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Most hazardous ATV-3 assignment

Handling more than seven tonnes of propellant is a physically demanding job that requires specialist expertise

Handling more than seven tonnes of propellant is a physically demanding job that requires specialist expertise

Of all the cargo vehicles that supply freight to the International Space Station (ISS), the ATV is the one that carries the most propellant: The ATV-3 alone was loaded with more than seven tonnes of various types of propellant in January 2012. The primary purpose of the propellant is to ‘reboost’ the ISS to a higher orbiting altitude and correct its position in space. The ISS loses altitude at a rate of between 50 and 100 metres a day, so it is completely reliant on ATV-3 for its continued operation.

The task of loading the ATV’s tanks with fuel is carried out at the European Spaceport in Kourou, French Guiana – and responsibility for the job lies with a special Airbus Defence and Space fuelling team.

Aerial view of the European Spaceport in Kourou, French Guiana © ESA

Left: Aerial view of the European Spaceport in Kourou, French Guiana

Handling propellants is never an easy business. They are generally highly flammable and highly toxic and, if handled incorrectly, can cause serious damage – or even put people’s lives at risk. So it comes as no surprise to learn that the task of loading the ATV with propellant is subject to a whole series of particular safety precautions. The Airbus Defence and Space employees in the ATV fuelling team, who are experts in this field, recently completed their ATV-3 ‘Edoardo Amaldi’ mission, loading the last of more than seven tonnes of propellant into the vehicle in January.

“Filling an ATV’s tanks with propellant is always a delicate task,” says Bernardo Laurenzana, who is in charge of the 16-strong fuelling team that has now successfully finalised its third ATV mission. “But it’s not just the quantity of propellant you have to put in the tanks that makes an ATV mission unique. You also have much stricter requirements for the testing and verification processes, for example the need to take multiple fuel samples at different points of the fuelling set-up before you even begin. That requires a lot of manpower and concentration – and of course you are always under time pressure,” says Bernardo.

It is a significantly more complex process than fuelling a satellite. “You can see that from the fact that it takes us three weeks to load propellant into a satellite, but three whole months to complete the same job for the ATV,” he adds. The length of the mission pulls people together and they often start to think of the team as a second family.

Part of the fuelling equipment of the FGSE at Airbus Defence and Space’s Lampoldshausen site (© Airbus Defence and Space)

Right: Part of the fuelling equipment of the FGSE at Airbus Defence and Space’s Lampoldshausen site

For the Airbus Defence and Space team from Lampoldshausen, Germany, this mission actually began several months ago back in their home country. The fuelling equipment, or FGSE (Fluid Ground Support Equipment), sets off on the journey to Kourou first, with the team of specialists following a few weeks later.

The fuelling team (from Lampoldshausen) in front of the ATV-3 ‘Edoardo Amaldi’ in Kourou (© Airbus Defence and Space)

 

The fuelling team (from Lampoldshausen) in front of the ATV-3 ‘Edoardo Amaldi’ in Kourou

“The conditions in which our team works in Kourou are really quite tough – it is a physically strenuous undertaking,” says Bernardo. “That is why medical checks are compulsory before each mission, to make sure everybody is fit for the job, in addition to the general training and safety sessions. Anyone who has seen the fuelling process will understand why this is necessary.”

The fuelling of the ATV-3 involved loading propellant into two distinct systems: firstly, the ATV propulsion system, which is used for flight and attitude control of the ATV during flight as well as for reboosting the ISS and, secondly, propellant tanks carried as cargo which are used to resupply the Russian fuel system on the ISS.

 Preparing to fuel the ATV (left) with MON-3 oxidizer for the ATV’s propulsion system (© Airbus Defence and Space)

Preparing to fuel the ATV (left) with MON-3 oxidizer for the ATV’s propulsion system

“The ATV propulsion system (PRSS) alone requires us to load more than six tonnes of the two components monomethylhydrazine and MON-3 oxidizer in two separate processes. Each individual fuelling process takes somewhere between 24 and 30 hours and is ideally performed without a break.”

Although the propellant flows through a sealed, self-contained system during the fuelling process, the team is still required to take maximum safety precautions (© Airbus Defence and Space)

Although the propellant flows through a sealed, self-contained system during the fuelling process, the team is still required to take maximum safety precautions

Although the propellant flows through a sealed, self-contained system during the fuelling process, the team is still required to take maximum safety precautions (© Airbus Defence and Space)

“Everyone involved in fuelling has to wear full-body protective suits during the entire process, even though fuelling is a completely sealed, self-contained process,” explains Bernardo. The length of the fuelling processes means that a sizeable team of people is called for. There is no doubt that fuelling is a physically demanding assignment, not only because of the length of time it takes, but also due to the high levels of care and concentration that are required when handling hazardous and, in some cases, actually poisonous substances – plus the equally demanding task of cleaning the fuelling equipment when the job is done.

With temperatures outside reaching up to 40°C, the team members wearing rubber boots and protective suits certainly notice the lack of air conditioning (©Airbus Defence and Space)

With temperatures outside reaching up to 40°C, the team members wearing rubber boots and protective suits certainly notice the lack of air conditioning

“When you are working in a room without air conditioning at temperatures between 25°C and 40°C, and you are wearing thick protective suits and rubber boots, the working day can seem very long indeed,” says Bernardo ruefully. He and his team are already back in Lampoldshausen. By the end of March, the FGSE fuelling equipment is once again back in the spaceport at Kourou, to be overhauled and prepared for  next year’s ATV-4 mission. “Edoardo Amaldi hasn’t even left the ground, but for me the mission is already over,” says our fuelling specialist. “As soon as I leave French Guiana my thoughts immediately start focusing on the next ATV mission.”

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