PhysOrg: Scientist eyes 39-day voyage to Mars

[bystander]

Scientist eyes 39-day voyage to Mars
PhysOrg Space Exploration - 2010 Feb 26

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.
...
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.
...
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.
...
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.
...
And the use of ionized fuel could have the extra benefit of helping create a magnetic field around the spacecraft to protect against radiation.

The 39 day trip sounds good, but that 18 month layover is a bit problematic.

NASA: Propulsion Systems of the Future (2003 June 14)
Variable Specific Impulse Magnetoplasma Rocket (VASIMR)

edit: The article was changed after I made my initial post. Wish I had an archive of the original post.

[rstevenson]

There is a mis-quote in this post. It says...

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

But the linked article says...

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

(My italics.)

Rob

[bystander]

They changed it. My quote was just a cut and paste. Hence my remark. But thanks for the update. It actually makes more sense, now.

[rstevenson]

That's how I caught it. I was automatically doing (39 days x 2) + 18 months ≠ 3 years in the back of my head, and something back there threw up a red flag.

Rob

[BMAONE23]

It would seem to me that IF we could propel ourselves out of Earth Orbit and attain a speed sufficient to reach Mars in 39 days, we wouldn't need to remain there for 18 months. Mars gravity is significantly less than Earth gravity and so we could likely attain a greater speed leaving Martian Orbit for the return trip to a then only slightly more distant Earth. (presuming a 3-5 day stay)
Unless we arrive there with empty fuel tanks and require time to create return trip fuel.

[rstevenson]

I can't imagine that anyone would fund a trip to Mars and then plan only a few days stay. We're not, thank goodness, in that kind of nationalistic space race any more. There are "pork chop" plots for Mars orbit insertions, based on our existing technology. I suppose someone will have to redraw them based on any such nearly-constant-propulsion system.

Speaking of which, I looked a while back for on-line (or downlaodable) software for creating pork chop plots. I was unsuccessful. Anybody know of any?