Last week I was fortunate enough to be able to visit and tour the Green Bank Telescope facility of the NRAO in Green Bank, West Virginia. The facility and the science carried out therein are amazing, and I highly encourage other engineers to put it on their 'to-visit' list. Here's my favorite of the dozen photos I took of the GBT:
As Radio Frequency Interference (RFI) is the bane of radio astronomy, the Green Bank Telescope is located in the center of the National Radio Quiet Zone (NRQZ) - a pretty remote location. Getting there entails a flight (usually to Pittsburgh, Washington Dulles, or Charlottesville, VA) and a 3-5 hr drive. I found a decent flight to Charlottesville on US Air, and really enjoyed the 3 hr drive through the mountains to Green Bank.
This path takes you right through the George Washington National Forest (and Shenandoah Valley) and the Monongahela National Forest. Here are a few photos from the drive:
I checked out Roadfood.com to see if there were any notable greasy spoons on my path. It called out "Wright's Dairy Rite" as a 'Top Pick" in Staunton, VA with the following description:
Three years before Ray Kroc began franchising McDonald’s, Wright’s Dairy Rite of Staunton, Virginia, started serving Superburgers. Two beef patties with cheese and lettuce, topped with special sauce and layered in a triple-decker bun, this monumental hamburger is still served as it was in 1952 – by car hops at the window of your vehicle in a car slip at the side of the restaurant.
I stopped there to check out a classic 50's burger stand and sample their Big Mac predecessor. While the setting is pretty neat, the burger didn't live up to the hype. Fortunately the sweet potato fries were good enough to carry me over.
As you might imagine, there aren't very many lodging options near Green Bank. Most visiting scientists and engineers stay in the houses and dorms on the Green Bank Telescope (GBT) grounds. Beyond that, there are a handful of Bed & Breakfast options in the area. I stayed at the Chestnut Ridge Country Inn, which was excellent. Owners Paula and Larry provided a comfortable stay and delicious home made breakfasts (quiche, french toast, pancakes, biscuits and gravy...).
Get to the GBT
We had a pretty busy week, but we were able to take an afternoon to tour the telescope. It was awesome, our guide had worked on the GBT since before it was constructed. He talked at length about different design decisions and tradeoffs in the construction and the control system (his area). Unfortunately, electronics (including digital cameras) are not allowed near the telescopes, so I only have 1 photo from a friend kind enough to share their disposable film camera!
Note: I don't think the public tour provides this level of access. As we were visiting the GBT as part of a technical workshop, we were granted insider access.
For a photo tour of the GBT, see this Wired article from 2009: Wired GBT Tour Photos. Here is a reference image with my tour stops marked:
Our tour started as 11 of us crammed into the tiny construction-style elevator at the base of the telescope (point A). This carried us up to the main level of the rotating portion of the telescope (point B).
At this point the transparent flooring of the metal grating reminded me of my intermittent acrophobia. Fortunately my colleague John goaded me enough to continue. We then traversed the walkway to the second elevator (point C) which travels diagonally to the receiver platform (point D). Here is my only photo from the tour (thanks Dave!):
At about 500 ft, the view from the platform is incredible. It provides an interesting perspective on the rest of the GBT site (including multiple telescopes) as well as the surrounding West Virginia countryside. The receiver structure was also very interesting - it's actually hinged to allow retracting the receiver head for cleaning and maintenance.
Next we took the stairs down one level (yikes!) to the receiver instrumentation room. With solid steel walls/floors, apparently the welders thought there was no way the structure could support the weight of this room (a comforting thought on the tour). Then back to the elevator to go down to the dish level (point E).
At this point it was raining, but this did not discourage our guide from walking out on to the dish to go over how the actuator system was able to perfectly control the dish surface (his area of expertise). Apparently they initially planned to install a laser system to actively monitor the shape of the dish, but found this unnecessary due to the accuracy of the control system.
Finally, we took the stairs back to the main level and toured the actuator control room - a mass of wires and circuit boards required to control the 2000+ panels. Our guide also gave us an overview of the custom tools he designed that allowed the precise installation of the panels and actuators of the dish.
At this point, the nearby lightning was enough to overcome our guide's excitement, and we took the small construction elevator back down to ground level. It was an awesome tour! Here are the rest of my photos from around the GBT site and the nearby historic Cass railroad (note the classic diesel vehicles - as they don't have sparkplugs, only diesel engines are allowed in the red zone):