June 17, 2019 - The team working on the Auxiliary Telescope for LSST had a big reason to celebrate this week, after completing a series of exercises on Cerro Pachón that demonstrated the successful integration of the telescope's software and hardware systems. The AuxTel (as it's fondly known) is located on a hill about 100 meters (328 feet) from the main LSST telescope, and it will measure atmospheric transmission during LSST Operations. This week the team tested the control software and network architecture of the AuxTel system by executing a series of software tests that controlled the Auxtel as though it were in normal operations…and it worked! Successful operation of a telescope requires this kind of specialized software that manages and synchronizes the motion of the many hardware components to create an observatory that can be operated remotely.
This video shows the telescope mount assembly and dome of the AuxTel operating in tandem, with the telescope turning to point through the open shutter. The software controlling the equipment runs through the server room in the LSST summit facility building, but the commands to operate the hardware can be entered from computers anywhere on the summit network (in this case, on the first floor of the two-story AuxTel building). According to Tiago Ribeiro, LSST Scheduler Scientist, "it's pretty awesome when you enter a line of code on your computer and the system does exactly what you wanted it to do." A rigorous set of safety mitigations has been integrated into the design of the AuxTel so that this remote operation can happen without risking damage to the telescope, or injury to a person in the vicinity of the telescope, from unexpected or sudden movements.
Not only is this a major milestone for the Auxiliary Telescope, but because the main LSST telescope will use essentially the same software system, the work on AuxTel and all the knowledge gained during the integration process will be critical when it's time to combine the software and hardware for the main 8.4-meter telescope. This milestone was a lot of work in the making, involving many preparatory activities and contributions from across the LSST Project, especially onsite in Chile.
The AuxTel has been using mirror and camera surrogates for testing, but the real mirror and a small alignment camera are scheduled to be installed in the coming months.