Project Title:
"Microsatellite Propulsion and Attitude Control System"
DARPA BAA 96-19
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Sponsored by:
Defense Advanced Research Projects Agency (DARPA)
Microsystems Technology Office (MTO)
Micro-Electro-Mechanical Systems (MEMS) Program
Clark T.-C. Nguyen, Ph.D.,
Program Manager
cnguyen@darpa.mil
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Digital Micro-Propulsion
Prototype Chip
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TRW
David H. Lewis, Ph.D.,
Program Manager
david.lewis@trw.com
Space & Technology Group
Space & Technology Division
One Space Park
Redondo Beach, CA 90278, U.S.A.
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The Aerospace Corporation
Siegfried W. Janson, Ph.D.,
Principal Investigator
siegfried.w.janson@aero.org
Mechanics & Propulsion Department
Mechanics & Materials Technology Center
P.O. Box 92957
Los Angeles CA 90009-2957, U.S.A.
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Sub-Contractors |
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California Institute of Technology
Prof. Erik K. Antonsson, Ph.D., P.E.,
Principal Investigator
Engineering Design Research Laboratory
Department
of Mechanical Engineering
Division of Engineering and Applied Science
1200 East California Blvd.
Pasadena, CA, 91125, U.S.A.
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Summary
The DARPA-funded TRW/Aerospace/Caltech
MEMS Digital Micro-Propulsion Program has two major goals.
The first is to demonstrate several types of MEMS microthrusters,
and to characterize their performance.
The second goal is to fly MEMS microthrusters in space and
verify their performance.
This Web site summarizes the concept and reports initial test results
of the "Digital Propulsion" concept.
Propulsion, station-keeping, and attitude control for
micro-spacecraft (1 kg class) will require a compact and light-weight
integrated system for controllably generating tiny amounts of impulse.
To accomplish these goals, we adopted a novel approach
to micro-propulsion that avoids tanks, fuel lines, and valves.
In this concept, an array of small sealed plenums are constructed
each with a rupturable diaphragm on one side. The plenums are loaded
with a fuel or an inert substance
in gas, liquid or solid form.
In the case of a fuel, it is ignited and reacts
to typically form a high-pressure, high-temperature fluid.
In the case of an inert substance, it is heated to raise its pressure.
Once the pressure exceeds the burst pressure of the diaphragm, the
diaphragm ruptures, and an impulse is imparted as the
fluid is expelled from the plenum.
Thus, each plenum can deliver one "bit" of impulse. The
size of the impulse is determined during fabrication by the
size of the plenum and the fuel that is loaded into it.
This approach eliminates valves (and valve leakage).
It substitutes one-shot (and therefore consumable) individual thrusters
for a multi-use conventional thruster and fuel tank
(with a consumable fuel supply).
The application of MEMS technology to space systems offers new
possibilities of increased orbit
and station-keeping capabilities at potentially lower cost.
Propulsion is one example of the application of MEMS technology to an
essential satellite function.
There are several advantages to this design.
These microthrusters have no moving parts, each engine has a low
parts count (3 layers bonded together),
no valves or lines or external tankage.
The propulsion function can be combined with the satellite structure.
The array of micro-thrusters is highly redundant.
The array can be programmed to fire
individual thrusters,
several thrusters at once,
or in controlled sequences.
Since the dimensions of the individual rocket engines are under the
designers' control, the creation of smaller and smaller "impulse bits"
is straightforward.
On the order of 106 thrusters can be fabricated on a wafer.
The current Digital Propulsion configuration is shown in
here (8k GIF).
As shown, it consists of a 3-layer sandwich.
The top layer contains an array of thin diaphragms (0.5 micron thick
silicon nitride, 190 or 290 or 390 microns square),
and is shown
here (14k GIF).
The middle layer contains an array of through-holes
(Schott
FOTURAN®
photosensitive glass,
1.5 mm thick, 300, 500, or 700 micron
diameter holes)
which are loaded with propellant,
and is shown
here (30k GIF).
The bottom layer contains a matching array of polysilicon
micro-resistors,
and is shown
here (37k GIF).
The bottom two layers are bonded together, then fueled, then
the top layer is bonded to complete the assembly.
With a series of different sizes of plenum holes, diaphragms, and
resistors, we have 90 different configurations that can be assembled.
An assembled and mounted chip
and is shown
here (42k JPEG),
and is shown on a penny
here (44k JPEG).
Initial testing, using
lead styphnate (5.6k GIF)
as the propellant,
has produced 0.1 milli-Newton-seconds of impulse
and about 100 Watts
(shown
here (20k JPEG)),
with the expectation that this can be increased by nearly a factor of 10
with more complete combustion of the fuel.
On this site are Presentation Slides and Images summarizing
various aspects of our project,
as well as Movies of thrusters firing in the laboratory.
We welcome your comments.
David H. Lewis, Ph.D.,
Program Manager
david.lewis@trw.com
Accomplishments/Demonstrations/Milestones:
- March 9, 2001:
Successful Suborbital Space Flight Test
- July, 1999: First space flight:
- NASA
Flight
STS-93,
Space Shuttle
Columbia
- Launched July 23, 1999 12:31 am EDT
- Altitude: 153 nm
- Inclination: 28.4
- Orbits: 80
- Duration: 4 days, 22 hours, 50 minutes, 18 seconds.
- Distance: 1,796,000 miles
- Landed July 27, 1999 11:20 pm EDT
- Mid-deck locker experiment: Micro-thruster fueled with water, not fired.
- Micro-thruster array survived launch, flight and landing.
- Flight-unit to be ground tested.
- September 30, 1998:
- First thrusters fired in vacuum.
- 100 W Thrust Power
- 1 N Thrust Force
- 0.1 mNsec Impulse
- August 4, 1998: First thrust-stand test data.
- July, 1998: First prototypes fired.
- May, 1997:
DARPA
contract N66001-97-C-8609 initiated.
Publications:
- May 16, 2001:
- January, 2001:
Helvagian, H.,
P.D. Fuqua,
W.W. Hansen,
and
S. Janson,
"Laser Microprocessing for Nanosatellite Microthruster Applications"
Riken Review,
(The Institute of Physical and Chemical Research),
No. 32,
Laser Precision Microfabrication (LPM2000),
pages 57-63.
- April, 2000:
"Digital MicroPropulsion"
by D. Lewis, S. Janson, R. Cohen and E. Antonsson,
Sensors and Actuators A: Physical, 2000,
80(2),
pp. 143-154.
(774k PDF)
- February, 2000:
Hall, A.,
"Pint-Size Satellites Will Soon Be Doing Giant Jobs",
Edited by Douglas Harbrecht,
Business Week OnLine Daily Briefing,
February 10, 2000.
- December, 1999:
Aerospace Corporation
Annual Report, Page 28,
(39 kbytes PDF).
Complete Annual Report,
(1,648 kbytes PDF)
- December, 1999:
Mirels, H., "Effect of Wall on Impulse of Solid Propellant Driven
Millimeter-Scale Thrusters", AIAA Journal, Vol. 37, No. 12, December
1999, pp. 1617-1624.
- October, 1999:
"La Micropropulsion s'adapte aux petits satellites"
by Cécile Bonneau,
L'Usine Nouvelle
21 October 1999, Page 79.
(447 kbytes JPG)
- October, 1999: Reference in:
"May the Micro Force by With You"
by Ivan Amato,
Technology Review,
page 82.
(131 kbytes HTML, JPEG, GIF)
- 1999:
H. Helvajian and S. Janson, "Microengineering Space Systems,"
Chapter 2 in Microengineering for Aerospace Systems,
ed. by H. Helvajian, ISBN 1-884989-03-9, Aerospace Press, El Segundo, CA,
and
AIAA,
Reston, VA, 1999.
- 1999:
S. Janson, H. Helvajian, and K. Breuer, "Micropropulsion Systems
for Aircraft and Spacecraft," chapter 17 in Microengineering for
Aerospace Systems, ed. by H. Helvajian, ISBN 1-884989-03-9,
Aerospace Press, El Segundo, CA, and
AIAA,
Reston, VA, 1999.
- September, 1999:
"Jet Engines Smaller Than a Penny Will Propel Satellites",
by Mark Prigg,
The Sunday Times
(London),
5 September 1999, Page 3-12.
(253 kbytes JPG)
(371 kbytes PDF)
- September, 1999:
S.W. Janson, "Mass-Producible Silicon Spacecraft for 21st Century
Missions," paper 99-4458,
AIAA,
Space Technology Conference and
Exposition, Albuerque, NM, Sept. 28-30, 1999.
- August, 1999:
D. Sorid,
"Micro-machines Herald Era of the Miniscule",
Space.com,
August 25, 1999.
- June, 1999:
S.W. Janson, H. Helvajian, and K. Breuer,
"MEMS, Microengineering and Aerospace Systems,"
AIAA
paper 99-3802, 30th
AIAA
Fluid Dynamics Conference, Norfolk, VA, June 1999.
- June, 1999:
J.E. Pollard, C.C. Chao, and S.W. Janson,
"Populating and Maintaining
Cluster Constellations in Low Earth Orbit,"
AIAA
paper 99-2871, 35th
AIAA/ASME/SAE/ASEE
Joint Propulsion Conference, Los Angeles, CA, June 1999.
- May, 1999:
"Pasadena Conference Focuses on Space Applications of Microtechnology",
Micromachine Devices.
- April, 1999:
P.Fuqua, S.W. Janson, W.W. Hansen, and H. Helvajian, "Fabrication of
True 3D Microstructures in Glass/Ceramic Materials by Pulsed UV Laser
Volumetric Exposure Techniques," Proceedings of the
SPIE,
Vol. 3618,
"Laser Applications in Microelectronic and Optoelectronic Manufacturing
IV," April 1999
- April, 1999:
S.W. Janson, H. Helvajian, W.W. Hansen, and Lt. J. Lodmell,
"Microthrusters for Nanosatellites,"
2nd International Conference on Integrated MicroNanotechnology for
Space Applications, Pasadena, CA,
April 11-15, 1999,
organized by
The Aerospace Corporation.
- April, 1999:
"Pocket Rocket"
by Ben Iannotta,
New Scientist,
10 April 1999, Vol. 162, No. 2181, page 38.
- January, 1999:
"Digital MicroPropulsion",
by D. Lewis, S. Janson, R. Cohen and E. Antonsson,
IEEE
MEMS'99
Meeting Oral Presentation,
Paper published in the Conference Proceedings.
(920 kbytes PDF)
- 1998:
G.F. Carrier, F.E. Fendell, S.F. Fink IV, and R.D. McGregor,
"Gaseous-Propellant Microthrusters, I. Completion of Burn Prior to
Venting", Combust. Sci. and Tech., 1998, Vol. 140, pp. 169-195.
- 1998:
G.F. Carrier, F.E. Fendell, and S.F. Fink IV, "Gaseous-Propellant
Microthrusters, II. Venting Prior to Completion of Burn",
Combust. Sci. and Tech., 1998, Vol. 140, pp. 197-223.
- November, 1998:
"Little Bangs",
by Gary Stix,
Scientific American, pages 50-51.
(8 kbytes HTML)
- October, 1998: Reference in:
"MICROMACHINES: Fomenting a Revolution, in Miniature",
by Ivan Amato,
Science,
16 October, 1998; 282, pages 402-405. (in News Focus).
- October, 1998: Paper presented at:
Formation Flying and Micro-Propulsion Workshop,
sponsored by AFRL, Lancaster CA
Presentation Slides:
- January, 1999 DARPA/ETO MEMS PI's Meeting and IEEE MEMS-99 Conference
- in HTML
- in PDF format (2,648 kbytes)
- June, 1998 DARPA/ETO MEMS PI's Meeting
- January, 1998 DARPA/ETO MEMS PI's Meeting
Images:
- Digital MicroThruster Chip on a Penny, July, 1999
- in JPEG format
(44 kbytes)
- in JPEG format (580 kbytes)
- Digital MicroThruster Chip Fired in September, 1998
- Overall view
in JPEG format (33 kbytes)
- Overall view
in JPEG format (42 kbytes)
- Central Region
in JPEG format (56 kbytes)
- Close-up
in JPEG format (94 kbytes)
- June, 1998 Digital MicroThruster Chip
- Overall view in JPEG format (38 kbytes)
- Close-up in JPEG format (82 kbytes)
- Digital Micro-Propulsion Tests (Arrays of Images)
- 3-D View of 2-D Simulation of
1 Micro-Spacecraft
(28 kbytes, JPEG)
- 3-D Simulation of 2 Micro-Spacecraft
(76 kbytes, JPEG)
- Stress/Deflection Analysis of Burst Diaphragm in GIF format:
Movies of Recent Results:
- Digital Micro-Propulsion Tests
- Test Stand Firing, August, 1998
(910 kbytes, QuickTime)
- Initial Test Stand Firing, June, 1998
(1,712 kbytes, QuickTime)
- Resistor/Initiator Firing, June, 1998
(891 kbytes, QuickTime)
- Micro-Spacecraft/Digital Micro-Propulsion Simulations
DARPA/MTO/MEMS Logo (Updated May, 1999):
Helper Applications:
Related Research:
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2:33:54 PM PDT, Monday, July 15, 2002
