Detection logic
Worked on improving the wake-up subsystem's launch-detection logic.
Earlier work · Embedded flight software
YPSat
How does a payload know that it is time to wake up?
I worked on YPSat's wake-up subsystem, improving its detection logic and contributing to tests and integration. The ESA payload flew on Ariane 6's first launch, recording key moments of the flight and views of Earth from orbit.
- My role
- Software · Test & integration
- Where
- ESA · Netherlands
- When
- 2023–2024 · Part-time
The mission
Be ready before the view appears.
YPSat was built by ESA's Young Professionals to witness Ariane 6's inaugural flight. Its imaging mission covered fairing separation, satellite deployment and Earth from orbit.
The payload stayed fixed to the launcher's upper stage throughout its mission. To catch the opening of the fairing, its systems had to become ready during ascent, while conserving battery power before launch.
Waking up
From a physical event to a software decision.
The wake-up subsystem monitors sensor readings autonomously. It looks for launch-related acceleration, then uses pressure measurements to confirm the event: a change in the environment becomes a decision to power up.
Once the rest of the payload is on, the onboard computer coordinates the mission sequence, including image acquisition. Wake-up detection is one part of that larger chain, linking sensors, power and operations.
The wake-up sequence, at a glance.
- Hibernation
Wait
Keep most of the payload off to conserve battery power.
- Acceleration
Sense
Monitor motion for the acceleration associated with lift-off.
- Pressure
Confirm
Assess barometric pressure to confirm the launch event.
- Power-up
Wake
Activate the electrical power system to start the payload.
My contribution
Software within a flight system.
I worked on improving the detection logic and contributed to the test and integration phase. The software had to work as part of the payload, within its interfaces and mission sequence.
Test & integration
Contributed to the test and integration phase, alongside technical coordination across the project.
Documentation
Wrote technical documentation for an operational payload.
Why it belongs here
This project connects instrument software to the observation it enables. A useful measurement depends on the instrument becoming ready at the right moment, as well as on what it can measure.
In flight
The view that came back.
YPSat flew on 9 July 2024, aboard Ariane 6's inaugural launch. The mission returned images and video of fairing separation, satellite deployment and Earth from orbit.
This is the team mission's outcome. My part was in the detection logic, tests and integration behind the payload's wake-up subsystem.
System context, sources & illustration notes
Reading the sequence
The sequence above summarises ESA's public description of the wake-up subsystem. It explains the functional chain rather than reproducing the flight firmware, thresholds, timing constants or measured sensor data.
Public subsystem descriptionMission outcome & personal scope
ESA documents the flight and returned imagery. These mission-level results do not reconstruct the subsystem's in-flight sensor readings or trigger path. My contribution concerned embedded detection logic, tests and integration, alongside technical coordination and documentation.
ESA · post-launch updateConceptual drawings & flight image
The generated paper drawings introduce the payload and its electronics. Their geometry is illustrative, not a reproduction of the flight hardware. The Earth photograph is actual YPSat mission imagery, credited to ESA–YPSat.
Image source & licence