Scientists say a new method, called ballistic capture, for transporting robotic rovers, satellites and astronaut-carrying spacecraft to Mars could save space agencies time and money.

Currently, the favored method for getting a spacecraft into orbit around Mars is the "Hohmann transfer." After rocketing through the Earth's atmosphere, the craft make a beeline for the Red Planet, barreling through space at high speeds. As it approaches Mars, its thrusters fire in the opposite direction -- slamming on the brakes and swinging the craft into orbit.

The Hohmann transfer is a highly effective move -- road-tested and reliable. But it is expensive and time specific. Launches are limited to a brief window when the orbit and rotation of Earth and Mars are just right.

Ballistic capture, on the other hand, would allow a more flexible launch window. It would also do away with the fuel-guzzling that Hohmann's high-speed braking requires. Instead of rocketing straight at Mars, a ballistic capture technique would see the spacecraft launched out ahead of Mars' orbital path. It would gradually slow and hold in place, waiting for Mars to swing by -- the Martian gravity pulling the craft into orbit as it approached.

"That's the magic of ballistic capture -- it's like flying in formation," Edward Belbruno, a visiting associated researcher at Princeton University, recently told Scientific American.

Belbruno, along with Francesco Topputo of the Polytechnic University of Milan, is responsible for a new paper on the subject of ballistic capture and its potential for enabling cheaper more frequent visits to Mars.

The study was published on arXiv, Cornell University's free science journal library, this week; it has also been submitted for formal publication to the journal Celestial Mechanics and Dynamical Astronomy.

As both Belbruno and Topputo are willing to admit, ballistic capture isn't perfect. It takes much longer than the typical six-month straight shot that has spit a number of Mars current orbiters into their paths around the Red Planet. Ballistic capture would also put a craft into a much higher orbit than most probes prefer for their scientific missions.

But the new study considers other options, too, including aerocapture, whereby a Hohmann transfer is tweaked to allow Mars' atmosphere to do some work in slowing down the craft's approach. That's why not as much fuel needs to be burned during the braking.

Ballistic capture may need some kinks worked out, but NASA is excited about its potential.

"It's an eye-opener," James Green, director of NASA's Planetary Science Division, told Scientific American. "This [ballistic capture technique] could not only apply here to the robotic end of it but also the human exploration end."

NASA has used the ballistic capture technique on one of its lunar missions -- the GRAIL mission in 2011. The European Space Agency also used the technique for its SMART-1 lunar mission in 2004.