Strengthening the strategic partnership with Japan

The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) opened its new office in Tokyo on 27 February 2013. In so doing, DLR is pursuing its objective of developing a strategic partnership with Japan. The duties of this office are to establish, foster and further develop research and technology collaboration across the full spectrum of DLR activities. DLR’s work in Japan and other partner countries in the region, such as China, South Korea and Indonesia will be represented locally and expanded.

"Germany and Japan are high-tech nations with very high levels of expertise in engineering and science," said Johann-Dietrich Wörner, Chairman of the DLR Executive Board, at the inauguration of the new office. "DLR and Japan are already jointly involved in about 40 research projects. That makes Japan, alongside the United States, a very important partner country for DLR. With our representative office in Tokyo, we want to build a strategic partnership with Japan and intensify our cooperation across Eastern Asia. This is not only intended to strengthen scientific and technological cooperation between our countries, but also aims to help both sides gain a better cultural understanding of one another," continued Wörner.

The new office will represent DLR's interests to political, scientific and industrial institutions in Japan and other partner countries in the region. It will support local cooperation projects and will analyse developments in politics, research and technology in Eastern Asia.

"Germany and Japan are linked by many topics of the future. These include new sustainable energy sources, the environmental and economic development of transport, and innovative applications in the aerospace sector. That is why the intensive exchange of personnel between research and development teams is particularly important," said Niklas Reinke, who will be in charge of the new office.

MASCOT – an example of successful cooperation

After the United States, Japan is DLR's most important non-European cooperation partner. At this time, DLR and the Japanese space agency, JAXA, are involved in 25 cooperation agreements. In the space sector this includes the Hayabusa 2 asteroid mission. For this project, DLR is developing the MASCOT asteroid lander that is scheduled to fly to 1999 JU3 in 2014 on board a Japanese spacecraft, where it will take measurements on the asteroid's surface. Also in progress are collaborative research and development projects in the field of Earth observation, such as the GOSAT satellite mission. Joint projects such as research under space conditions, natural disaster and major incident management, propulsion systems using liquefied natural gas and optical laser communication are progressing and their scope is being enlarged.

For the last 10 years or so, regular cooperation talks relating to the aviation sector have been held between JAXA and DLR. Focal points of these talks are computational fluid dynamics, global navigation satellite systems, turbulence effects, scramjet technologies and combustion processes. Long-standing collaborative ties also link DLR with the University of Tohoku in the fields of Temperature Sensitive Paint (TSP) and Pressure Sensitive Paint (PSP), processes for measuring temperature and air pressure while in flight through the use of sensitive paint coatings.

Japan possesses a significant level of research expertise in batteries and transport. Here, there is scope for cooperation with the DLR research fields of energy and transport.

JAXA, as well as the University of Tohoku – outside Germany, DLR's largest university partners – and seven other Japanese universities and research institutes are very interested in further expanding their relationship with DLR. This new strategic partnership will help to link mutual research interests and to make efficient use of the test facilities in both countries. In this way, more ‘Knowledge for Tomorrow’ will emerge from international cooperation.

The DLR office in Tokyo will be housed in the German Chamber of Commerce and Industry in Japan, next to the German Research and Innovation Forum (Deutsche Wissenschafts- und Innovationshaus). With its other offices in Brussels, Paris, and Washington D.C., DLR will now have four representative offices outside Germany.

When the Japanese Hayabusa-2 mission is launched towards asteroid 1999 JU 3 in 2014 to collect surface samples, MASCOT – the Mobile Asteroid Surface Scout – an asteroid lander developed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) will be on board. On arrival at the asteroid in 2018, it will be released from the main spacecraft, land on the asteroid, automatically orient itself and 'hop' from one measurement site to the next. DLR and the Japanese Aerospace Exploration Agency (JAXA) signed a memorandum of understanding on 1 October 2012, at the International Astronautical Congress (IAC) in Naples.

Upon arrival at 1999 JU 3, the Japanese Hayabusa-2 spacecraft will first make a close approach to the asteroid and take measurements of the body's surface from there. Following this initial cartographical phase, the MASCOT asteroid lander, which is being developed by DLR in collaboration with French space agency (Centre National d'Etudes Spatiales; CNES) and JAXA, will be put to work. A mechanism will push the 10-kilogram lander with its four instruments away from the spacecraft. "MASCOT will free-fall to the asteroid from an altitude of around 100 metres," explained project leader Tra-Mi Ho from the DLR Institute of Space Systems in Bremen. Sensors will then ensure that MASCOT knows which way is up and down, so it can orient itself and, if necessary, correct its attitude.

"This collaboration will enable us to consolidate and strengthen our existing cooperation with JAXA," said Johann-Dietrich Wörner, Chairman of the DLR Executive Board. "There is also a special 'first' with the Hayabusa-2 mission; it will be the first time that a lander on the surface of an asteroid is able to move around and perform scientific measurements in more than one place."

In-situ measurements

While Hayabusa-2 remains above the surface of the asteroid, the four instruments on MASCOT will carry out in-situ investigations into the properties of the surface. The DLR radiometer will measure the temperature, a magnetometer developed by Technische Universität Braunschweig will investigate the magnetisation of the rock, and the spectrometer supplied by CNES will analyse the minerals and rocks that make up the asteroid. The fourth instrument, a DLR camera, will image the fine structure of the surface to enable scientists to learn about the properties, size and shapes of the particles on the surface of the asteroid and map the area around the landing site.

Asteroid 1999 JU 3 is of particular interest to researchers because it consists of 4.5-billion-year-old material that has been altered very little. "Measurements taken from Earth also indicate that the asteroid's rock may have come into contact with water," explains Ralf Jaumann, a DLR planetary researcher and scientific spokesman for the experiments on the lander. "MASCOT is due to take measurements of the regolith itself, which will provide reference data about the surface and enable the samples subsequently brought back by Hayabusa-2 to be interpreted in the correct context." 1999 JU 3 belongs to a type of asteroid that is one of the most common among near-Earth asteroids, so information about its properties will be important in the event that one of these bodies is ever on a collision course with Earth.

At operation for two asteroid-days

Meanwhile, the Hayabusa-2 spacecraft will be using a suction nozzle to collect samples kicked up from the surface by impactor projectiles, and then return these to Earth for laboratory analysis. "MASCOT is the central piece of the puzzle in all the measurements,” said project leader Tra-Mi Ho. "That is, it is the link between the data on the asteroid that the probe collects remotely and the laboratory analyses of the samples." Once the DLR asteroid lander has carried out all its measurements at one site, it will then 'hop' to the next site and start taking measurements there. This mechanism is being developed at the DLR Institute of Robotics and Mechatronics. MASCOT will work on the asteroid for a total of 16 hours – two full asteroid-days.

DLR researchers begin evaluating data; as yet, no recovery of the spacecraft

Following the flight of the SHEFEX II spacecraft on 22 June 2012, researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have performed an initial assessment. "The flight of Shefex II followed the precomputed trajectory and we received extensive and valuable data from all the experiments in real time," says DLR Project Manager Hendrik Weihs. With SHEFEX II, researchers are investigating technologies to make spacecraft re-entry less expensive. The spacecraft landed west of Spitsbergen; here, a boat was intended to rescue the payload from the sea, but missing data during the last seconds of the flight and the harsh weather conditions have complicated this task. The researchers are now assessing the viability of locating and recovering it from the ocean floor.

Shortly after the completion of the 10-minute flight from the Andøya Rocket Range in Norway on the evening of 22 June 2012, a search aircraft received the first weak signals from SHEFEX II. "We know that the landing went as planned because the spacecraft was designed to emit a signal only after the parachute had opened," explains Weihs. Ideally, data from the last seconds of the flight would have been transferred to the ground station in Spitsbergen. "Unfortunately, the station was unable to track the spacecraft." It was planned that the experimental phase of the SHEFEX II flight through the atmosphere would last 55 seconds; researchers are missing data from the last five seconds. For the researchers, this was not such a great loss; the real challenge was the spacecraft's recovery from the ocean. "The signal received could only be from our spacecraft; we have analysed images acquired with the TerraSAR-X satellite and no other objects were visible at the landing site,” says Weihs. But waves nearly three metres high prevented the salvage vessel from getting to the landing zone. On 24 June 2012, the search was called off. "We are now trying to determine where, exactly, the spacecraft sank, and whether it can be salvaged."

Active control and cooling

To evaluate their experiments, the researchers acquired large quantities of data from the spacecraft, down to an altitude of 29 kilometres, from the ground stations at the launch site and on a nearby mountain. The experiment phase of the flight began at an altitude of approximately 100 kilometres, as the rocket re-entered the atmosphere, and ended at an altitude of 20 kilometres. "We know already that the 'fins', known as canards, functioned properly," says Weihs. The researchers were able to actively control the spacecraft, unlike SHEFEX I, which was launched in 2005. It was already clear during the flight that SHEFEX II had carried out the control manoeuvres as planned. In one of the experiments, nitrogen flows through a porous tile, actively cooling the craft during re-entry. "We have data for the gas outflow, and we have the spacecraft's surface temperatures – now, the evaluation begins." The researchers are also happy with the accurate trajectory of the spacecraft. "This is the first time that our mobile rocket base has developed and flown a launch system in this configuration." The experience gained with SHEFEX II will be incorporated to the follow-up project SHEFEX III – a spacecraft, whose atmospheric re-entry is scheduled to last up to 15 minutes. "The salvage of the spacecraft would be the icing on the cake," says Weihs.

An important milestone for the commissioning of a European 'information superhighway' in space has been reached; on 25 June 2012, Johann-Dietrich Wörner, the Chairman of the DLR Executive Board, Evert Dudok, CEO of Astrium Satellites, and Gerhard Bethscheider, CEO of SES ASTRA TechCom S.A. (Luxemburg) signed contracts for large parts of the ground segment of the new European Data Relay System (EDRS) in the German Space Operations Center (GSOC) at the German Aerospace Center (Deutsches Zentrum für Luft-und Raumfahrt; DLR) site in Oberpfaffenhofen. As a result, Europe is becoming increasingly independent in satellite telecommunications. The contract runs until 2030.

More data sent to Earth faster and for longer time intervals

The planned EDRS is based on two geostationary 'distributor' satellites that, because of their fixed position in space, will be able to receive high-speed communications from low-flying Earth observation satellites and relay them to Earth without any delay. As a result, these satellites will no longer be restricted to brief contact windows when they pass over their ground stations, which is currently the case. "This will mean that significantly greater data volumes can be transmitted faster and for longer time intervals from space to Earth. Above all, this is of huge importance for environmental monitoring, for the emergency relief services, for example during natural disasters, and even for weather forecasting," explained Johann-Dietrich Wörner. The ESA EDRS programme is therefore also a central component of the ESA and EU Global Monitoring for Environment and Security (GMES) programme. GMES is a European initiative for worldwide satellite-based environmental and security monitoring.

Public-private partnership

Like the German radar satellite mission TanDEM-X, EDRS is also a Public-Private Partnership (PPP), but in this case, ESA is the client and Astrium GmbH the prime contractor. DLR has been appointed as a subcontractor by Astrium and is responsible for constructing large parts of the ground segment and for controlling the payloads on the first satellites, referred to as EDRS-A. DLR will also manage and control the EDRS-C relay satellites during routine flight operations that will last for at least 15 years. For this purpose, a dedicated EDRS control centre will be developed within DLR's GSOC. The two geostationary relay satellites will transmit the data collected by the lower-orbiting Earth observation satellites to a total of four receiver antennas, which will be located on the sites of the existing ground stations at Weilheim (DLR) and Redu (Belgium), and at Harwell (United Kingdom). SES ASTRA TechCom S.A. will supply the four antennas and will operate the antenna at Redu on behalf of DLR. The data links will operate Ka band and be able to relay very large volumes of data – in the gigabit range – to Earth.

First operational deployment of optical laser communications

As part of EDRS, optical laser communications technology, also developed in Germany, will be used to transmit data operationally for the first time. "The European telecommunications infrastructure will be improved significantly," said Johann-Dietrich Wörner. "With EDRS, geostationary data relay services will be available to our partners and clients worldwide operationally for the first time. The project includes developing the necessary technologies to build the infrastructure on the ground and in space and the reliable operation of the completed system."

After its development phase – from the end of 2014 – EDRS will be used by the first two 'Sentinel' GMES Earth observation satellites to connect to the invisible 'data highway' in space. The Sentinel satellites will be equipped with small laser communications terminals, capable of transmitting data at speeds of up to 1.8 gigabits per second over a distance of 45,000 kilometres.

Successful launch of DLR’s SHEFEX II spacecraft

After a 10-minute flight, the sharp-edged SHEFEX II spacecraft landed safely west of Spitsbergen. Researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) launched the seven-ton and roughly 13-metre-long rocket and its payload from the Andøya Rocket Range in Norway at 21:18 CEST on 22 June 2012. As it re-entered the atmosphere, SHEFEX withstood temperatures exceeding 2500 degrees Celsius and sent measurement data from more than 300 sensors to a ground station. “The SHEFEX II flight takes us one step further in the road to developing a space vehicle built like a space capsule but offering the control and flight options of the Space Shuttle much more cost-effectively,” says project manager Hendrik Weihs.

Knowledge of atmospheric re-entry

DLR has been working on the SHEFEX programme for 10 years, developing a technology in which a spacecraft can re-enter the atmosphere and land without suffering damage. SHEFEX is angular and sharp-edged; its structure consists of planar surfaces, which are easier to manufacture and are thus less expensive than the usual rounded shapes. The sharp edges are also aerodynamically advantageous. DLR researchers have developed various thermal protection systems to control the high temperatures that the edges are subjected to during re-entry.

The SHEFEX I spacecraft, launched on 27 October 2005, enabled researchers to collect data during flight for the first time. That flight lasted 20 seconds and the craft re-entered at a speed of Mach seven. SHEFEX II reached a speed of 11,000 kilometres per hour – roughly 11 times the speed of sound – as it re-entered the atmosphere. It reached an altitude of approximately 180 kilometres.

Six DLR institutes involved in the project

The SHEFEX project is a collaboration between six DLR institutes. The DLR Institute of Aerodynamics and Flow Technology carried out numerous wind tunnel tests, computed the flow field at re-entry and equipped the rocket with sensors for measuring temperature, pressure and thermal stress. The DLR Institute for Structures and Design built the spacecraft and was responsible for designing and producing the ceramic thermal protection systems; in one of these systems, nitrogen flows through a porous tile, cooling the craft during re-entry. At the heart of the canard control system, developed by researchers at the DLR Institute of Flight Systems in Braunschweig, are control surfaces – the canards – on the front section of the research vehicle, which can be used to actively control the vehicle. The Institute of Materials Research manufactured the ceramic tiles and the Institute of Space Systems developed a navigation platform for determining the location of the spacecraft during the flight. DLR’s MoRaBa mobile rocket base operated the two-stage launch vehicle, controlled the spacecraft and received the data sent by SHEFEX during the flight.

On the way to developing a space plane

A salvage ship and an aircraft are on their way to the landing site to retrieve the spacecraft.  If the recovery is successful, researchers will receive a large amount of additional data. “The flight of SHEFEX II is a step towards developing a spacecraft that withstands higher temperatures while travelling faster and for a longer duration,” says Weihs. More than 300 sensors measured temperature and pressure, among other things, during the flight. “We have a wealth of data, which will be used for years to come.” SHEFEX III could be launched in 2016; it will be more like a space plane and will fly through the atmosphere for about 15 minutes. The objective of this research is to allow for experiments in microgravity that last for a number of days and then return to Earth.

Five years ago today, at 04:14 CEST on 15 June 2007, the German TerraSAR-X radar satellite was launched from Russia's Baikonur Cosmodrome in Kazakhstan. This marked the beginning of a new era in satellite remote sensing for Germany. Designed to operate for five years, the satellite has now completed its nominal service life but it remains in excellent condition; it is expected to continue functioning for several more years.

"TerraSAR-X has now been operating almost flawlessly for five years. The satellite's propellant consumption has been low, the solar arrays and radar instrument are in good condition, and all of the redundant systems are still available. We could not have hoped for more," says Michael Bartusch, TerraSAR-X mission Project Manager at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) Space Administration.

Dependable and high-precision

TerraSAR-X was constructed by Astrium on behalf of DLR and is the first Earth observation satellite to be developed entirely in Germany. Thanks to the on-board radar instrument, Earth's surface can be surveyed regardless of weather conditions, cloud cover or availability of daylight. The satellite has been providing unique datasets with resolutions down to one metre since the beginning of the mission. By so doing, TerraSAR-X has completely fulfilled its mission objective – the provision of high-quality X band Synthetic Aperture Radar (SAR) data for research and development purposes as well as for scientific and commercial applications. From the beginning of 2008, commercial distribution of the data has been performed by the German division of Astrium Geo-Information Services, Infoterra GmbH.

The high accuracy and dependability of TerraSAR-X data has enabled scientists from a wide variety of research fields to develop entirely new applications and processes. In particularly high demand are time-sequenced images, which enable changes in a specific region to be precisely determined.

Glaciers and wood frogs

This applies to the observation of glaciers in Greenland, for example. Their flow rates allow them to be used as indicators for global warming. In a research project being carried out by the Institute of Applied Physics at the University of Washington, the 20 most significant outlet glaciers are surveyed five times a year. Special attention is paid to Jakobshavn Isbræ, one of the fastest-moving glaciers in the world. TerraSAR-X is currently the only remote sensing satellite capable of supplying images for the project at the required resolution and time intervals.

The German radar satellite is even putting wood frogs in Northern Canada under the microscope for climate researchers. The eight-centimetre-long amphibians are also climate indicators; changes in climate and habitat immediately affect the sensitive population. The frogs breed in small ponds that form during the thaw period following the harsh winter and then dry out. Using high-resolution images from TerraSAR-X, scientists from the Terrestrial Wetland Global Change Research Network can now see when the frog ponds form and how they evolve over time. Previously, the usual method used was to set up microphones and use the sounds emitted by the frogs to work out what was happening. With remote sensing technology, biologists can now use entirely new methods.

Berlin Central Station

TerraSAR-X has also found a completely new application in the observation of important infrastructure components. This applies to bridges and, especially, safety-critical facilities such as dams. Using the latest processes, the radar satellite's images can be used to detect deformations down to the millimetre range with high accuracy. In collaboration with Technische Universität München, DLR Oberpfaffenhofen has demonstrated this for Berlin Central Station; over the course of a year, the steel complex deforms by up to 1.8 centimetres vertically and between 1.5 and 3.5 centimetres horizontally. The TerraSAR-X images reveal the seasonal differences with millimetric accuracy; the steel structure expands during the warmest months of the year, being largest between June and September. During the cooler parts of the year, the material contracts and the station 'moves' back to its previous state.

Natural catastrophes and major events

TerraSAR-X makes important contributions during natural catastrophes, major incidents and humanitarian relief efforts. To provide the best possible help on site, emergency services need comprehensive, detailed, up-to-date geographical information – regardless of the time of day or weather conditions. This is not a problem for TerraSAR-X, and this is why DLR is a member of the International Charter 'Space and Major Disasters'; the radar satellite has supplied emergency cartography data for natural disasters such as the severe earthquake in Haiti in 2010, the floods in Pakistan in 2011 and the earthquake and tsunami in Japan. Most recently, TerraSAR-X was used during the Champions League football final in Munich, for a test by the German Federal Office of Civil Protection and Disaster Assistance (Bundesamt für Bevölkerungsschutz und Katastrophenhilfe; BBK) of situational awareness during major events.

… and TanDEM-X

Over the past five years, the German TerraSAR-X satellite mission has successfully supported or enabled a wide range of relief efforts and projects. Since June 2010, the satellite has been in good company; TerraSAR-X has been orbiting the Earth in close formation with its almost identical twin, TanDEM-X. Together, they are creating a highly accurate digital elevation model of Earth. With its own unchanged mission targets still in focus, TerraSAR-X has been meeting all expectations here as well.

About the TerraSAR-X mission

TerraSAR-X is being implemented on behalf of DLR with funds from the German Federal Ministry of Economics and Technology (Bundesministerium für Wirtschaft und Technologie; BMWi). It is the first German satellite manufactured under what is known as a Public-Private Partnership DLR and Astrium. DLR is responsible for using TerraSAR-X data for scientific purposes; it is also responsible for planning and implementing the mission as well as controlling the satellite. Astrium built the satellite, shared the costs of developing it and is sharing the costs of operating it. Infoterra GmbH, a subsidiary company founded for this purpose by Astrium, is responsible for marketing the data commercially.

DLR space vehicle undergoes final tests prior to launch

The SHEFEX II (SHarp Edge Flight EXperiment) spacecraft successfully withstood vibration on a shaker and spinning at two rotations per second. These tests represented the final simulation of the conditions that the space vehicle will be subjected to during its launch in the summer of 2012. Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) will use SHEFEX to investigate how a space vehicle can re-enter Earth's atmosphere as safely and cost-effectively as possible following a spaceflight.

Equipped with numerous experiments, a camera, pressure, temperature and heat flow sensors, and antennas – the SHEFEX spacecraft will lift off from the rocket range on the Norwegian island of Andøya, reach an altitude of 250 kilometres and later re-enter the atmosphere at 11 times the speed of sound. "With this mission, we are entering uncharted technological territory," says project leader Hendrik Weihs from the DLR Institute of Structures and Design. The space vehicle must withstand temperatures of over 2000 degrees Celsius as it re-enters and lands by parachute in the vicinity of Spitsbergen. The shape of the experimental vehicle is particularly unusual; where conventional spacecraft tend to have rounded contours, SHEFEX II has straight edges and corners. "The straight-edged shape has the benefit of making manufacture of the thermal protection system significantly less costly. The straight leading edge also improves its aerodynamic properties," explains Weihs. The vehicle consists of separate, smooth faces that are easier, and therefore less expensive, to manufacture than, for example, the individually shaped tiles on a Space Shuttle. The researchers are also using the space vehicle to test various thermal protection systems during the 45-second re-entry phase. A total of six DLR institutes and facilities are involved in the SHEFEX II mission: the Institute of Aerodynamics and Flow Technology, the Institute of Structures and Design, the Institute of Flight Systems, the Institute of Materials Research, the Institute of Space Systems and the MORABA mobile rocket base (MObile RAketen BAsis).

Vibrating and rotating at high speed

Following tests in the laboratory at Astrium Ottobrunn, the researchers can be sure that the vehicle will withstand the loads during launch and the subsequent flight without problems. "In order to stabilise itself during flight, the rocket must rotate continuously," explains John Turner, who is responsible for the deployment of MORABA – which will launch SHEFEX from the Norwegian base. The engineers balanced the vehicle in preparation for this rotation similarly to how a car wheel is balanced. Evaluation on the shaker was also part of the final mechanical tests. In the first few seconds after launch, a rocket payload is subject to severe vibration – the shaker simulates this situation. "After each test we checked that everything was still functioning properly."

Test programme for re-entry technology

With the SHEFEX II mission, the researchers are drawing on their experience with the SHEFEX I vehicle, launched on 27 October 2005 from Andøya. But SHEFEX II will be flying at twice the speed, can be actively controlled during re-entry for the first time and offers twice the experimentation time. Plans for a third SHEFEX mission are currently underway. The aim of the three missions is to gather information for the design of a new type of re-entry vehicle able to return to Earth undamaged – and that is therefore reusable – following a period of experimentation in microgravity. The REX Free Flyer (Returnable Experiments in Space) is being looked at as an initial application example. As of 2020, this sharp-edged space glider could be flying microgravity experiments for a few days and then landing again at a conventional airport. "This would narrow the gap between a few minutes of microgravity, as with the DLR TEXUS flights, and the permanent microgravity on board the International Space Station," says Hendrik Weihs.

About DLR

DLR, the German Aerospace Center, is Germany's national research centre for aeronautics and space. Its extensive research and development work in aeronautics, space, energy, transport, defence and security is integrated into national and international cooperative ventures. As Gemany's Space Agency, DLR is tasked with the planning and implementation of Germany's space programme.

Rendezvousing at 28,000 kilometres per hour at an altitude of about 380 kilometres is hardly routine – even for experienced spaceflight engineers and astronauts, which is why applause broke out in the European Space Agency (ESA) Automated Transfer Vehicle (ATV) Control Centre in Toulouse when the third European space transporter, 'Edoardo Amaldi', docked with the International Space Station (ISS) at 00:31 CEST (22:31 UTC) on 29 March 2012.

"If everything goes to plan, ATV-3 will leave the ISS on 27 August 2012 and burn up during a controlled re-entry into Earth's atmosphere," explains Volker Schmid, Head of the ISS Division at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) Space Administration, who is responsible for coordinating the German contributions to the ESA ATV programme. The third model in the ATV series, named after Italian physicist and space flight pioneer Edoardo Amaldi, was launched six days ago, on 23 March 2012, from Europe's Spaceport in French Guiana. The 20-ton ATV 3 navigated autonomously and docked with the Space Station automatically. ESA astronaut André Kuipers monitored the process with his colleagues on the ISS.

ATV is the European supply and propulsion spacecraft for the ISS. Compared to its predecessors, 'Jules Verne' (2008) and 'Johannes Kepler' (2011), 'Edoardo Amaldi' has some 600 kilograms of additional payload on board. In total the ATV 3 is bringing almost seven tons of payload to the ISS. "Besides food and clothing, water and air, experiments and medical equipment, this mainly consists of fuel for the Russian Svezda module – which the ATV 3 is docked to – and for the nine planned ISS orbital corrections that will be carried out between now and August," says Schmid. These manoeuvres are necessary at regular intervals to compensate for the ISS being slowed by drag due to the residual atmosphere and the resulting loss of altitude.

From a scientific perspective, the valuable cargo includes a Re-entry Break-up Recorder (REBR). This device will record the accelerations experienced by the ATV 3 during re-entry and will not burn up. Says Volker Schmid: "The recorder will transmit data to a ground station via an Iridium communications satellite during the final flight phase. This will enable us to draw conclusions about the forces exerted on the ATV during re-entry." The ATV 3 has also brought nine experiments and hardware subsystems to the ISS, including two experiment modules for the US space agency, NASA, nine samples for ESA's ALTEA-Shield radiation dosimetry experiment, material for taking samples of human excreta for ESA's ENERGY experiment, replacement electronic components for the BIOLAB laboratory in the European Columbus ISS module and measuring equipment for the NASA VO2max experiment, which deals with changes in lung capacity during weightlessness. ATV 3 also carried a special fluid-management pump to the ISS, which is part of a system that the astronauts can use to convert urine into drinking water.

'Edoardo Amaldi' consists of a propulsion module with four main engines and 28 small thrusters for attitude control, an avionics module with the electronics required for the mission, and the integrated cargo space. It has docked directly with the Zvezda module and will gradually be emptied by the astronauts on board the space station over the coming months. The docking itself took around three and a half hours to complete, and was carried out using four optical sensors over the final 250 metres prior to docking. Laser pulses were directed at reflectors on the Zvezda module, in order to measure the distance, relative position and approach speed. ATV 3 first came to a halt some 40 kilometres behind the ISS before slowly approaching the Space Station.

An electrical engineer manages mission operations at the DLR ground station in Weilheim

Erica Barkasz is an early riser; her working day starts at six in the morning in the control room of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) ground station at Weilheim in Upper Bavaria. A petite woman with Hungarian and Slovenian roots, who grew up in the Argentinian capital of Buenos Aires, manages mission operations here and controls communications between the antennas in Weilheim and the satellites it serves.

Idyllic and high-tech

From the air, white dots are visible against a green background. On the ground, a country road winds its way through fields in ever-tighter curves. One final bend and there it is – the smallest DLR site appears – Weilheim. At the heart of the site there are twelve highly visible, white-painted antennas of various sizes, which are operated and monitored from the control room. Around the clock, Earth observation satellites fly over the site at regular intervals and both they and geostationary telecommunications satellites transmit their signals from altitudes ranging between 200 and 36,000 kilometres in seven different frequency bands. "Two special cases are NASA's LRO Moon orbiter and ESA's Integral gamma-ray observatory, which we also look after," Erica Barkasz recounts. The lunar orbiter has been travelling around Earth's natural satellite since June 2009; the Integral spacecraft has been orbiting Earth since October 2002 on an elliptical path at an altitude that varies between 9000 and 153,000 kilometres.

Barkasz has ten minutes to 'see', track, manage and control a satellite by sending and receiving commands. Everything is teamwork – and international – the DLR ground station is integrated into a worldwide network of satellite stations. Weilheim is largely responsible for the mission operations of the current German TanDEM-X radar satellite mission. With TanDEM-X, Earth's land surface is being fully mapped in 3D and at high resolution for the first time.

"Our control room is always busy; we operate a three-shift system. The early shift begins at 06:30, the late shift at 14:30 and the night shift at 22:30," the 39-year-old explains. "If I start at six in the morning and go home at three in the afternoon, I will have spoken with colleagues from all three shifts. We can discuss questions or problems concerning the operation of the satellites directly," says the energetic manager, describing her working day. The first and last thing she does is to look at the logbook. Logbooks are used not just in shipping and aviation, but also for satellite operations.

From Argentina to Upper Bavaria

Erica Barkasz has found her dream job. The electrical engineering graduate took telecommunications as a special subject during her studies in Buenos Aires, then worked for the US company Emerging Markets Communications Inc. (EMC). During this period, she came a few times to Raisting, very close to DLR Weilheim. EMC has operated a ground station there since 2006, serving telecommunications satellites. Barkasz was enthusiastic: "I thought, this region is so beautiful I want to come and live here. I also wanted to work with satellites," she says and laughs. Weilheim was "so safe" in comparison to Buenos Aires: "Here I didn’t have to worry about going out on my own," the engineer says. She is a nature lover and keen sportswoman, and speaks fluent Spanish, English, and now, good German as well. The only problem was that she still had to find the right job. In summer 2010, she got the opportunity to work as a systems engineer at the DLR ground station.  Six months later, she was able to take over as operations manager.

It's all a question of software

Her favourite activity is 'trouble-shooting' – that is, 'managing problems' concerning the control of the antennas. "We are just implementing some new software which we can use to control all the antennas. Our aim is a unified system with a consistent structure for every satellite mission we work with," the engineer explains. Although the software itself is more complex, it works more reliably and is simpler to operate.

The ground station in Weilheim is part of the German Space Operations Center in Oberpfaffenhofen; the DLR personnel in Weilheim receive their information about the satellites from there. Erica Barkasz: "We have the antennas for the transfer of telecommand data and telemetry, and send this information back to Oberpfaffenhofen."

It is a freighter, storage facility and propulsion system all in one – and an important link between the astronauts on board the International Space Station (ISS) and their base on Earth. The third European Automated Transfer Vehicle (ATV) space transporter was launched on 23 March 2012 at 05:34 CET (01:34 local time) on board an Ariane 5ES rocket, from Europe's Spaceport in French Guiana. The ATV-3 is named after Italian physicist and space flight pioneer Edoardo Amaldi. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is participating in the ESA mission.

The six astronauts on board the ISS are very happy; if all goes to plan, within the next week they will receive clean clothes, fresh food, air and water, inside the ATV-3. There will also be experiments, replacement parts and tools for maintenance work, medicines and medical supplies. In addition, there will be 3.3 tons of propellants for performing avoidance manoeuvres in the event of a threat from space debris and to raise the ISS orbit by means of regular reboost manoeuvres. This third transport spacecraft in the ATV series is scheduled to dock with the Russian Zvezda ISS module on 28 March 2012.

'Edoardo Amaldi' will serve the ISS for 5 months

"The third successful deployment of a European ATV is a repeated demonstration of the efficiency of the German aerospace industry," declared Johann-Dietrich Wörner, Chairman of the DLR Executive Board. "With its great technical reliability, the ATV transport system could form the basis for contemplating possible future developments in terms of international cooperation," Wörner added.

ESA astronaut André Kuipers and his Russian colleague Oleg Kononenko will monitor the docking and can intervene if necessary. 'Edoardo Amaldi' will remain attached to the ISS for five months, at an altitude of around 380 kilometres. The ATV has an integrated freight area, which is used by the ISS crew as a supply store and gradually emptied. Before undocking from the ISS, planned for 27 August 2012, the ATV-3 will be loaded with refuse that will burn up with the ATV during its controlled re-entry into Earth's atmosphere.

The largest, heaviest and most complex European spacecraft

The ATV-3 is the heaviest, largest and most complex space vehicle to have been built in Europe. "It weighs over 20 tons with cargo, has a diameter of four and a half metres and is 10 metres long. The deployed solar panels have a span of more than 22 metres," explains Volker Schmid, Head of the ISS Division at DLR Space Administration, who is responsible for coordinating the German contributions to the European Space Agency’s ATV programme.

"Germany is responsible for 48 percent of the production of the space transporter," says Schmid. In total, 30 companies from 10 European countries and eight companies from Russia and the USA have supplied parts and components for the space vehicle, which will navigate to and dock with the ISS fully autonomously. When this happens, the ISS and the ATV will be travelling around the Earth at a speed of about 28,000 kilometres per hour. But 'Edoardo Amaldi' will be travelling about seven centimetres per second faster than the ISS. "The ATV will use the GPS satellite navigation system, an integrated Russian radar system, a radio link, laser sensors and video cameras to carry out the docking to an accuracy greater than six centimetres," explains the DLR expert. However, this will also be carried out – as is standard during space missions – in tandem with a safety network and ground station link; the ATV Control Centre in Toulouse, France, monitors every movement of the space transporter.

DLR and the ATV programme

In addition to German industry, under the leadership of EADS Astrium GmbH, DLR is also involved in the ATV programme. The re-ignitable Ariane 5 upper-stage engines that are required for the ATV missions are manufactured in Germany and tested at the DLR site in Lampoldshausen. Communications for the control centres involved in operating the ATV, in Toulouse, Moscow, Houston and Redù in Belgium, are routed through DLR Oberpfaffenhofen. DLR Göttingen was involved in the basic research needed for the design of the ATV thrusters.

After a year in service, the German Earth observation satellite TanDEM-X, together with its twin satellite, TerraSAR-X, have completely mapped the entire land surface of Earth for the first time. The data is being used to create the world's first single-source, high-precision, 3D digital elevation model of Earth. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) controls both radar satellites, generates the elevation model and is responsible for the scientific use of TanDEM-X data.

The TanDEM-X mission – running like clockwork

It is reminiscent of ballet on ice; throughout the last year, Germany's radar satellites, TanDEM-X and TerraSAR-X, have been moving through space in close formation, at times just a few hundred metres apart. Strip by strip, they have recorded Earth from different angles and transmitted high-resolution radar data from their orbit at an altitude of 514 kilometres down to the three ground stations – Kiruna (Sweden), Inuvik (Canada) and O'Higgins (Antarctica). "The mission is running better than expected and there have been no unscheduled interruptions in the programmed formation flight of the two satellites. All safety mechanisms are functioning robustly and in a stable manner," enthuses Manfred Zink, project manager for the TanDEM-X ground segment at DLR. Over the course of 2011, the distance between the satellites was progressively reduced down to the minimum permitted value of 150 metres.

'Radar eyes' working with millimetric accuracy

This satellite mission is the first of its kind; it remains unique and is highly complex, even for experienced engineers. "Following the launch of TanDEM-X on 21 June 2010, there was a six-month test phase, during which we subjected the satellite and its behaviour in near-Earth orbit to intense scrutiny and carried out our calibration work," Zink recalls. During this time, TanDEM-X commenced formation flying with its identical partner satellite, TerraSAR-X, which was launched in 2007. On 14 December 2010, the operational part of its mission began, collecting data for the high-precision elevation model.

The radar system views the ground from two different points in space, achieving 'depth perception' in a manner similar to binocular vision in humans. "The generation of accurate elevation data calls for precise coordination of data from and between both satellites," explains Gerhard Krieger, systems engineer for the TanDEM-X mission. Differences, for example in the cable lengths on the two radar instruments, as well as the distance between the two satellites, need to be calibrated very precisely. "This is a truly enormous challenge when you consider that a millimetre of variation can cause up to one metre of elevation error," says Krieger.

The strips of terrain recorded by the satellites are processed into elevation models measuring 50 by 30 kilometres. Due to the ultra-precise calibration, when this 'basic data' is compiled at the end of the process to generate a global 3D map, it is already of very high quality. By mid-2013, TanDEM-X and TerraSAR-X will have imaged the complete land surface area of Earth – roughly 150 million square kilometres – several times. The intention is to create an exceptionally accurate, global and homogeneous 3D elevation model that promises to be of equal interest for commercial and scientific purposes.

Data quality depends on ground reflectance

Initially, at least two complete coverage cycles of Earth's land surface were planned. Some parts, one example being the vast majority of Australia's landmass, were recorded by the satellite duo with sufficient quality during the first overflight. "The level of precision depends on how well the ground reflects the radar pulses transmitted – and subsequently received – by the satellites," states Manfred Zink. For example, the Sahara is more difficult to image because the signal literally 'sinks into the sand' and is lost. For regions of dense vegetation, such as rain forests, additional imagery and careful adjustment of the distance between the satellites are necessary. "We are going to be left with a few blank areas on the map, but we do of course seek to minimise these gaps," states Zink as he thinks about the coming months.

Better understanding Earth as a system

"We want to gain a better understanding of Earth as a system and to employ the data for climate and traffic research, for example," says Irena Hajnsek, scientific coordinator for the TanDEM-X mission. In 2011, she gave the 'green light' for 166 of the research applications submitted to DLR. "Most of these originated in the USA and Germany. The TanDEM-X capabilities are to be used to address questions of land usage and vegetation, hydrology, geology and glaciology," explains Hajnsek. The two Earth observation satellites can also generate information about the height of the snowline or the change in ice masses of the two polar regions, as well as provide geological maps of regions subject to volcanic and/or earthquake activity. The speed of ships or road vehicles can be measured, as can changes in the natural world. The work performed by these two radar satellites is also valuable for agriculture. "Based on the height and structure of a plant – such as rapeseed, for example – it is possible to draw conclusions about its quality and biomass," states Hajnsek.

About the mission

TanDEM-X is operated by the German Aerospace Center (DLR) with funds from the German Ministry of Economics and Technology in the form of a public-private partnership with Astrium GmbH. DLR is responsible for the scientific use of TanDEM-X data, planning and implementiation of the mission as well as controlling the two satellites and generating the digital elevation model. Astrium built the satellite and shares the costs for the development and use. Commercial marketing of TanDEM-X data is managed by Astrium Services’ GEO-Information Division (formerly Infoterra GmbH), a subsidiary of Astrium.