LAI PD Meeting
10/7/03
SPACETUG:
Roles of
MATE-CON and
Traditional Design
Methods
Dr. Hugh McManus
Metis Design
Space Tugs
•  A vehicle or vehicles that can
–  Observe
in situ
–  Change the orbit of
–  Eliminate (clean debris)
–  Retrieve
–  Otherwise interact with
objects in orbit.
Potentially, an important national asset
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
2
Problem and opportunity
•  Single-use missions for such a vehicle tend to be
economically or physically infeasible
•  Little work on the potential for a general-purpose vehicle
and some of the key challenges associated with it
•  Recognized difficulties include:
–  Unfriendly orbital dynamics and environment
–  Vehicle complexity –  Market uncertainty A new look at the problem:
Exploring the Architectural Tradespace with MATE-CON
AND defining point designs with more traditional mission analyses
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
3
MATE: Developing A Trade Space
Attributes
Mission
Concept
•
•
•
•
•
•
Understand the
Mission
Create a list of
“Attributes”
Interview the
Customer
Create Utility Curves
Develop the design
vector and system
model
Evaluate the potential
Architectures
Define Design
Vector
Develop System
Model
Calculate
Utility
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
Estimate
Cost
Architecture
Trade Space
©2003 Massachusetts Institute of Technology
4
MATE: Multi-Attribute Tradespace Analysis
Spacetug System Attributes:
•  Total Delta-V capability - where it can go
–  Calculated from simple model (rocket equation)
•  Response time - how fast it can get there
–  Binary - electric is slow
•  Mass of observation/manipulation equipment what it can do when it gets there
–  Based solely on equipment mass (didn’t design
observation or grappling equipment)
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
5
Utilities (parametric) and Cost
DV Utility
1.00
Leo-Geo RT
1
Leo-Geo
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.9
0.8
Single-Attribute
Utility
0.80
0.7
Capability
DV single-attribute Utility
0.90
0.3
0.6
0.5
0.4
0.2
0.1
0
0.00
0
2000
4000
6000
8000
10000
12000
DV
DV Utility
Low
Medium
High
Extreme
Capability Utility
•  Response time utility binary (electric bad)
•  Total Utility a weighted sum
–  Examples will stress DV, then capability
•  Cost estimated from wet and dry mass
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
6
Design Space
•  Capability = Manipulator Mass
–
–
–
–
Low (300kg)
Medium (1000kg)
High (3000 kg)
Extreme (5000 kg)
•  Propulsion Type
–
–
–
–
Storable bi-prop
Cryogenic bi-prop
Electric (NSTAR)
Nuclear Thermal
•  Other more detailed designs
incorporated into study
–
–
–
–
Freebird (MIT class project)
SCADS (Aerospace)
GEO one-way or RT Tugs
GEO and LEO “tenders”
•  Most developed by ICE
method •  Fuel Load - 8 levels
Exhaustive survey - 139+ designs
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
7
Tradespace Evaluation
For each potential design:
•  Calculate attributes
–
–
–
–
Total DV capability - rocket equation
Response time - electric is slow
Mass of observation/grappling equipment - specified
Vehicle wet and dry masses - simple models •  Calculate individual utilities for first three
–  Utility curves
•  Calculate total utility
–  Weighted sum
•  Calculate cost from wet and dry masses
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
8
Spacetug Tradespace
Propulsion System as a Discriminator
4000
3500
Cost ($M)
3000
Biprop
Cryo
2500
Electric
Nuclear
2000
1500
1000
500
0
0.0
0.2
0.4
0.6
0.8
1.0
Utility (dimensionless)
Highest performance systems require high ISP propulsion
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
9
Sensitivities to shifts in user needs
1.00
1.00
Leo-Geo RT
0.90
0.60
0.50
0.40
0.30
0.20
2000
6000
8000
10000
0.50
0.40
0.30
0.00
12000
0
DV (m/sec)
4000
Cost ($M)
4000
5000
10000
15000
3500
Biprop
Cryo
3000
Electric
Nuclear
2000
1500
2500
500
500
0.6
0.8
1.0
Utility (dimensionless)
30000
35000
40000
Biprop
Cryo
Electric
Nuclear
1500
1000
0.4
25000
2000
1000
0.2
20000
DV (m/sec)
4000
Cost ($M)
0
0
0.0
0.60
0.10
0.00
2500
0.70
0.20
0.10
3000
Leo-Geo
0.80
Leo-Geo
0.70
DV single-attribute Utility
DV single-attribute Utility
0.80
3500
Leo-Geo RT
0.90
0
0.0
0.2
0.4
0.6
0.8
1.0
Utility (dimensionless)
Unlimited DV demand favors high ISP propulsion
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
10
Key Physical Limits and Dangers
Cost (M$)
4000.00
Low Biprop
3500.00
Medium Biprop
3000.00
Extreme Biprop
2500.00
Medium Cryo
2000.00
Extreme Cryo
1500.00
Medium Electric
1000.00
Extreme Electric
High Biprop
Low Cryo
High Cryo
Low Electric
High Electric
Low Nuclear
Medium Nuclear
500.00
0.00
0.00
High Nuclear
Extreme Nuclear
0.20
0.40
0.60
0.80
1.00
Utility (dimensionless)
Hits a “wall” of either physics (can’t change!) or utility (can)
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
11
Tradespace Reveals Promising Designs
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
12
Traditional Analysis: Requirements
developed for specific missions
80
Number Of Satellites
70
70-80
60-70
50-60
40-50
30-40
20-30
10-20
0-10
60
50
40
30
20
10
<40
40-42
42-44
44-46
46-48
48-50
50-52
52-54
54-56
56-58
58-60
60-62
62-64
64-66
66-68
68-70
70-72
72-74
74-76
76-78
78-80
80-82
82-84
84-86
86-88
88-90
90-92
92-94
94-96
96-98
98-100
100-102
102-104
104-106
106-108
108-110
110-112
112-114
114-116
116-118
0
]
[k m 1 4 0
de
0 -1
itu 1000
50
Alt 60
-1 1
0
0-7
00
20
0
0-3
0
00
Inclination[deg]
•
•
•
•
Target list developed
Specific mission plans
scoped
Orbital mechanics and
other analyses set
requirements
Possible product
family built up from
individual designs
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
13
Analyses of Specific “Tender” missions
1. Create a complete database (orbital elements, size, mass,
type of control, data rates, etc.).
2. See if objects can be grouped in terms of similar orbital
and physical characteristics.
3. Define specific target groups:
a)  Put reasonable constraints on altitude and inclination ranges.
b)  Identify predominant or average physical characteristics
(length, height, span, mass).
4. Create mission scenarios for each target group.
Project led by MIT graduate student Kalina Galabov
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
14
Database
S025388
S026884
S026859
S022051
S023333
S023350
S024913
S014163
S023716
S022049
S025867
S026886
S002770
S000098
S003951
19
20
20
19
19
19
19
19
19
19
19
20
19
61
19
98-041C
01-034A
01-027A
92-044C
94-071A
94-071C
97-045B
83-067A
95-062B
92-044A
99-040B
01-034C
67-040F
Kappa
69-046B
KM-V1
KM-V1
ISAS
1998 Jul 3
Genesis
Genesis
NASA/JPL 2001 Aug 8
MAP
Microwave Anisotropy
NASA GSF
Pro2001 Jun 30
Star 48B
Star 48B S/NMDAC
10076-18 1992 Jul 24
WIND
WIND
NASA GSF 1994 Nov 1
Star 48B
Star 48B
MDAC
1994 Nov 1
Delta 247 Delta/AJ-10-118K
Boeing/H
No. 2471997 Aug 25
Prognoz-9 SO-M No. 509
MOM
1983 Jul 1
Ariane H10-3Ariane H10-3Arianesp
1995 Nov 17
Geotail
Geotail
ISAS
1992 Jul 24
Chandra X-ray
AXAF
Observatory
NASA MSF 1999 Jul 23
Star 37FM Star 37FM Boeing/H
2001 Aug 8
Transtage 10Transtage 10USAF
1967 Apr 28
Explorer 10 P-14
NASA GSF 1961 Mar 25
ERS 26
ERS 26
USAF
1969 May 23
S003950
S002768
S002767
S000432
19
19
19
62
69-046A
ERS 29
67-040D
ERS 20
67-040C
ERS 18
B Gamma 1Explorer 14
S003952
S002769
19 69-046C
19 67-040E
OV5-9
ERS 27
S002765
S000693
19 67-040A
19 63-046A
Vela 4A
Vela 4A
IMP 1 (Explorer
IMP18)
A
S003145
S025989
19 68-014B
19 99-066A
Agena D 6503
Agena D 6503
NASA LeR
XMM
XMM
ESA
S025990
S003138
19 99-066B
19 68-014A
EPS 504
OGO 5
S020413
S019288
19 83-020D
19 88-059B
Blok D-1
11S824M No.
RVSN
7L
Blok D-2 No.11S824F
1L
No.RVSN
1L
S019282
S015664
19 88-058B
19 85-033D
S023646
S010370
S015661
S013901
In Earth orbit 1998 Jul 22 CLO
In Earth orbit 2001 Aug 13CLO
In Earth orbit 2001 Jul 10 CLO
In Earth orbit19921992
DecJul
31 24 CLO
In Earth orbit 1994 Nov 1 CLO
In Earth orbit 1994 Nov 1 CLO
In Earth orbit 1997 Aug 25CLO
In Earth orbit 1983 Jul 1 CLO
In Earth orbit 1997 Mar 14DHEO
In Earth orbit 1992 Oct 19DHEO
In Earth orbit 1999 Aug 27DHEO
In Earth orbit 2001 Jul 1 DHEO
In Earth orbit 1967 Apr 28 DHEO
In Earth orbit1968
1961
MayMar
31 25DHEO
In Earth orbit 1969 Jul 8 DHEO
27724
1916
97345 2E+05
12867
3144
13367
184
19700
186
19700
186
46267
172
36812
380
1516
926
2474.8
3905
3808.9
9999
9898.8
182
2831.2
8588
5010.1
220
3115.3 16977
592196
1E+06
347874
360211
470310
470310
840904
720000
73746
104552
138826
292492
111242
181000
111583
297056
694597
175509
180198
235248
235248
420538
360190
37336
54229
74413
146337
59915
90610
64280
23.8
28
28.3
28.7
28.7
28.7
28.8
65.5
0.4
22.3
28.5
28.7
32.8
33
33.1
ERS 29
USAF
OV5-3
USAF
ERS 18
USAF
EPE B (S-3A)
NASA GSF
1969 May 23
1967 Apr 28
1967 Apr 28
1962 Oct 2
In Earth orbit 1969 Jul 9 DHEO
In Earth orbit 1967 Jun 29 DHEO
In Earth orbit 1967 Jun 29 DHEO
In Earth orbit19641964
Dec Oct
31 20DHEO
3120.2
2831.1
2831.1
2157.9
16994
8981
8989
914
111712
110845
110839
96959
64353
59913
59914
48937
33.1
33.2
33.3
33.6
OV5-9
OV5-1
1969 May 23
1967 Apr 28
In Earth orbit
In Earth orbit
1970 Jul 20 DHEO
1967 Aug 9 DHEO
3116.7
2827.3
16958
9110
111642
110599
64300
59855
33.7
34.2
In Earth orbit 1967 Sep 29DHEO
In Earth orbit19651964
Nov Apr
30 3 DHEO
2827.9
5599.5
9193
2072
110534
194080
59864
98076
34.4
35.2
1968 Mar 4
1999 Dec 10
In Earth orbit
In Earth orbit
1968 Sep 6 DHEO
2000 Jan 9 DHEO
3713.2
2872.2
2102
7079
144003
114028
73053
60554
36.3
38.4
ESA
1999 Dec 10
NASA GSF 1968 Mar 4
In Earth orbit
In Earth orbit
2000 Jan 12 DHEO
1968 Dec 17DHEO
2603.8
3745.1
789
5075
111844
141939
56317
73507
38.7
41.2
1983 Mar 23
1988 Jul 12
In Earth orbit
In Earth orbit
1990 Jan 10 DHEO
1988 Jul 12 DHEO
5826.2
3246.5
6567
2499
195185
130000
100876
66250
48.3
50.8
Blok D-2 No.11S824F
2L
No.RVSN
2L
Blok SO-L Blok SO-L RVSN
1988 Jul 7
1985 Apr 26
In Earth orbit 1988 Jul 7 DHEO
In Earth orbit19931985
DecApr
30 26 DHEO
3267.7
5785
2628
420
130504
200320
66566
100370
50.8
64.9
19 95-039F
19 77-093A
Magion-4
Prognoz-6
Magion-4
Czech
SO-M No. 506
MOM
1995 Aug 2
1977 Sep 22
In Earth orbit
In Earth orbit
1996 Oct 31DHEO
1978 Apr 4 DHEO
5469.2
5683.2
14777
1850
178122
196379
96450
99115
71.3
74.3
19 85-033A
19 83-020A
Prognoz-10-IK
SO-M No. 510
MOM
Astron
1A No. 602 MOM
1985 Apr 26
1983 Mar 23
In Earth orbit19941985
Jan Dec
12 15DHEO
In Earth orbit 1985 Mar 20DHEO
5783.8
5915.8
5974
25129
194737
178818
100356
101974
76.7
79.7
EPS
OGO E
USAF
USAF
USAF
1967 Apr 28
NASA GSF 1963 Nov 27
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
15
Target Groups
80
70-80
60-70
50-60
40-50
30-40
20-30
10-20
0-10
60
50
40
30
20
10
0
<40
40-42
42-44
44-46
46-48
48-50
50-52
52-54
54-56
56-58
58-60
60-62
62-64
64-66
66-68
68-70
70-72
72-74
74-76
76-78
78-80
80-82
82-84
84-86
86-88
88-90
90-92
92-94
94-96
96-98
98-100
100-102
102-104
104-106
106-108
108-110
110-112
112-114
114-116
116-118
Number Of Satellites
70
m] 14
e 1[k
00
d
-1 5
00
itu
0-1
00
Alt 60
10
0-7
20
0
00
0-3
00
Inclination[deg]
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
16
Target Group #1
Miscellaneous
–  i = 98.1 to 99 deg
–  h = 770.5 to 861 km
–  Total: 345 satellites
–  1990-2001: 47 satellites
–  US: 76 sat. (29 recent)
–  Numerous rocket
bodies
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
–
–
–
–
600 kg
1.27 x 1.58 x 0.94 m
10.4 m solar array span
10 m deployed antennas
span
–  3-axis stabilized
OR
– 520 kg
– D = 1.31 m, H = 3.96 m
– Spin-stabilized
©2003 Massachusetts Institute of Technology
17
GEO Target Group (#5)
•
•
•
•
•
i = 0 to 5.2 deg
h = 35, 662 to 36,667 km
Total: 639 satellites
1990-2001: 333 satellites
US: 280 sat. (103 recent)
•
•
•
•
Spin-stabilized
~55 rpm
750 kg / 850 kg
D = 3 m, H = 3.3 m
Htot = 7 m
•
3-axis stabilized
•
1,880 kg / 2,200 kg
•
2.3 x 2.2 x 2.3 m
•
25 m solar arrays span
•
8.3 m span of antennas
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
18
Mission Scenario: LEO Tender I
Visit 5 satellites:
- 3 randomly within a 100 km altitude and 1
deg inclination box
- 2 in 200 km and 2.2 deg box Example:
- any 3 satellites within h = 770 – 870 km and i = 98-99 deg
- one at h = 670.5 km and i = 98.2 deg (NASA’s Terra, 99-068A)
- one at h = 778 km and i = 100.2 deg (USAF
Falconsat, 00-004D) Targets Properties:
- 520 kg
- 1.27 x 1.58 x 0.94 m box
- 10.4 m solar array span
- 8 m deployed antennas span Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
Missions: 1) Orbit Change
2) Rendezvous – 100 m/s
3) Dispose (increase the altitude of 100 km to decay altitudes) or
Move (ΔV = 167 m/s; 180 deg in one week) 4) Park (if disposal) and Return to LEO
Mission Life: 10 years
Assumptions: 1) The target properties are the same for all targets.
2) The tender is launched into a 99 deg orbit, h = 800 km. ©2003 Massachusetts Institute of Technology
19
Mission Scenario: GEO Tender
Visit 5 satellites:
- 3 randomly within a 400 km altitude and 5 deg inclination
box
- 2 in 1500 km and 15 deg box
Example:
- any 3 satellites within h = 35,600 – 36,000 km and i = 0 –
5 deg
- one at about h = 34,900 km and i = 0 deg
- one at about h = 35,800 km and i = 13 deg
Targets Properties:
- 2,200 kg
- 2.3 x 2.2 x 2.3 m box
- 25 m solar array span
- 8.3 m deployed antennas span
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
Missions: 1) Orbit Change
2) Rendezvous – 100 m/s
3) Dispose (increase the altitude of 400 km) or
Move (ΔV = 219 m/s; 180 deg in one week)
4) Park (if disposal) and Return to GEO
Mission Life: 10 years
Assumptions: 1) The target properties are the same for all targets.
2) The tender is launched into a 28 deg GTO orbit.
©2003 Massachusetts Institute of Technology
20
ICE: Integrated Concurrent Engineering
•  Rapid conceptual design of points in the tradespace
•  CalTech/JPL/Aerospace Corp. Integrated Concurrent
Engineering techniques used
•  Analysis Team: MIT/Caltech/Cambridge Students
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
21
Results based on MATE tradespace:
Bipropellant GEO Tug
•  Approx. 1300 kg dry mass, 11700 kg wet mass
•  Quite big (and therefore expensive); not very practical (?)
Solar Panels
Manipulator
System
Scale for all
images:
black cylinder is
1 meter long by
1 meter in diameter
Spacecraft Bus
w/subsystems
Propulsion System
w/fuel
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
The “Rocket
Equation Wall”
explored
©2003 Massachusetts Institute of Technology
22
Electric Propulsion RT GEO Tug
•  Approx. 700 kg dry mass, 1100 kg wet mass
•  Includes return of tug to safe orbit
•  A reasonable, versatile system The “Electric Cruiser”
on the knee of the tradespace
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
23
Results from Mission Analysis:
Bi-prop Tender Designs
•
•
•
•
Lower Utility, lower cost systems Can’t go to GEO (though can work there if inserted)
700-1000 kg dry mass; 1000-4000 kg wet mass
A family of potential vehicles with reasonable sizes and mass fractions
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
24
Integration of Mission Analysis Results
•
•
•
•
Modular family of possible vehicles Electric and conventional propulsion
Varying fuel loads
Variety of manipulators within fixed weight/volume/power envelope
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
25
Bringing it all together:
Trade Space Check - GEO missions
The GEO mission is near the “wall” for conventional propulsion
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
26
Trade Space Check - Tender missions
The Tender missions are feasible with conventional propulsion
General Tender is flexible (though not “optimal”)
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
27
Synergies Between Methods Results in
Powerful Conceptual Design Capability
MATE
ICE
Validation and
understanding
Design point
or attributes
and sensitivities
Feasible mission
concepts
Mission Analysis
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
Point design
requirements
©2003 Massachusetts Institute of Technology
28
Synergies Between Methods Results in
Powerful Conceptual Design Capability
MATE
Right Design(s) for
the Right Mission(s)
ICE
General design
Point designs
Feasible mission
concepts
Mission Analysis
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
Point design
requirements
©2003 Massachusetts Institute of Technology
29
QUESTIONS?
earth image from:
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
30
Synergies Between Methods Results in
Powerful Conceptual Design Capability
MATE
ICE
Validation and
understanding
Design
attributes &
sensitivities
Feasible
mission
concepts
Mission Analysis
Point design
requirements
Family concepts,
multi-mission tender
Right Design(s) for
the Right Mission(s)
Space Systems, Policy, and Architecture Research Consortium and the MIT Space Systems Laboratory
©2003 Massachusetts Institute of Technology
31