Another rover by 2020, and humans by the 2030s

NASA just announced the plans for the next phase of its Mars program, culminating in the arrival of humans in the Red Planet's orbit by the 2030s. "This announcement," per a NASA press release, "affirms the agency's commitment to a bold exploration program that meets our nation's scientific and human exploration objectives."

One of NASA's big plans for the Red Planet involves a new Mars robotic science rover -- Curiosity's cousin -- which will launch in 2020 and whose design will largely be based on the thus-far-flawless technology that the Mars Science Laboratory employs. That kind of Curiosity mimicry will minimize mission cost and risk, the thinking goes, while leveraging the learnings of previous work.

Another of NASA's plans for Mars, announced earlier this year, is InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) -- a Discovery Program mission that will place a geophysical lander on Mars to study the planet's deep interior. That's slated to launch in 2016.

Taken together, today's announcement means that NASA has a total of seven missions currently operating or being planned-to-be-operated on Mars, with the purpose of exploring our planetary neighbor.