Working on the eternal ice: DLR's GARS O'Higgins Antarctic station turns 25
14,205 kilometres from Berlin, storms rage across the Antarctic Peninsula at speeds of up to 250 kilometres per hour. Perched on the northern tip, the German Antarctic Receiving Station GARS O'Higgins, operated by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) has defied these conditions for 25 years, operating a nine-metre antenna and staffed by a small team 365 days of the year. During this time, the facility has received tens of thousands of data packages from satellites such as TerraSAR, TanDEM-X and BIROS, transmitted commands back up into orbit, and served the German Federal Agency for Cartography and Geodesy (BKG) as a radiotelescope. Now, 2.5 million euro are being invested to prepare the station for future missions: in addition to modernising the infrastructure, the antenna control system will be switched from analogue to digital. "GARS O'Higgins is important for DLR's Earth observation mission, and this modernisation is intended as preparation," says Stefan Dech, Director of the Earth Observation Center (DFD) within DLR.
Set to permanent receiving mode in the Antarctic
It all started 25 years ago when the nine-metre antenna first received data from the Earth observation satellite ERS-1 – marking the start of operations at the Antarctic station. In the beginning, four-man teams lived and worked at this remote location from October to March. GARS O'Higgins remained unoccupied for the rest of the year, 'mothballed' for the Antarctic winter. "In the end, it proved inordinately laborious to get the station up and running again six months later," reminisces Erhard Diedrich, Head of the International Ground Segment at the DLR German Remote Sensing Data Center and therefore directly responsible for the DLR Antarctic station. Demand for data reception has also increased. Ultimately, the start of the station's year-round operation coincided precisely with the launch of the radar satellite TanDEM-X in June 2010. Over one third of all data needed for the now complete, global 3-D elevation model produced as part of this mission was received at GARS O'Higgins.
Journey by air or sea
Now, the station and its 35 containers are staffed round-the-clock, a task that demands maximum flexibility and commitment on the part of the DLR team: most people travelling to the Antarctic will remain on the ground for several months. "And it is perfectly normal for a scheduled return by air or by sea to be delayed for up to four weeks due to inclement weather," says Diedrich. Simply travelling to the end of the world is a long affair: passengers set off from Punta Arenas on the Chilean mainland on board a Hercules transport aircraft owned by the Chilean or Brazilian air force, which flies them to the staging area on King George Island. From there, a 'Twin Otter' takes them to the glacier overlooking GARS O'Higgins and the neighbouring Chilean station General Bernado O'Higgins. The only alternative is to travel by ship, crossing the stormy Drake Passage from Punta Arenas. "We require the logistic support of our Chilean and Brazilian partners on all of these routes." The teams joined to celebrate an event marking the 25 anniversary of the station in the Chilean Antarctic Research Institute (INACH) to look back on this partnership, attended by the German Ambassador to Chile, Rolf Schulze, the Governor of the Region of Magallanes, Jorge Mauricio Flies Añón, as well as political representatives.
Receive, send, process
Nowadays, a veritable fleet of satellites send their data to the receiver system in the Antarctic: in addition to the radar satellites TerraSAR-X and TanDEM-X, these also include TET-1 and BIROS, which are part of the German FireBIRD mission. On an international level, the station is used for the German-US GRACE mission and for the Canadian Cassiope and NEOSSat missions. Unlike 25 years ago, when data was 'just' received from space, now the station also sends commands to the satellites. Processing the incoming data is another new task: some data with information on swell and sea ice coverage, or the position of icebergs, ships and oil slicks, is processed virtually in real time. The data can then be transmitted to assist ships or rescue missions.
New Year's Eve at the end of the world
As remote as the DLR station is, its residents can still stay in touch with home, although they spend long weeks in relative isolation. "Fortunately, it is fairly easy to call our families and friends, even in the Antarctic," says Ruslan Artemenko, a veteran of 21 Antarctic missions and scheduled to once again spend New Year's Eve at GARS O'Higgins. "Satellites are not concerned with the turn of a year." The station needs to be ready if a satellite flies over and sends data to Earth, even during the holidays. But colleagues do have the slight compensation of celebrating twice – a small get-together in the station kitchen at 20:00 when the fireworks start firing in Germany, and again, four hours later, as the clock chimes midnight in the Antarctic. Then, the team at the DLR station will join their colleagues in the adjacent Chilean station for a proper New Year's party.
The future of the Antarctic station
The station and its team may face additional tasks in the coming years: for instance, a substantially larger quantity of data will have to be received and then sent from the Antarctic to Germany if the Tandem-L radar mission proposed by DLR is indeed implemented. At the moment, the data is recorded on magnetic tapes, which are then sent by ship. The Chilean government is currently exploring whether the Antarctic research stations could be connected with the mainland by a sea cable. "This kind of fast and cost-efficient connection would allow us to transmit our recorded data quickly and continuously, and we could also create up-to-date and high-resolution information products. The recording capacities of future satellite missions would therefore increase significantly," emphasises Dech.