ALMA telescope reaches new heights
Wednesday, 23 September 2009
The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory has taken another step forward and upwards. One of its state-of-the-art antennas was carried for the first time to the 5000m plateau of Chajnantor, in the Chilean Andes, on the back of a custom-built giant transporter. The antenna, which weighs about 100 tons and has a diameter of 12 meters, was lifted to the high-altitude Array Operations Site, where the extremely dry and rarefied air is ideal for ALMA’s observations of the universe.
The conditions at the Array Operations Site on Chajnantor, while excellent for astronomy, are also very harsh. Only half as much oxygen is available as at sea level, making it very difficult to work there. This is why ALMA’s antennas are assembled and tested at the lower 2900 m altitude of the ALMA Operations Support Facility (OSF). It was from this relatively hospitable base camp that the ALMA antenna began its journey to the high Chajnantor site.
“Transporting our first antenna to the Chajnantor plateau is an epic feat which exemplifies the exciting times in which ALMA is living. Day after day, our global collaboration brings us closer to the birth of the most ambitious ground-based astronomical observatory in the world”, says Thijs de Graauw, ALMA Director.
The trip began when one of the two ALMA transporters lifted the antenna onto its back, carrying its heavy load along the 28 km road from the Operations Support Facility up to the Array Operations Site. While the transporter is capable of speeds of up to 12 km/hour when carrying an antenna, this first journey was made more slowly to ensure that everything worked as expected. This took about seven hours.
The ALMA antennas use advanced technology which has only been available for a few years, and are the most sophisticated submillimeter wavelength antennas ever made. These are designed to operate fully exposed in the harsh conditions of the Array Operations Site. This means surviving strong winds and temperatures between -20 and +20 Celsius whilst being able to point precisely enough that they could pick out a golf ball at a distance of 15 km, and to keep their smooth reflecting surfaces accurate to better than 25 micrometers (less than the typical thickness of a human hair).
“This milestone is the culmination of 8 months of effort by ALMA engineers and scientists in assembling and verifying the performance of the antenna over the range of operations needed to confirm its readiness for scientific commissioning”, says Joseph McMullin, ALMA Assembly, Integration and Verification (AIV) System Integration Lead.
Once the transporter reached the high plateau it carried the antenna to a concrete pad — a docking station with connections for power cables and fiber optics — and positioned it with an accuracy of a few millimeters. The transporter is guided by a laser steering system and, just like some cars today, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas which can be placed on any of about 200 pads, spread over distances of up to 18.5km and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations.
This first ALMA antenna at the high site will soon be joined by others, and the ALMA team look forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations in the second half of 2011.
ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, but also from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born and remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology.
More Information
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA
Links
More information about ALMA:
http://www.almaobservatory.org/
Contacts
William Garnier
ALMA Education and Public Outreach Officer
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
+56 9 77 67 61 99
Pictures
The first journey of an ALMA antenna to the plateau of Chajnantor. © ALMA (ESO/NAOJ/NRAO) An ALMA antenna begins the journey from the Operations Support Facility to the plateau of Chajnantor for the first time. The ALMA transporter vehicle carefully picks up the state-of-the-art antenna, with a diameter of 12 meters and a weight of about 100 tons, and begins the journey to the Array Operations Site, which is at an altitude of 5000 m. The antenna is designed to withstand the harsh conditions at the high site, where the extremely dry and rarefied air is ideal for ALMA’s observations of the universe at millimeter- and submillimeter-wavelengths.
An ALMA antenna en route to the plateau of Chajnantor for the first time. © ALMA (ESO/NAOJ/NRAO)
An ALMA antenna arrives on the plateau of Chajnantor for the first time. © ALMA (ESO/NAOJ/NRAO)
An ALMA antenna is positioned on an antenna station at the plateau of Chajnantor for the first time.
All of these pictures and much more about this milestone are available here.
A 3’20 trailer is also available here. Feel free to download it in high, medium or low resolution.
Comments
jmartinez2009-12-28 16:26:09
Muy bueno, espero ir a conocer lo antes posible el lugar, saludos!!
juantorom2009-12-28 16:23:56
Hace poco me enteré de ALMA y estoy feliz de que un país latinoamericano sea el
hogar de esta magnífica instalación astronómica. Como profesor de física en el
Colegio Colombo Británico, de Envigado, Colombia, estaré pendiente del proyecto
pues creo que para la formación científica de nuestros estudiantes es muy
importante estar en contacto con la ciencia real que ocurre en nuestro mundo.
Estaré atento a todos los recursos educativos que dispongan en su sitio y
trataré de usar todos los que pueda con mis estudiantes de secundaria.
Felicitaciones por su trabajo.
fernando_urra2009-12-28 16:23:20
Me sorprendí de qué manera están avanzadas las instalaciones del proyecto ALMA y
de tener la oportunidad de ver en video y fotos los avances del proyecto, ya que
hace un par de años atrás estuve en sus instalaciones por una empresa
multinacional (Eléctrica) y tuve la experiencia en ese momento de conocer
algunas antenas que realizaban pruebas. Felicito al team de trabajo y el
profesionalismo que aplican para tener un buen término. Ojala tenga la
oportunidad de visitarlos ya que no es común ver este tipo de tecnología y es
una experiencia diferente.
Un abrazo
Fernando Urra Venegas
Sergio Campos Aravena2009-12-28 16:16:19
Ha sido fascinante para el suscrito, seguir las alternativas del Proyecto ALMA a
través del tiempo.
Cuando se acerca la etapa final con la instalación de las antenas, siento la
emoción que debe embargar a todas las personas que trabajan en el Proyecto,
tanto técnicas, como administrativas; por cuanto si se mira hacia atrás, ahora
parece lejano cuando se planteó la idea y se eligió este Valle.
El Universo depara grandes sorpresas, la mente e inteligencia humana, permiten
conocerlo cada vez mejor y ubicarnos en una realidad que abruma pero fortalece
el deseo de aumentar nuestro conocimiento.
Como un aficionado a la Astronomía y Física; que por razones especiales del
momento que nací, no logré estudiarlas, ahora que pertenezco al grupo tercero,
me dedico a investigar, recopilar y tratar de incentivar en la juventud, el
estudio de la Astrofísica.
Puede que sea una lucha estéril, pero si una persona fuera tocada para
proyectarse en esta ciencia, me sentiría satisfecho.
Por esta razón, FELICITO a todo el equipo de ALMA, por su tesón y el logro de un
excelente trabajo. Sé que queda aún mucho por hacer, sólo me cabe, si el tiempo
así lo estima conveniente, estar vigente cuando inicie ALMA su trabajo del
Universo.
Un abrazo
Sergio Campos Aravena
Aficionado de la Astrofísica
