If the Apollo missions used fuel cells to power them, each Orion vehicle will use a set of four solar panels supplied by European company Leonardo. Alessandro Fumagalli, head of space engineering at Leonardo, and Arnaud de Jong, director of Airbus’ solar panel team in the Netherlands, explain to us the specifics of these panels and why it will be necessary to monitor them throughout the mission.
Launched by the powerful SLS booster rocket, NASA’s Orion vehicle flies toward the moon for a mission lasting more than 25 days. His return to Earth is scheduled for December 11th.
In order to function during its mission, Orion needs a power source. This electricity is supplied by four Solar panels on the service module, in contrast to the Apollo missions, whose power generation was based on fuel cells “. This explains to us Alessandro Fumagalli, Space Engineering Manager at Leonardo, who is responsible for their production. Leonardo also provided the control and power distribution units (PCDUs) that allow the control and distribution of power to the spacecraft. Granted, this element is maybe not the “sexiest” of all the vehicle’s subsystems, but it’s ” very special and crucial for the proper functioning of Orion “. He controls” the energy generated by the solar panels and distributes it to the battery and to all Orion devices for their operation. Just as the heart pumps blood into the human body, the PCDU pumps power into the spacecraft: it’s not sexy, it’s vital “.
These panels are installed on Orion’s service module. They were launched in a folded position,” is held by a special locking mechanism that ensures the safety of the system during launch “. In orbit, the locking mechanisms are released and the four solar panels unfold in an X configuration, very characteristic of rectangular panels. We find this configuration in X on ESA’s ATV automatic transfer vehicle, whose solar panels were provided by Leonardo. Zur Reminder: At the beginning of the Orion program, NASA considered round solar panels.
With a total mass of more than 260 kilos, these solar panels, also known as “wings”, are seven meters long. They each consist of four branches with three photovoltaic panels (PVA) each with 1,242 cells based on gallium arsenide “. Overall these Around 15,000 cells supply the Orion Service Module with 11.1 kW of power for its mission “. It is interesting to note that thanks to the Due to the technological advances that have been made since the development of the ATV, the solar cells used will provide more than twice the power of the ATV solar panels, but of a similar size “.
Solar panels with a much more complex design than it seems
For those who think that Orion’s solar panel design is actually quite simple, think again! As Arnaud de Jong, head of Airbus’ solar panel team in Leiden, The Netherlands, points out for a manned mission to the moon, the requirements are in the construction and development of solar modules are complex “. To limit the stresses exerted on the plates during launch into lunar orbit and during return to Earth, Branches must tilt forwards and backwards 60 degrees. This broad movement involves the design of branches from thin solar panels reinforced with hinges and pendulums “. Concretely during the translunar injection maneuver ” The end of the branches moves a distance of 1.06 meters “. A risk that is taken very seriously and closely monitored. Each of them is “ equipped with a camera aimed at the Orion capsule to closely monitor this movement “.
Another point of vigilance, and last but not least, although the solar panels are designed to avoid resonance with the service module motors, the panels have a certain resonant frequency. However, the motors of the service module are pulsed at a certain frequency in order to be able to control the direction and position. Checking for these frequency disturbances to make sure the panels don’t resonate and fall apart is one of the goals of this test flight.