The former Pan Am Clipper Lindbergh 747SP is being converted into a giant flying telescope platform in Palmdale, CA, and Waco, TX. It is carrying a 2.5 meter diameter, 20-ton Nasmyth reflector telescope that will be capable of imaging primarily in the infrared portion of the electromagnetic spectrum, as well as in the visible portion, for secondary tasks. The aircraft will fly 8 ~ 10 hour missions an average of three times a week through about the year 2030 (including down-time for maintenance/upgrades, relocation, etc.). The telescope has been installed and will perform observations through a 16 foot high, by 10 foot wide, opening in the upper left fuselage, just forward of the horizontal and vertical stabilizers. The aircraft has completed closed-door test flights with very favorable results, and will be undergoing eight months of computer, communications, and telescope instrument equipment installation and minor airframe modifications in Palmdale, CA, at the former Rockwell International / North American Aircraft B-1B Production Plant 40, adjacent to U.S. Air Force Plant 42, and its two 12,000-foot runways. In the Fall of 2008, SOFIA will begin a series of about 12 open-door flight tests to ensure that the aircraft can fly safely with the doors open various amounts, over a range of airspeeds and altitudes from about 38,000 to 45,000 feet MSL. By the Spring of 2009, SOFIA will begin limited "early science" missions while additional flight and systems tests are completed, and will begin full scientific missions in 2010. Instrument development will continue through at least 2014, when at least 20 different instrument packages will be available, with at least six installed aboard the aircraft on any given flight (instruments will be able to be installed and removed in a few hours between flights, as needed). The telescope is mounted in an oil-filled spherical bearing that allows it to roll from 15 to 75 degrees above the horizon, and three degrees fore-and-aft from the aircraft centerline, so that it is effectively decoupled from aircraft movements in calm to mildly-turbulent air. It will be able to remain bore-sighted on an astronomical target with an angle the size of a dime at a distance of over ten miles.
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3,500+ tourii line up for a look inside SOFIA - IMG_0265
The Kuiper Airborne Observatory, the predecessor to SOFIA, a modified former USAF C-141 Starlifter that flew from 1975 until 1996, carrying a 0.95 meter diameter reflector telescope for infrared and visible spectrum research - IMG_0277
SOFIA is a joint international effort between NASA and the Deutschen Zentrums für Luft-und Raumfahrt (DLR - the German Aerospace Research Center, an agency much smaller than NASA that coordinates efforts between aerospace contractors) - IMG_0284
The SOFIA aircraft was re-christened the Clipper Lindbergh, by the grandson of Charles Lindbergh, with its original moniker as one of Pan Am's 747SP Clippers that flew routes across the Pacific Ocean - IMG_0285
The NASA, DLR, and Clipper Lindbergh logos on the port (left) forward area of the fuselage, just forward of the front door - IMG_0290
The SOFIA telescope sensor instrument mounting platform - up to six instruments can be mounted at one time, selected from about 20 instruments that are being built, and can be swapped in/out in a few hours between mission flights - IMG_0297
Close-up of the telescope damping system components, made from German heavy-duty pneumatic truck suspension shock absorbers - these assist in isolating the telescope assembly from the aircraft so that the telescope assembly can remain bore-sighted on astronomical targets within an area the size of a dime, viewed from over 10 miles away - IMG_0298
Close-up of the telescope control circuitry wiring where it penetrates the aft pressure bulkhead into the telescope cavity, which is always at ambient atmospheric pressure corresponding to the aircraft's altitude - IMG_0299
Another close-up of the telescope control circuitry that ensures the telescope assembly is isolated from aircraft movements, up to +/- 3 degrees in yaw and pitch, sufficient to correct for mild turbulence at cruise altitudes between 38,000 and 45,000 feet above Mean Sea Level (MSL) - IMG_0300
The telescope assembly control system software user interface, running on a laptop computer here until the full system is installed in the aircraft - this translates operator inputs for aiming the telescope, and allows the control system to be monitored as it maintains telescope bore-sighting on an astronomical target - IMG_0304
View from the upper deck down into the aft portion of the operations and control area on the main deck (this would normally not be possible in a stock 747SP!) - IMG_0306
The Testing Universal Rack Device (T.U.R.D.) - no kidding, zoom in to see the acronym label in the upper right corner of the orange rack - this is one, of two, racks, that hold the in-flight testing equipment used to monitor and record aerodynamic control inputs and corresponding aircraft responses and performance - IMG_0307
View of the port (left) T.U.R.D. rack with an instrumentation server and hard drive, but, with the control laptop computer removed, which is mounted in the rack slides above the server - IMG_0308
FAA Airworthiness Certificate (don't leave the tarmac without it!) that took over 10 years to obtain, due to the extreme modifications made to the airframe - cutting a 10-foot wide by 16-foot high hole in an aircraft, among many other not-quite-so-extreme modifications, will make that more difficult than for the standard model! - IMG_0309
The SOFIA aircraft cockpit - pretty much your standard, run-of-the-mill, 747SP instrument panel, flight controls, and sheepskin-covered pilots' and flight engineers' seats (747s are pretty much the only passenger airline aircraft that still have flight engineers' consoles, as newer aircraft have much more computer automation of the engine control systems)