High-Altitude research

BOLT

Beamed Optical Light Transmission

Flying on rexus

The Mission

BOLT is a payload experiment and will be launched on REXUS 37 next March, reasearching Li-Fi subsystem communication for space applications.

The Experiments

BOLT explores Li-Fi for intra-satellite communication: a free-space optical link beaming data between subsystems without radio interference. The mission subjects the hardware to the same shocks, cold starts and potential faults we expect in orbit, giving us a realistic playbook for future payloads.

Building on the research of project SatelLight, we are part of the REXUS/BEXUS Programme, participating in the REXUS 37/38 campaign and flying on REXUS 37. It pushes light-based communications through launch loads and microgravity, helping us map out how optical links behave when the stakes - and the vibrations - are high.

Render of the BOLT payload for REXUS

LiFi experiments on the REXUS payload bus

  • Custom Test Controller: Data collection and ground communications is coordinated by our custom developed Bifröst TestController
  • Experiment 1: Space Disco examines the effects of atmospheric scattering and absorption on RGB-LiFi implementation
  • Experiment 2: Bouncy Castle tests the error resistance of LiFi against the temporary blockage of the optical path
  • Experiment 3: Floaty Boi implements a mostly isolated sensor, which studies the feasibility of combined power- and data transfer using LiFi.

BOLT will stress test the LiFi research from the Smart Sensors Group in a near-space environment and should raise the technology’s Technology Readiness Level.

Mission in Progress

Timeline

November 2025

REXUS/BEXUS Selection

At the selection workshop, our BOLT experiment was selected by the REXUS/BEXUS team to take part in Cycle 17 and fly on REXUS 37.

January 2026

Preliminary Design Review

Following a real-world aerospace development cycle, we presented our first design to a committee of experts from DLR, SNSA, and ESA and passed our PDR.

June 2026

Critical Design Review

After many iterations of our preliminary design, we reached design version 2.0. With the first prototypes assembled and the CDR passed, we are on track for launch.

August 2026

Integration Progress Review

Now that the critical design is finalized, we are deep in the process of iterating our prototypes, writing software, and getting our hands dirty with machining.

October 2026

Environmental Testing

At ZARM in Bremen, our experiment will undergo a series of vibration tests that simulate the forces BOLT will later have to endure on the rocket.

October 2026

Experiment Acceptance Review

If all these tests pass, our experiment will be accepted and we will have cleared a major barrier on the path to launch.

December 2026

Integration Week

At MORABA in Munich, BOLT will be integrated and tested with the actual REXUS systems.

January 2027

Bench Test

We will return to MORABA to run a full bench test with BOLT. There, BOLT will be mounted in its flight configuration, and the electrical systems will run through the launch sequence.

March 2027

Launch Campaign

Our team will travel to the far north of Sweden to finally launch BOLT from Esrange Space Center. We will run through simulations and tests until everyone gives the go-ahead. Then BOLT will be propelled to an altitude of roughly 85 km to perform its experiments.

What is REXUS?

Rocket Experiments for University Students

The REXUS/BEXUS programme is realised under a bilateral Agency Agreement between the German Aerospace Center (DLR) and the Swedish National Space Agency (SNSA). The Swedish share of the payload has been made available to students from other European countries through a collaboration with the European Space Agency (ESA). EuroLaunch, a cooperation between the Swedish Space Corporation (SSC) and the Mobile Rocket Base (MORABA) of DLR, is responsible for the campaign management and operations of the launch vehicles. Experts from DLR, SSC, ZARM and ESA provide technical support to the student teams throughout the project. REXUS and BEXUS are launched from SSC, Esrange Space Center in northern Sweden.

DLR Logo DLR Logo Rymdstyrelsen Logo Rymdstyrelsen Logo ESA Logo ESA Logo

Work with us

Meet the Team

BOLT is realized by the orbital division of the Hamburg Space Team. Interested in learning more? Reach out!