1. QCS – Quantum Communication Satellite Technion – Israel Institute of Technology
1
QCS - Quantum Communication Satellite
Technion - Israel Institute of Technology
Faculty of Aerospace Engineering
Project supervisor: Jacob Herscovitz
Project team members:
• Project Manager: Neta Engad
• Systems Engineer: Or Rivlin
• Structure & Thermal Control: Elya Pardes & Alex Zibitsker
• Propulsion: Nati Rozensweig
• Attitude Control: Or Rivlin & Shalev Eidelsztein
• Orbit Design: Neta Engad & Michal Zalmanovich
• Power & Electricity: Nati Rozensweig & Oron Meller
• Communication: Oron Meller
• Launcher: Avichay Yaish
• Space Environment: Michal Zalmanovich & Avichay Yaish
• Reliability: Avichay Yaish
• System Level Analysis: Neta Engad & Or Rivlin
QCS is the final project of a team of students in the Faculty of Aerospace Engineering at the
Technion. The project's focus was the design of a Quantum Communication Satellite (QCS)
with the main goal of delivering encrypted quantum communication keys between two
different ground stations using a satellite constellation.
The project involved cooperation with the Waterloo University, Canada, whose role was to
design the optical component allowing quantum key distribution in the space environment,
which was used as the satellite’s payload.
The Technion team designed a satellite bus consisting of the main subsystems: ADCS
(Attitude Determination and Control System), Propulsion System, Electric Power,
Communication, Structure and Thermal Control. Furthermore, the following mission
segments were designed as well: Orbit and Constellation Design, Space Environment,
Launch Plan, Reliability, Risk Management and Full Scale Development Work Plan.
The spacecraft’s conceptual design process emanated from the payload’s needs, its
limitations and capabilities which were detailed in the requirements document made by the
Waterloo team, with additional requirements defined by the Technion team and project
supervisor.
During the first semester an initial design iteration of the satellite was performed which
resulted in a micro-satellite class spacecraft with a mass of 33 Kg. For this concept the
structure, power subsystem, constellation orbits and attitude control system were

2. QCS – Quantum Communication Satellite Technion – Israel Institute of Technology
2
investigated. At the end of the semester a Preliminary Design Review was held, leading to
the proposal of attempting to design a smaller spacecraft that would adhere to the CubeSat
standard.
During the second semester a qualitative decision process was undertaken to determine
whether to go forth with this major pivot or stay with the previous concept. This ultimately
resulted in the decision to redesign the spacecraft. During the semester several additional
topics were investigated: Communication, Propulsion, Environmental Conditions, Reliability,
Risk Management and Full Scale Development Work Plan.
Finally, at the end of the semester a Critical Design Review was held and the final design was
presented. It featured a 22 Kg 20U CubeSat that adheres to all the requirements set forth at
the beginning of the project.
The main results of the design process are presented below:
 A satellite constellation consisting of 80 satellites in 8 orbit plane organized in a
Walker constellation pattern – 80/8/3.
 Optimized deployment and maintenance maneuvers requiring 0.62 [kg] fuel mass
and a disposal solution.
 A full mission scenario simulation including ADCS, power, propulsion, thermal
control and communication.
 An ADCS hardware architecture which enable the satellites to cycle between various
tasks such as maneuvers and pointing, with software including controllers and
estimation algorithms.
 A cold gas propulsion system including 2 tanks, using Krypton gas as the propellant.
 Complete SolidWorks models of the satellite, including ADCS, power, propulsion
communication and the payload components, amounting in a total a weight of 22
[kg] organized in a configuration of a 20U CubeSat. Static and dynamic load
simulations and thermal design.
 A launch plan for deployment of all the satellites in the shortest time possible.
Figure 1: Satellite Assembly and Constellation Concept