Following the decision not to launch Europe’s comet chaser Rosetta in January, scientists and engineers at the European Space Agency have been examining alternative mission scenarios.

Following the failure of Ariane Flight 157 in December, with the loss of two spacecraft, ESA and Arianespace decided not to launch Rosetta during its January launch window. This meant that Rosetta’s originally intended mission to Comet Wirtanen had to be abandoned.

Three mission scenarios were presented to ESA member states at the Science Program Committee meeting in February. Two scenarios would take Rosetta to a new target comet, Churyumov-Gerasimenko, while the third would take it to its original target, Comet Wirtanen.

All three options are being studied in detail so that the final decision can be made in May. In parallel, ESA is assessing the launch requirements for the various mission scenarios. This will include looking at alternatives to Ariane as back-up options, such as the Russian Proton rocket.