TEKNOLOGI CANGGIH
Canggih #08
Bisakah Teleskop Hubble Menguak Rahasia Alam Semesta?
Artikel Teknologi Canggih ini dimaksud untuk memberi motivasi kepada Pemerintah, Bangsa, dan Rakyat Indonesia, agar tergerak untuk memiliki dan menguasai Teknologi Canggih semacam ini. Memang hal ini adalah sebuah mimpi, tetapi mimpi yang bisa menjadi kenyataan, asal kita bisa menjalankan strategi yang benar dalam memajukan Bangsa dan Negara kita. Strategi jangka panjang yang baik harus disusun oleh ahli-ahli dan elit-elit kita, jangan elit-elit kita berantem melulu. Strategi untuk 30 tahun atau 50 tahun mendatang bagi Negara Indonesia yang kaya raya ini harus disusun, kalau undang-undang nya tidak memungkinkan untuk membuat strategi ini, ya undang-undangnya dirubah. Click banner readbud tersebut diatas
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Foto Awal Mula Alam Semesta Versi Hubble
Kamis, 7 Januari 2010 | 17:00 WIB
Dari sudut waktu, kondisi alam semesta yang digolongkan masih kanak-kanak tersebut setara dengan 600 juta tahun setelah peristiwa Ledakan Besar (Big Bang), yang dari teori fisika diyakini sebagai kelahiran alam semesta. Sejauh ini, foto tersebut dipercaya sebagai gambar paling lengkap dari masa awal alam semesta, yang menunjukkan galaksi dengan bintang-bintang berumur ribuan tahun.
Susunan bintang-bintang, seperti dalam foto Hubble, itu menunjukkan tanda awal yang kuat dari kelompok (kluster) bintang pertama kalinya. Susunan galaksi muda tersebut belum berbentuk spiral atau elips, dan sebagian besar lebih kecil berwarna kebiruan. Kondisi seperti itu terjadi karena galaksi tidak berisi banyak logam berat, seperti diungkapkan Garth Illingworth dari Universitas California, Santa Cruz. Illingworth merupakan profesor astronomi yang terlibat dalam peluncuran foto Hubble tersebut.
”Kita menyaksikan galaksi yang amat kecil, yang merupakan benih dari galaksi bimasakti saat ini,” ujarnya. Menurut Illingworth, hingga teleskop Hubble milik NASA selesai diperbaiki akhir tahun lalu, para astronom dunia hanya dapat melihat alam semesta pada kisaran usia 900 juta tahun setelah Ledakan Besar atau 300 juta tahun lebih tua daripada gambar terbaru yang diluncurkan dua hari lalu.
Teleskop Hubble merupakan kunci penting menentukan usia alam semesta, yang disepakati komunitas ilmiah dunia berumur 13,7 miliar tahun. Hasil itu sukses mengakhiri perdebatan panjang ilmiah pada dekade sebelumnya. Namun, semua itu dinilai belum cukup memuaskan.
NASA saat ini masih mengembangkan laboratorium baru, teleskop James Webb seharga 4,5 miliar dollar AS, yang rencananya diluncurkan empat tahun mendatang untuk pemahaman yang lebih pasti tentang awal mula alam semesta. ”Jadi, kita masih dalam tahap permulaan,” kata ahli astrofisika, Neil deGrasse Tyson, dari Museum Sejarah Alam Amerika. ”Setiap tahap mendekati permulaan memberitahu Anda sesuatu yang belum Anda ketahui sebelumnya.” (AP/GSA)
Catatan : Ya TUHAN, betapa kecilnya aku ini, ketika aku masih kecil sampai KAU memberiku umur panjang hingga sekarang, aku sering membayangkan, bahwa aku tinggal di Bumi yang diatas sana ada langit dimana terdapat bulan, matahari dan bintang-bintang. Kemudian menginjak dewasa akupun menjadi tahu dari para ilmuwan bahwa ada galaksi dengan bintang-bintang berumur ribuan tahun dan ada pula galaksi Bimasakti. Kemudian dengan bantuan Teleskop Hubble, para ilmuwan telah menyepakati bahwa usia dunia berumur 13,7 miliar tahun, umur yang tidak bisa terbayangkan oleh kami. Tetapi TUHAN, sebelum umur itu ada apa, diatas sana lagi ada apa, diatas sana lagi ada apa dan seterusnya, kami semua tidak tahu, hanya ENGKAU lah yang MAHA TAHU. TUHAN, berkatilah para ilmuwan, agar mereka dapat bekerja maksimal yang tidak melebihi batas kemampuan manusia, dan agar mereka dapat membantu umat manusia di Bumi ini dengan kemajuan teknologi. Amin.
Teleskop luar angkasa Hubble
Teleskop angkasa Hubble adalah sebuah teleskop luar angkasa yang berada di orbit bumi. Nama Hubble diambil dari nama ilmuwan terkenal Amerika, Edwin Hubble yang juga merupakan penemu hukum Hubble. Sebagian besar dari benda-benda angkasa yang telah berhasil diidentifikasi, adalah merupakan jasa teleskop Hubble.
Sejarah
Pada tahun 1962, Akademi Sains Nasional Amerika merekomendasikan untuk membangun sebuh teleskop angkasa raksasa. Tiga tahun kemudian, tepatnya pada tahun 1977, kongres mulai menugumpulkan dana untuk proyek tersebut. Pada tahun yang sama pula, pembuatan teleskop angkasa Hubble segera dimulai.
Konstruksi teleskop Hubble, berhasil diselesaikan pada tahun 1985. Hubble di'angkasakan' untuk pertamakalinya pada tanggal 25 April 1990. Padahal, Hubble direncanakan untuk mulai dioperasikan pada tahun 1986. Tetapi, pengoperasiannya ditunda sementara karena bencana Pesawat Angkasa Challenger. Beberapa tahun setelah dioperasikan, Hubble mengirim gambar yang buram dan tidak jelas. Pada akhirnya NASA menemukan bahwa lensa pada teleskop tersebut bergeser sebanyak 1/50 ketebalan rambut manusia! Pada bulan Desember 1993, Pesawat Ulang-Alik Endeavor, dikirim untuk memodifikasi Hubble dengan menambahkan kamera baru untuk memperbaiki kesalahan pada lensa primernya.
Ukuran
- Teleskop: Ketebalan mencapai 13.1 meter (43.5 kaki), berdiameter 4.27 meter (14.0 kaki) dan memiliki berat 11,000 kilogram. Ukuran Hubble hampir sama dengan sebuah bus sekolah. Juga, perhatikanlah tabung oranye yang ada pada teleskop. Ini adalah sumber tenaga Hubble.
- Lensa: Lensa primer teleskop Hubble, berdiameter 2.4 m (8 kaki), dan beratnya mencapai 826 kilogram. Lensa ini terbuat dari kaca silika yang dilapisi oleh lapisan tipis aluminum murni untuk merefleksikan cahaya. Selain lapisan aluminum, lensanya juga memiliki lapisan magnesium fluorida yang berguna untuk mencegah oksidasi dan sinar ultraviolet (UV) dari matahari agar lensa tidak cepat rusak.
Cara kerja
Pertama-tama, Hubble menangkap gambar, setelah diterima oleh teleskop, gambar tersebut akan diubah manjadi kode digital dan diradiasikan ke bumi dengan menggunakan antena yang memiliki kemampuan mengirimkan data 1 juta bit per detik. Setelah kode digital diterima oleh stasiun di bumi, kode itu akan diubah menjadi foto dan spektrograf (sebuah instrumen yang digunakan untuk mencatat spektrum astronomikal).
Teleskop ini dapat berjalan 5 mil per detik. Hubble dapat berkeliling lebih dari 150 juta mil per tahun (± 241 juta kilometer)!
( Teleskop luar angkasa Hubble )
The Milky Way ( Bima Sakti ) Galaxy
Our galaxy is a loose spiral disc of two hundred billion stars rotating around a compact centre. This is a diagram showing the main features of the Galaxy. ( An Atlas of the Universe )
( Hubble Space Telescope )
The Visible Universe ( visit An Atlas of the Universe )
Hubble Space Telescope
The Hubble Space Telescope (HST) is a space telescope that was carried into orbit by a space shuttle in April 1990. It is named after the American astronomer Edwin Hubble. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well-known as both a vital research tool and a public relations boon for astronomy. The HST is a collaboration between NASA and the European Space Agency, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.[4]
Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster. When finally launched in 1990, scientists found that the main mirror had been ground incorrectly, severely compromising the telescope's capabilities. However, after a servicing mission in 1993, the telescope was restored to its intended quality. Hubble's orbit outside the distortion of Earth's atmosphere allows it to take extremely sharp images with almost no background light. Hubble's Ultra Deep Field image, for instance, is the most detailed visible-light image ever made of the universe's most distant objects. Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.
Hubble is the only telescope ever designed to be serviced in space by astronauts. Four servicing missions were performed from 1993–2002, but the fifth was canceled on safety grounds following the Space Shuttle Columbia disaster. However, after spirited public discussion, NASA administrator Mike Griffin approved one final servicing mission, completed in 2009. The telescope is now expected to function until at least 2014, when its 'successor', the James Webb Space Telescope (JWST), is due to be launched.
Servicing missions and new instruments
Servicing Mission 1
Main article: STS-61
The telescope had always been designed so that it could be regularly serviced, but after the problems with the mirror came to light, the first servicing mission assumed a much greater importance, as the astronauts would have to carry out extensive work on the telescope to install the corrective optics. The seven astronauts selected for the mission were trained intensively in the use of the hundred or more specialized tools that would be needed.[61] The Space Shuttle Endeavour mission STS-61 took place in December 1993, and involved installation of several instruments and other equipment over a total of 10 days.
Most importantly, the High Speed Photometer was replaced with the COSTAR corrective optics package, and WFPC was replaced with the Wide Field and Planetary Camera 2 (WFPC2) with its internal optical correction system. In addition, the solar arrays and their drive electronics were replaced, as well as four of the gyroscopes used in the telescope pointing system, two electrical control units and other electrical components, and two magnetometers. The onboard computers were upgraded, and finally, the telescope's orbit was boosted, to compensate for the orbital decay from 3 years of drag in the tenuous upper atmosphere.[46]
On January 13, 1994, NASA declared the mission a complete success and showed the first of many much sharper images.[62] At the time, the mission had been one of the most complex ever undertaken, involving five lengthy periods of extra-vehicular activity, and its resounding success was an enormous boon for NASA, as well as for the astronomers who now had a fully capable space telescope.
Servicing Mission 2
Main article: STS-82
Servicing Mission 2, flown by Discovery (STS-82) in February 1997, replaced the GHRS and the FOS with the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), replaced an Engineering and Science Tape Recorder with a new Solid State Recorder, repaired thermal insulation and again boosted Hubble's orbit.[63] NICMOS contained a heat sink of solid nitrogen to reduce the thermal noise from the instrument, but shortly after it was installed, an unexpected thermal expansion resulted in part of the heat sink coming into contact with an optical baffle. This led to an increased warming rate for the instrument and reduced its original expected lifetime of 4.5 years to about 2 years.[64]
Servicing Mission 3A
Main article: STS-103
Servicing Mission 3A flown by Discovery (STS-103), took place in December 1999, and was a split-off from Servicing Mission 3 after three of the six onboard gyroscopes had failed. (A fourth failed a few weeks before the mission, rendering the telescope incapable of performing science observations.) The mission replaced all six gyroscopes, replaced a Fine Guidance Sensor and the computer, installed a Voltage/temperature Improvement Kit (VIK) to prevent battery overcharging, and replaced thermal insulation blankets.[65] Although the new computer is hardly a powerhouse (a 25 MHz radiation hardened Intel 486 with two megabytes of RAM), it is still 20 times faster, with six times more memory, than the DF-224 it replaced. The new computer increases throughput by moving some computing tasks from the ground to the spacecraft, and saves money by allowing the use of modern programming languages.[66]
Servicing Mission 3B
Main article: STS-109
Servicing Mission 3B flown by Columbia (STS-109) in March 2002 saw the installation of a new instrument, with the FOC (the last original instrument) being replaced by the Advanced Camera for Surveys (ACS). This meant that COSTAR was no longer required since all new instruments had correction for the main mirror aberration built in.[60]
The mission also saw the revival of NICMOS, which had run out of coolant in 1999. A new cooling system was installed that reduced the instrument's temperature enough for it to be usable again. Although not as cold as its original design called for, the temperature is more stable, in many ways a better tradeoff.[64] ACS in particular enhanced Hubble's capabilities; it and the revived NICMOS together imaged the Hubble Ultra Deep Field.
The mission replaced the solar arrays for the second time. The new arrays were derived from those built for the Iridium comsat system and were only two-thirds the size of the old arrays, resulting in less drag against the tenuous reaches of the upper atmosphere while providing 30 percent more power. The additional power allowed all instruments on board the HST to be run simultaneously, and reduced a vibration problem that occurred when the old, less rigid arrays entered and left direct sunlight. Hubble's Power Distribution Unit was also replaced in order to correct a problem with sticky relays, a procedure that required the complete electrical power down of the spacecraft for the first time since it was launched.[67]
Servicing Mission 4
Main article: STS-125
Servicing Mission 4 (SM4), was the last scheduled shuttle mission (STS-125) for the Hubble Space Telescope in May 2009.[68] The servicing mission was first planned for October 14, 2008.[69] However on 27 September 2008, the Science Instrument Command and Data Handling (SI C&DH) unit on HST failed. All science data passes through this unit before it can be transmitted to Earth. Although it has a backup unit, if the backup were to fail, the HST's useful life would be over.[70] Therefore, on 29 September 2008, NASA announced the launch of SM4 was postponed until 2009 so this unit could be replaced as well.[71] SM4, with a replacement SI C&DH unit,[72] was launched aboard Space Shuttle Atlantis on May 11, 2009.[73]
On SM4 astronauts, over the course of five spacewalks, installed two new instruments, Wide Field Camera 3 (WFC3), and the Cosmic Origins Spectrograph (COS). WFC3 will increase Hubble's observational capabilities in the ultraviolet and visible spectral ranges by up to 35 times due to its higher sensitivity and wider field of view. The telephone-booth sized COS assembly replaced the Corrective Optics Space Telescope Axial Replacement (COSTAR) that was installed in 1993 to correct Hubble's spherical aberration problems. (COSTAR was no longer needed after the replacement of the FOC in 2002, the last original instrument without the necessary correction built in.[60]) The COS will do observations in the ultraviolet parts of the spectrum, complementing the measurements done by the repaired STIS system. The service mission repaired two instruments that had failed, the Advanced Camera for Surveys (ACS) and the Space Telescope Imaging Spectrograph (STIS). They also performed other component replacements including: all three Rate Sensor Units (each containing two gas-bearing gyroscopes); one of three Fine Guidance Sensor (FGS) units used to help keep pointing accuracy and increase platform stability; the SI C&DH unit; all six of the 125-pound (57 kg) nickel-hydrogen batteries used to provide all Hubble's electrical power to support operations during the night portion of its orbit; and three New Outer Blanket Layer (NOBL) thermal insulation protective blankets. The batteries had never been replaced and were more than 13 years over their original design life.[74] After testing and calibration, Hubble resumed routine operation in September 2009.[75] These efforts are expected to keep the telescope fully functioning at least into 2014 and perhaps longer.[76]
Hubble was originally designed to be returned to earth on board a shuttle. With the retirement of the shuttle fleet this will no longer be possible. NASA engineers developed the Soft Capture and Rendezvous System (SCRS), a ring-like device that was attached to Hubble’s aft bulkhead which will enable the future rendezvous, capture, and safe disposal of Hubble by either a crewed or robotic mission.[77] Atlantis released the Hubble Space Telescope on May 19, 2009 back into space after all repairs were successfully made. The next mission will be to deorbit Hubble at the end of its service life.
( For more complete information visit Hubble Space Telescope )
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Hubble's View Of The Universe 1/7
Hubble's View Of The Universe 2/7
Hubble's View Of The Universe 3/7
Hubble's View Of The Universe 4/7
Hubble's View Of The Universe 5/7
Hubble's View Of The Universe 6/7
Hubble's View Of The Universe 7/7
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