ATLAS - Optical Tube Assembly (Asteroid Tracker)

The ATLAS (Asteroid Terrestrial-impact Last Alert System) 26" optical tube assembly is specifically designed to detect asteroids and provide warning of an impact with the Earth.  

The 0.5-m (20-inch) aperture F/2 wide field (7.5-degrees) flat-field Schmidt Camera allows light to enter through the fast shutter (upper left) and pass through a Schmidt 4th order corrector lens to the 26-inch aperture mirror (located lower right).

The optical tube assembly (OTA) of the telescope is a primary component and a critical factor in providing agility and precision of the ATLAS while maintaining superb image quality.  You can learn more about the ATLAS program at NASA's webpage.

You can see what these DFM Engineering optics are capable of in the recent ATLAS recording of Double Asteroid Redirection Test (DART)'s impact into Dimorphos, at a distance of 7 million miles (11 million kilometers) away from Earth.

CAMERA:
The camera attached to the ATLAS is a 110 megapixel resolution CCD Camera with a 94-mm by 94-mm format with a 9µm pixel size and a pixel scale of 1.86 arc seconds.

Invar spacers are used to minimize focus shift with temperature changes.

These Schmidt Cameras can be used for other science as well - anywhere a very wide field is needed.

From the primary mirror, the light is reflected through a 3-element field corrector, through 1 of 8 selectable filters, and to the focal plane.  The primary mirror of the ATLAS has a spherical surface.

The residual astigmatism and field curvature of a Schmidt Camera is corrected by the field corrector.  This field corrector also has all spherical surfaces. 

OPTICS:
The optics for the ATLAS asteroid tracker were produced at DFM Engineering in our optical shop.  The DFM Optics shop performs grinding, polishing, and testing of the mirrors to insure quality standards and delivery time.

Additionally, design and functionality of the optics in conjunction with the camera, detector, and filter changer were evaluated in the design phase.

The expertise of the optics shop is in polishing and testing 1.3-m telescope primary mirrors.  Therefore, the procedures are well established for quality, consistency and timeliness. The optics shop concentrates on fast, highly aspheric primary mirrors for wide field telescopes.

ATLAS TCSGalil™ Control System
The Schmidt Camera custom control system was created by DFM to provide convenient remote access and control of the ATLAS optical tube assembly.

The DFM electronics engineers developed the software for the computer control system (TCSGalil™) and the 20"/26" Schmidt Camera focus, shutter, and filter changer.