The report of the Millimeter Array Advisory Committee (MAC) following their meeting of November 15, 1997, appeared in the January 1, 1998 issue of the NRAO Newsletter. It can also be found on the NRAO web site. Since that meeting of the MAC the Committee's recommendations have been considered by the Observatory and this article presents the current position of the NRAO on the recommendations. Let me begin by thanking the Committee for assembling on rather short notice and for the time and hard work they invested in the meeting.

The Committee endorsement of the potential merger of the Millimeter Array (MMA) and the Large Southern Array (LSA) was welcome. We are continuing to work with the Europeans to achieve this goal, using the working groups in science, antenna and systems, receivers and electronics, and management. We are also, as the Committee recommended, keeping our options open with respect to the Large Millimeter Submillimeter Array (LMSA) project of the Japanese. A renewal of our Memorandum of Understanding governing this cooperation with the LMSA is being negotiated.

The Committee recommended against a heterogeneous array, opting instead for a homogeneous array of antennas of common diameter. That is the current NRAO plan. The Committee also recommended that the design effort be concentrated on an antenna diameter of 12 meters and that the "fall-back" issue should not dominate further discussion of antenna size. Because the National Science Foundation has required us to submit a plan for the design and development phase of the MMA that is specific, complete, and as independent of uncertainties regarding potential partners as possible, we have adopted as the baseline, stand-alone plan for the MMA a homogeneous array of 10m diameter antennas. This in no way precludes the modification of the antenna size should partnership arrangements be realized, nor does it indicate any change in the interest in such partnerships. Ten meter diameter antennas are the largest that are consistent with a stand-alone MMA, and, therefore, the largest step we can take at this time toward accomodating the wishes of both the Europeans and the MAC for larger antennas in a merger of the MMA and LSA. Should sufficiently concrete partnership arrangements be put in place in the next year or so, and should our studies of a 10 meter antenna design be encouraging, it will still be possible to place a contract for 12 meter diameter prototype antennas.

A fully international advisory committee is a necessity when partnerships with the European and/or Japanese projects have been realized. In the meantime, we have decided it would be better to proceed with a separate advisory committee that includes observer-members from the other projects. Accordingly, we will be reorganizing the MAC somewhat to reflect this, also adding Japanese observers. It is also likely that interested members of the Board of Trustees of Associated Universities, Inc. will be invited to attend the MAC meetings.

An international science meeting is under consideration.

Effective management structures for the partnerships we are trying to achieve are a constant topic of discussion. There is a joint MMA - LSA management working group that meets regularly just for this purpose.

The Millimeter Array Development Consortium (MDC) is playing a very important role and we fully intend to continue this arrangement, independent of partnership arrangements.

The Committee's concerns regarding software design and planning are noted, and it is planned to treat this area as equal to the other elements of the project

P. Vanden Bout.

13 February 1998