Dutch project goes to the International Space Station – a robotic arm that can walk too – wallpaper

On Wednesday afternoon, July 21 at 4.58 p.m., the most expensive Dutch space project ever will be launched into space. It’s about the European Robotic Arm, or ERA. It is mounted on the Nauka Module, a Russian research laboratory that will be linked to the International Space Station. A Russian Proton-M rocket launches the module and robotic arm from the Baikonur Cosmodrome in Kazakhstan.

The robotic arm is a project of the European Space Agency (ESA) and has been in development since 1985. ESAs widget and access Noordwijk has been on the robotic arm for the past decades. The Netherlands submitted to the main contractor and paid two-thirds of the costs. In total, the project cost about 360 million euros.

“We’ve had a huge string of launch dates, but they’ve been constantly pushed back,” says Philip Schöneggans, ESA project leader, ERA’s business plan hasn’t been at all for more than 35 years. Why did the robotic arm take so long to finally fly into space, what exactly can it do and does it make sense to launch such an ancient project into space now that the International Space Station is in its final stages? We talked about this with various stakeholders.

smart astronaut

from European robotic arm It is an 11-meter robotic arm, similar to a compass, with seven robotic joints. In fact, they are two arms each five meters long, with an elbow joint in the middle. Each of the arms has a wrist with three joints and the wrist with them transponder end. This is a mechanism that allows the arm to grab objects and attach itself to the space station.

This allows ERA to move the delivery over the three attachment points in the Russian laboratory unit. That’s why ESA calls the robotic arm “smart astronaut”. With three attachment points, the freedom to walk is limited, but the arm can therefore be moved around Nauka unit maneuver. The robot arm has a precision of 5mm and a working speed of 10cm per second.

The robotic arm is made of carbon fiber and aluminum and weighs 630 kg. In space, ERA can move objects weighing up to 8000 kg. A consortium of European companies built the arm. This was done under the leadership of the current Dutch company Airbus Defense and Space. That company was previously called the Dutch Aerospace Company and was in turn a subsidiary of the Dutch aircraft maker Fokker.

Several of the robot’s arms are already on the International Space Station. The most famous is Canadarm 2; A 17.6-meter arm, like the ERA, can move the hand over the space station and thus be positioned at various points. Canadarm2 uses different mounting points and therefore cannot reach the entire Russian part of the International Space Station. The Japanese Kibō unit has a ten-meter robotic arm, but is in a fixed location.

The unique feature of ERA is that the robotic arm can be operated from both inside and outside the International Space Station. The outside is a panel of buttons specifically designed for operation by astronauts who wear spacesuits during their lives. outside the vehicle activities. Other robotic arms on the ISS can only be controlled from the space station.

Practical applications

When the robotic arm with the Nauka module arrives at the International Space Station eight days after launch, the astronauts will quickly work on it. ERA will be used to assemble the new Russian laboratory, but the arm must first be prepared for use. This requires five spacewalks, during which the arm is unloaded and put into position.

ERA’s first tasks are to install an airlock and a large coolant on the Nauka unit. It has already been sent to the International Space Station before. The robotic arm could be used to perform tasks outside the space station that astronauts now perform, such as inspections. Like this spacewalk, or extravehicular activities, Risky and often time consuming. The robotic arm will also assist astronauts using extravehicular activities, for example by acting as a kind of aerial platform and moving heavy objects.

A considerable amount of time has already been planned in advance, but practice should show how ERA will be used further, says Schoonejans. “The robot arm is a tool for general use. We know the first missions, but not yet. Practice with the Canadian robot arm proves that once you have such an arm, you can do everything with it constantly. Don’t worry about it.”

Air lock installation on a Nauka with ERA. Photos: © Roskosmos

Long history of changes and postponements

The long development process has various causes; The target and destination that has been switched in ERA more than once. When the idea of ​​a robotic arm came up in 1985, it was still part of the plans for the European space shuttle Hermes. This would be a small variant of the US space shuttle, but plans for that were scrapped in 1992, in part due to high costs. At that time, the European Space Agency also entered into a new partnership with the Russian space agency Roscosmos, which allowed the Soyuz space capsule to be used to launch European cosmonauts. So the need for a special space shuttle no longer exists.

The European Shuttle was canceled, but the robotic arm was not; Another application has been developed for that. Because of said links with Roskosmos, the idea in the 1990s was for ERA to become part of a new Russian space station: Mir-2. However, this project also failed.

The robotic arm was originally part of the European Space Shuttle’s plans. Photos © ESA

Russia joined in the plans for the International Space Station, giving ERA another home. Between 1996 and 2005, the idea was for the robotic arm to be placed on the Russian scientific power platform. This was a planned ISS unit from Russia with its own solar panels, but that didn’t materialize in the end.

In 2005, the current plan for the Early Recovery Report was published; The robotic arm will be installed on the Russian multipurpose laboratory module, a new part of the International Space Station, also known as the Nauka. It was supposed to be launched in 2007, but technical setbacks prevented it delay again and again.

Nauka was created on the basis of a spare model of the Zarya unit. This is the first module of the International Space Station, which was launched in 1998. The backup copy was converted into a multi-purpose laboratory, but in 2013 it was discovered that a leaking fuel valve had significantly damaged the powertrains. Repair work was expensive and took years. Last year, Roskosmos gave the green light and a launch including a European robotic arm is planned for 2021.

Until recently, the launch was scheduled for July 15, but that was delayed by a week after preparations discovered that the tools used to maneuver the unit to its final location in space were not fitted with a heat shield.

Adjustments during long-term storage

During the long wait for release, the robotic arm has been in Russia for years. This happened in a tent filled with nitrogen gas to keep it dry and prevent moisture damage or rust. “It had to be moved every now and then and all the mechanisms were equipped with special lubricant that works in the vacuum, but you also have to move it every now and then. Every year we did something with a lever. Usually those were scheduled tests,” says Schoonejans.

The project never stopped completely. During the long wait, adjustments were made to the lever as well. Schoonejans: “About five years ago we had an electronic problem with the control system. We were able to solve it by using new printed circuit boards with new electronics. It was very complicated, because the arm was already in Russia at that time. If we had not modified it, It could cause problems. We were lucky with that.”

Except for some PCBs, the arm hardware is unchanged. However, the software is updated often. “We have several generations of laptops to control from the ISS. They don’t want to have all kinds of laptops circulating on the space station, so they update them all often. Usually, the software doesn’t” let’s run smoothly on This new laptop. Now we also have 1 million euros in our budget for software updates to move to the next generation of laptops. It will happen someday. “