Exactly three years to go before launch! That was the challenge facing approximately 80 scientists and mission managers from ESA member countries and the U.S. as they recently gathered at the European Space Research and Technology Centre (ESTEC) in The Netherlands for a progress report on the Rosetta mission to Comet Wirtanen.

An artist's concept of the Rosetta comet probe. Photo: DSS

At the Payload Review on January 18, the Principal Investigators for the instruments on the Rosetta Orbiter presented their status reports. This was followed on January 19-20 by the 5th Science Working Team Meeting, which included various presentations on scientific research, mission planning and spacecraft status. These included talks about the various phases of Rosetta's 10-year odyssey, the spacecraft's asteroid and planetary flybys, and its close encounter with the comet nucleus in 2012.

Summarising their comments, Rosetta Payload & Operations Manager Claude Berner expressed general satisfaction with the way the spacecraft development has progressed so far.

"There are still a few minor problems to be sorted out," he said, "but we are confident that there are no 'showstoppers'. The overall system design is expected to be finalised in the next few months."

The Rosetta Structural and Thermal model (STM) in the ESTEC test facility. Photo: ESA

Project manager Bruno Gardini told the meeting that spacecraft assembly and testing is on track, despite the tight schedule. The so-called Sine Test of the Rosetta Structural and Thermal Model (STM) is currently progressing well and should be completed next week.

This will be followed in early February by the Ariane Shock Related Test, which will examine the spacecraft's ability to survive the launch. A series of Thermal-Balance Tests are scheduled from late February onwards.

Looking further ahead, Bruno Gardini explained that the programme to assemble the Rosetta Electrical and Qualification Model (EQM) would begin in March, while development of the Orbiter was also generally on track.

"A number of EQM units have already arrived," he said. "We have received the first units of the Flight Model - the gyros and thermal louvres - and the manufacture of some other hardware for the Flight Model has started."

Despite some delays and minor technical problems, the ESA team is confident that the programme to build the Rosetta Lander will also be completed on time.

"The ESA Lander team has been enlarged to support its development and DLR (the German aerospace agency) has also considerably strengthened its Lander management team," commented ESA Project Scientist Gerhard Schwehm. "The Lander design will be consolidated in the next three months, and we do not foresee any major difficulties in meeting the tight assembly and testing schedule."