Planning and Scheduling of Payloads of AstroSat During Initial and Normal Phase Observations

  • R. Pandiyan
  • S. V. Subbarao
  • T. Nagamani
  • Chaitra Rao
  • N. Hari Prasad Rao
  • Harish Joglekar
  • Naresh Kumar
  • Surya Ratna Prakash Dumpa
  • Anshu Chauhan
  • B. P. Dakshayani
Review
  • 65 Downloads

Abstract

On 28th September 2015, India launched its first astronomical space observatory AstroSat, successfully. AstroSat carried five astronomy payloads, namely, (i) Cadmium Zinc Telluride Imager (CZTI), (ii) Large Area X-ray Proportional Counter (LAXPC), (iii) Soft X-ray Telescope (SXT), (iv) Ultra Violet Imaging Telescope (UVIT) and (v) Scanning Sky Monitor (SSM) and therefore, has the capability to observe celestial objects in multi-wavelength. Four of the payloads are co-aligned along the positive roll axis of the spacecraft and the remaining one is placed along the positive yaw axis direction. All the payloads are sensitive to bright objects and specifically, require avoiding bright Sun within a safe zone of their bore axes in orbit. Further, there are other operational constraints both from spacecraft side and payloads side which are to be strictly enforced during operations. Even on-orbit spacecraft manoeuvres are constrained to about two of the axes in order to avoid bright Sun within this safe zone and a special constrained manoeuvre is exercised during manoeuvres. The planning and scheduling of the payloads during the Performance Verification (PV) phase was carried out in semi-autonomous/manual mode and a complete automation is exercised for normal phase/Guaranteed Time Observation (GuTO) operations. The process is found to be labour intensive and several operational software tools, encompassing spacecraft sub-systems, on-orbit, domain and environmental constraints, were built-in and interacted with the scheduling tool for appropriate decision-making and science scheduling. The procedural details of the complex scheduling of a multi-wavelength astronomy space observatory and their working in PV phase and in normal/GuTO phases are presented in this paper.

Keywords

AstroSat mission multi-wavelength astronomy autonomy planning and scheduling of targets first light results of instruments 

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Copyright information

© Indian Academy of Sciences 2017

Authors and Affiliations

  • R. Pandiyan
    • 1
  • S. V. Subbarao
    • 2
  • T. Nagamani
    • 2
  • Chaitra Rao
    • 2
  • N. Hari Prasad Rao
    • 2
  • Harish Joglekar
    • 2
  • Naresh Kumar
    • 2
  • Surya Ratna Prakash Dumpa
    • 2
  • Anshu Chauhan
    • 2
  • B. P. Dakshayani
    • 2
  1. 1.Department of Aerospace EngineeringIndian Institute of TechnologyChennaiIndia
  2. 2.Mission Development Area, ISRO Satellite CentreBengaluruIndia

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