Excerpt from newsmaine.net

National Aeronautics and Space Administration (NASA) has always given priority to Mars mission but an announcement that NASA made showed that the agency will first begin work on an asteroid mission before it plans for Mars mission. 

NASA Associate Administrator Robert Lightfoot said that the Asteroid Redirect Mission (ARM) is going to give a first demonstration of various spaceflight abilities that will be required to send astronauts deeper into space and also finally to planet Mars.
“The option to retrieve a boulder from an asteroid will have a direct impact on planning for future human missions to deep space and begin a new era of spaceflight”, said Lightfoot.

Asteroid will be selected by the agency with an aim to study. It will be placed into a stable orbit around the moon. According to NASA, asteroid is expected to be selected by 2019. Up to know the main candidates are asteroids Itokawa, Bennu and 2008 EV5.

The agency put efforts to find and select the best asteroid for the mission and the researchers are going to study the candidate asteroids regarding their size, rotation, shape and precise orbit. NASA notified that ARM robotic spacecraft is going to test various capabilities that will be needed for a long term human mission. For instance, the advanced Solar Electric Propulsion (SEP) technology will be tested. 

Basically, SEP is going to be used to harness sunlight power and convert it to electrical power using solar arrays. Then, the energy that is converted will be used to propel spacecraft engine. 

According to experts, this technology is slower to work than making use of traditional propulsion. The cost is the difference because SEP doesn’t need large amounts of propellant. 

According to experts, if the mission will be the long that needs long journey such as mission to Mars then large amount of propellant will be needed in order to keep the craft moving and it is something that is going to cost millions of dollars more to make it work.