36 A·h lithium-ion battery for use during eclipses. Propulsion The spacecraft used a bipropellant integrated propulsion system to reach lunar orbit as well as orbit and altitude maintenance while orbiting the Moon. The power plant consisted of one 440 N engine and eight 22 N thrusters. Fuel and oxidiser were stored in two tanks of each. Navigation and control The craft was 3-axis stabilised with two star sensors, gyros and four reaction wheels. The craft carried dual redundant bus management units for attitude control, sensor processing, antenna orientation, etc. Payload The scientific payload had a mass of and contained five Indian instruments and six instruments from other countries. Indian instruments TMC or the Terrain Mapping Camera is a CMOS camera with resolution and a swath in the panchromatic band and was used to produce a high-resolution map of the Moon. The aim of this instrument was to completely map the topography of the Moon. The camera works in the visible region of the electromagnetic spectrum and captures black and white stereo images. When used in conjunction with data from Lunar Laser Ranging Instrument (LLRI), it can help in better understanding of the lunar gravitational field as well. TMC was built by the ISRO's Space Applications Centre (SAC) at Ahmedabad. The TMC was tested on 29 October 2008 through a set of commands issued from ISTRAC. HySI or Hyper Spectral Imager is a CMOS camera, performed mineralogical mapping in the 400–900 nm band with a spectral resolution of 15 nm and a spatial resolution of . LLRI or Lunar Laser Ranging Instrument determines the height of the surface topography by sending pulses of infrared laser light towards the lunar surface and detecting the reflected portion of that light. It operated continuously and collected 10 measurements per second on both the day and night sides of the Moon. LLRI was developed by Laboratory for Electro Optics Systems of ISRO, Bangalore. It was tested on 16 November 2008. HEX is a High Energy aj/gamma x-ray spectrometer for 30–200 keV measurements with ground resolution of , the HEX measured U, Th, 210Pb, 222Rn degassing, and other radioactive elements. MIP or the Moon Impact Probe developed by the ISRO, is an impact probe which consisted of a C-band Radar altimeter for measurement of altitude of the probe, a video imaging system for acquiring images of the lunar surface and a mass spectrometer for measuring the