The Infrared Astronomical Satellite (Dutch: Infrarood Astronomische Satelliet) (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths.[6] Launched on 25 January 1983,[2] its mission lasted ten months.[7] The telescope was a joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC). Over 250,000 infrared sources were observed at 12, 25, 60, and 100 micrometer wavelengths.[7]
![]() IRAS montage with all-sky images | |||||||||
Mission type | Infrared space observatory | ||||||||
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Operator |
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COSPAR ID | 1983-004A ![]() | ||||||||
SATCAT no. | 13777 | ||||||||
Website | irsa | ||||||||
Mission duration | Final: 9 months, 26 days | ||||||||
Spacecraft properties | |||||||||
Manufacturer |
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Launch mass | 1,083 kg (2,388 lb) | ||||||||
Dimensions | 3.60 × 3.24 × 2.05 m (11.8 × 10.6 × 6.7 ft)[1] | ||||||||
Start of mission | |||||||||
Launch date | 25 January 1983, 21:17 (1983-01-25UTC21:17) UTC[2] | ||||||||
Rocket | Delta 3910 | ||||||||
Launch site | Vandenberg SLC-2W | ||||||||
Entered service | 9 February 1983[3] | ||||||||
End of mission | |||||||||
Disposal | Decommissioned | ||||||||
Deactivated | 21 November 1983 (1983-11-22)[2] | ||||||||
Orbital parameters | |||||||||
Reference system | Geocentric | ||||||||
Regime | Sun-synchronous | ||||||||
Semi-major axis | 7,270.69 km (4,517.80 mi) | ||||||||
Eccentricity | 0.001857 | ||||||||
Perigee altitude | 879.05 km (546.22 mi) | ||||||||
Apogee altitude | 906.05 km (562.99 mi) | ||||||||
Inclination | 98.95 deg | ||||||||
Period | 102.8 min | ||||||||
Mean motion | 14.00 rev/day | ||||||||
Epoch | 19 November 2016, 04:15:30 UTC[4] | ||||||||
Main telescope | |||||||||
Type | Ritchey–Chrétien[5] | ||||||||
Diameter | 57 cm (22 in)[5] | ||||||||
Focal length | 545 cm (215 in), f/9.56[5] | ||||||||
Collecting area | 2,019 cm2 (312.9 sq in)[5] | ||||||||
Wavelengths | Long-wavelength to far-infrared | ||||||||
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Support for the processing and analysis of data from IRAS was contributed from the Infrared Processing and Analysis Center at the California Institute of Technology. Currently, the Infrared Science Archive at IPAC holds the IRAS archive.[8][9]
The success of IRAS led to interest in the 1985 Infrared Telescope (IRT) mission on the Space Shuttle, and the planned Shuttle Infrared Telescope Facility which eventually transformed into the Space Infrared Telescope Facility, SIRTF, which in turn was developed into the Spitzer Space Telescope, launched in 2003.[10] The success of early infrared space astronomy led to further missions, such as the Infrared Space Observatory (1990s) and the Hubble Space Telescope's NICMOS instrument.
IRAS was the first observatory to perform an all-sky survey at infrared wavelengths. It mapped 96% of the sky four times, at 12, 25, 60 and 100 micrometers, with resolutions ranging from 30 arcseconds at 12 micrometers to 2 arcminutes at 100 micrometers. It discovered about 350,000 sources, many of which are still awaiting identification. About 75,000 of those are believed to be starburst galaxies, still enduring their star-formation stage. Many other sources are normal stars with disks of dust around them, possibly the early stage of planetary system formation. New discoveries included a dust disk around Vega and the first images of the Milky Way's core.
IRAS's life, like that of most infrared satellites that followed, was limited by its cooling system. To effectively work in the infrared domain, a telescope must be cooled to cryogenic temperatures. In IRAS's case, 73 kilograms (161 lb) of superfluid helium kept the telescope at a temperature of 2 K (−271 °C; −456 °F), keeping the satellite cool by evaporation. IRAS was the first use of superfluids in space.[11] The on-board supply of liquid helium was depleted after 10 months on 21 November 1983, causing the telescope temperature to rise, preventing further observations. The spacecraft continues to orbit the Earth.
IRAS was designed to catalog fixed sources, so it scanned the same region of sky several times. Jack Meadows led a team at Leicester University, including John K. Davies and Simon F. Green, which searched the rejected sources for moving objects. This led to the discovery of three asteroids, including 3200 Phaethon (an Apollo asteroid and the parent body of the Geminid meteor shower), six comets, and a huge dust trail associated with comet 10P/Tempel. The comets included 126P/IRAS, 161P/Hartley–IRAS, and comet IRAS–Araki–Alcock (C/1983 H1), which made a close approach to the Earth in 1983. Out of the six comets IRAS found, four were long period and two were short period comets.[7]
Overall, over a quarter million discrete targets were observed during its operations, both inside and beyond the Solar System.[7] In addition, new objects were discovered including asteroids and comets.[7] The observatory made headlines briefly with the announcement on 10 December 1983 of the discovery of an "unknown object" at first described as "possibly as large as the giant planet Jupiter and possibly so close to Earth that it would be part of this solar system".[12][13] Further analysis revealed that, of several unidentified objects, nine were distant galaxies and the tenth was "intergalactic cirrus".[14] None were found to be Solar System bodies.[14][15]
During its mission, IRAS (and later the Spitzer Space Telescope) detected odd infrared signatures around several stars. This led to the systems being targeted by the Hubble Space Telescope's NICMOS instrument between 1999 and 2006, but nothing was detected. In 2014, using new image processing techniques on the Hubble data, researchers discovered planetary disks around these stars.[16]
IRAS discovered six comets, out of total of 22 discoveries and recoveries of all comets that year.[7][17] This was a lot for this period, before the launch of SOHO in 1995, which would allow the discovery of many more comets in the next decade (it would detect 1000 comets in ten years).[18]
3200 Phaethon | 11 October 1983 | list |
3728 IRAS | 23 August 1983 | list |
(10714) 1983 QG | 31 August 1983 | list |
(100004) 1983 VA | 1 November 1983 | list |
Several infrared space telescopes have continued and greatly expanded the study of the infrared Universe, such as the Infrared Space Observatory launched in 1995, the Spitzer Space Telescope launched in 2003, and the Akari Space Telescope launched in 2006.
A next generation of infrared space telescopes began when NASA's Wide-field Infrared Survey Explorer launched on 14 December 2009 aboard a Delta II rocket from Vandenberg Air Force Base. Known as WISE, the telescope provided results hundreds of times more sensitive than IRAS at the shorter wavelengths; it also had an extended mission dubbed NEOWISE beginning in October 2010 after its coolant supply ran out.
A planned mission is NASA's Near-Earth Object Surveillance Mission (NEOSM), which is a successor to the NEOWISE mission.
On 29 January 2020, 23:39:35 UTC,[20] IRAS was expected to pass as closely as 12 meters [21] from the U.S. Air Force's Gravity Gradient Stabilization Experiment (GGSE-4) of 1967, another un-deorbited satellite left aloft; the 14.7-kilometer per second pass[22] had an estimated risk of collision of 5%. Further complications arose from the fact that GGSE-4 was outfitted with an 18 meter long stabilization boom that was in an unknown orientation and may have struck the satellite even if the spacecraft's main body did not.[23] Initial observations from amateur astronomers seemed to indicate that both satellites had survived the pass, with the California-based debris tracking organization LeoLabs later confirming that they had detected no new tracked debris following the incident.[24][25]
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← 1982 · Orbital launches in 1983 · 1984 → | |
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Kosmos 1428 | Kosmos 1429 · Kosmos 1430 · Kosmos 1431 · Kosmos 1432 · Kosmos 1433 · Kosmos 1434 · Kosmos 1435 · Kosmos 1436 | Kosmos 1437 | Unnamed | IRAS · PIX-2 | Kosmos 1438 | Sakura 2a | Kosmos 1439 | OPS 0252 · OPS 0252 SSU-1 · OPS 0252 SSU-2 · OPS 0252 SSU-3 · LIPS-2 | Kosmos 1440 | Kosmos 1441 | Tenma | Kosmos 1442 | Kosmos 1443 | Kosmos 1444 | Molniya-3 No.34 | Ekran No.18L | Kosmos 1445 | Kosmos 1446 | Molniya-1-56 | Astron | Kosmos 1447 | NOAA-8 | Kosmos 1448 | Kosmos 1449 | Molniya-1 No.68 | STS-6 (TDRS-1) | Kosmos 1450 | Gran' No.23L | Kosmos 1451 | Satcom 1R | Kosmos 1452 | OPS 2925 | Rohini RS-D2 | Kosmos 1453 | Soyuz T-8 | Kosmos 1454 | Kosmos 1455 | Kosmos 1456 | Kosmos 1457 | Kosmos 1458 | GOES 6 | Kosmos 1459 | Kosmos 1460 | Kosmos 1461 | Kosmos 1462 | Kosmos 1463 | Intelsat V F-6 | Kosmos 1464 | Kosmos 1465 | Kosmos 1466 | EXOSAT | Kosmos 1467 | Venera 15 | Venera 16 | Kosmos 1468 | OPS 6432 · OPS 6432 SSU-1 · OPS 6432 SSU-2 · OPS 6432 SSU-3 | Kosmos 1469 | ECS-1 · OSCAR-10 | STS-7 (Anik C2 · Palapa B1 · SPAS-01 · OSTA-2) | OPS 0721 · OPS 3899 | Kosmos 1470 | Soyuz T-9 | HILAT | Kosmos 1471 | Galaxy 1 | Gorizont No.17L | Prognoz 9 | Kosmos 1472 | Kosmos 1473 · Kosmos 1474 · Kosmos 1475 · Kosmos 1476 · Kosmos 1477 · Kosmos 1478 · Kosmos 1479 · Kosmos 1480 | Kosmos 1481 | Kosmos 1482 | OPS 7994 | Molniya-1 No.66 | Kosmos 1483 | Kosmos 1484 | Kosmos 1485 | Telstar 301 | OPS 7304 | Kosmos 1486 | Kosmos 1487 | Sakura 2b | Kosmos 1488 | Kosmos 1489 | Kosmos 1490 · Kosmos 1491 · Kosmos 1492 | Progress 17 | Fanhui Shi Weixing 6 | Kosmos 1493 | Gran' No.24L | STS-8 (INSAT-1B) | Molniya-3 No.32 | Kosmos 1494 | Kosmos 1495 | Kosmos 1496 | Satcom 2R | Kosmos 1497 | Kosmos 1498 | Kosmos 1499 | Galaxy-2 | Soyuz 7K-ST No. 16L | Kosmos 1500 | Ekran No.25L | Kosmos 1501 | Kosmos 1502 | Kosmos 1503 | Kosmos 1504 | Intelsat V F-7 | Progress 18 | Kosmos 1505 | Kosmos 1506 | Meteor-2 No.10 | Kosmos 1507 | Kosmos 1508 | Kosmos 1509 | OPS 1294 | Molniya-1 No.48 | Kosmos 1510 | STS-9 | Kosmos 1511 | Gorizont No.18L | Kosmos 1512 | Kosmos 1513 | Kosmos 1514 | Kosmos 1515 | Molniya-3 No.35 | Kosmos 1516 | Kosmos 1517 | Kosmos 1518 | Kosmos 1519 · Kosmos 1520 · Kosmos 1521 | |
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets). |
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