Re: Ion Propulsion

Sean Morgan (
Sun, 08 Jun 1997 19:26:29 -0600

>Date: Tue, 20 May 1997 17:06:02 +0100
>From: Brian Wang <>
>To: sean <>
>Subject: plasma engine
>A tunable plasma engine designed by MIT is being tested by NASA.
>It can reduce the one way trip to Mars to 2.5 months and
>allow a round trip of 7 months duration.
>It uses microwaves to heat hydrogen to 10 million degrees which
>sends ions out at speeds of 50-300km/sec. (The nando article says
>per hour but that must be incorrect). Power source would be
>a nuclear reactor. They expect to flight test in 5 years.

[Nando is volatile, so the text follows]

Engine could propel humans to Mars

Copyright =A9 1997 Copyright =A9 1997 Agence France-Presse

HOUSTON, Texas (May 20, 1997 10:55 a.m. EDT) - A revolutionary rocket engine
using ions as fuel will cut the duration of a round-trip, manned mission to
Mars from more than three years to a mere seven months, scientists said.

The Tunable Exhaust Plasma Rocket is undergoing its first tests at the
Johnson Space Center near Houston. A flight test will come in five years
aboard a space shuttle.

With the ion engine, astronauts will take two-and-a-half months to reach
Mars, where they will remain for two months before completing their
round-trip space voyage in seven months.

With current rocket technology, Mars would be an eight-month space trip each
way, forcing astronauts to wait two years on the red planet for a favorable
alignment for the return to Earth.

Astronaut Franklin Chang-Diaz, who is researching the ion engine for the
Massachusetts Institute of Technology, said the technology forces plasma --
ionized gas heated to 10 million degrees -- through a tube topped by a
nozzle. Heating hydrogen to such high temperatures separates the atom from
its electron, creating an ion shot out at a speed of 50 to 300 kilometers
per hour.

Magnetic fields inside the main body of the rocket and at its openings
channel the plasma and "control the speed of ejection, just as you do for a
water hose," Chang-Diaz said.

Despite its modest size, three to four yards in length by one yard in
diameter, the ion engine will be able to propel a spaceship all the way to=

To heat up the gas, a microwave oven of sorts is used, powered by 10
megawatts of power supplied by a nuclear reactor.

The spaceship will be surrounded by several huge tanks filled with liquid
hydrogen, similar to those used by the shuttle at launch. The tanks will
shield the crew from dangerous solar emissions and, at the same time,
provide good insulation against heat.

In a trip to Mars, Chang-Diaz said, the ion engine would accelerate the
spaceship for half the distance and then decelerate it until it can settle
into an orbit around the red planet prior to a landing.

For now, Chang-Diaz is happy firing up his new engines every day inside a
special room at Houston's Sony Carter Training Center, where US astronauts
undergo their training.

If all goes well, he said, in five years a smaller version of the ion engine
will be dropped out of an orbiting space shuttle and fired up to see how it
cruises along.

Electricity during the tests will be supplied by a series of batteries.
Chang-Diaz believes that once proven in a Mars mission, the ion engine will
propel man further out, to Jupiter, Saturn or even Pluto.

Sean Morgan (