How to apply
Deadlines
The application and selection process follows the timeline below. Prospective teams are strongly encouraged to start early, attend the information sessions, and contact the REXUS/BEXUS team before submitting if they have questions about eligibility, platform suitability, team composition or proposal feasibility.
| Activity | Dates |
|
Information Sessions Accessible on ESA Learn |
1 July 2026, 15:00 - 17:00 CEST 10 September 2026, 15:00 – 17:00 CEST |
| Private Consultation Session | Can be arranged upon request |
|
Deadline for proposal submission Accessible on ESA Learn Deliverables: Experiment Proposal Form, Letter of Endorsement |
8 October 2026, 13:00 CEST |
|
Shortlisting of teams Shortlisted teams are invited to the Selection Workshop |
Shortlisted teams will be informed by email before 31 October 2026 |
| Selection Workshop at ESA ESTEC (the Netherlands) |
24 - 26 November 2026 Selected teams are announced within approximately 2 weeks after the Selection Workshop. |
Information sessions and consultation options
Prospective applicants are strongly encouraged to take advantage of the support activities offered during the Call period, especially if they are applying for the first time, come from a university new to the programme, or are unsure whether their experiment idea is suitable for REXUS/BEXUS.
Two online information sessions will introduce the programme, the rocket and balloon platforms, the application process, eligibility conditions, selection timeline and main proposal requirements, and answer questions from prospective applicants. Both information sessions have the same content and take place on:
- Wednesday, 1 July 2026, 15:00 - 17:00 CEST
- Thursday, 10 September 2026, 15:00 – 17:00 CEST
Attendance at the information session is recommended for all students, academic staff, and professors interested in the programme.
The information sessions can be accessed on ESA Learn.
Furthermore, student teams, academic staff, and professors are welcome to request individual consultation throughout the Call period. The REXUS/BEXUS team at the ESA Education Office can provide guidance on eligibility, platform suitability, technical feasibility, proposal preparation and the application process. Early contact is strongly encouraged.
To request a consultation or submit questions, please contact: rexus-bexus@esa.int
Experiment idea
When developing your experiment proposal, start from a clear and achievable concept.
A strong REXUS/BEXUS experiment does not need to be unnecessarily complex. The programme values well thought out, feasible and educationally meaningful ideas over technical complexity for its own sake. A good proposal may start from a scientific question, a measurement objective, a technology concept, a data collection need, or a phenomenon that your team would like to investigate in the conditions offered by a sounding rocket or a stratospheric balloon.
When shaping your idea, your team should be able to explain:
- what question, objective or hypothesis your experiment addresses;
- why the experiment needs to fly on REXUS or BEXUS;
- what data, observation or result you expect to obtain;
- how the experiment will operate during the flight;
- how the experiment can be designed, built and tested within the project schedule;
- what the main risks are and how your team intends to manage them;
- what the team will learn from developing the project.
Before submitting, discuss the idea within your team, review relevant scientific and technical literature, and check whether similar experiments or methods have already been developed. Your proposal should show that the experiment is not only interesting, but also feasible, safe and suitable for the chosen platform.
You do not need to have all technical details solved from the beginning. What matters at proposal stage is that your team can present a clear objective, a credible approach, an understanding of the main challenges, and a realistic plan to develop the experiment with the support provided by the programme.
Remember to: Keep it simple.
Submit your experiment proposal
Step by step
The following steps describe what is needed to apply for the REXUS/BEXUS programme:
1. Build your team and define your project
- Form a student team fulfilling the conditions for participation described below.
- Identify an endorsing professor or academic supervisor who can support your team and your university’s involvement in the project.
- Download the REXUS and/or BEXUS User Manual from the List of documents page and read it carefully to understand the possibilities and constraints of each platform.
- Define your experiment concept, discuss it within the team, and review relevant scientific and technical literature to understand whether similar or related work already exists.
- Check that your project is realistic for the selected platform, the available development time, your team’s skills and your expected resources.
- Consider what support you may need from your university, including laboratory access, specialised tools, technical advice, testing facilities and potential funding for materials or travel of any unsponsored team members.
- Consider who could be the end users of your experiment data/technology, or if there are any business applications. Where applicable, ensure that team members from a relevant field of study are included in your team. You may also want to engage with relevant professionals.
2. Use the available support
- Attend the information sessions to gain a clear overview of the programme, the selection process and what makes a strong proposal.
- Contact the ESA Education team at rexus-bexus@esa.int for guidance on team eligibility, platform suitability, technical feasibility or questions related to your proposal or the application process. All queries are welcome. Early contact is encouraged.
3. Prepare and submit your documents
- Download the Word format of the Experiment Proposal Form and complete it following the instructions provided.
- Ask your endorsing professor or academic supervisor for a formal Letter of Endorsement, confirming support for all team members and for the proposed project.
- All team members need to register to ESA Learn and follow the instructions found in the activity “REXUS/BEXUS - Cycle 18”.
- The Experiment Proposal and Letter of Endorsement must be submitted before the deadline 8 October 2026, 13:00 CEST.
I am studying in Germany – How should I apply?
As the programme is partly funded by DLR (the German Aerospace Centre), there is a different application process for students studying in Germany. Full details can be found on the REXUS/BEXUS webpage.
Selection process
The purpose of the ESA Education Office is to build competency across all ESA Member States and Associate Member States. For this, student teams from eligible countries or universities that have not yet participated in ESA Education Office programmes, are strongly encouraged to apply.
All submitted experiment proposals will be assessed by a panel of experts. Shortlisted teams will be invited to present their experiment concept during a Selection Workshop, where the final selection will be made.
Experiment proposals are marked based on the following criteria:
| Criterion | Weighting |
| Educational Return | 25% |
| Experiment Objective | 10% |
| Technical Approach | 20% |
| Probability to Succeed / Team Organisation | 20% |
| Overall Impression | 5% |
| Involvement of students, university departments and countries new to the REXUS/BEXUS and ESA Education programmes | 20% |
For the final selection of experiments, the accommodation of experiments on the chosen flight vehicles is also taken into account. This includes possible interference between experiments, as well as available power, volume and mass budgets.
If two proposals are of equal quality, priority will be given to teams that have not yet participated in ESA Education programmes.
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). Preference is generally given to new participants, however Swedish experiments are evaluated without consideration of the previous participation of Swedish teams or universities.
Conditions for participation
Team composition
The REXUS/BEXUS programme is open to teams from universities of ESA Member States, Associate Member States, and Canada.
The core team, including the team leader, shall be composed of at least four students who are all eligible for sponsorship. There is no limit to the maximum number of student team members.
Student teams are strongly encouraged to include members representing different fields of study and profiles, so that the team has the range of skills needed to develop the experiment from proposal to flight. Depending on the project, this may include students with backgrounds in science, engineering, electronics, software, data analysis, management, logistics, finance, and communication.
ESA is committed to achieving diversity and creating an inclusive professional environment. To this end, we welcome applications from all eligible students irrespective of gender, sexual orientation, ethnicity, beliefs, age, disability or other characteristics. ESA Education strongly encourages inclusiveness within its programmes.
Teams are expected to include at least 30% women among student team members at the time of proposal submission. If this level has not yet been reached when the proposal is submitted, the team shall include a clear and credible plan explaining how it intends to reach this level by the Selection Workshop. Gender representation should correspond to meaningful participation in the project. Students included in the team should have defined responsibilities and be actively involved in the preparation, development and execution of the experiment.
Student teams may include a limited number of students who are not eligible for sponsorship. Those students may be able to attend programme events under their own funding, provided that the minimum team requirements are still met. Students who are not eligible for sponsorship may not receive access to certain facilities used within the REXUS/BEXUS programme.
Endorsing professor(s) and letter(s) of endorsement
Student teams must demonstrate that the project is supported by their university through a Letter of Endorsement signed by a professor or academic supervisor.
The Letter of Endorsement shall confirm that the endorsing professor or academic supervisor supports the students’ application, the proposed experiment and the team’s participation in the REXUS/BEXUS programme. The endorsing professor or academic supervisor is expected to provide academic and institutional support to the team throughout the project.
The endorsing professor or academic supervisor must belong to the same educational institution as the team members. If the team includes students from different educational institutions, the endorsing professor or academic supervisor must be affiliated with the same educational institution that assumes primary responsibility for the experiment.
The endorsing professor’s roles and responsibilities include, but are not limited to:
- supporting the student team in accessing and navigating university policies and processes;
- assisting the team in accessing resources such as laboratory space, equipment, technical facilities or relevant academic expertise;
- supporting the application and, if selected, the development process of the team;
- helping ensure that the experiment is developed responsibly and in line with the university’s applicable rules and procedures.
If a student team is selected to participate in the REXUS/BEXUS programme, the endorsing professor or academic supervisor will be required to complete and sign an acceptance letter.
REXUS/BEXUS Code of Conduct
All participants are subject to the REXUS/BEXUS Code of Conduct.
Personal Data Protection
As part of their participation in the REXUS/BEXUS programme, teams must provide ESA with certain personal data. Which data is collected, the purposes it is used for, to whom it may be disclosed, and how long it’s kept for are all covered in the ESA Education Privacy Notice, which can be found on the ESA Learn Platform.
Please note that the information detailed above may be subject to change without prior notice.
