In parallel, three European Service Modules (ESMs) are being integrated in the cleanrooms of Airbus in Bremen. ESM-3 integration is nearly complete, ESM-4 integration is well underway, and the freshly delivered ESM-5 structure is the focus of initial integration procedures.
Each ESM calls for the integration of around 22,000 pieces. NASA has never before entrusted a non-US prime, Airbus via ESA, with constructing a mission-critical component for an American human spaceflight mission.
Along with the ESA, Airbus is delivering half of the spaceship that will return humans to the Moon, carrying them farther into space than ever before and returning them safely to Earth, according to Marc Steckling, Airbus’ Head of Space Exploration. Airbus has already delivered the first two ESMs, and ESM-2 is presently being installed into the Orion spacecraft at Kennedy Space Center. With the delivery of the ESM-4 structure in the summer of last year and the ESM-5 structure just before Christmas, the company has commenced serial manufacturing. He said that Airbus cleanroom facilities had been optimised to host three ESMs simultaneously, and the business is on schedule to satisfy NASA’s annual delivery requirement of one ESM.
The ESM is a crucial component of NASA’s crewed Orion spacecraft, as it provides the primary propulsion system and enables orbital manoeuvring and positioning control. In addition to generating and distributing electrical power, the ESM provides the crew with essential life support materials such as water and oxygen. In conjunction with the crew module, the ESM manages the temperature environment. Additionally, the unpressurised service module can transport additional cargo. ESA has invested approximately €2 billion in the Orion programme and hired Airbus to lead the European collaboration and construct six ESMs.
The first Artemis mission with an Orion spacecraft powered by the ESM-1 occurred in 2022. The spacecraft traversed more than 2 million kilometres, was exposed to temperatures above 200 degrees Celsius and reached a top speed of 40,000 kilometres per hour (or 11 kilometres per second). According to an Airbus press release, all tested systems operated well and reliably, some even exceeding expectations.
Florida received the ESM-2 in October 2021. It is now undergoing testing and integration at Kennedy Space Center. It will be a component of the crewed Artemis II Mission, transporting the first astronauts to orbit the Moon and return to Earth since 1972. The launch of Artemis II is presently scheduled for 2024.
ESM-3, currently undergoing final integration, will power the Artemis III Mission, which will witness the first woman and person of colour to step foot on the Moon. ESM-3 delivery is scheduled for the second half of 2023. This endeavour is scheduled for no sooner than 2025.
The ESM-4 structure arrived at Airbus’ cleanroom in Bremen in June 2022 and is undergoing integration. The newly-arrived ESM-5 structure is now undergoing construction.
ESMs 4, 5, and 6 will be utilised for the Artemis IV to Artemis VI missions, the first two representing the European contribution to the international Gateway, a lunar-orbiting space station. ESA and NASA intend to construct a Moon ecosystem (Gateway, Argonaut) to comprehend better and explore what the Moon has to offer and, in the long run, to prepare for crewed trips to Mars.
The ESA ministerial council authorised further ESMs 7, 8, and 9 in November 2022, and Airbus is presently finalising its offer to provide them.
The Orion ESM is cylindrical with a diameter and height of roughly four metres. It weighs just over 13 tonnes during launch, constituting nearly 60 per cent of the Orion spacecraft’s overall mass. Fueling the main engine, eight auxiliary thrusters, and twenty-four smaller thrusters for attitude control, it’s 8,6 tonnes of fuel. The European Service Module is positioned beneath the United States’ Kennedy Space Center crew module. Collectively, they constitute the Orion spacecraft.
Engineers from Airbus build the ESMs in collaboration with ESA and industry partners, including ten nations’ suppliers. ESM production is based on Airbus’s expertise with the Automated Transfer Vehicle (ATV), which flew five times to the ISS ( International Space Station) between 2008 and 2015.
Artemis I success
Artemis I was the first in a series of increasingly complicated missions that laid the groundwork for human exploration in deep space and was a significant step towards returning people to the Moon, with Europe playing a key role in the greatest space adventure in human history.
This initial flight provided a wealth of information, and all ESM-related mission goals were fully accomplished. Initial analysis of the test data indicated that the Orion spacecraft spent significantly less propellant and electrical power than predicted while producing significantly more power. As planned, the propulsion unit delivered thrust for precise orbital manoeuvres and vehicle attitude control. Due to the excellent performance of the propulsion system, additional flight test goals were executed to characterise the vehicle better. As intended, the ESM main engine was fired many times for a cumulative total burn duration of 10 minutes. NASA has reported that the overall performance of the mission exceeded expectations, with about 2 tonnes of fuel remaining at the mission’s end. This will make it possible for future missions with a longer length or greater mass (e.g. Gateway modules being transported by ESM). Most amazingly, solar panels produced 15% more electricity than anticipated. Simultaneously, the spacecraft required less electricity than anticipated due to lower temperature changes.
