The main item of discussion was about the meeting between the European representatives of the LSA project and some representatives of the MMA project which took place in Charlottesville on June 25 & 26th. Most of the basic results of this meeting and the individuals present were reported in my memo to everyone on 1 July.

The main results of that meeting was the signing of a resolution "to organize a partnership that will explore the union of the LSA and MMA into a single, common project to be located in Chile" and the establishment of 4 working groups to study various aspects of the collaboration. The project is viewed as a 50-50 partnership with a combined project budget in the neighborhood of $400M. There seems to be agreement that the Chajnantor site is acceptable for the array and the preferred site for submillimeter observations.

Bob Brown talked about the issue of antenna size. He said they got estimates from three firms on 8 and 10 m to determine alpha in his cost equation. The results are 1.8 < alpha < 2.8. He redid his optimization for imaging and point source sensitivity and found the following:

 Optimized for: 
             Best D 
                   Best N 
                         ND^2 
 ND
             7.5
                   40
                         2000
 ND^2
             14
                   < 20
                         2400

This assumed that we maintained pointing specs to a fraction of the beam. He also noted that our estimates lead to 35 k$/m^2, whereas the Europeans claim they can do an IRAM type antenna for 10 k$/m^2. The difference is lighter surface panels, lighter, less rigid backup which cuts weight. The pointing is then dealt with by the laser system.

Several questions were raised regarding the collaboration. Among these was the question of timing. Funding for the European part of the project is not likely to begin until 1999 or 2000. Is this likely to delay the MMA project? How do we proceed if NSF provides funding this Fall or Winter? Bob said that we would proceed with those aspects of the project that can be worked on immediately and proceed with other parts as it becomes possible to do so. There will, no doubt, be some delay of the original time line as some key items such as telescope size, etc. are not yet decided upon. Richard Hills asked about NSF's response to a European collaboration and Bob said that they are very pleased with this. The general consensus is that this will make the project easier to sell to members of Congress. The question of how a collaboration with European astronomers might affect our relationship with the Japanese and the LMSA project was also raised. Dr. Ishiguro was in Charlottesville just after the meeting with the Europeans and reported that the LMSA project will probably be delayed by at least 3-4 years.

The 3 working groups agreed upon at the June meeting were: the scientific group, the technical group, and the management group. A fourth one, the systems group, was added later. The Science Working Group's primary task will be to consider the realative scientific merits of a homogeneous (all antennae about 12m+-1m which will have adequate pointing precision and surface accuracy to operate at submill. wavelengths) versus a hybrid array with a mixture of precision 8m dishes which will operate with good efficiency and pointing at submillimeter wavelengths and 15 meter dishes with less stringent requirements for pointing and submillimeter efficiency.

The Technical Working Group will basically try to come up with the best array consistent with the budget constraints and the recommendation of the scientific working group regarding homogeneous versus hybrid arrays. They will be working particularly on getting antenna cost estimates firmed up and a pointing error budget for the 15m antennas.

The systems group will be concerned with compatibility issues associated with receivers, receiver boxes, electronics, LOs, IFs, etc.

The management group will deal with a range of management issues associated with the combined array and the different manage- ment styles of ESO and NRAO. Among these is a factor of 4 difference in the projected operating budget of the combined array.

The composition of these working groups is in the process of being constituted. They will consist of about equal numbers of US and European members and are expected to have joint meetings in late summer or early fall.

ALL FOUR OF THESE WORKING GROUPS ARE EXPECTED TO PRODUCE WRITTEN REPORTS BY LATE OCTOBER FOR VANDEN BOUT AND GIACCONI TO PRESENT TO THEIR RESPECTIVE FUNDING AGENCIES AND THEIR SCIENTIFIC COMMUNITIES.

It was agreed that the MAC should have a face-to-face meeting sometime late in October so that the various recommendations be discussed before final decisions are made. Bob will be sending out via email enquiries to determine the best time when most of us can attend.