Washington, Nov 20 (IANS): NASA is looking for ideas from public for innovative ways to help mitigate radiation exposure on deep space missions.

This is a critical issue scientists and engineers must solve before astronauts travel to Mars, the US space agency said in a statement.

NASA, through the Centre of Excellence for Collaborative Innovation (CoECI) at the agency's Johnson Space Centre in Houston, is teaming up with InnoCentive Inc. to offer public the opportunity to find solutions to this difficult issue.

A major health issue confronting future space travellers venturing beyond low-Earth orbit is the hazardous effects of Galactic Cosmic Rays (GCRs).

The exposure to GCRs, immensely high-energy radiation that mainly originates outside the solar system, now limits mission duration to about 150 days while a mission to Mars would take approximately 500 days.

NASA is seeking to identify key solutions that will reduce crew members' exposure to GCRs on long deep space missions by at least a factor of four.

These charged particles permeate the universe, and exposure to them is inevitable during space exploration.

The challenge is open until Dec 12, 2014.