The Stratoscopes were two

balloon A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or li ...

-borne astronomical

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

s which flew from the 1950s to the 1970s and observed in the

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultrav ...

and

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from aroun ...

regions of the spectrum. Both were controlled remotely from the ground. Stratoscope I possessed a 12-inch (30.48 cm) mirror and was first flown in 1957. It was conceived by

Martin Schwarzschild Martin Schwarzschild (May 31, 1912 – April 10, 1997) was a German-American astrophysicist. Biography Schwarzschild was born in Potsdam into a distinguished German Jewish academic family. His father was the physicist Karl Schwarzschild and ...

and built by the

Perkin Elmer Corporation PerkinElmer, Inc., previously styled Perkin-Elmer, is an American global corporation focused in the business areas of diagnostics, life science research, food, environmental and industrial testing. Its capabilities include detection, imaging, in ...

with funding provided by the

Office of Naval Research The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to pla ...

. A small secondary mirror focussed the image from the primary into a 35 mm movie camera, which captured the images on film. Schwarzschild used the telescope to study the turbulence and

granulation Granulation is the process of forming grains or granules from a powdery or solid substance, producing a granular material. It is applied in several technological processes in the chemical and pharmaceutical industries. Typically, granulation i ...

in the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared rad ...

photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

. Stratoscope II, a 36-inch (91.4 cm) reflecting telescope, flew from 1963 to 1971. This larger project proved to be beyond the ability of the university-led research team funded by ONR and, later, the

National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National ...

, so was managed by NASA as a beginning of its scientific ballooning program led by Nancy Grace Roman. The gondola it was mounted on weighed 3.5 tons. It studied planetary

atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. ...

s, the atmospheres of

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...

stars, and

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

. On early flights of Stratoscope II, photographic film was used, but this was soon replaced by television detectors.

References

External links

*Smithsonian National Air and Space Museum (NASM)
Mirror, Telescope, Stratoscope I
*Smithsonian National Air and Space Museum (NASM)
Perkin Stratoscope II Telescope model
* ttps://stratocat.com.ar/fichas-e/1957/NBR-19570925a.htm Detailed account of the third flight of Stratoscope from New Brighton (MN) 9/25/57br>Detailed account of the third flight of Stratoscope from Huron (SD) 10/17/57
Balloon-borne telescopes Infrared telescopes {{observatory-stub