Self-Deployable Deorbiting Space Structures


A design based on patents by Anders Schmidt Kristensen and Lars Damkilde from Aalborg University Esbjerg using a self-deployable highly elastic frame to deploy a drag sail is developed and called a Self-deployable Deorbiting Space Structure (SDSS).
An initial prototype of the SDSS for semi-controlled debris removal was launched in 2014. The SDSS module consists of 3 main systems, i.e. the drag sail unit (DSU), the release unit (RU) and the housing unit (HU). In the redesign a storage lid is introduced whereby the folded drag sail is completely separated from the housing unit during the release process. During the research, an updated version of the SDSS version are made for CubeSats. The prototype is for a CubeSat which will be scalable.

A crucial part of deorbiting of satellites with SDSS is the size of the DSU by gaining a higher folding ratio form from 1:3 up to 1:9, the area will increase 9 times. The unique physical behavior is utilized in the SDSS module for semi-controlled debris removal. Folding elastic structures by twisting, i.e. applying a torsional moment, triggers instability in the form of bifurcation. Multiple bifurcations can be obtained and for highly elastic structures, the elastic material behavior is maintained. The number of bifurcations determines the unfolded to folded ratio.
This research looks into the behavior of a highly elastic frame (HEF) during folding identifying several parameters by which the bifurcation is influenced, e.g. slenderness, cross sectional. Non-linear FEA are used for parameter studies identifying relevant force-displacement and/or moment-angle relations for determination of bifurcation points. This will be compared to analytical solutions and experiments. These studies will give insights in the bifurcation and the archived force to unfold the DSU in comparison to the cross section.

This research, using self-deployable structures for spacecraft applications, is unique and requires multidisciplinary research areas such as non-linear structural analysis, electronic systems, mechanical engineering, material technology, spacecraft dynamics and satellite mission analysis.


AAU Space Group - Researchers

Anders Schmidt Kristensen

Associate Professor

Department of Energy Technology

Phone: +45 9940 7673


Self-Deployable Deorbiting Space Structures






November 2007 - January 2021


  • Aalborg University
  • GomSpace
  • Airbus
  • University of Surrey