SOFIA, the two-fold stargazer

I have worked in the Space Science Department at the DLR Space Administration since October 2016. I could not imagine a better job than my own as SOFIA project engineer. I tend to commute between Bonn and California quite regularly as the NASA/DLR airborne observatory has its home base in Palmdale. But for around a month now, I have been in Hamburg with SOFIA.

Like any other aircraft, this one – registered as N747NA and named the Clipper Lindbergh – requires regular maintenance. This is no ordinary aircraft, though, as the Clipper Lindbergh is just one of 45 special variants of the classic Boeing 747 that were ever built: a so-called 747SP (special performance). Fewer than eight of these 'old timers' remain in service today. What is more, the Clipper Lindberg was modified to make space for the SOFIA telescope, which weighs 'just' 17 tons. So we are dealing with quite a few special features all at once. That is why inspections for its next certification are now on the agenda, and they are far more detailed than those for normal airliners or cars. read more

Why does SOFIA have a bulge?

SOFIA at German Aerospace Day in Cologne

You could say that SOFIA is the aircraft equivalent of the hunchback of Notredame, as unlike its elegant colleagues that we know and appreciate from normal air transport, our observatory has a hunch, or a bulge. Does that make SOFIA unattractive? Perhaps! But I believe that it is the bulge that makes the aircraft so interesting, as it hides SOFIA’s inner treasure: the telescope, the star trackers and last but not least the door system as well – with all the integral components. read more

Larsen C – A giant in motion

Displacement of the iceberg at the Larsen-C ice shelf between July and October 2017

The A68 iceberg has been making headlines again after calving from the Larsen-C in July 2017. What happened? It moved and shrunk minimally. And while that may not be unusual, it is still worth a blog post.

Close examination of satellite image sequences from the last two months reveals the striking events unfolding there. Remember, the 5800 square kilometre iceberg is seven times the size of Berlin and is permanently moving. The iceberg has collided repeatedly with the ice shelf, dislodging smaller pieces of ice. read more

Beaming instructions from space: robot experiment between the ISS and Oberpfaffenhofen

Rollin 'Justin and the solar panels he will inspect during the SUPVIS Justin experiment.

The Institute of Robotics and Mechatronics at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has long been a forerunner in the remote control of robot technology for space applications. In 1993, the ROTEX experiment was the first ever in which a robot was remotely controlled from the ground and actually caught a free-floating object in space. In a more recent experiment in December 2015, cosmonaut Sergei Volkov used technology that built on this experiment to operate a ground-based robot from the International Space Station (ISS). At the time, a finely-tuned joystick allowed the cosmonaut to shake hands with institute director Alin Albu-Schäffer and even raise a glass on the success of the Kontur-2 mission. read more

Larsen C - TerraSAR-X observes calving of A-68 iceberg

After detaching: TSX-ScanSAR image from Saturday, 22 July 2017, 23:40 UTC

In recent days, the gigantic iceberg that has broken free of the Larsen C ice shelf on the Antarctic Peninsula has been in the headlines. Although the dislodging of icebergs from ice shelves is a natural occurrence and does indeed take place regularly in the Antarctic, as the media aptly reported, this event made a far larger impression than many others. Why is that? Probably because scientists have been using satellite data for months now to observe this region of the Antarctic in greater detail and have effectively been waiting for the event to occur. Moreover, the section of ice that dislodged this time is comparatively large, approximately seven times the size of Berlin. read more

ROBEX Part 4: Ash, beetles and blustering winds

Dust is inescapable after four weeks of field research on Mount Etna: a tenaciously fine layer covers everything: equipment, transport crates and notebook keypads. It penetrates the mission container and sticks to hands and legs lathered in sunscreen. Every step in the black lava soil kicks up clouds of dust. Even the white body of the LRU-2 Rover is coated in black deposits. A small mercy is that the last few days have seen significantly fewer flies and beetles buzzing around Mount Etna who, despite the gaunt landscape, insistently settle on the jackets and hats of the ROBEX team members.

After all, Mount Etna is not a conventional laboratory and remains unpredictable. Gusts of wind up to 100 kilometres an hour pummel the mountain on Thursday, carrying with it not only dust but heavy rocks, putting a stop to any work with the Rover – the force of the wind against the Rover's body and arm would simply be too great and could well have damaged it. The lander is also packed away safely, the flaps on its charging port not just folded down, but securely strapped in place. Finally, the engineers face the battering wind to remove the signs on the lander that the Rover uses as points of orientation during its approach. read more

ROBEX Part 3: Hammering for science

Mount Etna is very close to being a substitute Moon for the planetary researchers of the ROBEX project – it is here that they find volcanic basalt in quantities similar to those of the constituents of the lunar soil. In addition, the Sicilian volcano is the only place in Europe that experiences earthquakes at a depth of up to 600 kilometres. Mount Etna is like the Moon in this respect as well, as Earth's lunar companion experiences most earthquakes 700 to 1100 kilometres below the surface. "Etna is the only place in Europe where we can measure earthquakes at a similar depth," says planetary researcher Martin Knapmeyer.

Two experiments are to be conducted on the mountain; in the active measurements, the scientists use a hammer to strike the surface and seismometers to measure the transmission of the sound waves through the ground. The volcanic ash of 2001 rests on top of a more solid layer in Piano del Lago, so waves that take different routes through the surface material arrive at the seismometers at different times, providing information on the structures below the ground. The passive experiment uses four measurement stations to listen to the processes inside the volcano. read more

ROBEX Part 2: Lander on a trolley

500. 350. 80. On Friday, these numbers set the rhythm. Weighing in at 500 kilograms, the RODIN lander will be taken 350 metres from its current location, 80 metres downhill. The lander was initially kept near base camp – the perfect location for carrying out repairs following its transit to Sicily and for the first tests and connection to the control room on Mount Etna. To conduct the actual 'Moon mission', the RODIN lander will be on the Piano del Lago.

The plain – located between Torre del Filosofo and La Montagnola crater – was once covered with meltwater. This changed when Mount Etna erupted in 2001; ash was spewn all over the plain and the Laghetto crater was formed. An ash blanket now covers a solidified layer of lava. It is its thickness that DLR planetary researchers want to measure. To do this, the heavy lander needs to be moved. Once lifted onto a trolley with rollers, the lander was able to start its descent down the slope. read more

ROBEX Part 1: Mission in the lava landscape

A journey to the Moon is an arduous one, even if this 'Moon' is located here on Earth, 2600 metres above sea level, directly on Mount Etna.

A heavy transporter winds its way slowly and laboriously through the narrow, serpentine roads above Catania in Sicily to arrive at our lunar destination. The landscape becomes increasingly black as the team from the HGF Alliance ROBEX (Robotic Exploration under Extreme Conditions) approaches its temporary work location. Everyone clambers into all-terrain vehicles at Rifugio Sapienza to cover the last stretch to base camp, which is located right in the middle of a lava field. There, one lander, two rovers and several seismometers have been prepared for this one and a half week 'mission'. For the next four weeks, the on-site containers will be home to the almost 50 team members from DLR, AWI, the University of Würzburg and the Technical University of Kaiserslautern, where they will function as multipurpose laboratories, workshops and offices. read more

DLR audio – The Sound of Science

Science is simulating, measuring, and evaluating data in order to gather knowledge. On an elementary level, however, science is a description of human experience: touching, observing, and listening. Helicopter rotors make a very particular sound; satellites send beacon signals from outer space; wind tunnels also produce a characteristic soundscape.

One of the latest audio recordings in the SoundCloud archives comes from the School_Lab in Göttingen, and it is a real treat for stereo enthusiasts. read more