TSU 2-m AUTOMATIC SPECTROSCOPIC TELESCOPE PROJECT Monthly Report for October, 1999 This monthly report for the TSU 2-m AST project covers the calendar month of October, 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 November; a third (XI), with shipping criteria. During October, 1999, we continued to have three part-time employees (Andre Hedrick, Bill Pilkinton, and Mike Williamson) working at TSU on the telescope program 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 we still have a consulting contract with him. Williamson is working roughly half-time on the project as a programmer/instrumentalist. I. OVERHEAD/ENCLOSURES Task 52: Boyd has had the floor of the telescope enclosure painted, so it will be able to cure long enough for us to put the telescope in it anytime after the middle of December. II. MECHANICAL INTEGRATION Tasks 75&95: Assembly of telescope: We have completed all the steps listed last month except adjustinng the clamps for the drive tractors (6 hours under tasks 75 and 77). We have finished adjusting those clamps for the altitude motions and run (successful) tracking tests for the altitude both by hand slewing and under motor control. Task 83: Insulation: We have received the insulation and will be applying it as time permits. Much of this task must be done as part of Task 131 after the telescope is taken apart for shipment to Arizona to get at the surfaces that have to be insulated. Task 84: Construct wiring harnesses: This task is about 70% complete with final wiring waiting on having the control-electronics boxes on the telescope. Tasks 87-89: Hook up amplifiers and make sure they run the motors: We have prepared the electronics boxes (Task109), put them in the telescope to receive the drive amplifiers, and wired in the two amplifiers for the altitude motion (see Tasks 75&79 above). The four other amplifiers are ready to put in the telescope once the clamps for the azimuth tractors are adjusted. Task 101: Wiring oil-pump controller: Williamson wired up the controller for the oil pumps (which contains an interface for computer control) and Eaton wired it into the pump and tested it for manual operation. We also made the cables and connectors for connecting the oil-pressure sensor to its computer interface and tested the interface. Tasks 100-104: Modify oil bearings: As explained last month, these tasks involve modifications requiring us to take the telescope apart and are therefore transferred to Task 131 with testing to follow with the bearing supporting the fork. Task 106: Centering the top end of telescope: This task is part of the procedures for mechanically making the telescope axes as perpendicular as practicable. For all practical purposes, it could be delayed until we move the telescope to Arizona, although we may do it in Tennessee if time permits. Task 107: Finish mirror-washing dam: This task is finished except for gluing the rubber seal on the inside of the band and putting it on the mirror. We will do this as part of Task 131 once the telescope is apart and we can get at the mirror conveniently. III. TESTING PRIMARY MIRROR Task 119: Testing 80-inch primary mirror: Since Scott Smith advises that a test of the primary could be useful for detecting misadjustment of the lateral supports, we have scheduled a test at Nashville, in the National Guard Armory. This test was originally supposed to be around 1 October, but the test equipment is tied up in its primary role for NGST until mid November. We now expect this test to be in the second half of November or early December. IV. CCD CONTROLERS (for the spectrograph) Tasks 142-144: Procure CCD controllers from SDSU: We have this contract in place and Bob Leach estimates delivery of about 1 June 2000. V. CONTROL SYSTEM Work on the control system in October 1999 concentrated on the tasks discussed in September's report. Most of this work is being done now by Williamson, who has concentrated on integrating the small systems into the control computer. Hedrick has been preoccupied with moving to California, but left us with versions of the basic device drivers adequate to do the servo and acceptance testing that will dominate work in November. Task 160: Implement servo loop: We got the NextMove controller to ru under the latest version of linux (Hedrick) and ran further tests in our lab simulator to determine what values of the parameters for the PID control algorithm will work with the full range of drive rates and inertias we expect to encounter. These tests give a good idea of what positional variations we can expect from the control system. They also discovered that the amplifiers in our simulator were configured wrong (by somebody besides Eaton) and that the system gives much better results when reconfigured. Task 171: Set up Apogee camera in lab: Williamson set this test camera up in the lab and ran it under linux with the programs (device driver plus applications programs) we bought from Clear Sky Institute (Univ. of Iowa). Also, he set up the Panasonic camera we plan to use for acquisition/guiding with its frame grabber, both with the native software under Windows and with a device driver/test programs from A. Rubini in Italy under linux, and got it to grab frames (Tasks 260&261). VI. SPECTROGRAPH CAMERA Tasks 187-191: Because David Warren has received two major new assignments at Aerospace Corp., we have retained Harlan Epps to design the spectrograph camera. We have established a contract with him, and he is expected to produce a preliminary design for the camera by 10 November. We also are expecting to use him to manage the design of the lens housing and manufacture of the camera. VII. SMALL SYSTEMS This work is mostly done and is being wound up into testing the control system. We have assigned most of it to Mike Williamson, who has begun testing these systems under computer control. Jobs that remain are Task 228, a contingency for modifying the absolute-encoder mounts (which requires a few small mechanical modifications), Task 239, testing of the secondary cell for stiffness (which requires Williamson and Eaton to set the cell up with indicators and move it around). VIII. CALIBRATION SYSTEM These tasks are going to be performed mostly by Frank Fekel, who has been away from Nashville for most of November. IX. DATA TRANSMISSION/REDUCTION Willard Smith discussed our plans for data transmission with the Withbroe committee at the ad hoc program review of 21 October. X. HIGHLIGHTS FOR THE NEXT MONTH During November, 1999, we expect (1) to finish fitting and adjusting the drive clamps (Tasks 75&77) and conduct tests of the basic telescope motions (Task 89) and electromechanical function of the limit switches and home-position detectors (Task 169), (2) to test the basic motions azimuth and altitude under computer control (Task 168), complete with acceptance tests for tracking accuracy and repeatability, (3) to finish all the wiring needed to run preliminary and some final tests of the control system, i.e., Tasks 89, 168, 169, and 175-176; possibly 119 (extension of Task 84), (4) to finish those parts of the control system necessary for the above, (5) to verify the functioning of the lateral supports for the primary mirror with an optical test of the primary mirror in Nashville (Task 119), (6) to finish the preliminary design of the spectrograph camera (Task 191), (7) to begin acquiring the parts for the calibration system (Tasks 258, 259, 263, & 267), and (8) to finish the contract for the data- reduction system. XI. SHIPPING CRITERIA We discussed the criteria for shipping the telescope to Arizona with the Withbroe committee (consisting of Withbroe, Sakimoto, and Stringfellow assisted by Scott Smith of MSFC, formerly of Contraves) at the ad hoc review of 21 October. Smith discussed the sort of acceptance tests that Contraves does for its telescopes, explaining that there are tests best done in the assembly building with test instruments and those best done in the field with stars. This division follows the shipping criteria we presented Withbroe and Gull in June, and the Withbroe committee agreed they would be acceptable if they indeed imply tests of repeatability of the pointing, such as ones Smith mentioned. Members of the Withbroe committee said it was not clear what we actually meant, and requested we amplify those criteria by adding details of exactly what we mean by them. The following is that amplification. CRITERIA FOR SHIPPING TELESCOPE TO WASHINGTON CAMP I. The telescope shall be MECHANICALLY SOUND: A. The MECHANICAL PARTS FIT TOGETHER. The physical pieces of the telescope shall fit together with all interferences remaining from design or manufacture eliminated. TSU shall either verify the fit of any parts not shipped with the telescope (e.g., possibly the secondary-mirror cell and the instrument heads) or measure their mechanical interfaces accurately enough to have them fit in the field. Exceptions: TSU reserves the prerogative of fitting parts of the instrument head, such as cabling for the fiber optics, until the telescope is in Arizona. B. The OIL BEARINGS WORK. The oil bearings shall support the telescope sufficiently to allow it to move freely in azimuth, even when hot, and the leakage of oil shall be slight enough to allow the telescope to work all night without maintenance. Specific requirements and tests follow. 1. TSU shall test the oil bearings by running them for a complete day (roughly 7:30AM to 3:30PM), perhaps overnight if that is practicable, and observing the leakage and changes in support. The oil system shall not lose more than two quarts of oil in these tests, enough to be replenished through routine maintenance. The telescope shall be able to move freely as tested every hour through moving it either by hand, hand controller, or computer at the discretion of TSU. These tests may be done initially with the telescope fully assembled, but the final acceptance tests for the oil bearings will be done after modifications with only the fork supported as explained in I.B.2 below. 2. TSU anticipates making certain modifications to the oil bearings as the result of pumping tests done in September. All these modifications to the oil bearings and their collection system shall be finished before TSU ships the telescope to Arizona, and these modifications shall be tested in the telescope with the bearings supporting the fork. C. The drive TRACTOR UNITS TRACK ON DRIVE CIRCLES. 1. The drive tractors must move along the drive circles without binding from friction or wandering (yawing in a plane tangent to the drive circle). TSU shall test this function by a) moving the telescope around by hand with each of the tractors separately in place and adjusted and b) running the drive motors in each tractor while observing the demand, both with a hand-held controller and with the computer in criterion II.1 below. 2. TSU shall verify that the motors do not slip at full demand under shop conditions with the clamps fully adjusted, or TSU shall establish limits on the demand consistent with any observed slippage. D. The MIRROR-SUPPORT SYSTEM WORKS MECHANICALLY. TSU with the advice and assistance of MSFC shall conduct a null test of the primary mirror to verify the function of the lateral-support system for the 2-m primary mirror. This test shall be done with the mirror supported vertically in its cell. MSFC will advise on any readjustment of the support system required and shall be responsible for interpreting the test and deciding whether the lateral support system is ready for shipment. Inasmuch as two competent optical engineers agree that the figure of the mirror would not have changed since its manufacture, no other optical tests of the primary shall be required of it. The secondary mirror shall be tested by observing stars in Arizona. II. The telescope's ELECTRICAL SYSTEM shall be READY FOR DETAILED TESTS: A. Drive TRACTORS MOVE THE TELESCOPE UNDER COMPUTER CONTROL. TSU shall run the telescope under computer control in the assembly building at rates simulating the range of motions required, specifically at 10 steps/s (appx 2 arcsec/s), 200 steps/s (siderial rate), 3300 steps/s for azimuth (largest tracking rate through meridian), and 50,000 steps/s (slewing rate). These rates will be used to verify or assess the following criteria. 1. The measured positioning of the telescope shall be repeatable to better than 20 encoder counts (3 arcsec). This shall be measured by running the telescope forward and back by various numbers of encoder counts and measuring the change in position with dial indicators or optical devices. 2. The azimuth zero point (home position) shall be measured and should be the same after a complete revolution of the telescope to within 3 arcsec. 3. TSU shall measure and record the variations in the summed positions of the various incremental encoders on the two axes to provide data for calibrating the motion-control system. This shall be done by recording the positions of these encoders every 1-2 degrees as the telescope slowly tracks in an axis. B. The LIMIT SWITCHES AND EMERGENCY-STOP SWITCHES WORK; ZERO-POINT DETECTORS ARE IN PLACE. 1. The limit switches and emergency-stop switches shall be in place and wired into the control computer through the motion-control breakout board. TSU shall verify their function by a) running the telescope into the four limits at both maximum tracking and slewing rates and b) by verifying that the controller actually stops the telescope in the emergency mode at the slewing rate. This is part of tests II.A above. 2. TSU will run the telescope into the four shock absorbers at slewing rate to verify the function of the runaway system. 3. The zero-point detectors shall be wired into the control breakout board, and TSU shall test them by executing homing routines on both azimuth and tilt under computer control. This is part of tests II.A above. C. The POWER DISTRIBUTION shall be IN PLACE. TSU shall wire up all lines for bringing AC power into the telescope prior to tests in II.A. These will be in a two-part umbilical that is to be secured at the top of the fork and at its outlet in the base. TSU shall verify that the ends of these wires are long enough to reach a distribution box on the south wall of the telescope enclosure. Also, the auxiliary DC power supplies shall be wired into the control box on the telescope. D. The WIRING HARNESSES FOR MOTION-CONTROL SYSTEM shall be IN PLACE. TSU shall hook up all the wires necessary to run the telescope's basic motions as part of tests II.A above. E. The WIRING HARNESSES FOR STEPPER MOTORS FIT (and are possibly in place). These harnesses shall be finished and fitted into the telescope prior to shipping; the placement and function of all holes through which they pass shall be verified. III. CERTIFICATION On completing these tests, TSU shall present a report to the Withbroe committee certifying that the telescope conforms to the stated criteria. Upon completion of this report, the telescope may be shipped to its site at the discretion of TSU.