From next steps in the commercial space revolution to a rocket-powered supercar, there's much to look forward to in 2018.

BBC News looks ahead to some of the biggest science and environment stories coming this year.

World in motion

Image copyright Akihiro Ikeshita / Jaxa Image caption Japan's Hayabusa 2 will follow in the footsteps of its pioneering predecessor

2018 will see a raft of space missions that highlight the international nature of present-day space exploration. First up is Chandrayaan 2, India's follow-up to its groundbreaking lunar mission launched in 2008.

While its predecessor was an orbiter, Chandrayaan 2 will comprise an orbiter, lander and rover developed by the country's space agency, ISRO. The mission is currently slated to launch on a GSLV rocket from Satish Dhawan Space Centre in Andhra Pradesh around March.

In May, Nasa will launch its Insight spacecraft to Mars. Insight will use a sophisticated suite of instruments to probe deep beneath the surface of the Red Planet, looking for clues to how it formed. It will also listen for "marsquakes" which could shed light on the planet's internal structure.

Image copyright NASA Image caption Nasa's Insight mission will look for "Marsquakes"

In July, the Japanese space agency's (Jaxa) Hayabusa 2 spacecraft will arrive at its target, the asteroid 162173 Ryugu, in an effort to return samples of this space rock to Earth. Its predecessor, Hayabusa, captured the world's imagination when, in 2005, it reached asteroid Itokawa.

Although that mission suffered some mishaps, it managed to return to Earth with some tiny specks of asteroid material - enough for scientists to get information from.

Engineers have made several improvements for Hayabusa 2, which aims to build on its pioneering predecessor by returning even more asteroid material and successfully deploying several small landers to Ryugu's surface.

Japan won't be the only country to visit an asteroid next year. Nasa's Osiris-Rex spacecraft, launched in 2016, is due to rendezvous with the object known as 101955 Bennu in August. Osiris-Rex will also aims to collect a sample of soil and rock and get it back to our planet for analysis.

Finally, Europe and Japan could despatch a mission to explore the first planet from the Sun: Mercury. The mission, Bepi Colombo, will seek to deepen and extend the knowledge gained at Mercury by the US space agency's recent Messenger spacecraft.

BepiColombo consists of two spacecraft launched on one rocket; the mission will carry out detailed mapping and investigate the planet's magnetic field. Scientists hope to shed light on key questions, such as why Mercury seems to consist of a large iron core with just a thin shell of silicate rocks on the outside.

Commercial space race

Image copyright SpaceX Image caption Elon Musk tweeted pictures of the Falcon Heavy under assembly

2018 should be the year Elon Musk's private launch company SpaceX lofts one of the most powerful rockets ever built: the Falcon Heavy.

In December, Mr Musk tweeted tantalising photos of the huge vehicle under assembly at the Kennedy Space Center in Florida. The heavy-lift rocket consists of two of the company's existing Falcon 9 boosters strapped to a central core stage. The 70m-long leviathan has been designed to launch payloads up to 57 metric tonnes into space, allowing SpaceX to move into new satellite launch markets and - eventually - loft astronauts beyond Earth orbit.

Private firms could also take significant steps towards their goal of transporting crews to the International Space Station (ISS) - but it's always possible the schedule could slip to 2019.

Under current plans, SpaceX and aerospace giant Boeing would perform the first crewed launches from US soil since Nasa's space shuttle was retired in July 2011. Since then, the US has been reliant on Russia's Soyuz launcher for transporting crew to the ISS - something that has rankled many who work in the American spaceflight sector.

Image copyright Boeing Image caption Boeing's Starliner could eventually transport astronauts to the International Space Station

Both companies plan to test their launch systems, performing uncrewed demonstrations in the first instance to gather engineering data. Then, they are expected to launch astronauts in the vehicles. But with the lives of Nasa astronauts at stake on a brand new launch system, nobody will be taking any chances - so delays are not out of the question.

But successful tests (whenever they happen) should lead to both systems being human-certified by the US space agency, allowing SpaceX and Boeing to begin fulfilling contracts to transport astronauts to the space station.

These craft should later be joined by Nasa's own launch system - the long-awaited (and expensive) Orion capsule and SLS rocket, which will be used to send people beyond low-Earth orbit. If everything proceeds to plan, Orion could be launched on an uncrewed test flight in 2019 and a launch with astronauts in 2021.

Need for speed

Image copyright EPA

After several schedule slips, the UK's Bloodhound car should step up its assault on the land speed record in the autumn.

Powered by a rocket bolted to a Eurofighter-Typhoon jet engine, the car was put through its paces on the runway at Newquay airport in 2017. That was "slow speed" testing - at just 200mph (320km/h).

Next, the team aims to exceed 500mph (800km/h) on South Africa's Hakskeen Pan this coming October.

That's still short of the existing world land speed record (763mph/1,228km/h), but it ought to provide the necessary engineering data to push the car to ever higher speeds in 2019 and 2020.

The eventual goal is to pass 1,000mph (1,610km/h).