NASA Exoplanet Science Institute
National Aeronautics and Space
Administration
Jet Propulsion Laboratory
California Institute of Technology
Design-a-Mission
Group Projects
2014 Sagan Summer Workshop
“Imaging Planets and Disks”
July 21, 2014
National Aeronautics and Space
Administration
Jet Propulsion Laboratory
California Institute of Technology
What is this group project about?
NASA Exoplanet Science Institute
 Design your own mission to detect exoplanets
 Three different mission classes: Probe, Mediumscale, Flagship
 Two different high-contrast instruments:
Coronagraph and Starshade
 Each class and hardware setup combination has a
cost cap and set of science goals
 Two groups for each type of mission: see who
can observe the most planets!
 You will sign up for a group on the sheets
provided, and start working towards your 7-10 min
presentation to be given on Friday afternoon.
February 26, 2013
NASA Keck MOWG - D. Gelino
2
National Aeronautics and Space
Administration
Jet Propulsion Laboratory
California Institute of Technology
Which group should I choose?
NASA Exoplanet Science Institute
Groups 1 & 2: Probe-scale mission with Coronagraph
Cost requirement: Under $1.5 Billion
Primary science goal: Maximize observations of cold Jupiters
Secondary science goal: Estimate potential capability of detecting
other types of planets
Groups 3 & 4: Probe-scale mission with Starshade
Cost requirement: Under $1.5 Billion
Primary science goal: Maximize observations of cold Jupiters
Secondary science goal: Estimate potential capability of detecting
other types of planets
Groups 5 & 6: Medium-scale mission with Coronagraph
Cost requirement: Under $4 Billion
Primary science goal: Maximize observations of exoEarth
candidates
Secondary science goal: Estimate potential capability of detecting
other types of planets
February 26, 2013
NASA Keck MOWG - D. Gelino
3
National Aeronautics and Space
Administration
Jet Propulsion Laboratory
California Institute of Technology
Which group should I choose?
NASA Exoplanet Science Institute
Groups 7 & 8: Medium-scale mission with Starshade
Cost requirement: Under $4 Billion
Primary science goal: Maximize observations of exoEarth candidates
Secondary science goal: Estimate potential capability of detecting
other types of planets
Groups 9 & 10: Flagship-scale mission with Coronagraph
Cost requirement: Under $12 Billion
Primary science goal: Maximize observations of exoEarth candidates
Secondary science goal: Estimate potential capability of detecting
other types of planets
Groups 11 & 12: Flagship-scale mission with Starshade
Cost requirement: Under $12 Billion
Primary science goal: Maximize observations of exoEarth candidates
Secondary science goal: Estimate potential capability of detecting
other types of planets
February 26, 2013
NASA Keck MOWG - D. Gelino
4
NASA Exoplanet Science Institute
National Aeronautics and Space
Administration
Jet Propulsion Laboratory
California Institute of Technology
What Questions Do I need to Answer?
1. What is the name of your mission and its primary goals?
a. Have fun with an acronym and logo if you like!
2. Define the telescope and instrument
a. Size
b. Coronagraph or starshade
c. Contrast
d. Inner Working Angle
e. Mission Lifetime
f. Any other modifications to default parameters
3. Estimate total mission cost
4. Present potential yield for each type of exoplanet
a. Earths, Jupiters, Neptunes, warm mini-Neptunes
5. Present yield as a function of astrophysical uncertainty
a. exozodi level
b. eta_planet
6. Present any lessons learned (e.g. yield scaling relationships)
February 26, 2013
NASA Keck MOWG - D. Gelino
5
Designing a Mission:
Calculating Science Yields
Christopher Stark (NASA GSFC, NPP)
Aki Roberge (NASA GSFC)
Avi Mandell (NASA GSFC)
Tyler Robinson (U of Washington)
Designing a Mission:
The Role of a Yield Calculator
1. Science goals determine a certain type of
observation needed for some number of planets
2. Make a tool (aka. DRM code) that calculates
approximate yields as functions of gross
astrophysical and mission parameters
3. Use it to figure out what those parameters need
to be to satisfy #1
4. Take those parameters to the engineers
5. Iterate until satisfied
Inputs to the DRM
DRM
Exoplanet yield
How To Calculate Planet Yield:
Completeness
Too
faint
IWA
“Completeness” = the chance of observing a given planet around a
given star if that planet exists
Calculated via a Monte Carlo simulation with synthetic planets
Depends on distance to star, planet’s orbit, radius, albedo, and
phase function, and the exposure time for the required SNR
9
How To Calculate Planet Yield:
Exposure Time
t = (Planet SNR)2 ×
(Planet count rate) + 2 × (Background count rate)
(Planet count rate)2
Background count rate =
Leaked starlight
+
Zodiacal light
+
Exozodiacal light
Kalas et al. 2005
Give’on et al. (2007)
Image: Stefan Seip
10
How To Calculate Planet Yield:
Optimizing Exposure Time to Maximize Yield
Starting the Hands-On Exercise
• Start VNC Viewer. Log in
• Open a Terminal window
– Under Applications / System Tools
• Type …
> cd Mon
> cp /ssw/Mon/* .
• This will copy the yield tool and two costing
spreadsheets to your /home/Mon directory
• Begin Quick Start guide examples …
Inner Working Angle
• IWA entered into yield tool in arcseconds
• For coronagraphs,
•
•
•
•
IWA = a × λ / D
OWA = b × λ / D
λ = 0.55 μm, a > 2, b < 20
You have to calculate what a, b your choices
correspond to before using the cost calculator
• For starshades, IWA can be anything. No OWA
• Small IWAs will increase the starshade / telescope
separation and the retargeting times
A Few Words About Costs
• The cost tools are Open Office spreadsheets,
one for coronagraphs, one for starshades
• May look complicated but are not hard to use
• These are estimates of what your missions will
cost
• The point of having cost caps is to put a
constraint on your design choices
• So you don’t all order up the premium versions of
everything
Click to edit Master title style
Exoplanet Exploration Program
Sagan Summer Workshop
Mission Group Project: Cost Estimation Tools
Keith Warfield (JPL)
Vritika Singh (JPL)
July 21, 2014
The Mission Costing Process
Exoplanet Exploration Program
1. Define the telescope, coronagraph / starshade
2. Input chosen parameters on front worksheet of
spreadsheet
•
For some parameters, have to choose from a drop-down list
of options. Choose option closest to your design value.
3. Choose orbit
4. Sheet calculates data volume, rate and downlink
5. Sheet calculates pointing requirements
6. Select spacecraft bus
7. Sheet calculates launch mass
8. Select launch vehicle
9. Estimate total mission cost
10. … then iterate
Exoplanet Exploration Program
Coronagraph/Telescope
Flight System Sizing
Design Worksheet
Exoplanet Exploration Program
•
•
•
Fill in all input information as an initial starting point
Orbit choice requires telecom data volume evaluation and mission duration choice
Spacecraft and Launch Vehicle are selected from lists on other worksheets
System
Parameter
Diameter (m)
Telescope
On-Axis (0) or Off-Axis (1)
Raw Contrast (log10)
Coronagraph
IWA (milliarcsec) (75-200)
Inputs 1 Instrument
Spectral Bands (number)
Bandwidth per Band (%)
Detector
CCD (1), CMOS (2), EMCCD (3)
Mission Duration Lifetime (years)
Orbit
LEO (1), L2 (2), Trailing Orbit (3), or GEO (4)
Spacecraft
Spacecraft Configuration Selection
Inputs 2
Launch Vehicle Launch Vehicle Selection
Payload Driven Spacecraft Pointing Requirement
Payload Power Requirement
Coronagraph
Data Generated per Day
Instrument &
Payload Mass
Telescope
Auto
Coronagraph Mass
Outputs
Telescope Mass
Launch Capability
Overall Mass
Launch Mass
and Cost
Launch Margin
Cost (FY14)
Option A
1.0 m
0
-8
200 masec
3
10%
2
5 yrs
2
Spacecraft D
L/V B
0.50 asec
281 W
691 Mb/day
520 kg
220 kg
300 kg
3700 kg
2079 kg
1621 kg
$725 M
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18
Orbit and Telecom Sheets
Exoplanet Exploration Program
• Trading telecom needs
vs. station keeping
requirements vs. mission
duration
• All subsystems can be
impacted by the decision
but Telecom is the most
important
• Make sure the daily
coronagraph data can fits
with the orbit capability
• Select a spacecraft
offering the required
telecom band
Earth Trailing
X/Ka
L2
X/Ka
HGA
MGA/HGA
DSN
DSN
Con’s
Large link distance; higher
cost launch; limited extended
mission
Station keeping required;
higher cost launch
Pro’s
No station keeping, extremely Constant geometry;
quiescent environment
extended mission option
Typical Downlink Band
Typical Downlink
Antenna
Ground Stations
Telecom Capability
Max Downlink Rate (kbps)
L2
Earth Trailing
S
20
n/a
X
3000
300/(ops year^2)
Ka
13000
1300/(ops year^2)
8 hrs/day
8hrs/day
S
576
n/a
X
86,400
8640/(ops year^2)
Ka
374,400
37400/(ops year^2)
Max Downlink Duration
Max Daily Data Volume (Mb/day)
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19
Spacecraft Selection Sheet
Exoplanet Exploration Program
• Select a spacecraft with:
–
–
–
–
Sufficient payload mass and power capability
Adequate pointing performance (requirement set by telescope)
Correct mission design life
Correct telecom band
Payload Power (OAV) (EOL)
W (EOL)
Spacecraft A
Spacecraft B
Spacecraft C
Spacecraft D
50
125
730
650
Spacecraft
Spacecraft F
E
1000
3000
Payload Mass Limit of Bus
kg
70
200
380
650
1700
2400
Bus Dry mass (w/o Payload)
kg
60
125
600
500
1500
2000
500
20,000
134,000
200,000
51,000
102,000
5
5
3
0.3
0.2
0.15
60
390
240
120
50
5
1
2
5*
5*
>5*
>5*
L/V A only
All L/V's
S-band
None
S-Band
Blowdown
hydrazine
All L/V's
S-band and Xband
Blowdown
hydrazine
All L/V's
S-band and Xband
Blowdown
hydrazine
All L/V's
X-band and
Ka-band
Blowdown
hydrazine
All L/V's
X-band and
Ka-band
Blowdown
hydrazine
$ 26 M
$ 53 M
$ 90 M
$ 142 M
$ 174 M
$ 264 M
Science Data Storage capability Mbit
Pointing Control
arcsec
Slewrate
deg/min
Mission Design Life
yrs
Compatible LVs
(names)
Downlink
Band
Propulsion type
Cost
$ FY14
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20
Launch Mass and Spacecraft Power Estimation Sheet
Exoplanet Exploration Program
• Worksheet used for estimating power requirement for spacecraft
selection, and launch mass for launch vehicle selection
• JPL standard mass and power margins are included
SYSTEM S WORKSHEET:
Spacecraft - Option 1
Mass
(kg)
Subsys
Cont.
%
CBE+
Cont.
(kg)
Mode 1
Power
(W)
Launch
Mode 2
Power
(W)
Science
Mode 3
Power
(W)
Science &
Telecom
Mode 4
Power
(W)
Safe
Mass
Fraction
Chronograph
Telescope
Payload Total
Spacecraft Bus
21%
29%
50%
220
300.0
520.0
43%
43%
43%
314.6
429.0
743.6
0
0
0
168
113
281
168
113
281
0
0
0
Spacecraft
S/C-Side Adapter
Bus Total
48%
2%
500.0
25.0
525.0
30%
5%
29%
650.0
26.3
676.3
100
100
150
100
100
381
431
100
0
100
121
502
121
552
0
100
Spacecraft Total (Dry)
1045.0
36%
1419.9
Subsystem Heritage Contingency
374.9
36%
36%
System Contingency
Spacecraft with Contingency
74.5
1494
7%
of total
7%
w/o addl pld
Propellant & Pressurant1
Spacecraft Total (Wet)
2%
40.0
2054
L/V-Side Adapter
Launch Mass
25.0
2079
Launch Vehicle Capability
3700
Launch Vehicle Margin
JPL Design Principles Margin
1620.7
57%
30% required
The technical data in this document is controlled under the U.S. Export Regulations, release to foreign persons may require an export authorization.
21
Launch Vehicle Selection Sheet
Exoplanet Exploration Program
• Select a launch vehicle with higher capacity than
the launch mass and power worksheet
• Minimize launch cost
600km LEO
L/V Max. Capacity
Earth
L2
Trailing
GEO
Cost
($FY14)
L/V A
1000 kg
N/A
N/A
N/A
$ 90 M
L/V B
14500 kg
3700 kg
3650 kg
3700 kg
$ 142 M
L/V C
13700 kg
4788 kg
4838 kg
5200 kg
$ 274 M
L/V D
16300 kg
6150 kg
6100 kg
6750 kg
$ 306 M
L/V E
21430 kg
9380 kg
9225 kg
12710 kg
$ 422 M
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22
Exoplanet Exploration Program
Starshade Flight System Sizing
Starshade Diameter Sensitivities
Exoplanet Exploration Program
Starshade Dia.
(m)
Mass
(kg)
Cost
($M FY14)
30
635
$120
32
680
$125
34
725
$130
36
775
$140
38
825
$150
40
880
$165
42
935
$200
Spacecraft Choices
Exoplanet Exploration Program
• Select a spacecraft suitable for the mission
– Can it support the payload?
– Can it support the intended mission design life?
– Does spacecraft choice put constraints on launch vehicle choice?
Spacecraft
W
Spacecraft
X
Spacecraft
Y
Spacecraft
Z
W (BOL)
730
650
1000
3000
Payload Mass Limit of Bus
kg
675
850
1700
2400
Bus Dry mass (w/o Payload)
kg
600
500
1500
2000
deg/min
240
120
50
5
Payload Power (BOL)
Slewrate
Mission Design Life
Compatible LVs
Downlink
yrs
(names)
Band
Propulsion type
Cost
$ FY14
2
3
5
All L/V's
All L/V's
All L/V's
except L/V F except L/V F except L/V F
>5
All L/V's
S-band and X- S-band and X-band and X-band and
band
X-band
Ka-band
Ka-band
Blowdown
Blowdown Monoprop or Monoprop or
hydrazine
hydrazine
biprop
biprop
$ 120 M
$ 165 M
$ 240 M
$ 300 M
Launch Vehicle Choices
Exoplanet Exploration Program
• Add starshade mass and spacecraft dry mass. Then add
400 kg/year for propellant. This is the launch mass.
• Select a launch vehicle with adequate capacity for the
intended destination
L/V Max. Capacity
GEO
Cost
($FY14)
N/A
$ 90 M
3650 kg
3700 kg
$ 142 M
4788 kg
4638 kg
5200 kg
$ 274 M
16300 kg
6150 kg
6100 kg
6750 kg
$ 306 M
21430 kg
9380 kg
9225 kg
12710 kg
$ 422 M
L/V A
600km
LEO
1000 kg
N/A
Earth
Trailing
N/A
L/V B
14500 kg
3700 kg
L/V C
13700 kg
L/V D
L/V E
L2
Cost Estimation
Exoplanet Exploration Program
COST SUMMARY (FY2014 $M) - Option 1
WBS Elements
Project Cost ($ FY14)
Development Cost (Phases A - D)
01.0 Project Management
02.0 Project Systems Engineering
03.0 Mission Assurance
04.0 Science
05.0 Payload System
Starshade
06.0 Flight System
07.0 Mission Operations Preparation
09.0 Ground Data Systems
10.0 ATLO
11.0 Education and Public Outreach
12.0 Mission and Navigation Design
Development Reserves
Operations Cost (Phases E - F)
Operations
Operations Reserves
8.0 Launch Vehicle
Total
$803 M
Basis of Estimate
$505 M Sum
$17 M 5% of WBS 05 thru 10 and 12
$17 M 5% of WBS 05 thru 10 and 12
$14 M 4% of WBS 05 thru 10 and 12
$5 M
$130 M Sum
$130 M Starshade look up table
$142 M S/C look up table
$15 M JPL OTS Earth-orbiting Missions (flat cost input)
$20 M JPL OTS Earth-orbiting Missions (flat cost input)
$25 M JPL OTS Earth-orbiting Missions (flat cost input)
$2 M 0.5% of WBS 05 thru 10 and 12
$3 M Guess
$115 M 30% of WBS 01 thru 12 except 08
$156 M
$125 M $25M/year
$31 M 25% of operations
$142 M L/V look up table
Exoplanet Exploration Program
Backup
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28
Payload Sheet
Exoplanet Exploration Program
• Coronagraph parameters are estimated for input requirements
• Telescope selected from a pick list
– Telescope sets a spacecraft pointing requirement which limits spacecraft choices
number
Bandwidt
h per
Band
(%)
kg
W
Mbps
Option 1
200
1
3
1
2
220
168
0.008
78
Option 2
0
No Input
0
No Input
0
-10
#NUM!
0.000
#NUM!
Option 3
0
No Input
0
No Input
0
-10
#NUM!
0.000
#NUM!
IWA
Coronagraph
Raw
Spectral
Contrast Bands
milliarcsec Log 10
Telescope
Detector
Mass
SPACECRAFT
Power Data rate Pointing Requirement
(asec)
Tech.
Visible
Dev.
(kg)
(W)
(kbps)
1
30
25
n/a
0.5
300
113
n/a
0.3
600
185
n/a
Pointing
960
263
n/a
0.21
Pointing
1380
338
n/a
0.17
Pointing
1860
413
n/a
0.15
Pointing
Mass
0.5m
1.0m
1.5m
2.0m
2.5m
3.0m
Telescope
Telescope
Telescope
Telescope
Telescope
Telescope
Power
Data Rate
Cost
FY14 $M
Cost
Off-Axis Cost
Adjustment
($ FY14)
Visible
$ 16 M
0%
$ 42 M
0%
$ 142 M
0%
$ 316 M
20%
$ 564 M
20%
$ 885 M
20%
Notes
- Purple cells have automatic calculations to provide the necessary outputs.
- Cyan cells are inputs that have been transferred from the Design Worksheet to this worksheet.
- Yellow cells are look-up table values.
- This sheet is locked; cells cannot be modified.
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29
Cost Estimation Worksheet
Exoplanet Exploration Program
•
•
Cost estimate is for the total project cost
Require inputs:
–
–
–
–
Coronagraph cost
Telescope cost
Spacecraft cost
Mission duration to set operations costs
COST SUMMARY (FY2014 $M) - Option 1
WBS Elements
Project Cost ($ FY14)
Development Cost (Phases A - D)
01.0 Project Management
02.0 Project Systems Engineering
03.0 Mission Assurance
04.0 Science
05.0 Payload System
Chronograph
Telescope
06.0 Flight System
07.0 Mission Operations Preparation
09.0 Ground Data Systems
10.0 ATLO
11.0 Education and Public Outreach
12.0 Mission and Navigation Design
Development Reserves
Operations Cost (Phases E - F)
Operations
Operations Reserves
8.0 Launch Vehicle
Total
$725 M
$427 M
$14 M
$14 M
$11 M
$5 M
$121 M
$78 M
$42 M
$142 M
$5 M
$5 M
$5 M
$1 M
$3 M
$99 M
$156 M
$125 M
$31 M
$142 M
Basis of Estimate
Sum
JPL percentage
JPL percentage
JPL percentage
Sum
JPL OTS Earth-orbiting Missions
JPL OTS Earth-orbiting Missions
JPL OTS Earth-orbiting Missions
NASA percentage
Guess
30% NASA Requirement
$25M/year Earth Mission (Sci + Ops)
25% NASA Requirement
Not included in AO
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30