# Chapter 4, The Point Design

## Section 4.10: Cost Estimate for Point Design

The New Initiatives Office (NIO) has prepared an initial cost estimate for design and construction of a GSMT in the form represented by the point design. As in other point design activities, this is a learning exercise that helps illuminate a number of issues, even though we make no claim that this is the design likely to be built. The purposes of the cost estimate include:

• Identifying the high-cost parts of the project

• Identifying areas where there is significant cost uncertainty and/or cost risk

• Identifying factors that will drive the costs (for example, understanding the relationship between the timing of the project and the overall cost)

• Targeting specific areas where cost-reduction initiatives have the greatest chance of significantly reducing the overall project cost

• Understanding the costs of options, such as individual instruments, so that intelligent trades can be made between performance and cost

• Facilitating comparisons between different proposed designs (by highlighting which costs would be the same and which would differ between two proposed designs, for example)

In developing the cost estimate, NIO has worked in collaboration with industry, other astronomy organizations, and other ELT conceptual design groups.

4.10.1 Telescope Capital Cost

Table 1 summarizes the capital cost of the GSMT point design, itemized by major subsystem, in year-2002 U.S. dollars.

 Component or Subsystem Cost Estimate   (2002 U.S. Dollars) Percentage of Capital Cost Primary Mirror System 95,126,000 17.1% Adaptive Secondary Mirror System 15,360,000 2.8% Other Optics 5,299,000 1.0% Telescope Structure 34,654,000 6.2% Site 5,000,000 0.9% Enclosure 50,000,000 9.0% Support Facility and Equipment on Site 3,419,000 0.6% Base Facility 4,000,000 0.7% Overall Control System 15,000,000 2.7% Co-alignment, co-phasing system 10,000,000 1.8% Adaptive Optics 64,858,000 11.7% Program Office & Engineering Cost 124,436,000 22.4% Subtotal 427,152,000 Contingency on above @ 30% 128,146,000 23.1% Telescope - Capital Cost 555,298,000

Table 1.  Initial cost estimate for the GSMT point design, not including instrumentation.

4.10.2 Instrumentation

Cost estimates have also been prepared for the instruments concepts.  Table 2 summarizes the estimated costs of these instruments.

 Instrument Cost Estimate (U.S. Dollars) MOMFOS 40,973,000 NIRDIF 33,402,000 NIrES 6,942,000 MIHDAS 15,123,000 MCAO Near-IR Imager 40,000,000 MEIFU 27,960,000 AO Coronagraph 16,558,000

Table 2. Initial cost estimates for conceptual instruments for GSMT point design.

4.10.3 Operations Costs

Historical costs for observatory operations fall within a relatively narrow range when compared to the capital cost of the observatory.  Over a wide range of facilities, and over a period of many decades, operational costs have fallen in the range of 3% to 6% of capital costs, in constant dollars, not including the cost of equipment upgrades such as new instruments.  Costs falling at the lower end of this range typically do not include the cost of scientific staff, libraries, etc., while costs at the higher end tend to include such scientific costs.  Depending on the number of instruments included in the facility and the operational model, GSMT operations costs are predicted to fall in the range of \$20 to \$40 million &year-2002) U.S. dollars per year.

In addition, the operations budget must provide for equipment upgrades including new scientific instruments and improved adaptive optics systems.  Most large observatories budget 2% to 5% of the observatory capital cost per year for instrument upgrades.