Project Telescope

Overview

In the summer break after my 10th boards, I took up the ambitious project of making a fully automated, goto-tracking telescope from scratch. In my first telescope I had used ready-made optics and an old telescope mount that I got from my school. After using it for a few months, I realised that it was very hard to locate distant and faint celestial objects from within city limits. Also it was difficult to keep the telescope aimed at a particular object when using high magnification. This was because of the Earth's rotation. At high magnification, the Earth's seemingly slow rotation(1/1440 rpm!) makes stars and planets zoom right across the field of view in a matter of a few seconds. So, I decided to make a tracking, goto telescope.

There were several stages to this project.

Firstly, making the optics. I wanted to learn how to make a telescopic mirror and so decided to use the mirror that I would make. To do so, I went to a 6-day training camp to IUCAA, Pune, India. There I was instructed by Mr. Tushar Purohit. He taught me how to grind a mirror blank to get a perfectly smooth spherical shape and showed me how to polish a mirror to prepare it for aluminizing. 

Secondly, the telescope mount. I wanted to make a sturdy mount that was easy to operate and so went for a dobsonian design. This is a form of an altitude-azimuth mount made popular by John Dobson (hence the name dobsonian). I made several modifications to the original design to incorporate the gears and motors required for automated movement.

Third step was the automation. Here ‘Automation’ means that I should be able use the telescope hands-free, with very high precision. I can enter coordinates of a celestial body and the telescope will automatically point to it. The idea was to have a system that is easy to setup and use and also one that would not prevent manual operation. So I used two stepper motors for the two axes which are controlled using an Arduino microprocessor. The Arduino microprocessor is a versatile programmable board with several applications. It can communicate with mobile devices(smart phones, tablets, laptops etc.) as a serial monitor. So I have used a smart phone to receive the coordinates. Once it is correctly positioned, the telescope tracks the movement of the stars, so that they remain in the field of view.

As this is an elaborate project, I will explain each part in detail in separate posts.

Stay tuned for the latest posts.