Hello Everyone!
This is our project for POTY 2021
Project Description
The GMT will possess multiple capabilities critical for breakthroughs in exoplanetary science. Its huge aperture will enable the acquisition of spectra of transiting planets 7.5 times faster than current 8.m telescopes, enabling a new generation of spectroscopic studies of exoplanet atmospheres in the short windows allowed by primary- and secondary-transit durations. The GMT’s 24.5 m effective diameter will allow it to achieve unprecedented spatial resolution. The potential for synergy when these capabilities are combined in one facility will be powerful. For example, while transit observations and spectroscopy with G-CLEF will identify and measure the masses of habitable planets, the GMT spectrographs will study their atmospheres, and near-IR imagers will be able to image the outer planets directly.
If planets form early by gravitational instability (rather than by core accretion) the GMT will be able to image them around very young stars and subsequently study their orbits and atmospheres.
With its large collecting area and high angular resolution in the diffraction-limited mode, the GMT will be able to uniquely contribute to our understanding of dense stellar systems. Globular clusters in Local Group galaxies and other close neighbours can be studied in great detail with the GMT, while integrated light studies can probe the dynamics and abundances in globular cluster systems associated with large galaxies and high stellar densities in the Virgo and Coma Clusters.
Teamwork
We are a team of 3 undergraduate mechanical students who share a passion for space exploration and technology. We have worked for 2 months in the ideation, research, designing, rendering and editing for this project. Throughout these 2 months, we have acquired wide knowledge and practise multiple features of SolidWorks, Visualize and Composer. We have also gained some expertise in the field of video editing, animation, and raw designing skill.
Innovation
The highlight of the entire project is the Adaptive optics system.
Quality and Complexity
The final GMT assembly with all the actuators contains about 4500 components in total and 518 unique components. The assembly contains from few tens of meter big to only a few millimetres in lengths. We used a top-down assembly-based format. To reduce/eliminate interdependencies between different mechanical structures we started by making mathematical calculations about sizes and fit keeping in mind the manufacturing limitations of the real world. We used various SolidWorks features like weldments for support structures like the trusses, surfacing for electronic components, Sheet metals for large covering like the M1 mirror cell, the M1 hub, M2 cover sheet and C -rings, Motion study was used to make the walk-though and the entire animations. Internal ridges were provided to all large structures for support and weight reduction.
The C-rings along with the azimuth track and azimuth structure provide the necessary 360-degree field of view to the telescope. All the assemblies and components above the Azimuth structure are designed with the motion of the telescope in mind, supports are provided as see fit.
The all the various load spreaders, load-bearing assembly, hardpoints, actuators in the AO system and the axial and lateral actuators have been designing separately.
The main truss is best described as a braced structural hexapod, which stiffly defines all six degrees of freedom for the top end assembly. The braced hexapod truss outperforms other designs due to its low wind area, excellent modal performance, minimal light blockage, reduced diffraction, and low thermal mass.
Sustainability
The ground-based project reduces the need for space program which requires burning immense amounts of rocket fuel and additional missions in the future for servicing.
Problem Statement and Solution
Ground-based space exploration is limited due to the distortion of light entering our atmosphere from outer space by wind, air particles(pollutants), varying air density, and refraction. One solution is to put the entire telescope in space at a stable orbit which is a tedious and expensive task. Added to those is the problem of data transferring, serviceability and maintenance of all electronics at near 0 Kelvin.
A huge advantage of ground-based telescopes is their sheer size which allows for a large amount of light to be concentrated giving sharper and bigger images. In order to achieve great optical clarity within the atmosphere, physicist and engineers have come up with a technique called adaptive optics(AO). The goal is to bring out of phase refracted light waves from space and synchronize them by bending the reflecting surface like a mirror or sheet in real-time to achieve images that are just as good as those taken from space. This is carried out by the M2 AO system which acts as a second reflecting mirror. This helps concentrate all the light which reduces the number of actuators required in the subsystem.
@VU
Edu POTY 2021-Project
