Airborne Observatory

It seems an airplane to observe, that is the name and the meaning. But all the aircraft seem to work under the same? Recognizance, spy or aerial surveying aircraft for mapping, they work in different scenarios and have different instruments to carry out the required task. An observatory as known is a location to observe, and widely used to look at the stars.

Having the idea, an airborne observatory is a platform to observe using an astronomical telescope. it could be an airplane, airship, or balloon. In the 1950s balloons were the main platform for observing from the stratosphere, an example, the Stratoscope I. This balloon was controlled from ground. Then, several balloons are used to perform observation.

Stratoscope. Source: US Navy.

The aircraft had started an important role when the USA military NC-135 carried out aerial observation of a solar eclipse, that was in 1965. The aircraft operated by the Atomic Energy Commission for solar eclipse observation was a flying laboratory.

AEC NC-135, used by Los Alamos National Laboratory for eclipse missions. Source: Archives of William Regan/sofia.usra.edu

A notable aircraft, the Concorde, it did not go unnoticed in this role. The prototype Concorde 001 was modified with roof-top portholes for a solar eclipse observation for a mission in 1973. The aircraft was capable to speed up to twice the speed of sound chasing the solar eclipse flying over Africa. Astronomers in France and the UK proposed this, because in theory, a supersonic transport (SST) could give them over 70 minutes to watch the eclipse ten times more observation time than statically on the ground, and it has sense. That was one advantage of having a moving fastest platform.

Concorde 001 taking off on 30th June 1973 for the eclipse flight. Source: jcgl.orpheusweb.co.uk
The QMC instrument installed in the cabin of Concorde 001.
Note the dark opening in the roof which holds the quartz window of the cabin. Source: jcgl.orpheusweb.co.uk

In 1974, the Kuiper Airborne Observatory (KAO) was carried aloft on a C-141A and performed infrared observations.

Kuiper Airborne Observatory in flight from NASA. It is visibel the lateral aperture on fuselage. Surce: NASA

The largest aircraft-borne instrument to date for astronomical observation mission is granted to SOFIA “Stratospheric Observatory for Infrared Astronomy”, a modified Boeing 747 fitted with a 2.5m diameter reflecting telescope. This aircraft has an aperture on side fuselage opened in flight and the telescope is mounted in the aft end of the fuselage behind a pressurized bulkhead. This Boeing was purchased by NASA. Then, Nasa and the German Aerospace Center (DLR) operate the aircraft for the research purposes.

SOFIA Aircraft. Source: Nasa
A German-built telescope is exposed during a flight on the SOFIA. Source: Nasa

The objectives of SOFIA are to study the composition of planetary atmospheres and surfaces. Looking at stars, their structures, composition, the physics and chemistry of the interstellar medium.

RELEASE 15-044 NASA’s SOFIA Finds Missing Link Between Supernovae and Planet Formation. Source: Nasa

So, having these aircraft in the space agency’s fleets gives the unique opportunities to observe, study, and chase the cosmic events that surround our planet. It is noticed that airborne platform and airborne observatory is one of the greatest ideas that came up when looking at stars.


Refrences:

ttps://web.archive.org/web/20050330100204/http://www.sofia.usra.edu/Edu/docs/97-Whiting_AeroHistory.pdf

http://jcgl.orpheusweb.co.uk/history/concorde/ChaseTheSun.html

https://www.vice.com/en/article/8q8qwk/the-concorde-and-the-longest-solar-eclipse

https://www.sofia.usra.edu/

Cover photo:

NASA / Jim Ross