Written for E&T
Forty-five years after the final Apollo lunar landing, the world’s space agencies are finalising plans for mankind’s return to the Moon – this time to stay for the long term.
However, today I am here to see another technology marvel. Before entering the giant hall, I must don an unfashionable clean room cap and coat and slip into disposable shoe covers. Despite the gloomy weather, the atmosphere in the hangar is full of excitement. Oliver Juckenhoefel, who leads the space department of Airbus’ operations in Bremen, welcomes me.
Right now, the room is rather quiet, but Juckenhoefel says some 200 people operate in three shifts seven days a week on what might be one of the most exciting pieces of technology being built in Europe – the service module for the Orion spacecraft.
The service module is one half of the vehicle expected to return humans to the lunar orbit in the early 2020s. There is a lot of secrecy around the technology. I can take a picture of the module’s fuel tanks, but taking photographs of the 4m-high and 4m-diameter body of the module itself is strictly off limits.
Engineers are installing cables and wires on the module, which is surrounded by scaffolding. As Juckenhoefel says, everything is on track for the module to be delivered to Nasa by the summer of 2018. Eight Aerojet Rocketdyne R-4D-11 auxiliary thrusters are already in place. The service module’s primary engine, an AJ10-190 Orbital Manoeuvring System left over from the Space Shuttle programme, is waiting to be attached.
This specimen is intended for the debut of unmanned test flight of Orion, scheduled for late 2019. Yet Airbus partners in Italy have already started welding together the structure for the second craft, which will carry astronauts to the Moon perhaps as early as 2021.
US aerospace giant Lockheed Martin is responsible for building the crew module, which will be mounted on top of the service module after its delivery to Nasa.
“The service module is 50 per cent of the Orion spacecraft,” says Juckenhoefel. “We cannot fly without [the Lockheed Martin crew module] and they can’t fly without us. We are delivering propulsion, consumables for the astronauts and power. The only thing we don’t have is the brain. That will be managed from the crew capsule.”
Orion will be lifted to space by the Space Launch System (SLS), which is set to become the most powerful rocket ever built. It will be able to take up to 70 tonnes of cargo to low-Earth orbit. Its future configurations expect to increase payload capacity even further to 130 tonnes. For comparison, Europe’s current workhorse, Ariane 5, can lift 16 tonnes of payload into low-Earth orbit.
With all the money spent on building Orion, as well as the SLS, Nasa hopes to do it differently from 50 years ago with the Apollo programme.
The reality is that in the 45 years since the final Apollo landing, human space exploration has not moved on any further. What global space agencies have achieved, however, is mastering the habitation in low-Earth orbit.
The International Space Station (ISS) has been permanently inhabited since November 2000 and, with the rare exception of when a national of a particular state makes it to the space station, it doesn’t really make the headlines anymore.
Moreover, the station’s lifetime will expire at some point in the 2020s. Right now, the ISS partners, including Nasa, the European Space Agency (ESA), Japanese space agency JAXA, Russian Roscosmos and the Canadian Space Agency, have agreed to keep funding the orbital outpost until 2024.
While the future of the ISS beyond 2024 is not yet clear, the agencies decided they are ready for a new challenge. For years, a potential future manned mission to Mars was in the spotlight, but the decision has been made that taking mankind from low-Earth orbit directly to Mars would be too big a risk.
Over the past two years, agencies involved in the ISS cooperation have been discussing their future steps and refining the Global Exploration Roadmap, the details of which are expected to be published in January 2018.
What emerged from the discussions is the establishment of long-term human presence in the orbit of the Moon – the logical next step. This would be made possible via a smaller space station, the Deep Space Gateway, which could orbit the Moon in less than a decade from now.
“The Deep Space Gateway will allow us to expand human presence beyond the low-Earth orbit,” says Dave Parker, director of Human Spaceflight and Robotic Exploration at ESA.
“It’s a thousand times further out into deep space than the ISS. It will allow us to learn to live and work in the deep space environment.”
There is a lot that’s different in deep space compared to low-Earth orbit, Parker said. The ISS is still shielded against the worst of the cosmic radiation by the Earth’s magnetosphere. If something goes wrong at the ISS, the crew can evacuate the station and be back on Earth in a few hours. The return trip from the Moon would last up to a week.
“If you think about Apollo, even though they went down to the surface of the Moon and went up again, those were only a few days long trips,” says Parker.
“The idea and the logic of the Gateway is to learn to live and work for weeks and months in deep space.”
At the Space Tech Expo Europe in Bremen in October last year, John Roth, vice president of Sierra Nevada Corporation, one of five companies contracted by Nasa to develop Deep Space Gateway architecture, said that in the early stages the Deep Space Gateway would be able to house a crew of four people for up to 40 days.
“The idea is that the Orion goes up to this habitat, people work on the habitat for up to 40 days, and then those people leave and they either go down to the Moon, they go back to the Earth, or they go to Mars,” Roth said. “It’s really a waypoint. Logistics is going to be a key piece for using this station as a jumping-off point to the Moon surface or Mars.”
With about 10 per cent of the volume of the ISS, the Deep Space Gateway could be assembled within four SLS launches, according to Nasa. In the first phase, astronauts would send robotic landers from the station to the lunar surface. In the 2030s, the station would become a starting point for missions to Mars.
In early November 2017, Nasa awarded contracts to Sierra Nevada, Lockheed Martin, Boeing, Orbital ATK and Space Systems Loral to develop concepts of the first module of the Deep Space Gateway – the Power and Propulsion Element.
The Deep Space Gateway project is expected to receive a formal go-ahead from Nasa in early 2018, when US President Donald Trump approves the space agency’s budget.
The excitement of Juckenhoefel and his colleagues is understandable. The last time mankind went to the Moon, the old continent’s engineers were only watching. According to Juckenhoefel, there has even been speculation about the possibility of ESA securing a seat for one of its astronauts on one of the early Orion flights.
However, ESA’s Parker cautions that the extent of ESA’s participation in the Deep Space Gateway endeavour is still undecided.
“Of course, we have the aspiration to have European astronauts eventually flying on Orion,” says Parker. “Yet it should be remembered that at present the Orion vehicles that we are building – the first and the second one – have been bartered with Nasa for services we obtain to get our astronauts to the ISS and to operate on the space station. There is no right, so far, for the European astronauts to fly on Orion.”
According to Parker, ESA and European aerospace companies have hopes to contribute more technology to the Deep Space Gateway beyond the first two Orion missions.
Nasa expects to continue flying Orions to the Moon at a rate of at least once a year. Juckenhoefel believes Airbus and its partners will retain the role of the service module supplier beyond the first two flights.
In addition to that, the European space industry hopes to offer its experience with habitation and life-support technologies, electric propulsion, and communication systems, according to Parker.
Speaking at the Space Tech Expo Europe, Frederic Masson, an engineer at French space agency CNES, revealed that CNES teams are already looking into concepts to boost performance of the upcoming Ariane 6 rocket to be able to serve the Deep Space Gateway.
“We think the most efficient thing would be to add a solar electric space tug as an additional stage to the Ariane 6 rocket,” Masson said. “If we use an Ariane 6 and a 60kW space tug, we could bring up nine tonnes of cargo to the Deep Space Gateway.”
He added that the technology could be ready for use in 2024 or 2025. However, before that, some key decisions have to be made.
“It’s all dependent on our member states’ interests,” says Parker. “We are talking to the national delegations from all ESA member states about future exploration. The next ESA ministerial council in 2019 is the key target point, but we will have to make some strategic decisions following the upcoming decision on the Nasa side.”
For Airbus, building the Orion Service Module has been an intense learning experience. The technology was originally conceived on the legacy of the Automated Transfer Vehicle (ATV) – a series of five expandable cargo delivery spacecraft that had docked at the ISS between 2008 and 2014.
According to Airbus’s Juckenhoefel, not much has remained from the ATV design in the Orion Service Module. The fuel tanks that I was allowed to photograph are from ATVs and so are the solar panels but, beyond that, the design of the service module was driven by completely different parameters.
“We learned that it’s a completely different design to fly to the ISS than flying to the Moon,” Juckenhoefel says. “One aspect of it is the mass. If you fly to the station, you need to be protected against a lot of debris that is flying there, so your protection means you put weight on your hips. If you fly to the Moon, you cannot do that because you want to get rid of mass as much as possible because the lighter you are, the further the propellant will carry you.”
Juckenhoefel says that while the service module will weigh 12 tonnes once fuelled, engineers had to chase every kilo during the design process. This was especially challenging, he says, as the module is going to provide breathable air and other essential systems required for the crew’s survival.
“For an exploration spacecraft, you cannot follow a full-redundancy concept,” he says. “You have to approach it more from the statistical and risk analysis point of view and take discrete decisions. We are continuously looking for improvements to burn mass, to get rid of brackets, to introduce new technologies.”
Despite the challenges, Juckenhoefel is confident the craft will bring the first crew to the Moon and back safely.
“Nasa made an assessment and they said they would be comfortable to put people already on the first flight,” says Juckenhoefel. “We designed the first one fully for crewed flights, but we expect to do some minor design changes after the first flight. We know quite well from ATV experience that as you are doing it for the first time, you are learning, and there will be areas that might need some changes.”
Companies from 10 European countries are contributing to the Orion Service Module. Juckenhoefel hopes that, perhaps, being jointly part of mankind’s next big space exploration endeavour could boost the fading European spirit. As he says, bold projects like this could never be achieved by any single European country alone.