says that Takahashi forged a very open collaboration. “Tad understands that BY MONYA BAKER make strong conclusions that someone else’s if you want to maximize the chances of suc- work is wrong with a capital W,” he says. cess, you have to have no barriers,” he says. biotechnology firm is releasing data on One study adds to existing criticism of a “Everybody has access to everything.” three failed efforts to confirm findings Science paper2 that suggested a cancer drug Astronomers around the world will be published in high-profile scientific might be a potential treatment for Alzheimer’s allowed to request observing time with Ajournals — details that the industry usually disease; a second counters earlier findings ASTRO-H. Each team will have exclusive keeps secret. (including some by Amgen researchers) access to the resulting data for one year, Amgen, headquartered in Thousand Oaks, connecting a gene to insulin sensitivity in after which JAXA will make them pub- California, says that it hopes the move will mice3,4; and a third counters a Nature paper5 licly available — a model long adopted by encourage others to describe their own rep- reporting that inhibiting one particular pro- NASA. ASTRO-H will be renamed after lication attempts, and thus help the scientific tein could enhance the degradation of others launch, although what it will be called is community to get to the bottom of work that associated with neurodegenerative diseases. yet to be determined. other labs are having trouble verifying. Amgen researchers did not contact the origi- A larger, higher-resolution version of the The data are posted online on a newly nal authors when they conducted their studies, SXS is due to fly aboard Athena, an ESA-led launched channel dedicated to quickly Kamb says. X-ray astronomy mission planned for the publishing researchers’ efforts to confirm sci- late 2020s. ■ entific findings (see go.nature.com/3zzea9), GAINING TRACTION hosted by F1000Research, the publishing plat- The main way that the scientific community Additional reporting by David Cyranoski. form of London-based publishers Faculty of spreads the word about irreproducible research 1000 (F1000). is through insinuation, which is inefficient and The ASTRO-H The idea emerged from discussions at a unfair to the original researchers, says Ricardo probe is preparing meeting in 2015 focused on improving scien- Dolmetsch, global head of neuroscience at for launch. tific integrity. Sasha Kamb, who leads research Novartis’s Institutes for Biomedical Research discovery at Amgen, said that his company’s in Cambridge, Massachusetts. “Anything we scientists have many times failed to reproduce can do to improve the ratio of signal to noise in academic studies but that it takes too much the literature is very welcome,” he says. effort to publish these accounts. The F1000 initiative is useful, but previous Bruce Alberts, a former editor-in-chief of efforts have tried and failed to encourage the Science who sits on F1000Research’s advisory reporting of replications and negative results, board, suggested that Kamb try the faster cautions John Ioannidis, who studies scientific F1000 route — an open-science publishing robustness at California’s Stanford University. In model in which submitted studies are posted general, the scientific community undervalues online (for a fee that ranges from US$150 to such work, he says.
Load more

Recommended publications
  • Building the Coolest X-Ray Satellite
    National Aeronautics and Space Administration Building the Coolest X-ray Satellite 朱雀 Suzaku A Video Guide for Teachers Grades 9-12 Probing the Structure & Evolution of the Cosmos http://suzaku-epo.gsfc.nasa.gov/ www.nasa.gov The Suzaku Learning Center Presents “Building the Coolest X-ray Satellite” Video Guide for Teachers Written by Dr. James Lochner USRA & NASA/GSFC Greenbelt, MD Ms. Sara Mitchell Mr. Patrick Keeney SP Systems & NASA/GSFC Coudersport High School Greenbelt, MD Coudersport, PA This booklet is designed to be used with the “Building the Coolest X-ray Satellite” DVD, available from the Suzaku Learning Center. http://suzaku-epo.gsfc.nasa.gov/ Table of Contents I. Introduction 1. What is Astro-E2 (Suzaku)?....................................................................................... 2 2. “Building the Coolest X-ray Satellite” ....................................................................... 2 3. How to Use This Guide.............................................................................................. 2 4. Contents of the DVD ................................................................................................. 3 5. Post-Launch Information ........................................................................................... 3 6. Pre-requisites............................................................................................................. 4 7. Standards Met by Video and Activities ...................................................................... 4 II. Video Chapter 1
    [Show full text]
  • JAXA's X-Ray Astronomy Mission ASTRO-H: Launch and First
    46th International Conference on Environmental Systems ICES-2016-157 10-14 July 2016, Vienna, Austria JAXA’s X-ray Astronomy Mission ASTRO-H: Launch and First Month’s In-Orbit Thermal Performance Naoko IWATA1 Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, 252-5210 Tel: +81-50-3362-3592, Fax: +81-42-759-8068 E-mail: [email protected] Takashi USUI2, Akihiko MIKI3, Mizuho IKEDA4 NEC Corporation and Yoh TAKEI5, Atsushi OKAMOTO6, Hiroyuki OGAWA7, Tadayuki TAKAHASHI8 Japan Aerospace Exploration Agency In this study, the thermal performance evaluation results of JAXA’s X-ray astronomy mission ASTRO-H are presented. ASTRO-H was successfully launched on February 17, 2016 from Tanegashima Space Center using an H2A rocket. ASTRO-H houses four telescopes and six detectors. Each detector has its own radiator and heat pipes for heat dissipation. The most major mission will feature a soft X-ray spectrometer having four loop heat pipes (LHPs) for heat transport from two cryocoolers. Six fans have been mounted close to each cryocooler for ground cooling in the fairing just before the launch. Hard X-ray imagers (HXIs) are mounted on an HXI plate; this plate is expanded by 6.4 m via an extensible optical bench (EOB) in orbit to achieve the necessary focal length. The EOB was successfully expanded 11 days after the launch. Heat pipes appropriately functioned in orbit. The two LHPs for the compressors have been operated properly for more than one month Measured inflight temperatures agree well with predicted ones for an attitude condition. Nomenclature
    [Show full text]
  • The AKARI/IRC Mid-Infrared All-Sky Survey*
    A&A 514, A1 (2010) Astronomy DOI: 10.1051/0004-6361/200913811 & c ESO 2010 Astrophysics Science with AKARI Special feature The AKARI/IRC mid-infrared all-sky survey D. Ishihara1,2, T. Onaka2, H. Kataza3,A.Salama4, C. Alfageme4,, A. Cassatella4,5,6,N.Cox4,, P. García-Lario4, C. Stephenson4,†,M.Cohen7, N. Fujishiro3,8,‡, H. Fujiwara2, S. Hasegawa3,Y.Ita9,W.Kim3,2,§, H. Matsuhara3, H. Murakami3,T.G.Müller10, T. Nakagawa3, Y. Ohyama11,S.Oyabu3,J.Pyo12,I.Sakon2, H. Shibai13,S.Takita3, T. Tanabé14,K.Uemizu3,M.Ueno3,F.Usui3,T.Wada3, H. Watarai15, I. Yamamura3, and C. Yamauchi3 1 Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-860, Japan e-mail: [email protected] 2 Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan 3 Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Sagamihara, Kanagawa, 229-8510, Japan 4 European Space Astronomy Center (ESAC), Villanueva de la Cañada, PO Box 78, 28691 Madrid, Spain 5 INAF, Istituto di Fisica dello Spazio Interplanetario, via del Fosso del Cavaliere 100, 00133 Roma, Italy 6 Dipartimento di Fisica, Universita’ Roma Tre, via della Vasca Navale 100, 00146 Roma, Italy 7 Radio Astronomy Laboratory, University of California, Berkeley, USA 8 Department of Physics, Faculty of Science, University of Tokyo, 3-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0003, Japan 9 National Astronomical Observatory of Japan, Mitaka, Tokyo, 181-8588, Japan 10 Max-Planck-Institut
    [Show full text]
  • AKARI in Orbit—Scientific Potential for Understanding Galaxy Evolution
    Galaxy Evolution across the Hubble Time Proceedings IAU Symposium No. 235, 2006 c 2007 International Astronomical Union F. Combes & J. Palouˇs, eds. doi:10.1017/S1743921306006879 AKARI in Orbit—Scientific Potential for Understanding Galaxy Evolution H. Matsuhara1, H. Murakami1,T.Nakagawa1,T.Wada1, S. Matsuura1,S.Oyabu1, T. Takagi1,C.P.Pearson1,H.Kaneda1, F. Usui1, M. Shirahata1, H. Shibai2,M.Kawada2,T.Onaka3, Y. Doi4, and AKARI team 1Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagwa 229-8510, Japan email: [email protected] (HM) 2Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan 3Department of Astronomy, The University of Tokyo, Tokyo 113-0033, Japan 4College of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan Abstract. The AKARI (formerly known as ASTRO-F) mission is the first Japanese satellite dedicated for large area surveys in the infrared (Murakami et al. 2004). AKARI was launched successfully on February 22nd 2006 (JST) from JAXA’s Uchinoura Space Centre, Japan. AKARI is now orbiting around the Earth in a Sun-synchronous polar orbit at the altitude of 700 km. The 68.5 cm aperture telescope and scientific instruments are cooled to 6K by liquid Helium and mechanical coolers. The expected liquid Helium holding time is now found to be at least one year after the successful aperture lid-opening on 2006 April 13th (JST). AKARI will perform the most advanced all-sky survey in 6 mid- to far-infrared wavebands since the preceding IRAS mission over 2 decades ago. Deep imaging and spectroscopic surveys near the ecliptic poles with pointed observations are also on-going in 13 wavelength bands at 2-160 µm (see Table 1, details are given in Matsuhara et al.
    [Show full text]
  • THE ASTRO-D MISSION Y. TANAKA Institute of Space and Astronautical
    THE ASTRO-D MISSION Y. TANAKA Institute of Space and Astronautical Science 3-1-1 Yoshinodai, Sagamihara, Kanagawa-ken 229, Japan Abstract. Astro-D, the fourth X-ray astronomy mission of IS AS following Ginga, is a high-throughput imaging and spectroscopic X-ray observatory, scheduled for launch in early 1993. It utilizes multilayer conical X-ray mirrors which provide a large effective area over a wide range energy range up to 12 keV. The focal plane instruments comprize a set of CCD cameras and Imaging gas scintillation proportional counters. Main features of Astro-D are described, and the important astrophysical objectives are discussed. 1. Introduction The Institute of Space and Astronautical Science (ISAS) has launced three X-ray astronomy satellites so far. The first small X-ray astronomy satellite "Hakucho" was launched in 1979. "Tenma", carrying for the first time the large-area gas scintilla­ tion proportional counters, was launched four years later (1983). The third X-ray astronomy observatory "Ginga" launched in early 1987 carries a large-area (4000 cm2) proportional counter array jointly prepared by the Japanese and the U.K. groups, and is currently operational for its fourth year in orbit. Astro-D is the fourth X-ray astronomy mission of ISAS, following Ginga. Astro- D is designed to be a high-capability X-ray observatory from which a number of important astrophysical investigations can be carried out. The main features of Astro-D are given in Table I, and the schematic view is shown in Fig. 1. It will be equipped with multilayer thin-foil telescopes which provide a large effective area over a wide energy range from below 1 keV up to 12 keV.
    [Show full text]
  • AKARI Observer's Manual for Phase 3
    AKARI Observer’s Manual for the Post-Helium (Phase 3) Mission Version 1.1 — for Open Time Observation Planning — AKARI User Support Team in Institute of Space and Astronautical Science / JAXA contact: iris [email protected] European Space Astronomy Centre / ESA contact: http://akari.esac.esa.int/esupport/ June 12, 2008 Revision Record 2008 May 12 Version 1.0 released, adapted from ASTRO-F Observer’s Manual Version 3.2, 2008 June 12 Version 1.1 released. Cookbook section added in Appendix. Contents 1 Introduction 1 1.1Purposeofthisdocument............................... 1 1.2RelevantInformation.................................. 3 2 Mission Overview 5 2.1 The AKARI Mission.................................. 5 2.2 Satellite . ........................................ 6 2.2.1 TheBusModule................................ 6 2.2.2 AttitudeDeterminationandControlSystem................. 7 2.2.3 Cryogenics................................... 8 2.3Telescope........................................ 9 2.3.1 Specification.................................. 9 2.3.2 Capability and Performance in Phase 3 . ................ 10 2.4Focal-PlaneInstruments................................ 11 2.4.1 SpecificationOverview............................. 11 2.4.2 Focal-PlaneLayout............................... 13 2.4.3 TheFocal-PlaneStarSensor(FSTS)..................... 14 2.5 The AKARI ObservationProgrammsinPhase3 .................. 15 2.6References........................................ 16 3 Satellite Operations 17 3.1OrbitandObservingAttitude............................
    [Show full text]
  • The ASTRO-H X-Ray Astronomy Satellite
    The ASTRO-H X-ray Astronomy Satellite Tadayuki Takahashia, Kazuhisa Mitsudaa, Richard Kelleyb, Felix Aharonianc, Hiroki Akamatsud, Fumie Akimotoe, Steve Allenf, Naohisa Anabukig, Lorella Angelinib, Keith Arnaudh, Makoto Asaif, Marc Audardi, Hisamitsu Awakij, Philipp Azzarelloi, Chris Balutaa, Aya Bambak, Nobutaka Bandoa, Marshall Bautzl, Thomas Bialasb, Roger Blandfordf, Kevin Boyceb, Laura Brennemanb, Greg Brownm, Edward Cackettn, Edgar Canavanb, Maria Chernyakovac, Meng Chiaob, Paolo Coppio, Elisa Costantinid, Jelle de Plaad, Jan-Willem den Herderd, Michael DiPirrob, Chris Donep, Tadayasu Dotania, John Dotyq, Ken Ebisawaa, Megan Eckartb, Teruaki Enotor, Yuichiro Ezoes, Andrew Fabiann, Carlo Ferrignoi, Adam Fostert, Ryuichi Fujimotou, Yasushi Fukazawav, Stefan Funkf, Akihiro Furuzawae, Massimiliano Galeazziw, Luigi Gallox, Poshak Gandhip, Kirk Gilmoref, Matteo Guainazziy, Daniel Haasd, Yoshito Habaz, Kenji Hamaguchih, Atsushi Harayamaa, Isamu Hatsukadeaa, Takayuki Hayashia, Katsuhiro Hayashia, Kiyoshi Hayashidag, Junko Hiragaab, Kazuyuki Hirosea, Ann Hornschemeierb, Akio Hoshinoac, John Hughesad, Una Hwangae, Ryo Iizukaa, Yoshiyuki Inouea, Kazunori Ishibashie, Manabu Ishidaa, Kumi Ishikawar, Kosei Ishimuraa, Yoshitaka Ishisakis, Masayuki Itoaf, Naoko Iwataa, Naoko Iyomotoag, Chris Jewellah, Jelle Kaastrad, Timothy Kallmanb, Tuneyoshi Kamaef, Jun Kataokaai, Satoru Katsudaa, Junichiro Katsutav, Madoka Kawaharadaa, Nobuyuki Kawaiaj, Taro Kawanoa, Shigeo Kawasakia, Dmitry Khangulyana, Caroline Kilbourneb, Mark Kimballb, Masashi Kimuraak,
    [Show full text]
  • Japanese X-Ray Satellite Loses Communication with Earth Future of the Major Astronomy Probe Remains Unclear As Pieces of Space Debris Are Reported
    NATURE | NEWS Japanese X-ray satellite loses communication with Earth Future of the major astronomy probe remains unclear as pieces of space debris are reported. Alexandra Witze 27 March 2016 The Japan Aerospace Exploration Agency (JAXA) lost contact with its flagship X-ray astronomical satellite, Hitomi, on 26 March. The observatory, launched on 17 February, had been going through initial check-outs and calibrations. Hitomi's status remains unknown as JAXA engineers work to re-establish communication. Ominously, the US Joint Space Operations Center, which tracks space debris, reported spotting five objects in the vicinity of the spacecraft around the time that it went silent. The centre characterized the objects as pieces of a “break-up”. The space debris could consist of minor pieces that were blown off Hitomi, as opposed to indicating complete destruction, says Jonathan McDowell, an astronomer and space analyst at the Harvard–Smithsonian Center for Astrophysics in Cambridge, Massachusetts. Hitomi, which was known before launch as ASTRO-H, is designed to study X-rays streaming from cosmic phenomena such as black holes, galaxy clusters and dark matter. It carries a high-resolution spectrometer to measure X-ray wavelengths in exquisite detail. Earlier versions of the same instrument have twice met a grim fate on JAXA missions: in 2000, the ASTRO-E telescope crashed on launch, and in 2005, a helium leak aboard the Suzaku satellite crippled its spectrometer within weeks of launch. Hope for recovery JAXA lost contact with Hitomi at 4:40 p.m. Japan time on 26 March. “The cause of the communication failure is under investigation,” the agency said.
    [Show full text]
  • The Akari Project: Legacy and Data Processing Status
    Publications of the Korean Astronomical Society pISSN 1225-1534 32: 005 ∼ 009, 2017 March eISSN 2287-6936 c 2017. The Korean Astronomical Society. All rights reserved. https://doi.org/10.5303/PKAS.2017.32.1.005 THE AKARI PROJECT: LEGACY AND DATA PROCESSING STATUS Takao Nakagawa & Issei Yamamura1 1Institute of Space and Astronautical Science, JAXA E-mail: [email protected] & [email protected] (Received July 21, 2015; Revised October 27, 2016; Accepted October 27, 2016) ABSTRACT This paper provides an overview of the AKARI mission, which was the first Japanese satellite dedicated to infrared astronomy. The AKARI satellite was launched in 2006, and performed both an all-sky survey and pointed observations during its 550 days in the He-cooled mission phases (Phases 1 and 2). After the He ran out, we continued near-infrared observations with mechanical cryocoolers (Phase 3). Due to a failure of its power supply, AKARI was turned off in 2011. The AKARI data are unique in terms of the observed wavelengths as well as the sky coverage, and provide a unique legacy resource for many astronomical studies. Since April 2013, a dedicated new team has been working to refine the AKARI data processing. The goal of this activity is to provide processed datasets for most of the AKARI observations in a Science Ready form, so that more users can utilize the AKARI data in their astronomical research. The data to be released will include revised All-Sky Point Source Catalogues, All-Sky Image Maps, as well as high-sensitivity images and spectra obtained by pointed observations.
    [Show full text]
  • Hard X-Ray/Soft Gamma-Ray Experiments and Missions
    Noname manuscript No. (will be inserted by the editor) Hard X–ray/Soft gamma–ray experiments and missions: overview and prospects Erica Cavallari · Filippo Frontera Received: date / Accepted: date Abstract Starting from 1960s, a great number of missions and experiments have been performed for the study of the high–energy sky. This review gives a wide vision of the most important space missions and balloon experiments that have operated in the 10–600 keV band, a crucial window for the study of the most energetic and violent phenomena in the Universe. Thus it is important to take the stock of the achievements to better establish what we have still to do with future missions in order to progress in this field, to establish which are the technologies required to solve the still open issues and to extend our knowledge of the Universe. Keywords high-energy astrophysics · hard X-ray astronomy · space missions · balloon experiments 1 Introduction It is recognized that hard X–ray/soft gamma–ray astronomy (10–600 keV) is a crucial window for the study of the most energetic and violent events in the Universe. An increasing number of missions devoted to observations in this band or including instruments specifically devoted to perform hard X–ray observations have been performed (e.g., BeppoSAX , Rossi XTE) or are still operational (e.g., INTEGRAL, Swift, Fermi). Actually in the remote past this was only considered an ancillary energy band. The bands which were considered key for astrophysical observations were the 2–10 keV band, also dubbed classic en- ergy band, and the soft X–ray band (≤ 2 keV).
    [Show full text]
  • Hitomi Experience Report: Investigation of Anomalies Affecting the X-Ray Astronomy Satellite “Hitomi” (ASTRO-H)
    Hitomi Experience Report: Investigation of Anomalies Affecting the X-ray Astronomy Satellite “Hitomi” (ASTRO-H) June 8, 2016 JAXA All times are given in JST unless stated otherwise. 1 Agenda 1. Summary 2. Background information on ASTRO‐H 3. Anomaly description and ground‐based observations 4. Causes of the anomaly 5. Factors contributing to the anomaly (Updated in the last ver.) 6. Measures and reforms (Updated in the last ver.) 7. Summary (Added in this slide deck) 2 1. SUMMARY 3 1. Summary After the anomaly in communications with the X‐ray Astronomy Satellite “Hitomi” (ASTRO‐H), the Japan Aerospace Exploration Agency (JAXA) set up an emergency headquarters to perform investigations and consider measures for future operations. For the cause analysis, experts from every branch of JAXA collaborated in the investigations such as analysis of telemetry data sent from the satellite, simulations, examination of the design, and analysis of the ground test data. In addition, the private enterprises that developed the satellite with JAXA also helped with the investigations. JAXA have been inspecting the direct causes and extending the investigation to trace back to the design policy and process in order to determine the design of the spacecraft. In Chapter 2 and later, JAXA reports the current status of the investigation. 4 2. BACKGROUND INFORMATION ON ASTRO‐H 5 2.1 Mission Overview ASTRO-H was developed to reveal the structure and evolution of the universe by observing high-energy objects that are visible in the X-ray and gamma-ray bands, objects such as black holes, supernova remnants (SNRs), and galaxy clusters.
    [Show full text]
  • Astronomy Satellites
    Astronomy Satellites Jonathan McDowell June 28, 1994 1 Why Space Astronomy? • SHARPER PICTURES (Spatial Resolution) The Earth’s atmosphere messes up the light coming in (stars twinkle, etc). • TECHNICOLOR (X-ray, infrared, etc) The atmosphere also absorbs light of different wavelengths (col- ors) outside the visible range. X-ray astronomy is impossible from the Earth’s surface. 2 What are the differences between satellite instruments? • Focussing optics or bare detectors • Wavelength or energy range - IR, UV, etc. Different technology used for different wavebands. • Spatial Resolution (how sharp a picture?) • Spatial Field of View (how large a piece of sky?) • Spectral Resolution (can it tell photons of different energies apart?) • Spectral Field of View (bandwidth) • Sensitivity • Pointing Accuracy • Lifetime • Orbit (hence operating efficiency, background, etc.) • Scan or Point What are the differences between satellites? • Spinning or 3-axis pointing (older satellites spun around a fixed axis, precession let them eventually see different parts of the sky) • Fixed or movable solar arrays (fixed arrays mean the spacecraft has to point near the plane perpendicular to the solar-satellite vector) 3 • Low or high orbit (low orbit has higher radiation, atmospheric drag, and more Earth occultation; high orbit has slower preces- sion and no refurbishment opportunity) • Propulsion to raise orbit? • Other consumables (proportional counter gas, attitude control gas, liquid helium coolant) 4 What are the differences in operation? • PI mission vs. GO mission PI = Principal Investigator. One of the people responsible for building the satellite. Nowadays often referred to as IPIs (In- strument PIs). GO = Guest Observer. Someone who just want to use the satel- lite.
    [Show full text]