Ever watch shows about air disasters? It seems you shouldn’t open hatches while the plane is at 45,000 feet! Video from events like that are similar…everything in the cabin, including people, swirling around. Things, including people, getting sucked out of the opening. That’s a recipe for disaster.
And, apparently, a recipe for an observatory. That’s right, an airplane with a gaping hole in its side and a telescope looking out. On the face of it, this sounds unlikely. Yet, with design and engineering advances, it became a reality way back in 1965! How embarrassing, there have been aircraft observatories for over 50 years, and I was mostly ignorant of it.
OK, I got to the party late – while SOFIA was doing astronomy and had been unaware of SOFIA’s predecessors: Galileo, Learjet, and Kuiper. So, a little airborne observatory history is due.
The concept of high-altitude astronomy is solid – get above 95% of the atmosphere for a much clearer view, especially infrared light – which is absorbed by atmospheric water vapor. Starting in 1957 Helium balloons took instruments up to the edge of space but were not maneuverable and had little in the way of corrective measures if problems with instruments arose. An observatory within a jet aircraft was something NASA contemplated in the early 1960’s. Planes can go pretty much anywhere, up to 50,000 feet altitude, with scientists and engineers on board. Once solutions to mitigate challenges such as airstream turbulence, vibration, air pressure differentials, and temperature variations were developed NASA just needed a plane.
Meanwhile, the United States and Soviet Union were racing to see who would be first to land a human on the Moon! Maybe that’s why little media attention was given to NASA’s first airborne astronomical observatory…Galileo.
The Galileo Airborne Observatory was produced from a General Dynamics Convair-990 aircraft – similar to and in competition with Boeing’s then current 707. It was fitted with 13 ports on its upper left fuselage and used primarily for viewing/recording total solar eclipses. The first version, Galileo I was destroyed on April 13, 1973, ending on top of a Navy P-3 Orion aircraft as both approached landing on the same runway. Only one person survived, from the Naval craft. Its replacement, Galileo II was destroyed in 1985 after metal from a wheel failure pierced the wing fuel tank, causing a fire during takeoff. Fortunately, all survived.
The next observatory was a Learjet 23 fitted with a 12” infrared telescope, commissioned in 1968 and used into the 1970s.
Then came Kuiper – a converted C-141, fitted with a 36” Cassegrain telescope. It provided a platform for research from 1975 to 1995, discovering rings around Uranus, Pluto’s tenuous atmosphere, a ring of star formation around the Milky Way’s center, complex organic molecules in space, water in comets and in Jupiter’s atmosphere.
And SOFIA? Next week.
What’s in the Sky?
Daylight Saving! Begins 03/12 – 2 am.
Follow the waning Moon from March 13-16 an hour before sunrise as it moves through Scorpius and Sagittarius in the south.