 The flight spare for the satellite | |
| Names | Astronomische Nederlandse Satelliet ANS |
|---|---|
| Operator | SRON /NASA[1] |
| COSPAR ID | 1974-070A |
| SATCATno. | 07427 |
| Mission duration | 20 months[1] |
| Spacecraft properties | |
| Launch mass | 129.8 kilograms (286 lb) |
| Start of mission | |
| Launch date | August 30, 1974 (1974-08-30)[1] |
| Rocket | Scout |
| Launch site | VandenbergSLC-5[2] |
| End of mission | |
| Decay date | 14 June 1977 |
| Orbital parameters | |
| Perigee altitude | 266 km[2] |
| Apogee altitude | 1176 km[2] |
| Period | 99.2 min[2] |
| Main | |
| Wavelengths | X-ray andultraviolet |
| Instruments | |
| Hard X-Ray (1.5 to 30 keV[3]) Ultraviolet (5 channels, 150 to 330 nm[4]) | |
TheAstronomical Netherlands Satellite (ANS; also known asAstronomische Nederlandse Satelliet) was aspace-basedX-ray andultraviolettelescope. It was launched intoEarth orbit on 30 August 1974 at 14:07:39 UTC in aScout rocket fromVandenberg Air Force Base, United States. The mission ran for 20 months until June 1976, and was jointly funded by theNetherlands Institute for Space Research (NIVR) andNASA.[1][2] ANS was the first Dutch satellite, and theMain Belt asteroid9996 ANS was named after it.[5] ANS reentered Earth's atmosphere on June 14, 1977.
The telescope had an initial orbit with aperiapsis of 266 kilometres (165 mi), anapoapsis of 1,176 kilometres (731 mi), withinclination 98.0° andeccentricity 0.064048, giving it a period of 99.2 minutes.[2] The orbit wasSun-synchronous, and the attitude of the spacecraft could be controlled through reaction wheels. The momentum stored in the reaction wheels throughout the orbit was regularly dumped viamagnetic coils that interacted with theEarth'smagnetic field. The satellite also had two masses that were released shortly after orbit injection, to remove most of the satellite'sangular momentum induced by the launcher. The attitude could be measured by a variety of techniques, includingsolar sensors,horizon sensors, star sensors and amagnetometer.[1]
ANS could measureX-ray photons in the energy range 2 to 30 keV, with a 60 cm2 detector, and was used to find the positions ofgalactic and extragalactic X-ray sources. It also measured theirspectra, and looked at their variations over time.[1] It discoveredX-ray bursts, and also detected X-rays fromCapella.[5]
ANS also observed in theultraviolet part of the spectrum, with a 22 cm (260 cm2)Cassegrain telescope. Thewavelengths of the observed photons were between 150 and 330 nm, with the detector split into five channels with central wavelengths of 155, 180, 220, 250 and 330 nm.[4] At these frequencies it took over 18,000 measurements of around 400 objects.[1]
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