Obama shut down the space shuttle, and encouraged the growth of a commercial space industry. Credit: Lucy Nicholson/Reuters

As Barack Obama prepares to leave office, Nature examines the scientific highs and lows of his presidency. Read the other stories in this series about his policies on biomedicine, research integrity and climate change.

Barack Obama tried to shake up the US space programme, including NASA’s long-standing plan to send people to Mars. But nearly eight years — and a series of U-turns — later, he has little to show for his effort.

“Where NASA is today is really not all that different from where it was during the last presidential transition,” says Marcia Smith, a space-policy analyst in Arlington, Virginia, who runs SpacePolicyOnline.com.

A crewed Mars mission remains two decades away. Its schedule is constrained by the funding available to develop the necessary hardware — a new heavy-lift rocket and crew capsule to sustain astronauts in deep space. That is almost exactly the situation NASA was in eight years ago, bar one detail: Obama ditched the Moon as a first stop for astronauts on their way to Mars.

That decision, in February 2010, stunned NASA, Congress and space-policy experts. Obama cancelled the Constellation programme, which his predecessor George W. Bush created to send US astronauts back to the Moon in preparation for an eventual Mars trip. Two months later Obama announced a different course: astronauts would visit a yet-to-be-chosen asteroid before heading off to the red planet. The White House did not consult Congress on the switch, angering powerful members who represent space-industry employees in states such as Florida, Texas and California. “The hostility created by the way the Obama administration rolled that out still lingers in Congress,” says Smith.

The decision also alienated traditional US space partners such as Europe and Japan, says Scott Pace, director of the Space Policy Institute at George Washington University in Washington DC. “Little to no weight was given to the international implications of the decision to abandon efforts to lead an international return of humans to the lunar surface,” he says.

NASA was forced to modify its Mars plan in 2013, when it became clear that it did not have the technology to support astronauts in deep space. The White House introduced a controversial stopgap measure: instead of a crewed mission to visit an asteroid, a robot would drag an asteroid near the Moon where astronauts could then visit it.

Asteroid scientists have roundly denounced the plan, but it is moving forward despite slipping schedules and ballooning costs. The hardware for crewed deep-space journeys is also at risk of schedule and budget delays, the Government Accountability Office said last month. The heavy-lift rocket is scheduled for its first test flight in November 2018, while the crew capsule’s is set for August 2021.

Obama extended US participation in the International Space Station for four more years, to 2024 — a move generally acclaimed by scientists. And he oversaw the shutdown of the space-shuttle programme, a process begun by Bush. After the last shuttle, Atlantis, flew in July 2011, the United States turned to Russia to buy rides to orbit for its astronauts.

NASA is relying on commercial companies to fly equipment and — eventually — astronauts to the space station. The first commercial cargo flights began in 2012, and the first astronauts are scheduled to fly aboard commercial spaceships no earlier than 2017.

Many critics see NASA’s human-spaceflight programme as adrift. Eileen Collins, a former space-shuttle commander, told the Republican National Convention in July that the agency needs “visionary leadership again”.

Scientists grumble about the relative lack of flagship missions in development. One of the biggest, a proposed mission to Jupiter’s moon Europa, has been pushed through not by the White House or NASA, but by a Republican congressman from Texas who is enamoured with the idea of life on icy worlds.