MESSENGER mission: first electronically steered antenna for deep space communications

The MESSENGER mission to orbit the planet Mercury poses significant design challenges for its deep space communication system. These challenges include a wide pointing range, tight packaging, and a high temperature environment. To meet these challenges, the spacecraft incorporates the first steerable phased array antenna flown for deep space communications. The invention of a method for achieving circular polarization in a high-temperature (+300°C) environment has doubled the science return of the mission relative to its initially proposed implementation. Cross-strapping between the phased array antennas and solid state power amplifiers (SSPAs) enables both amplifiers to be turned on when sufficient power is available, enhancing the scientific return at the planet. A science return of 25 Gbits/year is achieved using only one SSPA in Mercury orbit. The science return increases to 100 Gbits/year if both SSPAs are used in the orbital phase.