Design, Testing and Qualification of a Deployable Rigid Boom System for Electric Field Measurements on board a Sounding Rocket

The Lower-thermosphere–ionosphere (LTI) is a unique region located between
80-200 km above the surface of our planet. It is a transition region between the
atmosphere and space, making it a complex system coupled to both regions.
As such, it is home to a number of unique characteristics, one of which is the
energy sink the region acts as. A primary source of energy deposited from the
solar wind to the region is through Joule Heating (JH), of which there are still a lot of open questions.
SYstematic Study of lower Thermosphere Energetics by a Rocket (SYSTER)
is a sounding rocket mission due to launch in late 2025 from Esrange,
Sweden, with the objective to provide measurements to answer some of
these uncertainties. Sounding rockets have long been the go-to method of
performing in-situ measurements in the LTI, as the altitudes in which it resides
make it hard to access by other means.
To fulfill the mission goals the electric field needs to be determined. This is
done through electric field probes, that collects measurements as the rocket is
traveling through the region. To avoid interference from the rocket itself, these
probes should be well removed from the body. This can be done by placing
them at the end of long extendable booms.
The mechanical design of such a boom, is the topic of this thesis.
For this purpose a Rigid Deployable Boom System (RDBS) was designed,
manufactured and tested. The RDBS designed is a two hinge solution, capable
of extending the electric field probes 3.3 meters from each other. Finite Element Analysis (FEA)
simulations for the launch loads (static loads & random vibrations) were
performed, and showed excellent performance of the RDBS with low stresses
across all components.
The deployment of the RDBS was both simulated and tested on a spin
table, and both methods show promising results. During the deployment test,
the RDBS got caught on the test setup, causing a glue joint to break and
twisting the boom. Despite this, the boom deployed fully and locked both
hinges meeting the primary goal of the test.
Future work includes refining the test setup and redoing the deployment test
to ensure successful deployment in flight.