Demonstration of Autonomous Rendezvous Technology
(DART)
Inter-Agency AR&C Working Group
May 22-23, 2002
Chris Calfee
DART Project Manager
256-544-5788
Chris.Calfee@msfc.nasa.gov
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Agenda
– Introduction to DART
• Overview & Objectives
• Organization & Schedule
– DART Mission Description
• “Chaser” Vehicle - DART
• “Target” Vehicle - MUBLCOM
• Launch Vehicle - Pegasus
• Mission Operations - Flight & Ground
• System Test Summary
• Technology Readiness Levels
– Advanced Video Guidance Sensor (AVGS)
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Introduction to DART
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Project Overview
• DART Stands for: Demonstration of Autonomous Rendezvous Technology.
• DART Is a Flight Demonstration of the Hardware and Software Required to
Autonomously Rendezvous with a Satellite (MUBLCOM) Currently in Orbit.
– Hardware: Advanced Video Guidance Sensor (AVGS)
• Heritage: VGS Developed by MSFC for Automated Rendezvous &
Capture (AR&C) Project. Flown Twice on Board the Shuttle in an OpenLoop Mode
• AVGS is next generation system with advanced optics and electronics.
Design goals: Longer Range, Lower Power and Weight
– Software: Based on Autonomous Rendezvous and Proximity Operations
(ARPO) Algorithms Also Developed by NASA/MSFC.
• Both the AVGS and the ARPO Algorithms Will Become Embedded Technology
on Board a Pegasus ELV, Making the DART Vehicle an Extension of the ELV
Rather Than an Independent and Isolated Payload
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DART Objectives
Primary Objective: Demonstrate in space Autonomous Rendezvous and
Closed Loop Proximity Control Between a Chase Vehicle, DART, and a
Passive, Cooperative Target Vehicle, MUBLCOM
• Raise AVGS/ARPO Technology Readiness Levels (TRL) from a 3/4 to a 7/8
• Validate Ground Test Results of the AVGS and ARPO Algorithms
• Mission Objectives
– Transfer from parking orbit to MUBLCOM orbit
– Demonstrate Autonomous Proximity Operations While In the Vicinity of
the Target Vehicle Using The AVGS
• V-Bar Approach and Stand-Off to 15 meters
• Collision Avoidance Maneuver (CAM)
• Docking Axis Approach and Stand-Off to 5 meters
• R-Bar Approach and Stand-Off to 50 Meters
• Autonomous Departure at End Of Mission
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Second Generation RLV Relevance
– The United States Has Successfully Performed Numerous Rendezvous
and Docking Missions in the Past.
– The Common Element of All US Rendezvous and Docking is That the
Spacecraft Have Always Been Piloted by Astronauts.
– Only the Russian Space Program Has Developed and Demonstrated a
Routine Autonomous Capability.
– The European Space Agency and Japanese Are Developing Similar
Technology.
– The DART Mission Provides a Key Step in Establishing an Autonomous
Rendezvous Capability for the United States.
– All 2nd Generation Architectures and AAS Can Benefit From ARPO
Technology.
– Even Manned/Piloted Vehicles Can Benefit Through Robust System
Performance and Reduction of Potential Piloting Errors.
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DART Project Overview Schedule
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Project Team
– OSC - Overall Project Integration, Launch Vehicle Buildup & Test, AVGS
Development, Test, Manufacture, & Integration, DART Buildup & Test, LV/DART
Integration & Test, Launch & Mission Operations
– MSFC - Overall Project Management, AR&C Algorithms, AVGS S/W
Development, Test Facilities & Support, Mission ops Support
– Draper – GNC System, Flight Vehicle S/W
– Advanced Optical Systems (AOS) - AVGS Design & Engineering Support
– KSC - Launch Services Support
– GSFC - IV&V
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2nd Generation RLV Organization
Program Office
Consultants
E.G. F. Wojtalik, G. Oliver, B. Lindstrom
Ext. Rqmts. Assessment Team
Manager
Dennis Smith
Deputy
Dan Dumbacher
Quality Assurance Man.
C. Chesser
Chief Engineer
Robert Hughes
Tech. Asst.
B. Morris
ESA
Jill Holland
MSA
Judy Dunn
Program Planning
and Control
Sys. Engineering,
& Integration
Rose Allen, Manager
Jerry Cook, Deputy
Dale Thomas, Manager
Chuck Smith, Deputy
Airframe
(LaRC)
Operations
(KSC)
Flight Mechanics
(MSFC)
Manager D. Bowles
LSE
Julie Fowler
Manager Scott Huzar
LSE
Manager Scott Jackson
LSE
Jack Mulqueen
Procurement
Legal
M. Stiles
J. Seemann
Program Integration
& Risk Management
Architecture
Definition
Danny Davis, Manager
Bart Graham, Deputy
Steve Creech, Manager
Arch. Mgr.
Arch. Mgr
Arch. Mgr
CTV
AAS
Bob Armstrong
Charlie Dill
Pete Rodriguez
Steve Davis
Chris Crumbly
NASA Unique
(JSC)
Manager
LSE
Dave Leestma
Subsystems
(GRC)
Manager
LSE
Mike Skor
Tom Hill
IVHM
(ARC)
Manager
Bill Kahle
Asst. Mgr./LSE Kevin Flynn
Flt. Demos & Exp. Integ.
(MSFC)
Propulsion
(MSFC)
Manager
Garry Lyles
Dep. Mgr.
Steve Richards
Lead Sys. Engr. George Young
Manager, acting
Deputy
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Susan Turner
DART_NRL.ppt
Flight Demos & Experiment Integration Organization
Flt. Demos & Exp. Integ.
Susan Turner
X-37
DART
Kistler K-1
Jeff Sexton
Chris Calfee
Jimmy Lee
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DART Organization
2nd Generation RLV Program
Dennis Smith, Manager
Flt. Demos & Exp. Integ.
Susan Turner, Manager
Contracts
Earl Pendley
Penny Battles
Carol Greenwood
DART
Chris Calfee, Manager
Pegasus Procurement
S&MA
Van Strickland
Marcie Kennedy
Wanda Harding - KSC
Business
Jimmy Black
Rich Leonard
Louise Hamaker
Asst. DART Manager
Dexter Waldrep
Lead Systems Engineer
Lead Software Engineer
AVGS/Pegasus
Lead Engineer
Mark Krome
Meg Stroud
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Keith Higginbotham
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OSC DART Organization Chart
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DART Mission Description
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Mission Overview
Description of DART Vehicle
Pegasus Stage 4 / HAPS
• Hydrazine Auxiliary Propulsion System (HAPS)
–
–
3 thrusters with 56.9 Kg (125 lbm) supply
Delta-velocity, pitch and yaw attitude
• Pegasus Reaction Control System
–
–
Ybody
6 nitrogen thrusters with dedicated 5.8 Kg (13
lbm) supply
3-axis attitude control during rendezvous and
retirement
Zbody
• Proximity Operations Reaction Control System
–
–
16 N2 thrusters with dedicated 29 kg (64 lbm) Tank
6-axis attitude and translational control during proximity operations
• Lithium Ion Battery Powered Avionics and Transient Power Busses
• UHF Antenna & Receiver System
• SIGI INS and Standalone GPS Navigation Solution
AVGS Bus
• Advance Video Guidance Sensor
• Maximum wet mass: 362.3 Kg (798 lbm)
–
Assuming Pegasus XL launch to 500 km orbit at 97.7° inclination
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DART Mechanical Configuration
• Within Pegasus Stage 4 Avionics
Structure is Top of HAPS Tank, Two
RCS Tanks, SIGI
– Mostly Heritage Components and
Layout for Stage 4
Pegasus Stage 4
• Within AVGS Bus Structure is Top of
Proximity Ops RCS Tank
– Most New Components Mounted to
Exterior of Cylindrical Structure,
Forward AVGS Panel
AVGS Bus
DART Expanded View
Forward Looking Aft
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DART Mechanical Configuration, Cont
MACH
Batteries
Proximity Ops RCS
Tank, Tubing,
Other Components
HAPS Tank,
Tubing, and Other
Components
DART Expanded View
Aft Looking Forward
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Description of MUBLCOM Target Vehicle
FAR
RANGE
GROUP
• Launched in 1999 aboard a Pegasus Rocket
• Currently in a nearly circular orbit at 765 km
• Near-polar orbit with 97.7 inclination (nearly sun-synchronous)
• Gravity-gradient stabilized with momentum wheels for yaw control
• Long and short-range retroreflectors mounted ~parallel to velocity vector
• Far-range retroreflectors mounted along vehicle z-axis (nadir pointing)
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MUBLCOM
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Expanded View of Pegasus w/DART
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Mission Overview
DART Launch Operations Overview
• Pegasus launch from
Vandenburg AFB, CA on
4/15/04
• Launch will deliver DART to a
circular orbit at 500 Km
altitude
• Ascending node and
inclination matching those of
the MUBLCOM satellite
• Hydrazine budgeted to allow
Pegasus use of HAPS to
correct launch dispersions
t=0
h = 11887 m
v = 243 m/sec
• ±30 second drop window assumed
– Minimizes ascending node errors
– Drop position accuracy relaxed to allow better drop time accuracy
• Launch opportunity every 3-5 days
– Phasing with MUBLCOM at launch constrained to less than 100°
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Mission Overview
DART Rendezvous Operations Overview
40 km
• Early orbit checkout
Phasing Orbit 1
Phasing Orbit 2
Target Orbit
DART Trajectory
C
• DART “catches up” to target
vehicle at ~13 deg/hour
– Up to 7.5 hours spent in Phasing
orbit 1
3 km
A
E
• Hohmann transfer from 500 Km to
~755 Km altitude
D
B
– Rendezvous ends with DART 40
Km behind and 7.5 Km beneath
MUBLCOM
A. Insertion into phasing orbit 1
B. Begin transfer to phasing orbit 2
C. Insertion into phasing orbit 2
D. Begin transfer to target orbit
E. Insertion into target orbit
• Rendezvous algorithms employ Pegasus PEG guidance
– PEG functionality extended with rendezvous phasing calculations
• Ascending node and inclination errors corrected during transfer using HAPS
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Mission Overview
DART DRM Timeline
Event
Drop From Aircraft
Stage 3 Separation
Pegasus HAPS Burn (nominally not required)
Begin Early Orbit Checkout
Begin Haps Transfer Burn For Rendezvous
Start Haps Out-Of-Plane Correction Burn
MUBLCOM UHF Signal Acquisition
Begin Haps Burn For Rendezvous Insertion
Start Proximity Operations GN&C
Begin CW Transfer To -3 Km On -V Bar
AVGS To Standby Mode
Insertion At -3 Km On -V Bar
AVGS To Spot Mode
Insertion At -1 KM On -V Bar
AVGS to Acquisition Mode
Station Keep At -300 M
Station Keep At -15 M
Station Keep At -100 M
Station Keep At -300 M
Depart To Maximum AVGS Tracking Range
Begin Forced Motion Return To -300 M
Station Keep At -300 M
Begin CW Transfer To 150 M On R Bar
AVGS To Spot Mode
Station Keep At 150 M On R Bar
Station Keep At 50 M On R Bar
Station Keep At 300 M On R Bar
AVGS Off
Start Retirement Burn
End of 24 Hour Mission
Time from Drop
(Hours)
00:00:00
00:08:58
00:09:00
00:20:00
07:25:41
07:40:46
07:55:45
08:08:36
08:10:50
08:37:39
08:37:39
09:28:34
09:33:34
10:51:32
11:23:20
11:31:32
11:52:33
13:27:28
14:08:49
14:13:49
14:25:08
14:36:46
15:06:46
15:32:42
15:32:42
16:08:38
16:26:52
16:33:52
16:33:52
24:00:00
22
• Worst-case phasing at launch assumed
– 7+ hours in phasing orbit 1
• Proximity operations begin 8 hours
into the mission
– 8 hours in proximity operations
– Includes 3.5 hours of station keeping at
various positions
• Retirement burn 16.5 hours into
mission
– 7.5 hour time margin remaining
DART_NRL.ppt
DART Mission Profile
GPS State Vector Differencing
(Propagated Target State)
Communications
Range (~100 km)
770
Altitude(km)
Proximity Sensor
(AVGS)
GPS State Vector Differencing
(Space-to-Space Target State)
Visible
Range
(~500 m)
-3km
Target
Vehicle
755
Orbit Transfer
Free Drift
Start of
Proximity Operations
DART
Retirement
Burn
Phasing
500
Launch
Ascent
Far Range
MET From
L1011 Drop
00:09:00
Mid Range
08:00:00
Near Range
11:00:00
16:30:00
Note: Altitude and Ranges are not to scale
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DART Proximity Operations Flight Profile
Velocity Vector
Orbital Motion
+VBar
MUBLCOM
50 m
5m
300 m
15 m
100 m
CAM
1 Km
3 Km
500 m
150 m
Last HAPS Burn
40 Km behind
7.5 Km below
End of Rendezvous
Start of Prox Ops
300 m
Baseline Profile
Extended Profile
+RBar
Retirement
Burn
Free Drift
Orbit
Transfer
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DART-MUBLCOM
Rendezvous Visual
QuickTime™ and a
decompressor
are needed to see this picture.
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Mission Overview
DART DRM Ground Station Coverage
• Three ground stations selected for telemetry coverage (VAFB for launch only)
– Poker Flats, Alaska
– McMurdo, Antarctica
– Svalbard, Norway
• Polar stations provide at least two telemetry downlink opportunities per orbit
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DART Testing
• Desktop Simulation
– Performed at OSC
– Psuedo Flight Code (CMDH, GN&C,Telemetry)
• Hardware in the Loop – Static
– Performed at OSC
– Flight Computer, GPS, INS, UHF, AVGS
• Hardware in the Loop – Dynamic
– Performed at MSFC Flight Robotics Lab
– Flight Computer, GPS, INS, AVGS
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Addressing SLI Program Goals:
Increasing Technology Readiness Level
TRL
Level
Start: AVGS
and ARPO at
TRL 4
Finish: AVGS
and ARPO at
TRL 7/8
Description Summary
1
Basic principles observed and reported
2
Technology concept and/or application formulated
3
Analytical and experimental critical function and/or characteristic proofof-concept
4
Component and/or breadboard validation in laboratory environment
5
Component and/or breadboard validation in relevant environment
6
System/subsystem model or prototype demonstration in a relevant
environment (ground or space)
7
System prototype demonstration in a space environment
8
Actual system completed and “flight qualified” through test and
demonstration (ground or flight)
9
Actual system “flight proven” through successful mission operations
Addressing SLI Program Goals:
ARPO Technology Readiness Levels
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Advanced Video Guidance Sensor (AVGS)
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OLD VGS SENSOR
(HEAD AND ELECTRONIC MODULE)
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Proximity Sensor
Comparison to Flight proven Unit
VGS
Optics
8 lasers
AVGS
4 lasers
(reduced complexity and power)
Laser not in optical path
Lasers in optical path
(Increased laser return)
Camera
Electronics
Analog Camera
Digital CMOS Camera
(resolution 640 X 480)
(resolution 1000 X 1000)
5 Hz update
50 Hz update
2 boxes (50 lbs total)
Single box (20 lbs)
(10” X 12” X 8”)
Performance
Signal processing in separate VME
Single DSP board in sensor box
60 watts power
8 watts power
150 m range
1-5 km range (spot mode)
300-500 m (full 6DOF)
(Range & Target Specific)
+/-0.30 cm position, accuracy
+/-0.12 mm position, accuracy
+/-0.30 cm/s velocity, accuracy
+/-0.10 mm/s velocity, accuracy
+/-0.25 deg attitude, accuracy
+/-0.10 deg attitude, accuracy
32
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AVGS Functional Flow
From “On-Orbit Testing of the Video Guidance Sensor” by Richard T. Howard, Thomas
C Bryan, Michael L. Book, NASA/MSFC
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AVGS Design, Analysis and Test
– Brassboard Development Phase (6/1/01 - 1/28/02)
• Parts and Material Review
– EEE Parts Availability
– Outgasssing
– Radiation Environment Analysis
• Begin AVGS Software Development
• Evaluate Optics Performance
– Initial Prototype (IP) Development Phase (6/1/01 - 3/29/02)
• Power Supply Design
• Electronics Packaging Concepts
• Initial Structural Analysis
• Initial Electrical Analysis
• Initial Thermal Analysis
• Radiation Hardening
• Continue AVGS Software Development
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AVGS Design, Analysis and Test (Cont)
– Final Prototype (FP) Development Phase (4/1/02 - 10/18/02)
• 2 Prototype Units (Form, Fit & Function)
• FMEA
• Update Thermal Analysis
• Finalize Electronic Packaging Concepts
• Final Design for Radiation Environment
• Finalize Structural Analysis
• Finalize Electrical Analysis
• Begin AVGS Software functional Verification and Validation
– Qualification Unit Development Phase (9/23/02 - 5/29/03)
• Acceptance Testing (random vibe and thermal vac)
• Qualification Testing (EMI/EMC, Vibe, Shock, Thermal)
• AVGS Flight Load Software Delivery
– Flight Unit Development Phase (5/1/03 - 11/17/03)
• 3 Units
• Acceptance Testing (random vibe and thermal vac)
• Final AVGS Software Load Delivery (Jan04)
35
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New AVGS Initial Proto-Type Unit
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AVGS Development Breadboard Sensor Optics
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Addressing SLI Program Goals:
DART-AVGS Technology Readiness Levels
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DART POP02
Summary by Center
NOA $K
FY01
FY02
FY03
FY04
Totals
Actual RQMT OGL/UGL RQMT OGL/UGL RQMT OGL/UGL RQMT OGL/UGL
MSFC Subtotal
9,502
8,105
GSFC Subtotal
0
69
0
6,111
5,940
0
KSC Subtotal - Pegasus
Total DART
15,613 14,114
0 11,736
3,654
4,697
512
135
2,096 -5,527
710
-591 34,040
914
647
7,806
6,027 21,953
500
0 14,542 -1,361 12,638
5,571 56,907
4,209
39
135
3,062
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Automated Rendezvous and Capture Documentation
Technical Publications
http://alternate.msfc.nasa.gov/AR&C/
a.
Application of Neural Networks to Autonomous Rendezvous and Docking of Space Vehicles, Richard W. Dabney, AIAA Paper 92-1516, AIAA Space Programs and
Technologies Conference, March 24-27, 1992, Huntsville, AL.
b.
United States Patent Number 5,109,345, CLOSED-LOOP AUTONOMOUS DOCKING SYSTEM, Richard W. Dabney and Richard T. Howard, April 28, 1992.
c.
A Plan for Spacecraft Automated Rendezvous, A. W. Deaton, J. J. Lomas, and L. D. Mullins, NASA TM-108385, October 1992.
d.
Guidance and Targeting Simulation for Automated Rendezvous, James J. Lomas, John M. Hanson, and M. Wade Shrader, AAS Paper 94-162, AAS/AIAA Spaceflight
Mechanics Meeting, February 14 - 16, 1994, Cocoa Beach, FL.
e.
Guidance Schemes for Automated Terminal Rendezvous, John M. Hanson and Alva W. Deaton, AAS Paper 94-163, AAS/AIAA Spaceflight Mechanics Meeting,
February 14 - 16, 1994, Cocoa Beach, FL.
f.
A Solution to the 3 Point Inverse Perspective Problem for Automated Rendezvous and Capture, Richard Dabney and Philip Calhoun, MSFC Memorandum ED13-9421, September 30, 1994.
g.
Cargo Transfer Vehicle (CTV) Reference Design for Autonomous Rendezvous and Capture Simulations, Richard Dabney, MSFC Memorandum ED13-94-22 , October
26, 1994.
h.
MSFC-RQMT-2371 B, Automated Rendezvous and Capture (AR&C) System Requirements Document (SRD), Craig A. Cruzen, July 1, 1996.
i.
MSFC Flight Robotics Laboratory (FRL) Description, A World Class Simulation and Test Facility, Linda L. Brewster, Team Lead, Orbital Systems & Robotics Team,
MSFC, November 1997.
j.
AR&C Ground Program System Test Plan, D. L. Kelley, Hernandez Engineering, December 19, 1997.
k.
MSFC Automated Rendezvous and Capture Simulation (MARCSIM) Description, Linda L. Brewster, Team Lead, Orbital Systems & Robotics Team, and Dave W.
Allen, Team Lead, Simulation Software Team, MSFC, April 1998.
l.
Active Sensor System for Automatic Rendezvous and Docking, Richard T. Howard, Thomas C. Bryan, Michael L. Book, and John L. Jackson, Working Paper.
m. Video Guidance Sensor Flight Experiment Results, Richard T. Howard, Thomas C. Bryan, and Michael L. Book, Working Paper.
n.
Automatic Docking System Sensor Analysis & Mission Performance, John L. Jackson, Richard T. Howard, Helen J. Cole, and Ronald A. Belz, Working Paper.
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