AIM has been conceived with a triple set of objectives: asteroid deflection, technology and science. In this frame there is a very strong technology demonstration component, in fact, AIM will prepare the way for future interplanetary missions by testing deep-space optical communications, inter-satellite communication between the main AIM spacecraft and the micro-lander as well as the two CubeSats, and proximity operations in the asteroid's low-gravity environment. These are technologies relevant to future missions, such as the Phobos sample-return or novel exploration missions with distributed systems. In addition, the platform itself will be capable of performing other small deep-space missions (like missions to Lagrange-points).
The large amounts of data generated by the AIM payload and main spacecraft will be returned to Earth via its laser communication system, maintaining a high-bandwidth link back to ESA's optical ground station in Tenerife.
Optical communication in general is not a well-established technology for space applications and the recently launched ESA's European Data Relay System (EDRS), also called the space data highway, is the first commercial application. With EDRS, data from low-orbiting satellites, such as most earth observation satellites, can be transferred back by a superfast laser link on a real-time basis.
But the AIM optical communication system will need to be operated from much further away. About 75 million kilometres is being benchmarked as the maximum span for the operation, which is about half the distance between Earth and the Sun.
AIM will also validate the concept of inter-satellite links in deep space between the main spacecraft, the lander, and two CubeSats, which will be deployed to further the mission goals. It will be the first time that CubeSats are being deployed and operated in deep space. Being able to maintain communications and rendezvous operations between separate spacecraft in deep space will be essential in accomplishing future missions to Mars or other targets.
The deployment of the lander onto Didymoon, the secondary asteroid of the Didymos system, will gain experience of operating a spacecraft in extreme low-gravity environments. The bistatic low-frequency radar installed on both the main spacecraft and the lander will provide valuable information about the inside structure of the asteroid. Operating such construction in deep space requires careful planning of the mission.
AIM will thus provide an unique opportunity to trial out a range of technological and indeed scientific "firsts". To do so within the available budget many trade-off options have already been discarded during the conceptual design phase. The spacecraft design has deliberately been kept simple, with maximised on-board automation to keep operational cost low.
Moreover, the chosen technologies on-board have been designed with multi-tasking features in mind. For instance, the visual imager that will be used to fully characterize the asteroid surface and the orbital period will also be used for guidance and navigation during the journey there. The laser intended for the optical communications back to Earth will also be performing ranging measurements with the asteroid for close proximity operations and scientific studies.
This extremely tight focus in terms of mission design will lead to a new type of deep space mission, one that is low in cost, high in innovation and put together as fast as possible. Applying the lessons learned from previous interplanetary missions, such as Rosetta, as well as many studies developed within ESA's Concurrent Design Facility (Don Quijotte, Marco Polo, MarcoPolo-R), it will become feasible to ready AIM for its tight 2020 launch window and arrival only one and a half years later at the asteroid.