Science goals and objectives of the NEST mission

The NEST mission will explore the near-Earth space and rendez-vous with several Near-Earth Asteroids, including the Potentially Hazardous Asteroid Apophis.

NEST is a mature, flexible, modular mission concept, being designed for a launch with ESA ARIEL Spacecraft in 2028, and a delivery in the Sun-Earth Lagrance Point L2, from which it will start its journet in the near-Earth environment. NEST aims at rendez-vous with multiple near-Earth asteroids, presenting a variety of physical properties. In the baseline scenario, we consider 2 NEAs to be visited with mission duration of less than 5 years.

Our first target will be the 370-m Potential Hazardous Asteroid (99942) Apophis, which will have in 2029 a very close approach with the Earth (< 40000 km). Multiple impact solution exist durig the course of the next century. Obtaining a detailed, in-situ physical characterisation of this body is of paramount importance fro being able to make precise predictions of future trajectory of Apophis.

For the second mission target, presently we identified 36 promising NEA small (< 100 m) targets and hundreds of preliminary 2- (or 3-, for a possible extened mission) asteroid sequences for the time window 2028-2032. We can easily adapt our mission scenario to varying constraints in terms of, e.g., launch date, propulsion specifics, mission architecture and duration.

Our mission can be broken down into several complementary modules:

i) Radar investigation of asteroid interiors; for the first time ever, the radar technique will be used to in-situ characterise asteroid interiors, in different size regimes. Information on composition, porosity, and their spatial variation will be obtained.

ii) Complementary in-situ scientific investigation, using also a smallsat for Apophis investigation; a mothercraft/daughtercraft mission architecture will allow to perform both remote and in-situ investigation with a number of scientific instruments. The mothercraft will release a smallsat (daughtercraft) at Apophis, and will operate in proximity of each target for few months, allowing a complete characterisation of surface, subsurface and interior properties of Apophis and of the selected target(s).

NEST mission architecture relies on significant payload heritage and high-TRL available technology, based on our established Italian-German-French-Swiss consortium, with important contribution from Poland. However, we will consider possible complementary contributions from further ESA member states and partners willingly.