Starship Asterisk*

A journey from Earth to Mars could soon take just 39 days -- cutting current travel time nearly six times -- according to a rocket scientist who has the ear of the US space agency.
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The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) is quick becoming a centerpiece of NASA's future strategy as it looks to private firms to help meet the astronomical costs of space exploration.
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rocket would use electricity to transform a fuel -- likely hydrogen, helium or deuterium -- into plasma gas that is heated to 51.8 million degrees Fahrenheit (11 million degrees Celsius). The plasma gas is then channeled into tailpipes using magnetic fields to propel the spacecraft.

That would send a shuttle hurtling toward the moon or Mars at ever faster speeds up to an estimated 35 miles (55 kilometers) per second until the engines are reversed.
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this rapid acceleration could translate into a round trip voyage to Mars that would last as little as three years, including a forced stay of 18 months on the Red Planet, as astronauts await an opening to return to Earth.

this rapid acceleration could allow for trips of just 39 days instead of the current anticipated round trip voyage to Mars that would last three years, including a forced stay of 18 months on the Red Planet, as astronauts await an opening to return to Earth.
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And the use of ionized fuel could have the extra benefit of helping create a magnetic field around the spacecraft to protect against radiation.

this rapid acceleration could translate into a round trip voyage to Mars that would last as little as three years

this rapid acceleration could allow for trips of just 39 days instead of the current anticipated round trip voyage to Mars that would last three years