A Consumable.less Propulsion System Based on a Bare-Photovoltaic Tether (Pro-BPT) is an Early Technology Development Project funded by the Discovery Programe of the European Space Agency with 175 k€. The main goal of Pro-BPT is to demonstrate the feasibility of the Bare-Pv Tether (BPT) and assess its potential impact on ElectroDynamic Tether (EDT) technology. BPTs have a tether segment made of thin film solar cells interposed between the anodic (bare tether) and the cathodic (electron emitter) contacts. The photovoltaic segment harvests power from the Sun passively and this power is injectedit in the tether-plasma circuit to improve the performance of the BPT. In the new BPT architecture proposed in the project, the power can also be used by the payload of the spacecraft. The team of Pro-BPT includes Universidad Carlos III de Madrid (UC3M, prime contractor), the Technical University of Dresden (TU Dresden), the University of Padova, and the Spanish company SENER Aeroespacial.

Figure. Samples of Bare-Photovoltaic Tethers manufactured and tested in the project

To following tasks were implemented in the project:

  • The most promising pv technology for EDT applications was identified and an electrical and mechanical design of the BPT was prepared.
  • The feasibility of the BPT was demonstrated by manufacturing samples of BPTs and by performing a detailed electrical and mechanical characterization.
  • Electrical models for computing the current and voltage profiles of BPTs in the active and the passive mode were prepared and incorporated in the simulation tool BETsMA v2.0.
  • The performnaces of BPTs were studied through simulation and a roadmap for the development of the technology was prepared.


G. Sánchez – Arriaga
Associate Professor
M. Sanjurjo
Associate Professor
A. Del Pino
PhD Student

L. Tarabini Castellani
Inudstrial Project Manager
S. García
System Engineer
A. Ortega
Mechanical Leader

E. Lorenzini
Full Professor
C. Bettanini
Assistant Professor
G. Colombatti
Assistant Professor
A. Valmorbida
Research Associate

M. Tajmar
Full Professor
L. Peiffer
Research Scientist