CONVENTIONAL ROCKET

PROPULSION

NON-CONVENTIONAL PROPULSION

SOLAR SAILS

TETHERS

ELECTRIC SAILS

THE REASON?

DISTANCE!!!

CONVENTIONAL ROCKET

PROPULSION

NON-CONVENTIONAL PROPULSION

SOLAR SAILS

TETHERS

ELECTRIC SAILS

A motional electromotive force is generated across a

tether as it moves relative to the Earth’s magnetic field

given by Faraday’s Law of Induction

A motional electromotive force is generated across a

tether as it moves relative to the Earth’s magnetic field

given by Faraday’s Law of Induction

The tether moves relative to the Earth’s magnetic field. The positive

end of the tether collects ionospheric electrons forming an electrical

current; a force on the wire will be generated via the Lorentz Force

14

Magnetic field strength

and direction varies over

each orbit

Forces have components

both:

In-plane (orbit

raising/lowering)

Out-of-plane

(inclination change)

Tether current can be

modulated over one or

more orbits to change all

six orbital elements

spacecraft launch datelaunch

vehicleorbit mass

SEDS 1 +

deployerMar. 30, 1993 Delta 7925

195 × 705 ×

34°25 kg

SEDS 2 +

deployerMar. 10, 1994 Delta 7925

350 km

(circular)25 kg

Jovian Electrodynamic Capture

Hyperbolic Intercept

Electrodynamic

Decay Region

(V in km/sec)

0.03

0.06

0.12

0.33

0.73Perijove = 1.2 RJ

Parabolic 100 Day

Capture Orbit

(0.5 km/sec V

required for capture)

V= 5 km/sec

Tethered Satellite System

before it broke

Tethered Satellite System after it

separated from the Space Shuttle

CONVENTIONAL ROCKET

PROPULSION

NON-CONVENTIONAL PROPULSION

SOLAR SAILS

TETHERS

ELECTRIC SAILS

22

23

Sail

Thrust

Vector

Sun

Angle

Incident

Photons

Reflected Photons

Sail

“normal

vector”

Sail

Thrust

Vector

Sun

Angle

Incident

Photons

Reflected Photons

Sail

normal

vector

Real Solar Sails Are Not “Ideal”

Sail

Thrust Vector

Sun

Angle

Incident

Photons

Reflected Photons

Sail

normal

vector

Ideal Case

Billowed QuadrantDiffuse Reflection

Thrust Vector Components

24

SailF(normal)

Sun Angle

Reflected Photons

Sail normal

vector

CM

CP

F(tangential)

F(total)

M(total)

25

Image courtesy of Colorado Center for Astrodynamics Research

26

• 135-foot rigidized inflatable balloon satellite • laminated Mylar plastic and aluminum • placed in near-polar Orbit • passive communications experiment by NASA on January 25, 1964

When folded, satellite was packed into the 41-inch diameter canister shown in the foreground.

27

Znamya (Space Mirror)

♦ Russian experiment that flew

on Progress after undocking

from Mir Space Station in

1993.

♦ Purpose was to reflect sunlight

onto the ground from space.

♦ 20-m diameter sail

successfully deployed

♦ 5-km spot illuminated Europe

from France to Russia moving

at 8 km/sec.

♦ Follow-on mission flew, but

was damaged during

deployment.

NASA GROUND TESTED SOLAR SAILS IN THE MID-2000’S

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♦ Two solar sail technologies were designed, fabricated, and tested under thermal vacuum conditions in 2005:

♦ Developed and tested high-fidelity computational models, tools, and diagnostics

♦ Multiple efforts completed: materials evaluation, optical properties, long-term environmental effects, charging issues, and assessment of smart adaptive structures

400 m2

31

NANOSAIL-D DEMONSTRATION SOLAR SAIL

♦ 10 M2 SAIL

♦ MADE FROM TESTED GROUND DEMONSTRATOR HARDWARE

32

NanoSail-D in Flight

33

Interplanetary Kite-craft Accelerated by Radiation

of the Sun (IKAROS)

34

Interplanetary Kite-craft Accelerated by Radiation

of the Sun (IKAROS)

Jacob Peter Gowy's

The Flight of Icarus

•

•

•

35

5 to 100 m DIA

= 10 g/m2

500 - 800-m DIA

= 1 - 2.5 g/m2

MID-TERM

SAILS

2015 - 2025

4000-m DIA

0.1 g/m2

1-km DIA

= 0.1 g/m2

INTERSTELLAR PROBE

2025 - 2050

• NEA Scout / Lunar Flashlight

• Solar Polar Imager

• NON-KEPLERIAN EARTH ORBITS

TECH

DEV

TECH

DEV

TECH

DEV

TECH

DEV

TECH

DEV

INTERSTELLAR

MEDIUM EXPLORATION

• NanoSail-D

• LightSail

• InflateSail/CubeSail

= Areal Density (Sail Mass/Sail

Area)

4.5 LY

INTERSTELLAR

PROBE FLYBY

40 LY

INTERSTELLAR

PROBE

RENDEZVOUS

• INTERSTELLAR PROBE

• EUROPA LANDERS

• COMET SAMPLE RETURN

• OORT CLOUD

4-km DIA

= 0.1 g/m2

1000-km DIA

= 0.1 g/m2

NEAR-TERM

SAILS

2010 - 2015

3 – 5 m DIA

Solar Powered

Laser Powered

CONVENTIONAL ROCKET

PROPULSION

NON-CONVENTIONAL PROPULSION

SOLAR SAILS

TETHERS

ELECTRIC SAILS

•

•

Electric Sail Concept

•

•

•