Large Millimeter Telescope (GTM in Spanish)

Creado: 11 September 2009 | Modificado: 03 November 2009

CIATEQ has been fundamental participant in the development of the largest scientific Project in the history of Mexico: The Great Millimeter Telescope, located in the Sierra Negra volcano, state of Puebla.

The National Astrophysics, Optical, and Electronics (INAOE) and the University of Massachusetts Amherst (UMass Amherst) started the process for the construction of the Great Millimeter Telescope, GMT, in 1998, which is the largest scientific project that has been done in the country in all the history.

In these more than eleven years in development, CIATEQ has been invited to collaborate in different stages, since the tendering of the engineering and its participation in the technical committee to review the proposals of the different companies that designed it.
CIATEQ is also part of the international committee which supervises the engineering and supports the inspection of the structure.

Furthermore it was in charge of inspecting the quality of the used welds and then it has been asked to create important mechanisms for the operation of the telescope.

The GMT has three mirrors: the primary is the plate, a parabolic antenna with 50 meters of diameter, which concentrates the space radiation. The type of radiation that captures depends on the exactitude of the parable, but it can detect signals coming from the universe, from a distance of 13 thousand 400 million of light years to investigate about the origin of the same universe. This first plate “floats” and adjusts the parabola, with 25 micron accuracy, that is to say, pieces practically without defect.

Once the primary mirror receives the space radiation, is as a parabola that concentrates the signal in one spot: the second mirror was also made by CIATEQ from its design and production of the mold until its manufacture.

The second mirror, denominated M2, is made of carbon fiber, because of the accuracy which permits when receiving the signal, in addition it has a greater mechanical resistance and the adequate weigh to be handled on an hexapod, which has to be able to position this secondary plate 2 meters of diameter and 200 kilos of weight, with a an exactitude of 5 microns (a micron is the same as a 0.0001 cms., or what is the same, a millionth of a meter).

The development of the hexapod, demanded CIATEQ to do vanguard things in terms of engineering, due to the level of accuracy required. It is a parallel robot of six degrees of freedom, with six legs (hence the name hexapod) and that has to comply with the very strict design conditions; in addition, it must endure the weather and the pressure to an altitude of 4 thousand 600 meters, outdoors, at the top of the Sierra Negra volcano in Puebla, where the GMT is located.

Each of the six  legs, have more than a meter long, were certified with the accuracy of one micron, a precision that can hardly be overcome with the technological elements that exist actually in the world. The control of the hexapod was made by computer, with very sophisticated programs also developed in CIATEQ.

The technological development for electronic control of the GMT took about a year and a half, as it was necessary to send to make an encoder of 13 thousand 400 lines to Germany.

CIATEQ adjusted the M2 in the hexapod, with the exact position to capture the concentration of the radiation of the first mirror and send it to the third in an accurate way.

Due to CIATEQ’s experience in the area of servo motors, it also participated in the construction and installation of the M3 or third mirror, which is the one that introduces the information to the center of the machine.

The M3 is of polished aluminum and has the peculiarity of turning in a very precise form and  of being used at more or less 45 degrees to send the information to the referred center of the machine.

CIATEQ also participated in avoiding the problem that shows in a mechanic transmission, gear, called “lash”. This mechanism consists in two servomotors: one makes the traction and the other generates an opposite force so that, when it reverses, at the moment of the reverse, there is no deface.

With the performed work by CIATEQ, avoids what is known as a back lash, that is to say, an error in the movement, which would make to modify the displacement of the mirror from the radar in various degrees.

The work performed by CIATEQ for the construction and putting into operation the Great Millimeter Telescope, has involved the work of specialists in practically all the center facilities: the hexapod was developed in the unit of Aguascalientes, the secondary mirror, M2, in the unit of the municipality of El Marques; the third mirror, M3, and the anti back lash were made in San Luis Potosi.
Information of: Juan Carlos Jauregui – Miguel Angel Alcantara - Miguel Angel Vega