SRMSAT - 2

SRMSAT - 2 is the second mission of Team SRMSAT. SRMSAT - 2 is a progressive conceptual student small satellite mission and a step forward in deep space exploration, pushing horizons of robust small satellites to regimes beyond earth. The mission is directed towards the design of a small orbiter spacecraft to orbit and study moon in a Low Lunar Orbit (LLO). The primary objective of the SRMSAT - 2 is to attain a stable lunar orbit achieved by low energy transfer exploiting Weak Stability Boundary theory. As a part of the science mission, a Microwave Radiometer is selected as the primary payload to study the lunar regolith and a Radiation Dosimeter is chosen as the secondary payload to characterize the radiation environment along the trajectory. A Narrow Angle Camera is chosen as outreach payload. Other options like Hyperspectral/Multispectral Imager and Infrared Spectrometer were also considered, but the final decision regarding the selection of payload is subject to outcomes of the design review.

The mission assumes launch vehicle support till the GTO and starts going through a series of phasing orbits to reach the WSB region to move from the Sun-Earth Manifold to the Moon-Earth Manifold, which are traced using Poincare maps with an approach from initial conditions. The apogee of the final phasing orbit is close to 1.5 Million Kilometers, and that point has some of the most critical and precise maneuvers to be executed.

Exploded view of the Satellite Design
Exploded view of the Satellite Design

SRMSAT – 2 is a cube-shaped spacecraft with the following key features

Dimensions500mm × 502mm × 600mm (cube)
Mass86 Kilograms
PayloadMicrowave Radiometer, Radiation Dosimeter, Narrow Angle Camera, possibly Hyperspectral Imager (Final decision pending)
PropulsionBipropellant Primary Propulsion System, Monopropellant Reaction Control System
TrackingS-Band two-way Doppler ranging
ThermalActive control
Attitude controlRCS and Reaction Wheels (3-axis stabilized)
StructureAluminium 6061-T6 alloy with honeycomb sandwich panels
Antenna20dBi Parabolic Reflector, S-band Omnidirectional
PowerOne body mounted and two deployed solar panels generating 142W at End of Life; 234 Wh battery.
Power transmitted7 dBW typical, 15 dBW in special cases
Uplink2110 to 2120 MHz1, 100 kbps
Downlink2200 to 2290 MHz1, 4 kbps
1. Frequencies assumed from CCSDS recommendations. Actual frequencies may vary based on ITU allocation.

The objectives of the project are:

  • To prove capabilities of small satellite systems beyond Earth.
  • To demonstrate the value of small-satellite science platform for lunar/planetary exploration.
  • To acquire lunar surface and subsurface geology and morphology data of the Moon.
  • To characterize radiation environment in the chosen mission profile.
  • To acquire local brightness temperature data over moon’s surface.
  • To investigate regolith characteristics by microwave radiometry.
  • To demonstrate the capability of COTS component in lunar orbiter type spacecraft systems in harsh earth-bound and deep space radiation environments.

Indian Space Research Organization’s launch support along with IDSN support for Telemetry, Tracking and Command is aspired and elementary to the mission. For the mission operations, support with respect to Space Link Extension (SLE) is established for interfacing Flight Dynamics facility, Data processing center and Mission Operation Centre established at SRM University with ISTRAC and IDSN stations is planned and proposal has been sent to ISRO.
A primary data center (SRM Lunar Science Data Center) will be established to collaborate with DSN and University tracking station with capabilities to support handling of downlinked science data and, maintaining and regulating data archives will be established. It will be responsible for interfacing with the scientific community and students of SRM University in providing acquired science data.