BEXUS 36 returns to flight
From 15 to 22 August 2026, students, engineers and programme partners worked through a compact campaign focused on preparing, integrating and launching the experiments.
At Esrange Space Center in northern Sweden, the final hours before a balloon launch are shaped by a familiar sequence of checks. Teams confirm data connections, follow the weather forecast and work through procedures that have been rehearsed in advance.
The 2026 campaign followed an unsuccessful launch in October 2025, when an issue during launch prevented the balloon flight from proceeding as planned and the experiments from completing their missions. Following the investigation and coordination between the REXUS/BEXUS partners, a new flight opportunity was organised for August 2026.
Preparing BEXUS 36 for launch
The campaign included the following experiments:
The experiments were kept in the qualified configuration used for the 2025 campaign. The focus was therefore on ensuring readiness rather than redesign the experiments. Before travelling to Sweden, the teams inspected their hardware, carried out authorised maintenance or component replacements where needed, and repeated complete functional tests at their universities.
This preparation was especially important because the campaign schedule left little room for troubleshooting on site. Each experiment had to arrive largely assembled, tested and supported by a clear operational plan.
“The preparation for the campaign was intense. We had to pick up the experiment again after a break and get everything ready in a very short amount of time," said a student from the SUNFLOWER team. “At first, it was a bit challenging to get back into everything and understand what still needed to be fixed, but as a team we managed to organise ourselves quite quickly. We dare to say we are proud of ourselves, emotionally and practically speaking.”
A compact campaign
The campaign ran from 15 to 22 August 2026, with one clear objective: preparing BEXUS 36 for launch as efficiently as possible.
The first day was dedicated to final experiment assembly, inspections and individual functional tests. On the second day, the experiments were tested as part of the complete gondola system, including power, communication and operational interfaces. From the third day onwards, BEXUS 36 was ready to launch as soon as weather and operational conditions allowed.
The compressed schedule required close coordination between the experiment teams and the engineers supporting the campaign. Issues that might normally be addressed over several days had to be anticipated before arrival and handled quickly when activities began.
“The campaign was absolutely amazing! The fact that the launch only happened at the end of the week made it a bit more stressful maybe, as we were wondering if the weather was ever going to be good enough. But it was still overall very nice, it’s always good to get to know and talk with the other teams and the organisers. And Esrange is definitely a very cool place to spend a week!” shared a student from the GLITCH team.
Launch and flight
On Friday 18 August, after a few days of windy and rainy weather, BEXUS 36 was cleared for launch.
At 11:02, the balloon lifted the gondola away from Esrange, carrying the student experiments into the stratosphere. The launch marked the culmination of the teams’ preparation and the start of the operational phase of their experiments. BEXUS 36 reached an altitude of 27.3 km and floated for almost 3 hours.
The gondola landed at 15:47 and was recovered in less than 2 hours. Preliminary assessments indicated that all experiments performed nominally, pending confirmation through post-flight data analysis.
“The experiment was extremely successful and all the expected features worked” concluded a student from the SVAROG² team. “We managed to deploy the sail and spin it across a wide range of speeds, collecting data for future designs. Also, we tested the sail beyond the design point to see how fast it can be deployed without damage.”
Analysing the results
The flight data will now be analysed by the teams at their universities. Their results will contribute to student theses, academic publications and future experiment developments.
Beyond the individual datasets, the campaign gave the students experience of preparing and operating hardware in a real flight environment, working to fixed interfaces and procedures, and responding to technical and operational constraints as part of an international project. The teams can now turn to analysing their data and completing the final phase of their experiments.
Call for proposals is open
Interested in flying your own experiment? The call for proposals to take part in the Cycle 18 of the REXUS/BEXUS programme is open. The call will close on 8 October 2026 at 13:00 CEST. Find more information here: ESA - Your student experiment could fly on a sounding rocket or a stratospheric balloon
About the programme
The REXUS/BEXUS programme is realised under a bilateral Agency Agreement between DLR and SNSA. The Swedish share of the payload is made available to students from other European countries through collaboration with ESA. EuroLaunch, a cooperation between SSC and DLR MORABA, is responsible for campaign management and launch operations. Experts from DLR, SSC, ZARM, and ESA provide technical support throughout the project.
For more information about the REXUS/BEXUS programme, visit: https://www.esa.int/Education/Rexus_Bexus