Observation program

After the initial eight-month ``Performance Verification" (PV) phase, when the data belong to the Astro-D PI Yasuo Tanaka, observing time on Astro-D will be open to competitive proposals. The observing time will be apportioned as follows:

• 60 per cent for Japanese and European proposals,
• 15 per cent for US proposals, and
• 25 per cent for US/Japan collaborative proposals.

The first Announcement of Opportunity (AO) to observe with Astro-D will be for six months and will be issued just before launch in January 1993. Later AOs will be for year-long periods. US observers will be able to propose either for US-only time or for the US/Japan time. Proposals in the US/Japan category will be initiated by the US for final approval by the Japanese. US observers bidding for US/Japan time may either arrange for a Japanese collaborator or be assigned one by the Japanese.

It was expected initially that Astro-D observations would be scheduled at the rate of one per day, as for Ginga. However, to facilitate mission planning, NASA, through a grant to MIT, is supporting the incorporation of the Space Telescope scheduler, SPIKE (Scientific Planning Interactive Knowledge Expert system), into the ISAS mission-planning software. This enhancement will allow up to seven observations per day. Based on this figure and on the potential US share of up to 40 per cent of the observing time, as many as 700 observations per year will have some US involvement (270 US-only targets; 450 US/Japan targets). It is anticipated that GOs who have US-only targets will prefer to analyze their data in the US, as will those GOs who have relatively straightforward observations. In this category there will be about 100 astronomers per year. In addition, about twenty US astronomers per year may wish to visit Japan for several months at a time to work on extended collaborations as a part of the US/Japan program. Based on the experience of US GOs from the NASA Ginga Visiting Investigator Program who found that conducting research in Japan often requires a lot of assistance, one of the US Astro-D GOF staff will be present at ISAS to provide this service.

Astro-D operations will be managed and run by Japanese astronomers and engineers who will schedule observations, direct the satellite, collect the data and monitor the health of the satellite and its payload. Two US duty scientists, recruited under the joint NSF/JSPS postdoctoral program, will assist in this work.