It has been believed that Hall thrusters, an efficient kind of electric propulsion widely used in orbit, must be large to produce a lot of thrust. Now, a new study from the University of Michigan suggests that smaller Hall thrusters can generate much more thrust—potentially making them candidates for interplanetary missions.

"People had previously thought that you could only push a certain amount of current through a thruster area, which in turn translates directly into how much force or thrust you can generate per unit area," said Benjamin Jorns, U-M associate professor of aerospace engineering who led the new Hall thruster study to be presented at the AIAA SciTech Forum in National Harbor, Maryland, today.

NASA is partnering with a Pentagon research agency to develop a nuclear-powered rocket engine in preparation for sending astronauts to Mars.

NASA Administrator Bill Nelson said Tuesday that the US space agency will team up with the Defense Advanced Research Projects Agency (DARPA) to "develop and demonstrate advanced nuclear thermal propulsion technology as soon as 2027."

"With the help of this new technology, astronauts could journey to and from deep space faster than ever –- a major capability to prepare for crewed missions to Mars," Nelson said in a statement.

DARPA is the Pentagon's research and development arm and has played a role in many of the notable innovations of the 20th century including the internet.

NASA said nuclear thermal rockets can be three or more times more efficient than conventional chemical propulsion and would reduce transit time, essential for an eventual mission to Mars.

In a nuclear thermal engine, a fission reactor is used to generate extremely high temperatures.

Heat from the reactor is transferred to liquid propellant which is then converted into gas, which expands through a nozzle and provides thrust.

The European Commission will present a strategy to bolster the EU's security and defence efforts in space in March, Internal Market Commissioner Thierry Breton said Tuesday, with Russia's war in Ukraine raising tensions in space.

Moscow's invasion last year led to Europe and Russia calling off their previously close cooperation in space, delaying a range of missions and affecting European efforts to launch satellites.

"In the current geopolitical context, we need to enhance the Union's strategic posture to be able to defend our interests, protect our space systems and services and become a more assertive space power," Breton told the opening of the European Space Conference in Brussels.

EU foreign policy chief Josep Borrell called Russia's invasion of Ukraine a "wake-up call", saying that the bloc needs to examine "how space assets and services are crucial" to common European action.

A little less than 10 percent of the roughly 5,500 satellites currently orbiting the globe are run by militaries, Borrell said.

"But many others are dual use and they provide critical information to support our security and defence," he added.

Breton said Europe's space strategy would be based on four pillars.