Preparations for the launch at Sriharikota. (PTI)

Chennai, Oct. 21: The 11 scientific payloads aboard Chandrayaan-1, India’s first lunar orbiter, will include one instrument about the size of a 21-inch TV carton which is headed for a suicide mission to the moon.

The 29kg Moon Impact Probe (MIP), designed by a team led by aeronautical engineer Madan Lal at the Vikram Sarabhai Space Centre, Thiruvananthapuram, will be hurled by the orbiter towards the moon for a 20-minute descent and crash.

Although the moon has only one-sixth the gravity of Earth, the fall will be hard and wreck the probe. Lal has calculated that the probe is likely to strike the lunar surface at 1.8km per second and be smashed into pieces.

If Chandrayaan-1 reaches the lunar orbit and releases the probe, scientists believe India’s first imprint on the moon will be a spray of electronic innards and metallic pieces of the probe scattered on the lunar surface.

“It won’t survive the crash,” said Lal, 61, who retired last year from the Thiruvananthapuram centre after serving there for 39 years. But the kamikaze act of the MIP will help the Indian Space Research Organisation (Isro) prepare for its second lunar mission — a lunar lander.

The MIP has three instruments — a radar altimeter to indicate its height from the lunar surface, a video camera that will transmit pictures of the surface as it falls towards it, and a mass spectrometer, an instrument to study the constituents of space just above the lunar surface.

Isro hopes to launch Chandrayaan-1 on a Polar Satellite Launch Vehicle at 6.22am tomorrow from the Sriharikota island launch pad.

The spacecraft will release the MIP only when it has reached its intended 100km orbit above the lunar surface. A rocket motor on the MIP will first decelerate the probe and allow it to be captured by the moon’s gravity.

The other 10 payloads on Chandrayaan-1 will help generate a three-dimensional atlas and chemical map of the lunar surface during the orbiter’s planned two-year life in lunar orbit.

Eyes on weather

The countdown to the lunar orbiter launch went on today despite clouds in the sky, with engineers pumping liquid rocket fuel into the second stage of the launch vehicle this afternoon.

At the Satish Dhawan Space Centre, Sriharikota, scientists sent weather balloons into the sky every hour. The balloons will relay data about the likely wind speeds the launch vehicle might encounter during its flight.