Don Quijote is going to fight Asteroids

ESA is preparing a future mission to test whether a spacecraft could successfully deflect an asteroid on a collision course with Our planet. The mission, Don Quijote, is named after the fictional Spanish knight from Miguel de Cervantes renowned novel, El ingenioso hidalgo don Quijote de la Mancha, who charged against a windmill, thinking it to be a giant. But this time will be an asteroid and a real giant.

credit: Sérgio Sousa

ESA's Don Quijote is an asteroid deflection precursor mission concept, designed to assess and validate the technology that one day could be used to deflect an asteroid threatening the Earth.

The mission concept consists of two spacecraft which are to be launched in separate interplanetary trajectories:

• An Orbiter spacecraft, called Sancho After arriving to the target asteroid and be inserted into an orbit around it, it will measure with great accuracy its position, shape, mass, and gravity field for several months before and after the impact of the second spacecraft. In addition, the Orbiter will operate as a backup data relay for transferring all the data collected by the Impactor during approach and image the impact from a safe parking position. It will also investigate the surface composition of the asteroid and, after completion of the primary objective, carry out the ASP-DeX.
• An Impactor spacecraft, named Hidalgo After following a very different route from that of the Orbiter, the spacecraft will Impact an asteroid of approximately 500 m diameter at a relative speed of about 10 km/s. This spacecraft will demonstrate the ability to autonomously hit the target asteroid based on onboard high-resolution camera. 

The primary objective of the Don Quijote concept is to impact the target Near-Earth Asteroid (NEA) and to be able to determine the deflection resulting from the impact. To achieve this, it will measure with extreme accuracy the asteroid's position in space before and after impact.

There is also a secondary objective, involving the so-called Autonomous Surface Package Deployment Engineering eXperiment (ASP-DeX). In this experiment a small device, an Autonomous Surface Package or ASP, would be released from the Orbiter spacecraft while it's on orbit about the asteroid. It would then passively free-fall towards the asteroid surface after its release, and touchdown within a certain distance of a target landmark, most likely the crater resulting from the impact of the Hidalgo spacecraft.

The key moment of the Don Quijote mission: the Impactor spacecraft (Hidalgo) smashes into the asteroid while observed, from a safe distance, by the Orbiter spacecraft (Sancho)

Credits: ESA - AOES Medialab

It will study the asteroid's surface chemical composition and the characterization of the thermal and mechanical properties of the asteroid surface.
 
The mission of the Impactor spacecraft is a peculiar one: the spacecraft should remain in a dormant state during most of its lifetime until the last days of asteroid approach where the autonomous guidance takes over and targets it toward the asteroid. During the cruise phase only minimum functions are required but before the impact all the sub-systems have to be up and functional with high level of reliability.

A major system design constraint is also on the spacecraft mass that (contrarily what normally is required) shall be above a certain threshold to achieve the required asteroid orbit deflection and lower than the launch system escape performance.

In order to increase the impact mass, the propulsion module is not jettisoned at escape but is kept attached during the whole mission until impact as a ballast.


Possible Targets

Originally, the ESA identified two near-Earth asteroids as possible targets: 2002 AT₄ and (10302) 1989 ML. Neither asteroid represents a threat to Earth. In a subsequent study, two different possibilities were selected: the Amor asteroid 2003 SM84 and 99942 Apophis; the latter is well known to us as, it will make a close approach to Earth in 2029 and 2036.


Present status

According to ESA the Don Quijote project is still in assessment phase, there is no confirmed launch date yet.

A movie presentation of the mission: CLICK HERE