Infrared Space Observatory
|Infrared Space Observatory|
|Begin:||November 17, 1995, 1:20 UTC|
|Starting place:||CSG , ELA-2|
|Launcher:||Ariane 44P V-80|
|Status:||out of service since May 16, 1998|
|Rotation time :||approx. 24 h|
|Orbit inclination :||5.2 °|
|Apogee height :||70578 km|
|Perigee height :||1038 km|
The Infrared Space Observatory ( ISO ) was a space telescope for the infrared range from 2.4–240 µm. As a space observatory above the earth's atmosphere , ISO was able to investigate celestial objects between 1995 and 1998 even at wavelengths that cannot be observed from the earth due to the absorption of the atmosphere. ISO moved in a highly eccentric earth orbit with an orbital time of 24 hours.
ISO was developed by the European space agency ESA with minor contributions from NASA and the Japanese space research institute ISAS (part of JAXA since 2003 ). The ISO telescope had a main mirror of 60 cm in diameter and was cooled with liquid helium to suppress its own heat radiation .
The four observation instruments were contributed by consortia from different European countries:
- the infrared camera ISOCAM, which covered the wavelength range 2.5–17 µm with two detectors of 32 by 32 pixels each
- the photo polarimeter ISOPHOT for the wavelength range 2.5–240 µm
- the shortwave spectrometer SWS for the wavelength range 2.4–45 µm
- the long wave spectrometer LWS for the wavelength range 45–197 µm.
ISO was launched on November 17, 1995 at 1:20 UTC with Arianespace Flight V 80 on board an Ariane 44P from the Center Spatial Guyanais into an orbit between 500 and 71,850 km altitude with an inclination of 5.25 ° at the equator . Before starting the observations, ISO then changed its orbit to an orbit between 1,038 and 70,578 km altitude with 5.2 ° equatorial inclination and a 24-hour orbit.
The nominal operation of the satellite lasted until the coolant was exhausted on April 8, 1998. After that, observations could be continued until May 10, 1998 with only passive cooling with some of the detectors. ISO carried out a total of over 26,000 observations on behalf of over 500 teams of astronomers. Just before ISO was shut down on May 16, 1998, which was swathheight reduced to the re-entry to speed.
ISO was able to build on the results of the IRAS mission, in particular its sky survey . Despite the same telescope size as IRAS, ISO was much more efficient for examining individual objects thanks to the further developed instruments and pronounced spectroscopic capabilities. Key discoveries that ISO contributed to infrared astronomy include:
- Discovery of water in a wide variety of objects, from planets in our solar system to distant galaxies
- Molecules , ice compounds and chemical processes in the interstellar medium and in the vicinity of stars
- Determination of the energy sources of infrared galaxies
- Discovery of infrared galaxies at a redshift of 1, which were much more abundant at this earlier stage of the universe than they are today.
|Takeoff mass||2498 kg|
|Cryostat||2250 l superfluid helium -4, temp. 1.8 K .|
|Diameter or width||2.3 m|
|Mirror diameter||60 cm|
|Duration of use||approx. 2 years and 7 months|
|train||Earth orbit 1038 - 70,578 km high|
|Start date||November 19, 1995|
|Mission end||May 16, 1998|
- The Infrared Space Observatory website (English)
- ISO at ESA (English)
- ISO on the Science and technology website of ESA (English)
- ISO in the NSSDCA Master Catalog (English)
- ESA: Looking Back at ISO Operations (PDF, English; 797 kB)