Three space agencies, DLR, ESA and NASA, as well as their astronauts tweet, blog and post messages on a wide array of social media channels; often, they or respectively their astronauts even do so from space. Why do they do this, and how does it work? Here is what astronauts and social media experts at DLR, ESA and NASA had to say on this subject at re:publica 2012, Germany’s largest and most prominent conference on the future of society and all things digital.

Quite some time has passed since my previous blog post – it was on the launch of the third European space transporter, ATV-3. This isn't due to any 'blog fatigue' on my part, but rather to the many activities that have simply kept me from writing my next entry. But I guess you could say that this is a fairly weak excuse, since it does not really take all that long to write a blog post. Blog entries give me the opportunity to report on my work as Chairman of the DLR Executive Board outside the 'normal' channels of communication and thus to allow all interested parties, both within and outside DLR, to gain a little more insight.

Live webcasts have become increasingly common, enabling any Internet user to follow spaceflight events such as launches, dockings or daily life on board the International Space Station (ISS). But there is a way to experience the wonder of spaceflight even more directly – with your own eyes. This is because the Space Station is visible at certain times as a small, bright point of light moving rapidly across the morning or evening sky. Many people are fascinated when they observe the ISS in this way, especially for the first time. In this blog entry I will explain how you can observe the ISS yourself.

I have great pleasure in announcing that members of DLR, NASA and ESA will be participating in a session at re:publica Berlin from 2 to 4 May 2012. According to the organisers, re:publica is “Germany’s largest and most prominent conference on the future of society and all things digital.”

Last week, on 28/29 March 2012, the fourth European SpaceTweetup took place in Toulouse, France. A good reason to blog about the reach and numbers of such a communication measure. Plenty has already been written about the first European Space Tweetup, organised by DLR and ESA, which took place in September 2011, so I will - with some delay - now just concentrate on the numbers here. For any readers who want to know more about the SpaceTweetup and find out what it was all about, I recommend this or that blog article.

On 23 March 2012, an Ariane 5 rocket took off from Europe's Spaceport in French Guiana carrying the third European ATV space transporter to the International Space Station (ISS). I had the opportunity to witness the launch on location together with the representatives of other ESA member states, and to discuss future activities in the European space sector. It was an ideal opportunity to prepare the formal agreements for the next few weeks and months leading up to the ESA Ministerial Conference.

As a lunar observer, I am repeatedly asked whether the tracks of the six Apollo missions can be seen through a telescope. After all, the descent stages of the lunar modules, three lunar rovers and a lot of scientific equipment were left behind there. Unfortunately, this is impossible even with the largest ground-based telescopes. But on the Internet, it is possible for everyone to go out and explore.

It all began when Mathias Schindler of Wikimedia Germany contacted us here at the DLR Communications Department in May 2009 with an enquiry regarding the usage rights for DLR image material by Wikipedia and the associated Wikimedia Commons media archive. Here is a brief summary of the telephone conference that followed shortly afterwards – if DLR content, specifically our image material, continues to be associated with traditional ‘all rights reserved’ terms of use, it cannot be used by, for example, Wikipedia. The use of the Creative Commons (CC) licensing model might represent a solution.

Alongside numerous blogs and Wikipedia articles on aerospace, the Internet has more information to offer on this subject. There are, for example, podcasts – in addition to those available at Raumzeit (Space-time), jointly produced by DLR and ESA, I would now like to draw your attention to the podcast site omega tau . Podcasts are an interesting channel for science communicators to disseminate information about science and technology.

All the latest stories about DLR's sites, institutes and missions are now also available in a version for smartphones. Simply go to www.dlr.de/ or m.dlr.de/en/ on your mobile device.

With today's contribution I want to fulfil the promise I made in the blog entry I wrote on 12 July 2011 to inform you about the results of the tests on the usability of the German Aerospace Center's (Deutsches Zentrum für Luft und- Raumfahrt; DLR) new web portal.

On 18 September 2011, German Aerospace Day, DLR and ESA staged the first European SpaceTweetup. A tweetup is an event in which users of the social media platform Twitter meet up. Together with ESA, we invited our Twitter followers to come and find out more about the European aerospace industry, meet scientists and astronauts and have a look at our research facilities and aircraft.

The German ROSAT research satellite was launched on 1 June 1990 on a Delta II launcher and successfully scanned space for X-ray sources for nine years. Its record of achievements extends from discovering countless X-ray sources to analysing galactic clusters, X-ray binary stars and black holes to discovering the reflection of the Sun's X-ray radiation by the Moon. The findings by the scientists involved in the mission have appeared in over 7000 publications. After orbiting Earth for 21 years, ROSAT re-entered the atmosphere over the Bay of Bengal. It is not known whether any parts reached the Earth's surface.

The airborne observatory SOFIA will arrive at Cologne-Bonn Airport on Saturday 17 September 2011 at about 06:50 CEST. The aircraft will be one of the attractions during German Aerospace Day, which takes place on the following day. The flight from the United States to Germany can be followed live online from 19:10 CEST – learn how in this blog post.

Here is a list of the social media channels for German Aerospace Day and the associated SpaceTweetup; nearly all the events can be followed in (almost) real time.

Camilla Corona SDO is ready for the Space Tweetup! File this one under ‘humour’: A fabulous and very tongue-in-cheek press release has been issued by one of our favourite rubber chickens.

On 18 September 2011 DLR is hosting, for the eleventh time, German Aerospace Day in Cologne, offering young and old alike the opportunity to take a look behind the scenes of DLR's research work. For those interested in following this special day online and those active in social networks, we will be reporting live throughout the event here on this blog as well as on Facebook, Twitter, YouTube and Flickr.

A great deal has happened since DLR’s participation in the Aerospace trade show at Le Bourget in June, and it can all be followed on the recently revamped DLR homepage. Last week’s events mainly focused on the MAKS Aviation and Space Salon in Moscow, the third trade fair for the international aerospace industry, where DLR has been showcasing its work, following its appearances at Le Bourget (Paris) and ILA in Berlin. Just as at the Le Bourget trade fair, at MAKS we were once again able to engage in many interesting and important talks.

After more than 5 months of successful flight operations by GSOC, the operational control was re-handed over again to the control center in Solna, Sweden. Since handover to GSOC in March this year, various experiments could be performed. My colleagues already reported corresponding details within the Blog. I’ll now try to describe the topic of a satellite mission handover.

The new version of DLR's iOS App provides a wealth of information right at your fingertips - now also supporting the features of the iPad.

Today we sent off the last invitation letters for the first european SpaceTweetup, jointly organised by DLR and ESA. I cannot make clear enough how happy I am to organise and host this event together with our friends from ESA's communication department. But before I give you a little bit of background information on how the event came about, let me first answer the often heard question:

The Space Shuttle Atlantis announced its arrival at the Kennedy Space Center (KSC) in the early morning hours of 21 July 2011 with a double sonic boom. Just over three minutes later, the spaceship touched down on the runway and at 05:57:54 local time "wheels stop" was called for the last time. Atlantis and its crew had safely returned to Earth. NASA's space shuttles have travelled into orbit 135 times; this era ended today. The space shuttles have shaped US space policy for the last 30 years and have stood as an icon of human spaceflight for a whole generation.

Finished at last! The redesigned web portal for the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is ready to receive the first of its close to 500,000 visitors per month. We have been working on the redesign for some time now, and are more than pleased with the result.

Astronomers on board SOFIA fly over most of the water vapour in the atmosphere; it is precisely this that makes the desired infrared observations possible. But the fact that SOFIA flies has another major advantage: it is a mobile observatory. In contrast to ground-based observatories, it can be used at different locations around the globe. This can be very useful, for example, for the Pluto occultation that will take place these days.

In my last blog entry, I focussed on a farewell to the shuttle fleet and some observations on the paradigm shift occurring in the space sector. Space Shuttle Endeavour has now landed safely and Atlantis is being prepared for launch. Images of the International Space Station (ISS) with Space Shuttle Endeavour and docked with the European space transporter ATV 'Johannes Kepler', taken from a Soyuz capsule as it was departing, already have historical value. This time, I would like to focus on my reappointment as Chairman of the DLR Executive Board and on the aspects that will be of central importance in my ongoing work.

I had already been working on the SOFIA project for some years, when back in 1998, a consortium of German research institutes (Max-Planck Institute of Radio Astronomy in Bonn, University of Cologne, Max-Planck Institute of Solar System Research and the DLR Institute of Planetary Research) decided to develop the German Receiver for Astronomy at Terahertz Frequencies (GREAT) as the Principal Investigator-class Science Instrument for the first generation at the SOFIA Observatory. At this time, the aim was for the observatory to be operational by the end of 2001. It was not only the optimists who were expecting the GREAT spectrometer to soon enter operational service. Back then, who could have thought that it would take 13 years for GREAT to fly on SOFIA for the first time?

On 16 May, the Space Shuttle Endeavour was launched en route to the International Space Station (ISS). On board was the large science experiment, AMS, designed to look for evidence of dark matter and antimatter. The flight is Endeavour's last, and it heralds the end of the shuttle era. In parallel with this somewhat technical farewell, we have also had to say goodbye to Thomas Reiter, who has been Director of Human Spaceflight and Operations for the European Space Agency (ESA)since mid-April. Two departures in the area of space exploration were sufficient reason for me to start reflecting on fundamental issues in spaceflight.

From the 14th of April the ECAPS High Performance Green Propulsion System (HPGP) experiment started its final campaign HPGP-4, the one planned for the extended mission period.

The small space shop on site at the Kennedy Space Center gives an indication of the fast-approaching end of space shuttle flights from the cape; everything is reduced in price. Although many people here on the ‘Space Coast’ are unsure about the coming months and years, the spirit needed to carry this historic space location into the future of spaceflight is unbroken. The day before the launch of STS-134, the press conferences were not just looking forward to the imminent mission.