Spacecraft Tracking with the SKA
  The possibility of using the SKA for occasional support of scientific space missions should be considered, along with all other science goals, in the design of the array. The benefits of higher data rates from distant spacecraft during high priority, short duration mission phases can be dramatic, while the technical requirements on the SKA to allow this capability are very few. The most fundamental requirement is coverage of the primary downlink frequencies for deep space missions. Additional benefits can result from real-time high precision angular position measurements of spacecraft. Such measurements allow spacecraft navigation with reduced errors and reduced risk, but require at least some long (thousands of km) baselines. 
D. L. Jones (JPL, Caltech)