IISc Bangalore

Challenges of Mission Planning of an Astronomy Satellite ASTROSAT – India’s Multi-Wavelength Space Observatory


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-wave length.  Four of the payloads are
co-aligned along positive roll axis of spacecraft and the remaining one is placed along 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 about two of the axes
in order to avoid bright Sun within this safe zone and a special constrained manoeuver is exercised during manoeuvres.  The planning and construction period of
the entire spacecraft was about 12 years 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 entire 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.   Procedural details of the spacecraft construction, mission planning aspects and
complex scheduling of a multi-wavelength astronomy space observatory and their working in PV phase and in Normal / GuTO phases are described in this

Date(s) - 15/03/2019
4:30 pm - 5:30 pm

Map Unavailable