On the occasion of the Odin launch

Sun Kwok
Department of Physics & Astronomy, The University of Calgary

   On February 20 08:48 UT, the Odin satellite was successfully launched from eastern Russia. The solar panels were deployed and communications with the ground station has been established. In the coming weeks, the scientific instruments will be turned on and their performance tested. Two Canadians, Steve Torchinsky and Kevin Volk are in Sweden to assist in the commissioning period of the satellite.

Odin is an international mission led by Sweden with Canada, France, and Finland as partners. Odin has the capability to observe a large number of molecular species, and is expected to have major impact in our study of interstellar chemistry and physics.

Canadian involvement in the project began in 1991 when Sun Kwok began informal discussions with Swedish astronomers on the submillimetre-wave astronomy mission being promoted in Sweden at the time. The possibility of Canada joining this mission was discussed in the Joint Committee on Space Astronomy (JSSA), resulting in the invitations of a Swedish delegation by the CSA to Ottawa in January 1992.

Following the meeting, Sun Kwok was commissioned by the CSA to write a report on the possible Canadian participation in the Odin project. The report was endorsed by the JSSA and submitted to the CSA in May 1992.

The following two years were taken up by negotiation between the CSA and Sweden on the exact contribution by Canada to the mission. The first priority of the Canadian astronomical community was to supply the digital spectrometer, an effort championed by Peter Dewdney. Unfortunately this was not successful. The eventual Canadian contributions include an optical-infrared imaging spectrometer (OSIRIS, for use in the aeronomy part of the mission), manpower for the radiometer and software developments, testing of the attitude control system, the cryo-cooler, and a share of the launch costs. The agreement between the CSA and the Swedish National Space Board was signed in 1994.

In proportion to our share of financial contributions to the mission, Canada was allocated a quota of six Odin scientists by the Odin International Science Team. A panel consisting of Jim Hesser (D.A.O.), Denis Leahy (U. of Calgary), and Dick Bond (CITA) was set up by the Canadian Space Agency and the Canadian Astronomical Society to make this selection. Proposals were solicited from the Canadian community and as the result of this process, the Canadian Odin Astronomy Working Group (COAWG) was created, with Lorne Avery (H.I.A.), Peter Dewdney (H.I.A.), Mike Fich (U. of Waterloo), Sun Kwok (U. of Calgary), George Mitchell (St. Mary's U.), and Christine Wilson (McMaster U.) as members.

On the side of the CSA, David Kendall is the CSA project scientist for Odin and Victor Wehrle serves as the CSA project manager. Sun Kwok and Ted Llewellyn (University of Saskatchewan) were named as astronomy and aeronomy PIs of the mission, respectively. The astronomy PIs for our partner countries are Roy Booth (Sweden), Pierre Encrenaz (France) and Kaleva Mattila (Finland). Following the award of a contract by the CSA to the University of Calgary, Steve Torchinsky and Kevin Volk were appointed as Odin project engineer and project scientist respectively. Over the next 6 years, Torchinsky worked on the optics design of the radiometer and participated in the system integration and testing. Volk was responsible for the development of the scheduling program.

In 1995, Peter Bernath of the University of Waterloo was invited by the International Science Teams as an expert to assist in the laboratory spectroscopy aspects of the mission. A proposal with Kwok as PI was made to the collaborative special projects program of NSERC for support in the scientific aspects of the mission. In spite of the problems arising from the cancellation of the CSP program after the submission of the proposal, the proposal was funded in 1997.

For astronomy, a number of topical teams were set up by the international science team to develop the observing program and the target list. Canadians who serve as co-lead scientists in the topical teams are Fich (galactic plane survey), Wilson (giant molecular clouds, galaxies), Kwok (stellar envelopes), and Mitchell (chemistry). Paul Feldman became a member of the COAWG following the resignation of Peter Dewdney from the team. Through a series of meetings and workshops, an observing program covering the first two years of observations was finalized.

It was clear that the original launch date of 1997 was overly optimistic. As the result of problems, e.g. those associated with the development of the digital correlator and the attitude control system, the launch date was postponed several times. In 1999, SWAS was successfully launched and the ground-state 557 GHz transition of water was detected. However, the oxygen molecule still remained elusive. With Odin?s larger antenna and the dedicated 119 GHz receiver for the ground-state transition of oxygen, we will continue the search for oxygen. The 4 tunable submm receivers of Odin will also allow it to observe many other molecular species and to carry out a spectral scan program.

At the time of the approval of the Odin mission, space astronomy was very much a new area for the CSA. We are grateful to the CSA for their unwavering support and faith in our team, and to NSERC for its patience as we struggled through the delays.

In selecting Odin as our first major effort in Canadian space astronomy, we were guided by the following principles:

1. the project has to be scientifically exciting and at the frontier of astrophysics;
2. it has to fit into the space astronomy budget of the CSA;
3. Canada has to be a significant partner in the project.

It has now been almost ten years since the beginning of the Odin project. Through this time, we have demonstrated that Canada can play a major role in both the technical and scientific development of a space astronomy mission and work within a modest budget. We are looking forward to the coming months toward the achievement of our scientific goals in exploring the submm spectrum for interstellar molecules.

Link to the ODIN homepage: http://www.ssc.se/ssd/ssat/odin.html

Sun Kwok is a professor in the Department of Physics & Astronomy, The University of Calgary and a Canada Council Killam Fellow. His research interests include advanced stages of stellar evolution, stellar winds, planetary nebulae, interstellar molecules, and infrared spectroscopy. He is Principal Investigator (Astronomy) for Canadian participation in the Odin mission.