With Nasa's high-profile landing tomorrow of a robot geologist on Mars, an important year for the US space agency kicks off slightly early.
The InSight spacecraft, should its landing go to plan, will dig into the Red Planet to study the geological similarities and differences to Earth.
According to Nasa, InSight "won't be looking for life on Mars. But studying its insides - what it's made of, how that material is layered and how much heat seeps out of it - could help scientists better understand how a planet's starting materials make it more or less likely to support life".
Nasa's next Mars rover, designed to seek signs of life, will be launched in 2020.
Last week the agency announced that it had decided on a landing site for that craft - an ancient lake bed called the Jezero crater. The method of landing is complex: Nasa will use a rocket-powered sky crane. The spacecraft will be slowed down and the rover lowered on to Mars via cables. The rover will be equipped with a drilling system to collect and store rock samples.
Missions to Mars show off the agency's engineering prowess in spectacular ways. They don't risk precious human cargo. But next year the agency, with partners SpaceX and Boeing, will move closer to the goal of again putting astronauts in space from the US. It is seven years since the shuttle was retired in 2011.
SpaceX is hoping to launch its Dragon spacecraft without crew in January and with crew by June. Boeing's first flight without crew is pencilled in for March.
The two private companies have faced development problems since being awarded contracts by Nasa in 2014. A safety advisory panel this year found that SpaceX was struggling with its parachute system while Boeing had key tests to complete.
Separately, Nasa has ordered a safety review into the two companies to assess workplace culture, also to begin next year. The Washington Post reports that the review was sparked by the erratic behaviour of Elon Musk, the SpaceX founder.
Billionaires Musk, Richard Branson and Jeff Bezos all hope to put humans in space. Four years after Virgin Galactic lost a pilot in a crash, Branson's company is soon due to launch SpaceShipTwo in flight.
Will the standards of an admired government agency survive the jump to commercialisation? And how much private involvement is too much?
A Nasa committee is looking into selling seats for revenue on the spacecraft being built for its astronauts.
The White House wants to end direct funding of the International Space Station by 2025 and privatise it. Aside from the growing private role in space development, the Trump Administration is also pushing for a Space Force - a military department to fight war in space.
As Nasa administrator Jim Bridenstine, who wants its brand boosted commercially, said: "The reality is, we're in a new era now."