The period of office for the current ESA Director General, Jean-Jacques Dordain, ends in 2011. Because so far only one German, Reimar Lüst, has been director general of the European Space Agency since its inception, it seems fairly obvious for a German candidate to be in the running for the forthcoming election of a successor. Preliminary discussions with all ESA member states confirmed that a German candidate would have very good prospects.

With finalisation of the functional tests for the satellite bus and instrument, we have reached another important milestone. Evaluation of the test data confirmed that everything was nominal. In one of the last tests, the satellite was powered up solely by its internal supply and the external power was switched off. This too was successful, so the satellite was turned off and the wiring to the electrical test equipment was removed – a slightly melancholic moment. The next time we receive a signal from the spacecraft it will be in orbit, having separated from the launcher.

When we pay our electricity bill, we are paying for more than just the operation of wind turbines or nuclear power stations. What with rental for the electricity meter, costs for using the power grids, value-added tax and a tax on electricity, coupled with a surcharge for the preferred sourcing of green power, the final price we pay is effectively double the generation cost. Having said that, is it conceivable that there is such a thing as free electricity in the ever more dynamic power market?

The Stratospheric Observatory For Infrared Astronomy, SOFIA, is a cooperative German-US space research project. The 2.7-metre telescope, housed in a Boeing 747SP, is designed to observe in the infrared. During flight, a four-by-six-metre door opens at the rear of the aircraft, through which the telescope can view the night sky. The plane is based in California; the telescope was designed and built in Germany.

Today, with the commencement of the Abbreviated Functional Test, the final checkout of the radar instrument began. The team is now complete - travelling yesterday from Moscow, additional colleagues from Astrium and the German Research Centre for Geosciences (GFZ) arrived at just the right time. For most of them this is not their first stay here in Baikonur - they previously worked on TerraSAR-X and the facility and the working environment are familiar to them.

DLR staff member Thilo Kranz took this great image in his leisure time last Sunday. It shows a transit of the Sun by the International Space Station ISS with Space Shuttle Atlantis docked.

The fueling of the TanDEM-X satellite with hydrazine was completed on Saturday 22 May. This potentially hazardous operation was performed successfully by Astrium. Following this, the satellite was packed into its container and transported from the fueling station back to the integration facitity. After the arrival of new personnel from Germany on Tuesday, the final checkout of the satellite bus and instruments will start in the middle of this week.

'Mobile electricity' - that is, electricity available on the move - is the most valuable form of electrical power. This is why it is worthwhile equipping notebooks and laptops with expensive lithium-ion batteries that need to be recharged at regular intervals by plugging them into power sockets. The iPad, which looks set to spur the market for electronic reader devices, remains uninteresting without its batteries. However, solar cells and hand cranks are already able to generate standalone power for mobile devices. Will these devices be able to cope entirely on their own without power sockets someday?

TanDEM-X has left the integration facility for its reaction control system tank to be filled with hydrazine over the next few days. To do this, the satellite has been moved to the fuelling station as was reported earlier. Fuelling is a dangerous job, because the propellant used is quite toxic. When you enter the fuelling hall, the sign over the entrance reminds everyone to not forget the dangers. Translated, it reads, "Regardless of how urgent your work is, safety comes first." This is a reference to the devastating Nedelin fuelling catastrophe here in Baikonur in 1960, which took 126 lives.

We are now in the second week of our TanDEM-X launch campaign here in Baikonur. The satellite has been installed on its test rig and a quick check shows that the instrument and spacecraft are in good health. Meanwhile, the propulsion and cold gas systems have been pressurised to check that they are leak tight.

Ninety-nine percent of the Earth is hotter than 1000 degrees Celsius. Inside Earth's core, temperatures rise to 7000 degrees. In total, the power within our planet amounts to thousands of billions of watts. This reservoir has its origins in the residual heat dating from the time the Earth was created, roughly 4.6 billion years ago, and in the ongoing radioactive decay of long-lived isotopes of uranium, thorium and potassium. The question we need to ask ourselves is why, given these gigantic amounts of energy, does geothermal power still only account for far less than one percent of our energy usage?

It was a long, long way to Baikonur. Already, at the beginning of the trip, the cargo plane – loaded with 37 tons of TanDEM-X and its support equipment in six containers – was delayed for several hours. It was not until 22:45 that we were able to leave Munich. One might have hoped that the stop in Ulyanovsk would be short – but on the contrary, the customs checks were extensive and time consuming.

Since my last report, the satellite, weighing in at 1350 kilograms, has arrived safely at Franz Josef Strauss Airport in Munich, packed in its air-conditioned transport container, and will set out at 18:00 today on the next leg of its journey on board an Antonov AN-124 bound for Baikonur in Kazakhstan. Immediately after it lands on 12 May, the launch campaign will start. The satellite will be unpacked, filled with hydrazine fuel and then put through a series of tests. One week before its launch date, the satellite will be transported to its silo, in which the Dnepr-1 launch vehicle that will take it into orbit is ready and waiting. The satellite will then be installed on the launcher, its batteries will be charged and the final tests will be conducted. Then, all anyone can do is to cross their fingers and wish it well!

Solar cells are good at converting sunlight directly into electricity. However, they come nowhere close to the efficiency of natural photosynthesis. Using chlorophyll, green plants have mastered the art of producing energy-rich molecules such as sugar and starch from carbon dioxide, water and sunlight. Would it not make sense to harness this natural process to generate energy?

Rising fuel costs are urging shipowners all over the world to find ways to deliver cargo across the seas more economically. In the 1920s, the German Aerospace Center's predecessor institute developed Flettner rotors. Some 80 years later, a cargo ship is again sailing with rotating cylindrical sails. But is this change worth it?