QUBE II – The Future of Secure Communication

14.11.2025

Mission Overview

QUBE-II is the next step following the successful QUBE mission. The mission aims to demonstrate quantum-based key exchange between a CubeSat and a ground station for the first time, marking an important step towards cost-effective, global, and secure communication.

Compared to QUBE, QUBE-II features a more powerful platform, an improved optical infrastructure, a larger optical aperture, and more precise alignment. This significantly improves the link budget for satellite-based quantum key distribution. While QUBE has already successfully tested the core technology of QKD on a CubeSat, QUBE-II is intended to demonstrate, for the first time, a quantum-key exchange between a CubeSat and an optical ground station.

QUBE-II Successfully in Orbit

QUBE-II was launched on Sunday, May 3, 2026, as part of SpaceX’s CAS500-2 rideshare mission on a Falcon 9 rocket from Vandenberg Space Force Base in California. The satellite was successfully placed into orbit; only a few hours after launch, first contact was established and the proper functioning of the satellite was confirmed.

With the successful launch, the next mission phase has begun: commissioning, functional tests, and preparation of the QKD experiments between satellite and ground station.

Key Mission Features

• Demonstration of real quantum key generation and distribution
• Quantum key exchange between CubeSat and ground station
• Improved QKD link budget from space
• Larger optical aperture compared to the predecessor mission QUBE
• Very high pointing accuracy: < 0.1°
• Platform size and mass
  • 8U CubeSat
  • Dimensions: 100 × 226.3 × 454 mm
  • Total mass: 11.5 kg
• Launch: May 3, 2026
  • Launch vehicle: Falcon 9
  • Mission: CAS500-2 Rideshare
  • Launch site: Vandenberg Space Force Base, California, USA
  • Status: successfully launched, first contact established

QUBE-II in the Media

The popular science channel Urknall, Weltall und das Leben recently dedicated an episode of its video podcast to the QUBE-II mission.

Links Related to the Launch of QUBE-II

• May 3, 2026: SpaceX: CAS500-2 Mission
• May 3, 2026: Exolaunch: CAS500-2 Mission
• May 5, 2026: Kongsberg NanoAvionics: QUBE-II on SpaceX CAS500-2

Media Coverage of QUBE-II

• May 16, 2025: scinexx: QUBE, QUBE II und die Zukunft
• November 26, 2024: Süddeutsche Zeitung: Wie Satelliten Kommunikation weltweit abhörsicher machen sollen
• November 27, 2025: Mainpost: Für Erdbeobachtung und Telekommunikation: Zehn Würzburger Satelliten vor dem Start ins Weltall

Consortium

• OHB System AG consortium leader
• DLR – Institute of Communications and Navigation
• FAU Erlangen-Nürnberg
• LMU Munich
• Zentrum für Telematik e.V.

Funding

QUBE II is funded by the Federal Ministry of Research, Technology and Space.