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

Special: the results of ESA's call for proposal

Mission: "Earthguard I"

Description of the study :

Earthguard I is a study with the goal of defining a mission to search for NEOs with orbits that are mostly or completely inside the Earth's orbit (Atens and IEOs) which are difficult or even impossible to detect from groundbased locations.
The Earthguard study finally resulted in a design for a telescope (including sensor electronics, data processing etc) which could be accomodated on a plannes spacecraft such as Bepi Colombo Mercury orbiter or a dedicated spacecraft.
This dedicated spacecraft would cruise to a heliocentric orbit around 0.5 AU using low thrust propulsion such as solar sailing or solar electric (ion) propulsion.


The study team

Kayser-Threde GmbH
M. Leipold, M. Erdmann, S. Müncheberg, A. von Richter
German Aerospace Center (DLR) E. Kührt, A. W. Harris, S. Mottola, G. Hahn, D. deNiem
International Space University J. Farrow
Spaceguard Central Node G. D'Abramo
German Space Operations center N. Hanowski


 

Technical solutions

In the case of a dedicated spacecraft Earthguard-I could make use of a solar sail or an ion engine as a propulsion system to realize a low-thrust spiral transfer to an orbit closer to the Sun (in-between Earth and Mercury). The innovative solar sail technology, for which DLR has already developed functional models in cooperation with ESA, has the advantage of allowing a very compact spacecraft to be developed, compared to a conventional chemical propulsion system, therefore allowing a low-cost launch and reducing the total cost of the mission. The sailcraft possesses basically unlimited Dv capability for the orbit transfer from Earth to an orbit near the Sun, such as a circular orbit at 0.5 AU within the ecliptic plane. Here the sailcraft would "brake" against the solar pressure, such as a sailboat would tack against the wind, but in a 2-dimensional way orbiting the Sun.

This innovative technology, for which DLR has already developed functional models, has the advantage of allowing a very compact spacecraft to be developed, compared to a conventional chemical propulsion system, therefore reducing the total cost of the mission.


To know more: a question to Earthguard's Study Manager, Dr. M. Leipold

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

Answer: "Earthguard-1 will contribute to enhance the data base of detected NEOs, especially for the Earth crossers, in order to allow advance orbit simulations of these objects, say for the next 30 years. This way we can determine potentially hazardous objects which posses a chance to collide with Earth in the future, and potentially cause devastating damage to our civilization. This is vital in order to prepare for such an event, and to give as sufficent time for designing and launching a space mission which hopefully would succeed in deflecting the object from its collision course with Earth."

 


Earthguard in the media:

ESA's GSP web site (14/03/2003): "Earthguard I" link

Tumbling Stone n.15 (25/07/2002) "Earthguard I" by Stefano Mottola (DLR): link


Downloads (click on the images to download):


Image: Artist impression- credits: Kayser Threde

Image: Solar Sail functional model at the DLR facility in Cologne credits: DLR

Document: Presentation document
credits: Kayser Threde