Advanced Propulsion Comes Of Age
- Advanced Propulsion Comes Of Age
By Leonard David
Senior Space Writer
posted: 07:00 am ET
22 May 2002
NASA is known worldwide for routinely putting people into Earth orbit. The
agency is also revered as the only organization that has flung humans at
escape velocity speeds to the Moon. However, NASA could also be known as an
agency that's going nowhere fast.
The Earth has a magnetosphere, produced by the terrestrial magnetic field
and plasma from the ionization of the upper layers of the atmosphere. The
M2P2 will parallel these naturally occurring systems by creating an
electromagnetic bubble or mini-magnetosphere around the spacecraft. Credit:
Robert Winglee. Click to enlarge.
Mini-Magnetospheric Plasma Propulsion (M2P2) is an advanced plasma
propulsion system that will enable spacecraft to attain unprecedented
speeds, with minimal energy and mass requirements. This rendering depicts a
mini-magnetosphere deployed around a spacecraft. Plasma or ionized gas is
trapped on the magnetic field lines generated onboard, and this plasma
inflates the magnetic field much like hot air in a balloon. Photo courtesy:
R. M. Winglee, Univ. of Washington
Even NASA's new chief, Sean O'Keefe, is keen about the need for speed. The
agency is stuck in slow gear, he gripes, scooting about in spacecraft today
at velocities not much greater than when John Glenn first sped into Earth
orbit over 40 years ago.
To help put some "momentum" into NASA, the agency is pushing forward on a
nuclear propulsion and power initiative. Welcome news in contrast to the
past. Over the years, NASA's advanced propulsion agenda has done little but
advance in age.
Fits and starts of funding have dogged NASA's quest for advanced space
propulsion. Hoped for high-tech concepts have come and gone. Nuclear
thermal, ion, magnetic, and chemical systems to antimatter, solar sailing or
laser propulsion - converting these concepts and others from paper studies
to reality has proven elusive. But that may change given a spurt of money
for several types of advanced space propulsion.
To open up the solar system to vigorous robotic and future human
exploration, new forms of space propulsion are being sought. Not only are
faster trip times to select targets made possible. Advanced propulsion
allows more exhaustive, long-term surveys of planets and their moons, as
well as comets, asteroids, and other bodies.
NASA has kick-started an In-Space Transportation Investment Area effort.
This new endeavor embraces a wish-list of high, medium, and low priority
technologies, evolved from a space agency-wide look last year that focused
on advanced missions over the next 10 to 15 years. Better yet, there is
money now targeted to boost wish-list technologies into being.
NASA's Marshall Space Flight Center, Huntsville, Alabama, is leading the
In-Space Transportation investment work -- spread out through the NASA
research network --. They are spearheading the endeavor for the space
agency's Office of Space Science in Washington, D.C.
"I think we've got a real chance here," said Les Johnson, the implementation
manager for the advanced propulsion work. "We're trying to take the things
people have talked about for years, but get sustained commitment to go make
them happen," he told SPACE.com.
Making them happen, Johnson added, means maturing propulsion ideas to a
technology readiness level just short of actual flight.
High-priority in-space propulsion technologies include:
Aerocapture: Using a planet's atmosphere to slow a spacecraft. A vehicle
built for aerocapture can slip into orbit in one pass through an atmosphere.
No need for on-board propulsion. This saves mass and permits use of a
smaller, less-expensive launcher. These technique gets a vehicle to a
destination quickly, hastening start-up of science operations;
Next Generation Electric Propulsion: Improve the performance of this
technology, from ion engines to fission propulsion drives. High-throughput,
lightweight, and more powerful ion engines, for example, enable a host of
future space missions, including a Europa Lander, a Saturn Ring Observer, a
Neptune Orbiter, and a Venus Surface Sample Return probe; and
Solar Sails: Strong, lightweight composite materials fashioned into a large
sail. Requiring no fuel, a solar sail relies on the steady push of photons
from the Sun. A major challenge is how best to unfurl a thin sail in space,
then control its direction. Sail propulsion is seen as the way to launch an
interstellar precursor mission in the next decade.
Go fly status
Johnson said by combing the work of NASA centers with industry and academia,
these high priority technologies and others -- particularly, nuclear
electric propulsion -- will be moved up in technological readiness for
flight in space.
"We want to get these technologies to the point that everything that can be
done on the ground has been done�and they are ready to go fly," Johnson
said. NASA calls this pre-flight status as Technological Readiness 6 or
No single propulsion scheme fits all needs.
For instance, in some cases, rapid trip time is not as critical, contrasted
to more payloads delivered to the target. "That's why we're investing in
more than one technology�because there's no one answer for everything," he
Inside and outside NASA, a range of promising propulsion schemes being
One intriguing prospect is a propellantless propulsion concept tagged by
some as a plasma sail. The scheme is the brainchild of Robert Winglee, a
scientist at the University of Washington in Seattle.
His Mini-Magnetosphere Plasma Propulsion, or M2P2 for short, takes advantage
of the natural environment of space. M2P2 technology creates a huge magnetic
bubble around an interplanetary craft. In deploying the mini-magnetosphere,
this plasma "balloon" interacts with high-speed ionized particles shed by
the Sun that, in turn, push the vehicle through space.
"The technology seeks to do what space does -- deploy a magnetized sail to
travel with the winds," Winglee said. Plasma sail technologies could cut
conventional trip times to the outer planets in half. The NASA Institute for
Advanced Concepts (NIAC) funded early work on Winglee's M2P2 notion.
A new test chamber at the university, Winglee said, has proven helpful in
exploring the intricacies of creating a plasma balloon. "We're very happy
with the results to date that we are seeing�very similar to computer
simulations. That's a great relief, actually," he said.
If the flow of funding continues full-throttle, Winglee feels the plasma
sail can be pushed to the NASA TR-6 level. Ultimately, the concept's
enhanced thrust could be tested in some sort of geosynchronous orbit, he
Meanwhile, at NASA's Johnson Space Center (JSC) in Houston, Texas, lab work
continues on the Variable Specific Impulse Magneto-plasma Rocket.
Better known as the VASIMR, this technology could result in shorter trip
times to the planets than now available, made possible by varying the
rocket's specific impulse. It can be operated in a mode that maximizes
propellant efficiency or a mode that maximizes thrust, reported Andrew Petro
at an aerospace gathering this past January.
Petro, a JSC spacecraft engineer, and astronaut Franklin Chang-Diaz are part
of a team of advanced space propulsion experts engaged in shaping a proposed
test of the rocket on the International Space Station (ISS).
The ISS experiment would show the prototype engine's ability to help negate
electrical charging on the outpost and also counter drag forces that act on
the orbiting facility.
"This experiment will provide an opportunity to demonstrate the performance
of the rocket in space and measure the induced environment," Petro reported.
In for a fling?
One advanced space transportation technology is tether-based propulsion.
A NASA team, including the University of Illinois at Urbana-Champaign,
Tennessee Technological University in Cookeville, and Tethers Unlimited of
Lynnwood, Washington are developing the Momentum Exchange, Electrodynamic
Reboost (MXER) tether. This spinning, tether-based satellite in low Earth
orbit would snare slower-moving objects and toss them at increased speed
toward higher orbits.
This idea is akin to two ice skaters that "crack the whip" - launching one
another at high speed across the ice.
By briefly linking a slow-moving object with a faster one the slower
object's speed may be dramatically increased as some of its counterpart's
momentum is transferred between the two.
MXER follow-on work could pave the way for chucking payloads beyond
low-Earth orbit, perhaps paving the way for a human return to the Moon or
flinging cargo and crew outward toward the distant dunes of Mars.
Glow, and still go
The arena of laser propulsion continues to bloom, said Leik Myrabo, CEO of
Lightcraft Technologies, Inc., headquartered in Bennington, Vermont. He
predicts a revolution in low-cost access to space, and actively promotes the
use of beamed energy propulsion to accelerate vehicles called Lightcraft
into orbit for a fraction of the cost it currently takes to get any object
Recent experiments, Myrabo said, have centered what heat-thwarting materials
can be applied to the ceramic engine of a Lightcraft. Engine coatings must
take the ferocious high temperature environment that laser propulsion
produce, permitting a Lightcraft to "glow, and still go," he said.
The first national workshop on laser propulsion is slated for this November
in Huntsville, Alabama, Myrabo said, organized to transform the embryonic
work on laser propulsion technology into real space transportation systems
of the future, he said.
If you want an uplifting view of laser propulsion ask Tom Meyer of the
Boulder Center for Science and Policy in Colorado. He has led a study team
on the feasibility of building a laser elevator, reporting their findings
recently in the Journal of Spacecraft and Rockets, a publication of the
American Institute of Aeronautics and Astronautics (AIAA).
"The laser elevator works much like a lift in a garage, raised by a piston.
But in this case, the piston is replaced by an intense beam of light that
recycles between a spacecraft-mounted mirror and a mirror fixed to the laser
source," Meyer said.
This laser elevator requires technology that is not too distant from the
current state-of-the-art, Meyer said. Once developed, such propulsion
hardware could rapidly deploy a lightsail to scrutinize a threatening
asteroid or comet. Also studied was using the recirculating beam system to
launch a probe to Pluto, reaching that far-away world in about 6.5 years, he
Leave no stone unturned is seemingly a propulsion ploy of NASA's Glenn
Research Center in Cleveland, Ohio. This center is home for the Breakthrough
Propulsion Physics Project.
All manner of "exotic" research is ongoing. That includes delving into
transient inertia effects, quantum vacuum energy, zero-point electromagnetic
energy and Casimir forces, or exploring anomalous superconductor gravity
effects and superluminal quantum tunneling.
In short, any near-term success in any of these areas might foster the space
drives of tomorrow.
"We're basically on a steady course, albeit running at the slow pace typical
of such small projects. Our work is presently operating at a funding level
of about a half-million dollars per year," said NASA's Marc Millis who
manages the effort.
Millis said that a significant step for the project took place in January of
this year. A Breakthrough Propulsion Physics Research Consortium has been
established via a cooperative agreement with the Ohio Aerospace Institute.
"This research consortium will reach out to geographically dispersed
researchers to find, support, and coordinate the best research to make
credible progress toward the visionary goals we have, and to disseminate the
results for the benefit of all," Millis said.
While there is no shortage of interesting advanced propulsion designs, many
proposals could remain in the realm of visionary speculation. What is needed
is commitment and doses of research dollars and lab time to bring them into
"NASA has to do things differently in the future," explains NASA chief, Sean
O'Keefe. "One of the major obstacles of deep space travel is finding fast
and efficient ways to get around�to get to anywhere."
"Conventional rockets and fuel simply aren't practical as we reach further
out into the cosmos," O'Keefe notes. "If we're going to pioneer the future
as only NASA can, we're going to need new ways to get us there," he
Wanna go for a ride?
Skywatch International, Inc.
Fiat Lux et Veritas
MSN Photos is the easiest way to share and print your photos:
- Sorry, but none of the mentioned systems will
ever really be of any importance for Real Space
Guess why they never looked in the One Terminal
Too inexpensive, it will make rockets and
multi-billion nuclear reactors obsolete, reaching
the Moon in a few hours or Mars in one day will
do harm to the economy, like the Barf-Bag
Manufacturers and the Doctors who specialize in
Tried to contact Nasa many times, "Too busy to
answer e-mail" (Millis)
Maybe it should go to another country.
Joseph Hiddink vliegschotel@...
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