diaz franklin

Mapping a Path to the Solar System and

Beyond

Franklin R. Chang DíazAd Astra

RocketCompanyHouston, TX

We have learned to live and work efficiently in space

But we are still very close to home

And we long to move outward

Saturn Mission

Titan closest approach Oct. 2004

Titan Huygens Landing Jan. 14, 2005

Ad Astra Rocket Company, U. S. A

Enceladus March 2006

How do we go to these places fast?

Chemical rockets will not be suitable for these journeys


Thrust and power of a rocket

THRUST

umT ×=

400500020000005,000,000,000

muTP

====

Example:

Newtons

m/sec

kg/sec

212

P m u= ×POWER

Watts

The best chemical rocket

Isp = 450

To reach higher temperatures we move

into plasma physics

(limited by materials and the temperature

of chemical reactions)


• Plasma is a super heated gas made up of free electrons and ions. It is sometimes called the 4th state of matter and makes up 99% of the visible universe.

Propulsion

Lightning The sun Stars and nebulae Plasma

processing

Many others

What is Plasma?


Propulsion technologies ranked by specific impulse (Isp)higher is better


The Propellant Issue

fuel oxidizer

exhaust

thrust

fuel

exhaust

thrust

Chemical rocket Electric rocket

electricity

Low fuel efficiency

Low temperature

High temperature

High fuel efficiency

Electric rockets are more fuel efficient.

Use electricity rather than chemical

combustion to produce hot exhaust gases.

Solar panels


Propellant feed Ionizing antenna

(helicon)

Magnetic field lines

Exhaust

Heating antenna (ICRF)

Plasma

Superconducting Magnet coils

RF generators

POWER

Thrust

The VASIMR Concept


nn

nn

ii

ii

ICRF heating

(Ion Cyclotron Range of Frequencies)

Injected electromagnetic waves accelerate the ions by resonating at magnetic beach with their fundamental cyclotron frequency (and associated harmonics.)

Magnetic Nozzle

When particles see an expanding magnetic field, they are accelerated

axially at the expense of their rotational motion.

Ions get extra kick from ambipolar electric field

Both ions and electrons leave at the same rate

Plasma Source

RF waves establish a “helicon”discharge, which ionizes neutral gas to produce a dense plasma with an electron temperature of a few eV

--

--

Physics of VASIMR

+ -


Important Advantages

• No electrodes or other materials in direct contact with the plasma.

• Therefore, potential for very high power density, high reliability, long life.

• Multiple propellants: Helium, Hydrogen, Deuterium, Nitrogen, Argon, Neon, Xenon, others…


VX-200 prototype development

Thermal subsystem

Superconducting magnet subsystem

Plasma experiments

Cryogenic subsystemRF subsystem


Ad Astra Rocket Company FormallyOrganized July 15, 2005

Wholly owned subsidiary in Costa Rica Established October 2005


Present Status

• Conducting high power experiments with Argon

• Major development of VX-200 prototype

• Two new vacuum chambers to support new experimental facilities

• New Houston location

• Both companies fully operational

• Negotiating Investment SPVs (special purpose vehicles) in Costa Rica, USA and Europe


VX-50 Experiment at JSC


VX-100 Installation, Nov 2006


VX-50 Recent Results

• Significant flow velocity with neon, about 4000 second equivalent Isp.

• Three different measurement techniques.

• VX-100 will enable similar results with Argon to achieve our specific impulse goal.

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.40

1

2

3

4

5

6

7x 104

time (seconds)

velo

city

(m/s

)

fluxprobe/interferometerRPA


VX-50 promising performance

• Using flow velocity and measured flux we can calculate a jet power and efficiency of the acceleration process, 50 to 75%.

• About 0.5 N of apparent thrust, with only about 30 kW of power.

• This is agrees with predictions and validates predictions for VX-200 performance.


The Economics


Lower fuel launch costs

• The cost of launching rocket fuel into space is a major driver in the cost of space operations.

• Plasma rockets require much less fuel to operate


Cost effective Moon cargo capability VASIMR delivers the highest fraction of the initial mass in low Earth orbit (IMLEO) to the Moon vs. a chemical thruster or the Hall thruster, thereby reducing the cost per kg.

• Here, VASIMR can deliver 39% of IMLEO to the Moon’s surface.

• Hall thruster: 32%.

• Chemical: 17%

Cargo ship elements see slide

32


Lower intrinsic fuel costs

50ManufacturedAmmonia2120.03.0x10-5 (ppm)Xe42.03.2 (ppm)Argon250.05.0x10-3 (ppm)Neon4.020 (ppm)Nitrogen

7,700.0.00015 of seawaterDeuterium1,010.0 0.11 of seawaterHydrogen

Market Price($/kg)

Earth abundance(by weight)

Propellant(listed by increasing

weight)

• VASIMR uses less expensive and more abundant fuels: hydrogen, argon, neon, potentially ammonia.

• Competing electric rockets such as the ion engine and the Hall thruster use Xenon, a rare and expensive gas.


The Plan


• Near term goals:

– demonstrating VASIMR in space

– developing a generic electric power and propulsion test platform for attachment to the International Space Station (ISS).

The Plan


The Market


Electric Power Requirements

• For missions near Earth and The Moon, the electricity will come from solar panels.


Collaboration with ENTECH Inc.

• Advanced solar power technology for space applications– ENTECH to build 100kW

solar array for the VF-200-1 VASIMR engine

– Electric power density is 300 Watt/m2 (technology improvement expected to 400 Watt/m2


Electric Power Requirements

• For missions to Mars and beyond, the electricity must come from nuclear reactors.


Concept by Prof. Samim Anghaie, Director, Innovative Nuclear Space Power and Propulsion Institute, INSPI; University of Florida, Gainesville.

Vapor Core Reactor with MHD power conversion

VASIMR configuration with Vapor Core Reactor System

Space Nuclear Power


Radiation is a big problem

• Not from the nuclear reactor…but from space itself

• Solar flares (eruptions)

• Cosmic rays


Potential solutions

• We go fast!• Magnetic shielding• Material shielding • All of the above

Depth, g/cm20 10 20 30 40 50

GC

R D

ose,

mSv

/day0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Aluminum

Water

Polyethylene

Liquid hydrogen

Magnetic shielding.

Liquid hydrogen shielding.


High thrust Earth spiral (30days)

HeliocentricTrajectory(85days)

Robotic Mars orbitinsertion

Isp profile forpiloted segment

Crew Lander(60.8 mT Payload)31.0 mT Habitat13.5 mT Aeroshell16.3 mT Descent System

Departing LEOMay 6, 2018

188 mT IMLEO12 MW power plant

α = 4 kg/kW

115day Mission Architecture


200MW Earth to Mars Missionsα = 0.5; Maximal Isp = 30,000

Payload Mass 22 MT

Total Initial Spiraling around Earth Heliocentric trajectory Final relative Total tripMass (mT) fuel (mT) time (days) fuel (mT) time (days) velocity (km/s) time (days)

600 180 7 298 34 0 41350 117 5 111 42 0 47250 88 4 40 49 0 53

600 152 8 324 31 6.8 39

High Power dramatically reduces trip time


Superconducting toroidal radiation

shield

Other Ship Architectures

Crew compartment

Lander Liquid hydrogen tanks


• Modularity• Suitable for both cargo and piloted

missions• Redundancy

Power and Propulsion Module

System Design


Asteroid Missions


Strong participation of students at both graduate and undergraduate levels

Industry• MEI Technologies• Creare Inc.• TYR• ManSat (Isle of Man)• Entech Inc.• Nautel Ltd. (Canada)• Everson Tesla• Scientific Magnetics (U.K)

Academia• UT-Austin • Rice U• U of Maryland• U of Houston• U Alabama H.• MIT• U Florida• U Michigan

Government• NASA

• DOE: ORNL, LANL

International• National Center for High Technology (Costa Rica)• Australian National University• Alfvén Laboratory (Sweden)• kyushu University (Japan)• University College Dublin (Ireland)

Collaboration


Costa Rica subsidiary

• Established Oct. 28, 2005• Formally incorporated Nov. 15, 2005 to support USA

operation• Initial engineering tasks:

– Helicon plasma source thermal management– Life testing of VASIMR components– Engineering support of hazardous waste processing

using plasma technology • Initial 700 m2 laboratory facility in EARTH La Flor

campus


Architectural concept


Construction Initiated Feb. 16, 2006

12/28/05


Facility Inauguration July 15, 2006


The Team


First Plasma Dec 13, 2006