|Mars image, NASA, used from public domain.|
NASA has announced plans for new Mars missions in 2020. The rover's chassis and landing system will be based on the $2.5 billion Curiosity rover and the proven design will bring down the cost of the 2020 mission to about $1.5 billion. NASA Administrator Charles Bolden said, "with this next mission, we're ensuring America remains the world leader in the exploration of the Red Planet, while taking another significant step toward sending humans there in the 2030s."
The latest rover on Mars, the Curiosity rover, is mainly designed to measure the radiation levels on Mars, determine the habitability of humans on Mars and investigate the chemical composition found on Mars instead of finding signs of life on Mars. The most effective way to confirm the exisitence of life on Mars is to send the carefully selected samples back to Earth for more accurate analysis and data. The 2020 rover should help prepare NASA for the purpose although the precise details of the mission have not been drafted out and will be determined by a scientific team earliest by next year. The scientific instruments on board will be based on the best combination from all the instruments proposed by all parties, just like the Curiosity rover.
Sample returning is the top priority of the report from Mars Program Planning Group (MPPG) and this will test drive NASA's ability to send humans to Mars in 2030s since sending samples back to Earth is technically similar to sending astronauts to Mars and returning them safely. The report suggests that humans will be involved in the sample-returning process: a rover will launch the samples into deep space, the astronauts abroad the Orion's capsule will intercept the samples in deep space and make sure that the transfer process will not contaminate the samples, then the astronauts will return the samples back to Earth.