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| The fascination of outer space – “Marriage” in the cleanroom Dr. Ulrich Walter, Astronaut and Professor of Aerospace Technology, is the keynote speaker at the Cleanzone Congress in Frankfurt am Main, a new knowledge platform that is being launched alongside Cleanzone, the international cleanroom technology trade fair, on 24 and 25 October 2012. In "Clean Room, Clean Space – Cleanroom Technology in Space Missions", his keynote address on the first day of the congress, Prof. Dr. Walter will be discussing his work in space, "marriage" in a cleanroom and the vital importance of cleanliness in the laboratory. Dr. Walter, an experienced astronaut, does not mince words: "Cleanliness is absolutely essential for success in outer space. This is true not only for the quality of the scientific results achieved, but for survival in the space station itself." In 1993, Dr. Walter was sent into space with the D2 mission as a payload specialist. Today he conducts research and teaches at Munich Technical University, where he is also building satellites for current space travel projects. "Marriage" and thwarting espionage in the cleanroom: an interview with Prof. Dr. Ulrich Walter You are the keynote speaker at the Cleanzone Congress. What will you be talking about in Frankfurt? Cleanroom technology plays a key role in manned and unmanned space flight. In space, everything has to be 100-percent clean. If it's not, the lives of the astronauts and the mission itself are at risk. That is why I will be talking about concrete fields of application for cleanrooms in space travel, as well as their special requirements – and naturally about the fascination of outer space. What areas of space travel are impacted by cleanroom technology? In principle, every single aspect is affected, as the space station is basically a single giant cleanroom. From the tiniest screw to the complete interior, each and every component must be particle-free at the very least – perhaps even sterile as well. We work with every category of cleanroom in order to satisfy the specific requirements. Requirements for the field of optics are particularly strict: on account of the Hubble telescope's high resolution, for example, it was necessary to ensure that the lenses and housing were kept particle-free throughout the entire manufacturing, assembly and operation processes – something that was quite difficult for a telescope as large as this. In research, cleanrooms have a second essential function: access control. Not only is access to the laboratory strictly controlled and recorded, but access authorisation is highly restricted as well. This helps to keep unauthorised individuals from obtaining access to confidential information. This means that cleanrooms are also an instrument for protecting against espionage. What role did cleanroom technology play when you served as a scientist and astronaut on the D2 space mission? As a research astronaut, I was responsible for the payload in the space shuttle's cargo bay, which happened to be Spacelab. During my years of preparation I probably spent more time in cleanrooms than I did outside of them, as both the experimental facilities and Spacelab itself, with which we had to train, were built and stored in cleanrooms before the mission. Spacelab was located at EADS Astrium in Bremen, which many people still know as DASA. The experimental facilities that were installed in the Spacelab for the mission were constructed and tested by various international research institutes, and in most cases I trained with them on location. Then, before the flight, all of the experimental facilities were taken to Bremen and "married" to the Spacelab, i.e. integrated into the unit. It is worth noting that throughout this entire process – from construction and testing through to transportation to the Spacelab for their "marriage" – each of the individual components had to be kept under cleanroom conditions. What are the special requirements that cleanrooms now have to fulfil in order to be suitable for practical space travel applications? Today, the International Space Station (ISS) serves as our research laboratory in space. It is slated to remain in use until at least 2020, meaning it will be in operation for more than 20 years, and during this time, no one will be dusting or cleaning behind the instruments or racks. In other words, the atmosphere in the ISS must be so pure that cleaning is not even necessary. Seeing as every astronaut (like every human) emits moisture and organic compounds, astronauts emitting these substances into the ISS pose the danger of fungal contamination. This means that space stations must not only be free of particulate matter, but must also be kept sterile. If this is not done, they would quickly become unusable. How are cleanrooms in space different from cleanrooms on Earth? The cleanrooms used in space travel are not fundamentally different from those used in other industries – except, perhaps, with regard to two factors: for one thing, a space station is a closed system. This means that it cannot be continually supplied with fresh new filtered air as it could on Earth. As a result, the materials used in the ISS must not outgas nor generate any type of odour, as this would make working conditions unbearable for the astronauts. That is why metal accounts for much more surface area in the ISS than does plastic. Another significant factor relates to the fact that satellites can be up to ten metres long. As they must be manufactured in cleanrooms while in the vertical position, providing a cleanroom of sufficient height poses quite a challenge. What is the biggest challenge facing people working in outer space? One of the biggest problems that astronauts have to deal with is psychological stress. They have to work for months on end in a completely sterile and purely technical environment, and do so in close quarters, without plants, without any real variety. That causes stress. As a result, astronauts are selected not only for their education, training, knowledge and physical constitution, but also for their personalities and psychological stability. What measures are taken to ensure proper hygiene in the shuttle? Due to the fact that the entire space station – from the sleeping quarters to the work areas – is essentially a cleanroom, everything is organised and perfected down to the tiniest detail, from precisely counted packages of sterile clothing to tightly sealed packages of precooked foods. Some areas are easier to control – some less so. Dealing with water is dangerous, as any stray droplets cannot be allowed to get into the electronics in the instruments and racks, yet even everyday tasks like shaving can turn into a real challenge. Here, for example, special shavers have been developed that are able to directly suck in the stubble. You are involved in research at the Technical University Munich, where you are working with your students to construct satellites. What cleanroom classes do you use? Due to the fact that we are building satellites that do not contain any sensitive optical instruments, we are using a Class ISO 6 cleanroom. How has the role of cleanrooms changed since your space flight in 1993? I have been dealing with cleanroom technology for 25 years now, but the principle has hardly changed. The innovations that have taken place primarily concern the details. Today, for example, more attention is paid to increasing air pressure within the laboratories in order to avoid contamination from outside, and on avoiding arc flashes impacting electronic components as a result of airborne moisture, conductive floor materials or direct body earthing. What challenges will be of particular importance for cleanroom technology in future? Today’s cleanrooms are already so good that we can work within them perfectly. Even so, there are always ways to make things better – regarding comfort, for example, for when an astronaut has to work for months on end in tight spaces without any plants or fresh air, even the smallest improvement is worth its weight in gold. What are the most urgent tasks facing space travel? Right now the biggest challenge lies in optimising the use of resources within the closed processes of a space station. This is quite logical, as everything that is used in space has to be transported there from Earth. The question, therefore, is: How can I more effectively recycle used air? Or: How can I more effectively transform wastewater – including that from the toilet – into drinking water? These are areas that call for innovation. Speaking of innovation: numerous technologies from space travel end up being utilised in other industries as well. What is the situation for cleanroom technology? Space travel is more of a user than a driver in this regard. We make use of the technology that is in existence, and do not need to make a great deal of modifications. Even so, there are also a number of fields in which the demands are so great that we challenge the industry directly, particular with the aforementioned examples of constructing space telescopes and extremely large cleanrooms. On your Munich Technical University website, you include a ‘warning’ with your course of study: “Attention: experience has shown that this broad-based course of training will also result in job offers from outside the aerospace industry.” Where do you think the greatest opportunities lie for your graduates? It is a fact that more than half of our graduates are working outside the aerospace industry. Only some 20 percent go into the aviation industry, with the same number staying in the space sector. There is a very simple reason for this: aerospace engineering is a textbook example of an interdisciplinary technology. This field is home to write your comments about the article :: © 2012 Exhibition News :: home page |