Europe celebrates performance of Orion service module

As the Artemis 1 mission nears its conclusion, European Space Agency and industry officials praised the performance of the Orion spacecraft’s service module, which some see as a step towards a European crewed spacecraft. The Artemis 1 mission is set to conclude Dec. 11 with the reentry and splashdown of the Orion crew capsule, shortly after it separates from the European Service Module. That module provided power, propulsion and other services for the spacecraft since its Nov. 16 launch. “We are coming towards the end of what you might think of as a 100-meter race that’s followed a marathon,” said David Parker, ESA’s director for human and robotic exploration, during a Dec. 9 briefing. “The marathon was the 10 years of effort and preparation needed to build and prepare the first European Service Module for its journey to the moon and back again, and 100-meter race has been that actual mission itself.” During that 100-meter sprint, the service module has not broken stride. “The mission has gone really perfect from our point of view,” said Ralf Zimmermann, head of moon programs and the Orion European Service Module at Airbus, the prime contractor for the module. “We have absolutely flown a perfect mission so far.” There have been minor issues with the module, he noted, “but nothing mission critical.” One persistent issue has been with devices called latching current limiters in one part of the spacecraft’s power system. Those devices, similar to circuit breakers, have opened at least 17 times during the course of the mission without being commanded to do so, NASA officials said at a Dec. 8 briefing, but have not significantly affected spacecraft operations.

A view of the aft section of the European Service Module of the Orion spacecraft taken as the Artemis 1 mission nears its conclusion. Credit: NASA

“It’s not a big deal because they can be recommanded on,” said Philippe Deloo, ESA program manager for the service module. “We don’t have an idea of what is the root cause. We are investigating, looking at all possible options.”

One possibility, he said, is that electromagnetic interference or noise in the power system is causing the latching current limiters to open. Another possibility is they are being affected by transmissions from spacecraft antennas. Engineers are doing as much testing as they can before the end of the mission to identify the cause. “This is going to be a difficult one to troubleshoot.”

Zimmermann emphasized the issue was not serious. “When they open uncommanded, the effect on the mission is not that big,” he said, noting it affects only one of eight power lines on the spacecraft. “It is a glitch, not a mission-critical failure.”

Other parts of the European Service Module have exceeded expectations. The spacecraft is producing more power than expected, yet using less power than planned. Deloo said the reduced power consumption is, in turn, linked to the spacecraft dissipating less heat than expected, meaning it has to use heaters less frequently to maintain its proper temperature. “This is one of the major lessons learned.”

The service module has also produced many of the stunning images and video the mission has returned, thanks to GoPro cameras mounted on the tips of each of the four solar arrays. “We are calling them now four selfie sticks,” quipped Matthias Gronowski, chief engineer for the European Service Module at Airbus.

The Artemis 1 mission, and excellent performance of its service modules, comes as some in Europe advocate for ESA to develop its own human spaceflight capability. Human spaceflight was one of the long-term “inspirator” concepts endorsed by ESA member states a year ago, and remains a topic of debate in Europe.

“We have to see how far politicians are willing to look into this,” ESA Director General Josef Aschbacher said in a Dec. 1 speech at a Space Transportation Association luncheon here, noting the topic would come up at a second European “space summit” scheduled for late 2023. “Does Europe want to be more independent, more autonomous in human space transportation?”

“In terms of technical capability, can Europe build a human-rated space vehicle? I don’t doubt it,” Parker said, citing the success not just of the Artemis 1 mission but work on International Space Station modules and elements of the future lunar Gateway. What would be needed, he said, was experience in end-to-end operations of a crew spacecraft and development of safety systems, like a launch abort system, as well as a human-rated launch vehicle.

During the International Astronautical Congress in September, ArianeGroup released a concept for a vehicle called Smart Upper Stage for Innovative Exploration (SUSIE). The vehicle is designed to be a new, reusable upper stage for the Ariane 6 rocket, but could be used as a cargo and crew transportation vehicle. Morena Bernardini, head of strategy and innovation at ArianeGroup, said in an interview at the conference that a cargo version of SUSIE could be ready as soon as 2030 followed by a crewed version “immediately after.”

At the briefing, Zimmerman suggested Airbus was more interested in working with others, along the lines of the existing partnership on Orion, than developing a European crewed vehicle. “We need to unite forces and share the costs,” he said, noting he was offering his personal opinion. “This is, to me, much more important than saying its Germany, France, England or Europe in total against the Americans.”

Parker said the success of the service module shows ESA is ready for the next phases of Artemis. “We learned that we can send a crew-rated capsule to the moon and back again on its first flight, and that means it gives us a lot of confidence to go forward in the next steps in Artemis.”

ESA has a contract with Airbus to produce service modules through Artemis 6, at a total value of a little more than two billion euros. ESA’s member states approved plans to produce three more service modules at November’s ministerial meeting, and Parker said the agency will get those under contract some time in 2023.

The Artemis 1 service module will end its mission about 40 minutes before splashdown when it separates from the crew capsule shortly before reentry. The service module will burn up in the atmosphere, with any surviving pieces falling into the Pacific Ocean west of Peru.

“It’s a little sad, but we’ve accomplished the mission,” Zimmerman said of the impending demise of the service module. “We are proud of all that has happened.”

“You cannot be sad when you accomplish your mission,” Deloo said. “Everything has a life. The end of the life is part of the life. As long as the life has been successful, this is a great success. So, I’m happy about it.”

Orion enters lunar distant retrograde orbit

NASA’s Orion spacecraft entered a high-altitude orbit around the moon Nov. 25 in the latest major step in the Artemis 1 uncrewed test flight. The Orion spacecraft fired the main engine in its European Service Module at 4:52 p.m. Eastern for 88 seconds. The maneuver changed the velocity of the spacecraft by about 110 meters per second, placing the spacecraft into a distant retrograde orbit (DRO) around the moon. The use of DRO is unique to Artemis 1. The Artemis 2 mission will fly a free return trajectory around the moon, while Artemis 3 and later missions will go into a near-rectilinear halo orbit around the moon, which will also be used by the lunar Gateway. NASA chose DRO for this mission since it is a stable orbit that enables testing of the spacecraft without requiring much fuel to maintain the orbit. Orion, though, will not remain in DRO for long. The spacecraft will perform a maneuver Dec. 1 to depart DRO, heading back towards the moon. The spacecraft will conduct another burn during a lunar flyby Dec. 5 to put the spacecraft on track for a reentry Dec. 11, splashing down in the Pacific Ocean off the California coast. Since its Nov. 16 launch, the Artemis 1 mission has gone well, with only a few minor issues. “In terms of overall systems failures, we haven’t seen a single thing on the rocket or on the spacecraft that would have caused us to question our reliability or our redundancy,” Mike Sarafin, NASA Artemis 1 mission manager, said at the most recent briefing about the mission Nov. 21.

A view of Earth taken by a camera on an Orion solar array Nov. 24, a day before the spacecraft entered a distant retrograde orbit around the moon. Credit: NASA

At the time of that briefing, NASA said it was looking at two issues with the spacecraft, one involving the spacecraft’s star trackers and what Sarafin called “funny indications” on the power system on the service module, where one of eight units used to distribute power opened without being commanded to do so. Neither issue, he said, were “hard concerns or hard constraints” on the mission.

“We don’t fully understand what the system and the flight hardware is telling us, but we’ve got ample redundancy and we are recovering from these ‘funnies’ that we see,” he said.

On Nov. 23, NASA reported that it lost communications with Orion unexpectedly for 47 minutes starting at 1:09 a.m. Eastern. The loss of signal took place during one of a regular series of reconfigurations of the link between Orion and the Deep Space Network. It was unclear if the problem was with Orion or ground stations, and NASA has not provided an update on the issue since first reporting the glitch.

Sarafin also said at that Nov. 21 briefing that the Space Launch System rocket that launched Orion met or exceeded requirements. “The results were eye-watering,” he said. “Everything was either on predict or off by less than 1%.”

Engineers are also reviewing the status of the mobile launch platform, which sustained some damage from the launch, including having its elevator blast doors blown off and damage to the platform’s deck. “The mobile launcher has a little bit of damage to it, but it will be ready to fly the crewed launch on Artemis 2,” he said. That mission is scheduled to launch no earlier than late 2024.

Airbus wins ESA contract to construct third European Service Module for NASA's Orion spacecraft

The European Space Agency (ESA) has signed a contract with Airbus for the construction of the third European Service Module (ESM) for Orion, the American crewed spacecraft. The contract is worth around euro 250 million. By ordering this additional service module, ESA ensures the necessary continuity in NASA's Artemis programme. The third European Service Module (Artemis III Mission) will be used to fly astronauts to Earth's neighbour in space in 2024 - the first to land on the Moon since Apollo 17 following a hiatus of more than 50 years. "Our know-how and expertise will enable us to continue to facilitate future Moon missions through international partnerships," said Andreas Hammer, Head of Space Exloration at Airbus. "By working together with our customers ESA and NASA as well as our industrial partner Lockheed Martin, we now have a reliable planning basis for the first three lunar missions. This contract is an endorsement of the joint approach combining the best of European and American space technologies." David Parker, ESA Director of Human and Robotic Exploration, said: "By entering into this agreement, we are again demonstrating that Europe is a strong and reliable partner in Artemis. The European Service Module represents a crucial contribution to this, allowing scientific research, development of key technologies and international cooperation - inspiring missions that expand humankind's presence beyond Low Earth Orbit."

The first non-crewed Orion test flight with a European Service Module (Artemis I) will fly in 2021. It is as part of the following mission, Artemis II, that the first astronauts will then fly around the Moon and back to Earth.

The ESM will provide propulsion, power, air and water for the astronauts, as well as thermal control of NASA's new spacecraft.

More than 20,000 parts and components are used in each ESM, from electrical equipment to engines, solar panels, fuel tanks and life support supplies for the astronauts, as well as approximately 12 kilometres of cables.

The first service module was delivered to NASA in November 2018 and has already been mated with the Crew Module. The fully integrated spacecraft already finished the thermal-vacuum testing at NASA's facility in Ohio, USA, and returned to the Kennedy Space Center in Florida, USA, while the second service module is now being integrated and tested by Airbus in Bremen, with delivery set for the first half of 2021.

During the development and construction of the ESM, Airbus has drawn on its experience as prime contractor for ESA's Automated Transfer Vehicle (ATV), which provided the crew on board the International Space Station with regular deliveries of test equipment, spare parts, food, air, water and fuel.

The ESM is cylindrical in shape and about four metres in diameter and height. It has four solar arrays (19 metres across when unfurled) that generate enough energy to power two households. The service module's 8.6 tonnes of fuel can power one main engine and 32 smaller thrusters.

The ESM weighs a total of just over 13 tonnes. In addition to its function as the main propulsion system for the Orion spacecraft, the ESM will be responsible for orbital manoeuvring and position control. It also provides the crew with the central elements of life support such as water and oxygen, and regulates thermal control while docked to the crew module.

Last stop before launch: Orion passes tests and returns to Kennedy Space Center

The Orion spacecraft that will fly on the Artemis 1 mission around the Moon has returned to NASA's Kennedy Space Center in Florida, USA, after finishing space environment tests. The spacecraft, including ESA's European Service Module, is now at its final destination before launch. Orion spent four months at NASA's Plum Brook station where it was subjected to the vacuum and temperatures of -175C to 75C it will experience on its flight to the Moon. After proving its space-worthiness, the electronics - including the thousands of parameters and functions of the European Service Module that control the engines, electrical power and steering the solar panels to face the Sun - were checked for electromagnetic interference. ESA's Dominique Siruguet from the European Service Module integration and verification team says "The tests were successful and the behaviour of the vehicle was good, passing all requirements." Plum Brook station was chosen for the tests because thermal vacuum and electromagnetic compatibility could be performed in the same facility. This avoided additional transport of Orion, which is the size of a two-story house. Having passed its trials, the spacecraft was wrapped and moved by truck to an airport in Ohio for its return flight on NASA's Super Guppy aircraft.

Adding wings to Orion
The tests are not completely over for Orion, at Kennedy Space Center the crew module will be further prepared and more leak tests conducted. The European Service Module has tanks for fuel, oxygen and water that are critical for the astronauts. The gas tanks are pressurised and are connected to many pipes and valves, so it vital to make sure there are no leaks.

The solar wings that generate power during its mission will be installed, as well as protective covers called the Spacecraft Adapter Jettisoned fairings for the intense moments of launch on the world's most powerful rocket.

Later this year ESA will formally transfer ownership of the European Service Module to NASA and the spacecraft will move into the ground system phase where it will be united with the SLS rocket for a lift-off to the Moon.

Orion is a key component of Artemis 1 - an uncrewed test flight around the Moon that paves the way for the Artemis 3 mission, which will land the first woman and next man on the lunar surface by 2024. ESA is designing and supplying the European Service Module for the Orion spacecraft. This provides electricity, water, oxygen and nitrogen. It also keeps the spacecraft at the right temperature and on course, propelling it to the Moon and back once it has separated from the launcher.