TSU 2-m AUTOMATIC SPECTROSCOPIC TELESCOPE PROJECT Monthly Report for November, 1999 This monthly report for the TSU 2-m AST project covers the calendar month of November, 1999. The first part of the report (I--IX) covers the status of various tasks in the schedule; a second part (X), with highlights for December. During November, 1999, we continued to have one part-time employee (Mike Williamson) working at TSU on the telescope program, in computer programming and electronic instrumentation, in addition to M. Krebs and M. Wells, who provide machining work at their private shops. Hedrick has taken a job in California with SuSE, a linux company, although he is returning for a week in early December to work on various tasks for us, including the telescope project. I. ADMINISTRATION Since we haven't heard to the contrary, we assume that the criteria for shipping the telescope, which we included in October's report and which were essentially what you and we agreed to at the one-site review in October, are acceptable to you. II. MECHANICAL INTEGRATION Tasks 75&95: Assembly of telescope: We have all three of the drive tractors in the telescope and have adjusted them well enough to begin mechanical tracking tests. We have run such tests under computer control in which we drive both motors in a given tractor simultaneously. All six motors move under electrical control with an analogue demand imposed on the amplifier. However, the aformentioned tests under computer control show that the three tractors still require various amounts of further modification. One of the azimuth drive tractors works reasonably well but requires changing two of its guide rollers(about 2 days of work with tests; the new rollers are in hand). The other azimuth tractor requires more extensive attention, specifically changing guide rollers and adjustment of its hanger (about 1 week of work). The altitude tractor has problems with binding in certain positions, which leads to excessive vibration. We have designed and fabricated some modifications to the tractor and its mount to reduce this binding and will test them on the telescope in December (about 1 week of work concurrent with that on the second azimuth tractor). Task 84: Construct wiring harnesses: This task is still about 70% complete because we decided to remake some of the cables for better electrical shielding. Tasks 87-89: Hook up amplifiers and make sure they run the motors: We have wired up all six amplifiers and verified that they will turn the motors. All six seem to work under computer control in our first round of tests as explained above. Tasks 100-104: Modify oil bearings: The oil beraings seem to be working a lot better (specifically the oil-return system) now that the weather is cooler and the oil more viscous. We still plan modifications mentioned in a previous report to make the bearings less likely to stop up and to reduce the oil leakage when we tear the telescope down, and we have our machinist making some of the parts now. III. TESTING PRIMARY MIRROR Task 119: Testing 80-inch primary mirror: This test, which is being set up by Scott Smith and Ron Eng of MSFC, was due to be done in mid December, but it seems now to have slipped to mid January because of inavailability of some of the necessary optical equipment. Smith has also talked to Tourus Optics and plans to get the test plate they made for the secondary mirror and test the secondary in various orientations to look for flexure in the mirror mount. Scott also plans to conduct certain mechanical tests at the same time, specifically a repeatability test for the drives, a sag test for the top end of the telescope, and some vibration tests of the mount under tracking conditions (relatively slow drive rates). IV. CCD CONTROLERS (for the spectrograph) Tasks 142-144: Procure CCD controllers from SDSU: This contract in proceeding toward its completion around 1 June 2000. SDSU was ordering the dewar for the CCD this month. V. CONTROL SYSTEM Work on the control system in November 1999 concentrated on the the basic, device- dependent parts for the motion control. Eaton has been writing code that exercises the NextMove motion-control board to determine which of the (somewhat incompletely documented) functions actually work reliably and can be used in the control system and to integrate the various signals (such as limit switches) into the control system. The resulting code is well documented internally and will be directly integrated into the telescope motion- control program that does the slewing and tracking (Tasks 156&157, which we have discussed previously). This effort has given a system that could move the telescope in two axes simultaneously at continuously varying drive rates, and we have used various versions of these programs in tests of hardware on the telescope as described elsewhere in this report. Williamson is continuing to work on computer control of the smaller systems and on the acquisition camera. He can now grab frames with the Panasonic acquisition camera, display them on a computer, copy them into and out of the computer's memory (so as to process them and display overlays on them), all under linux (Tasks 260&261). Williamson also began tests using this camera to detect artificial stars in a lab simulator, which eventually will let him write the software to look at the field of the telescope. Williamson has also shown an interest in the basic motion-control system, and he may start contributing to it in the next couple of months. VI. SPECTROGRAPH CAMERA Tasks 187-191: After taking over the camera design as described last month, Harlan Epps has produced designs for two cameras, which he has integrated into a model for our spectrograph using Zemax. One has a 500-mm focal length, which is probably too big to fit the whole spectrum onto the CCD we have for the instrument. The second has a 330-mm focal length and could fit the whole spectrum onto the chip. This shorter camera, however, has lower resolution at the edges of the orders, which Eaton and Fekel consider undesirable for the scientific program of the telescope. We have therefore decided to use the 500-mm design, switching between the long and short wavelengths by rotating the secondary grating. This preserves the full resolution of the spectrograph, gives a better registration of critical lines in the red (which tend to be somewhat away from centers of orders with the actual grating we have in hand), and thereby supports TSU's basic scientific program of the AST better than the alternative design. Epps is preparing a formal report, which should be finished in early to middle December, which we will forward to Maymon, as promised. This report should include all the details of the optical system as well as estimates of its cost. VII. SMALL SYSTEMS We have begun integrating the small systems into the telescope structure, first by attaching the tilt absolute (15-bit) encoder and the mount for its electronics onto the top of the fork. This mount required a spacer plate to get clearance for a timing belt and for holes to be laid out, drilled, and tapped. Holes for attaching the azimuth absolute encoder are already in place. We fitted the secondary-mirror cell and the two instrument heads into the telescope previously. Task 235: Add limit switches to secondary-mirror cell: We have wasted a great deal of time over the last several months stewing over how to put limit switches (actually home switches at one end of the run) on the six motions of the secondary cell. In November, we chose the switches, procured them, designed mounts for them, and had the mounts machined. There are still some modifications to do to the spider that holds the secondary mirror to make surfaces for these switches to contact, but we are now in the position to finish assembling and testing the secondary-mirror cell. IX. CALIBRATION SYSTEM Tasks 255-257: Assembly/modification of the guiding head: We have continued assembling the guiding head, a low priority, since it is not needed until we begin tasks 179-181. This month we finished aligning and pinning the slide and mount for the pickoff mirror and reamed out the hole for the transfer lens for the guide/acquisition camera (which was slightly too small as manufactured. Tasks 258&259: Design and build the pickoff mirror: We released the drawings for the overall design of this mirror, decided to build three of these mirrors, and sent the drawings to our machinist. He will make the mirrors out of aluminum, polish the active surface of one of them for testing the optical quailty, but leave cutting the holes for the fiber optic cables until the final design is done, probably after we get results of tests with the first mirror. X. HIGHLIGHTS FOR THE NEXT MONTH During December, 1999, we expect (1) to finish testing the telescope drive enough to support mirror/mechanical tests planned by MSFC in January, (2) to finish acquiring the parts to make modifications of the oil pads and their pumping/return system, (3) to get a computer permanently into the telescope for motion-control (perhaps not the final one we will use for telescope operations), (4) to build a better simulator for development of the software to look at the focal plane, (5) to finish assembling the secondary-mirror cell, complete with modifications and test its actuators under computer control, and (6) to receive and evaluate Harlan Epps's report on the spectrograph camera.