Submillimeter Wave Astronomy Satellite

Submillimeter Wave Astronomy Satellite ( SWAS ) is a space telescope that wins spectra of interstellar matter in the submillimeter range. The aim of SWAS is the study of the chemical composition and the state of interstellar gas clouds in star-forming regions of the Milky Way.

Construction

SWAS has a relatively small telescope with an elliptical primary mirror of 71 × 55cm size. Through observation of molecules such as water and molecular oxygen were still able results are obtained which can not be achieved with large ground-based radio telescopes because they are hampered by the Earth's atmosphere. By design, SWAS observed exclusively following spectral lines:

• Water ( H2O) at 556 936 GHz
• Molecular oxygen (O2) at 487249 GHz
• Neutral carbon ( CI) at 492 161 GHz
• The isotope carbon monoxide ( 13CO ) at 550 927 GHz and
• The water isotope ( H218O ) at 548 676 GHz.

The spatial resolution is about 4 arc minutes. SWAS is a Small Explorer project of NASA in collaboration with the American Research Institute and the University of Cologne.

Start

The launch took place with an airborne Pegasus XL rocket. The carrier aircraft type L -1011 lifted on 5 December 1998 at 23:58 UTC from Vandenberg Air Force Base in California and unlatched the rocket an hour later over the Pacific Ocean in the Point Arguello Western Air drop zone. According to local time was December 5, according to UTC already December 6th. An attempt to start two days earlier had been canceled due to software problems in the discharge area.

Deep Impact measurement campaign

To protect SWAS was shut down on 21 July 2004. The satellite was reactivated on 5 June 2005 to observe the comet Tempel 1, on the July 4, struck a part of the Deep Impact spacecraft. The observations were continued until 1 September 2005. Contrary to expectations, the released matter contained hardly any water vapor.