DFM Engineering installs a 1.3 Meter Telescope
for NASA-MCAT The NASA Meter Class Autonomous Telescope on Ascension Island
In June 2015 DFM finished the installation of another double horseshoe 1.3 meter telescope, this one for NASA on Ascension Island.
The Meter Class Autonomous Telescope (MCAT) will provide mid Atlantic coverage for NASA's ability to track orbital debris.
With an ever increasing load of orbiting objects to keep track of, NASA was looking for non-traditional telescope sites out in the oceans near the equator to fill gaps in their debris tracking system. (see below: "The Optical Telescope Advantage")
In 2008 NASA approached DFM to optimize our new double horseshoe equatorial mount design to track satellites.
Tracking satellites requires much higher than normal slew and tracking speeds and very high fidelity tracking in both axes at non-sidereal rates.
The unique DFM double horseshoe mount configuration is ideally suited to this application.
The double horseshoe mount provides access to all but a small portion of the sky while minimizing the field rotation problems associated with altitude/altitude (Alt-Alt) mounts, and eliminating the typical zenith "dead zone" of altitude/azimuth (Alt-Az) mounts.
When the Atlantic Ocean site on Ascension Island became available, DFM was asked to modify the mount for the different latitude and hemisphere while the new site was being prepared. DFM was able to accommodate this unusual request with minimal complications.
The Ascension Island site is very different from most observatory sites in that it is less than ½ mile from the open ocean, and only 300 feet above sea level.
Furthermore, the continuous trade winds carry volcanic pumice and high relative humidity.
The harsh environment prompted the development of a dry air purge system for the optics and critical drive components.
The DFM installation team consisted of Mark Kelley, Ian Huss, and Richard Neel.
With combined experience of more than 80 years in the field this was our "A" team.
The new MCAT observatory building is exceptional. The attention to detail displayed by NASA's on-site lead Tom Glesne was greatly appreciated.
While the island itself is isolated enough to make technical work difficult, the local support, construction, and crane personnel were all excellent.
It was very gratifying to confirm Tom's building alignment to within 2 arc minutes of true north.
The MCAT project scientist, Dr. Susan Lederer, joined the DFM team for the final 4 weeks of the installation to acquire as much hands-on experience as possible with installing and tuning the optics and mount.
We believe her new insight and experience will play a large part in the future success of the project given the remoteness and harsh environment of the site.
The Optical Telescope Advantage:
Optical telescopes and radar are tools used to obtain a more complete picture of the orbital debris environment.
Each of these tools sees a somewhat different debris environment. Some debris objects will reflect radar well, but sunlight poorly; while some will reflect sunlight well, but radar poorly.
An advantage to using an optical telescope rather than radar is that telescopes can more easily detect debris objects in higher altitudes, such as geosynchronous (GEO) orbits.
Excerpt from NASA Orbital Debris: Quarterly News, Vol. 19, Issue 3, July 2015
The fast tracking telescope follows debris targets in any direction across the sky. It eliminates both the blind-spot at the zenith that is so typical of astronomical telescopes as well as the need to flip the telescope when it crosses the meridian. It will enable NASA to deepen the understanding of the debris environment around Earth.
MCAT is a unique telescope, one
of only two like it in the world - a [20,000 lb. fast-tracking] double horseshoe mount telescope designed by DFM Engineering that allows NASA to track not just Geosynchronous Orbit (GEO) debris, but fast-moving low Earth orbit (LEO) debris.