A growing number of satellite-based automatic identification systems (AIS) make it easier for maritime surveillance to tie ship-tracking data with high-resolution satellite imagery. Used with AIS, space-based synthetic aperture radar (SAR) and optical remote-sensing platforms determine not only the presence of ships, but their identity, position, speed, heading, load, size and type.

Like London buses, three Chinese satellite platforms are coming at once.

Dennis Tito, who originally believed he could send two humans on a Mars flyaround in 2018 with funds from his own fortune and the philanthropy of others, has concluded he needs NASA's heavy-lift Space Launch System (SLS) to do the job, with $100 million a year in upper-stage upgrades from public funds spread over seven years.

As defense manufacturers become accustomed to the prospect of lower Pentagon budgets, there is growing concern over the health of the supply chain, particularly the lower tiers and specifically small companies that may be the sole source of critical parts or a unique technology.

Venezuela's first Earth-observation spacecraft is also China's first export of a high-resolution optical-imaging spacecraft.