According to new FAST report announced by NASA on 18 February 2016 there are no recognized precautions for Asteroid Redirect Mission.
Asteroids are in the center of attention of widely considered space industry. In spite of Russian initiatives with targeting modified ICBM into asteroids, there are more interesting, less dangerous and more economy targeted solutions and conceptions. Latest changes in space law in USA and Belgium gave opportunity for developing space mining industry. Of course gathering minerals from asteroids and developing necessary technology could be very expensive, but it also could become necessary. During deep space exploration or during long term human missions, possessing minerals which could be transformed into fuel seems necessity. Such technology could also be utilized for changing trajectory of asteroids which could be danger for Earth. It is worth to remind that NASA collected data about over 1000 potentially dangerous asteroids. Planetary Defense Coordination Office (PDCO) stated that criteria for describing asteroid as potential danger are simple – diameter should exceed 140 m. But still smaller asteroids are also danger. Chelyabinsk disaster in 2013 was caused by asteroid with diameter at only 20 m. Its atmospheric explosion had power of 500 Kt and damaged over 7000 buildings and caused non-fatal injuries to 1491 people. Now it seems that NASA established research program which could be utilized in different roles – from space mining, changing asteroids trajectory or even servicing satellites remaining in deep space. It is called Asteroid Redirect Mission.
Predecessor of ARM was developed since 2012 as Asteroid Retrieval and Utilization (ARU) program by the Keck Institute for Space Studies. On 2014 NASA started financial participation under the human mission to Mars program and name was changed to Asteroid Redirect Mission. It is considered as experiment which could serve for gaining the experience for future asteroid mining (which after additional changes in law in USA and Belgium could start to develop rapidly), rendez vous and autonomous docking, autonomous spacecraft servicing and planetary defense. General conception of ARM is based on launching autonomous spacecraft which will reach asteroid, land and grab boulder from surface, take-off and fly to cislunar space. This vehicle would be powered by ring shaped, high efficient solar arrays (providing at least 50 kW of power) and will be equipped in electric propulsion to provide long range and necessary operational lifespan. Proposed propulsion is Xenon powered ion thrusters with at least 13 t of fuel. Satellite would weigh around 5.5 t and would require at least sum thrust of 300 kW. According to NASA first mission could be possible in 2020 with possible delay to 2023. ARM lander, called Asteroid Redirect Vehicle, would be launched on atop of Delta IV Heavy or Falcon Heavy, reach asteroid and return boulder to Moon orbit in five years. In announced report Formulation Assessment and Support Team (FAST) described potential target – 2008 EV5 asteroid. Asteroid was chosen due the simple reasons – its orbit and composition is well known. 2008 Ev5 is carbonaceous and due this fact it usually contains water. It is important for conception of recovering water for further splitting it into hydrogen and oxygen for producing rocket fuel in space. Another objective for ARM lander could be changing trajectory of asteroids. Asteroid Redirect Vehicle after mining and removing part of the asteroid, could also help in changing its trajectory to prevent collision with Earth. It is very good solution because it could change trajectory in deep space and preventing any risk of collision with Earth before it will get closer. Of course in case of large asteroids one ARM lander could not manage to grab boulder large enough to change trajectory, but few Asteroid Redirect Vehicles surely would manage. Whole program seems to be very promising for both commercial and scientific purposes. NASA is considering it very seriously – it is worth to mention, that in January 2016 NASA awarded contracts for the following companies to develop electric propulsion for ARM: Lockheed Martin Space Systems, Boeing Phantom Works, Orbital ATK and Space Systems/Loral.
On picture above You can see vision of ARM lander with boulder gathered from asteroid.