Number 19: 24/03/2002
A scientific publication by SGF and NEODyS

Special: the results of ESA's call for proposal

Mission: "Don Quijote"

Description of the study

Don Quijote is an asteroid investigation, geophysical characterisation and deflection technological experiment mission. The mission is made of two spacecrafts which are to be launched in separate interplanetary trajectories.
One spacecraft, which will be referred to as Hidalgo, will impact an asteroid of approximately 500 m diameter at a relative speed of at least 10 km/s while the other spacecraft, called Sancho, will arrive earlier at the same asteroid along a very different route, perform a rendez-vous and remain in orbit around the asteroid for several months before and after the impact.Sancho will also deliver a number of penetrators to form a seismometernetwork on the asteroid.At the time of the impact, Sancho will retreat to a safe distance to observe the impact without taking unnecessary risk (with an attitude appropriate to its name). It will later return to a close orbit, to observe the changes in the asteroid internal structure, shape, orbit and rotation state of the asteroid.

The study team

Deimos Space S.L. Jose A. Gonzalez (DEIMOS Study Manager); Migel Bello' Mora (Mission Analysis)
Astrimu GmbH Ralf Münzenmayer (Astrium Study Manager ); Roger Förstner (Technical Responsible); Bernd Kunkel (Instrument Inventory and performance); Karl Honnen (S/C configuration)
University of Pisa Andrea Milani; Paolo Policchi
Spaceguard Foundation G.B. Valsecchi
IPGP Philippe Lognonne
University of Bern Willy Benz



Scientific objectives

"The logic behind the proposal for the "Don Quijote" mission is clear: we want to investigate the internal structure of an asteroid, and at the same time develop and test the technology necessary, in a worst case scenario, to deflect a sizeable asteroid. Myself with my co-workers of NEODyS and Giovanni Valsecchi with his co-workers at SCN are contributing the definition of scientific goals and requirements. (...) 
The top level definition of the mission is as follows: there need to be two spacecraft, one named Hidalgo will intercept a small asteroids (nominally 500 meters in diameter) at a relative speed of at least 10 kilometres per second, and impact on it. The second spacecraft, Sancho, will rendezvous with the same asteroid a few months in advance, measure carefully the asteroid and possibly deploy a few penetrators with seismometers.  At the time of the impact, Sancho will retreat to a safe distance to observe the impact without taking unnecessary risk (with an attitude appropriate to its name). It will later return to a close orbit, to observe the changes in the orbit and rotation state of the asteroid, and to collect samples from the dust ejected by the crater formation. It will also collect the data from the penetrators, including the seismic data from the impact itself.

From a technical point of view, the main conclusion reached up to now is that seismic tomography is probably the best way of investigating the interior of bodies. In addition to he impact of Hidalgo, smaller explosive devices could be used the explorer the asteroid, recording the seismic waves with the seismometers (as already done in the Moon by the Apollo astronauts) (...)

Maximum reuse of existing expertise and technologies is envisaged, in order to reduce as much as possible the cost of the mission. Nevertheless, tailoring for the specific mission requirements and reduced spacecraft mass will be required.
Seismology is used everyday on Earth to look for minerals, gas, oil. Technology exchange in this area could benefit applications down here and in space."

from the article by Andrea Milani (NEODyS - UniversitÓ di Pisa) , taken from Tumbling Stone's special issue Link to the full article  

To know more: an interview to Deimos' Study Manager, J.A. Gonzalez

Question: "Which are the main social objectives of the mission?"

Answer: "NEO are our closest neighbours in space, but we know very little about them. Knowing more about their composition, structure, formation and history will tell us a great deal of your past and the origin of the solar system.
It has been acknowledged by the scientific community that NEO may represent a hazard to Earth. Although the probability of a big impact is very small, for the first time in human history we have the means of avoiding such a catastrophic event. But it is essential that we improve our knowledge of asteroids. We must know in detail the internal structure of asteroids, and how they respond to impacts before we can design effective mitigation methods.
The mission has a very high scientific value, but it will also help in testing technologies required for future deflection missions and raise interest in people for space exploration.

Question: "Why and how do you think that NEOs should be studied? Do you think that NEOs are a suitable target for this kind of low-budget mission and why? Which place do you think that NEO-exploration will have in the future of space missions?"

Answer: "NEO are close to the Earth: they are important from the scientific point of view, they attract the interest of people and they may have economical interest (mineral resources). Furthermore, most of the technologies needed to visit them already exist. There are two kind of missions to NEOs, both of them essential: discovery of NEO and in situ investigation of NEO.
The Don Quijote mission we are proposing addresses the second type, and is the best way of investigating the interior of these bodies, providing the best possible science for its cost."


Don Quijote in the media:

ESA's GSP web site (10/03/2003): "Don Quijote" link

Tumbling Stone n.15 (25/07/2002) - "Don Quijote (who is afraid of an asteroid?)" by Andrea Milani : link

from "BBC", (09/08/2002), "Ready to tackle Armageddon" by Ivan Noble: link

from "El Pais" (17/07/2002), in spanish: link

from "Der Spiegel" (12/08/2002), in german: link

from "La Razon" (28/07/2002), in spanish: link

from "El Nuevo Dia" (28/07/2002), in spanish: link


Downloads (click on the images to download ):

Image: an image of Don Quijote
credits: DEIMOS
Image : a drawing of the mission timeline - credits: Deimos Video: an animation of the mission (6.49 Mb) - credits Deimos
(to view it, download the coded from here)