Mini-tracker concept development for the Southern African Large Telescope (SALT)

Abstract

The preliminary concept development phase of the Southern African Large Telescope (SALT) mini-tracker (MT) project was completed. The addition of up to four MTs to the telescope would in effect create multiple four-to-six-meter class telescopes using SALT’s 10-m diameter primary mirror. Each MT would be able to provide spectroscopic follow up for current and future large astronomical surveys (e.g. MeerKAT, eROSITA, Gaia, LSST, SKA, etc.). This phase included development of a novel optical design for the spherical aberration corrector, preliminary mechanical design for the telescope interface and the MTs themselves, and simulation tools to calculate the effective illumination of each MT for a selected target. A detailed project management plan and documentation framework were also created, including a prototype development path, a project cost estimate, and a schedule to completion. Following a review of the project near the end of this concept development phase, the decision was taken to put the project on hold. Although the MTs were deemed to be technically feasible, a more detailed science case was required in order to proceed with the project. In addition, several personnel-intensive projects to improve the performance and reliability of the telescope, either now underway or soon to be started, would need to be completed prior to beginning a project of this magnitude and complexity. However, a number of valuable tools and results that will benefit SALT emerged from this concept development phase, and are outlined here.