Europa Clipper March 2014

1Jet Propulsion Laboratory,

California Institute of Technology

2Applied Physics Laboratory,

Johns Hopkins University

Europa Clipper Update CAPS

March 4, 2014

Barry Goldstein1

Robert Pappalardo1

Brian Cooke1

Tom Magner2

Louise Prockter2

Dave Senske1

Copyright 2014. All rights reserved. Pre-Decisional — For Planning and Discussion Purposes Only

2

The Ocean That Beckons

“Europa, with its probable vast subsurface ocean sandwiched

between a potentially active silicate interior and a highly

dynamic surface ice shell, offers one of the most promising

extraterrestrial habitable environments, and a plausible

model for habitable environments beyond our solar system”

The Planetary Decadal Survey

3/4/14

Overview

• Key work accomplished since the last CAPS meeting

– NASA selected 15 Instrument Concepts for Europa Exploration (ICEE)

teams

• Europa team has had fruitful interactions clarifying mission accommodations,

operational and other constraints.

• Team has learned a great deal about the needs of the notional payloads for our

mission

– Conceived a more cost effective way of performing the gravity science

investigation by using fixed fan beam antennas

– Performed science evaluations of the latest mission trajectory

• Have now baseline 13F7 as target orbital tour

– Initiated science and technical risk reduction activities

– Conducted an independent mission solar power feasibility review

– Continued assessments with the Space Launch System (SLS) Program

Office on a potential launch vehicle

3/4/14 3 Pre-Decisional — For Planning and Discussion Purposes Only

Preliminary Concept Review

and Mission Concept Review

• Will conduct the PCR (next week) to focus on technical approach

• Technical designs & products are sufficiently mature for MCR

– Science traceability mission requirements flow down completed

• Top level requirements exist and have been flowed to system level

– Technology/engineering development risks understood and being mitigated

• Significant effort in process to mature the programmatic plan for the MCR

– MCR has been approved by NASA and is scheduled for September 16-18,

2014

– In preparation for this review, Pre-Project has begun development of

integrated master schedule (>1,600 line item) and conducted a

implementation workshop in early January • Outcome of this workshop as necessitated with Pre-Project moving earliest launch opertuinity

to May of 2022.


Top Level Schedule

(May 2022 Launch)


Europa Science Definition Team

• Full Science Definition Team (SDT) engaged

– 20 scientists from 7 research institutions and 4 NASA Centers

– Ensures that a broad range of expertise is represented in discussions

of science maturation during formulation phase

• Recent SDT telecons

– Trajectory update

– Reconnaissance observation planning update

– Discussion of Europa plume report

• Recent and planned In-person meetings

– Feb. 4, 2014: Implications of possible plumes for traceability matrices

– Jun. 2–3, 2014: Community input and discussion on plume implications

• Additional individual and group discussions of questions and issues

pertinent to science and recon traceability

• Recent presentations to SDT are publicly posted

– http://solarsystem.nasa.gov/europa/technical.cfm


http://solarsystem.nasa.gov/europa/technical.cfm

http://solarsystem.nasa.gov/europa/technical.cfm

Europa Clipper Goals and Objectives

• Science Goal: Explore Europa to investigate its habitability

– Ocean & Ice Shell: Characterize ice shell and subsurface water, including heterogeneity, ocean properties, and surface-ice-ocean exchange

– Composition: Understand habitability of Europa's ocean through composition and chemistry

– Geology: Understand formation of surface features, including sites of recent or current activity, and characterize high science interest localities

• Reconnaissance Goal: Characterize Safe and Scientifically Compelling Sites for a Future Lander Mission to Europa

– Distribution of surface hazards, load-bearing capacity of surface, structure of the subsurface, and regolith thickness

– Composition of surface materials, geologic context, potential for geologic activity, proximity of near surface water, and potential for active upwelling of ocean material

Science Traceability Matrix

8 Pre-Decisional — For Planning and Discussion Purposes Only

3/4/14

Goal Objective Investigation

Exp

lore

Eu

rop

a to

in

ves

tig

ate

its

hab

itab

ilit

y

Ice

Shel

l an

d O

cean

Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange.

IO.1 Characterize the distribution of any shallow subsurface water and the

structure of the icy shell.

IO.2 Determine Europa's magnetic induction response to estimate ocean salinity

and thickness.

IO.3 Search for an ice-ocean interface.

IO.4 Correlate surface features and subsurface structure to investigate processes

governing material exchange among the ocean, ice shell, surface, and

atmosphere.

IO.5 Determine the amplitude and phase of gravitational tides.

IO.6 Characterize regional and global heat flow variations.

Co

mp

osi

tio

n

Understand the habitability of Europa's ocean through composition and chemistry.

C.1 Characterize the composition and chemistry of the Europa ocean as expressed

on the surface and in the atmosphere including potential plumes.

C.2 Determine the role of Jupiter's radiation environment in processing materials

on Europa.

C.3 Characterize the chemical and compositional pathways in Europa's ocean.

Geo

log

y

Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities.

G.1 Determine sites of most recent geological activity, including potential

plumes, and characterize localities of high science interest.

G.2 Determine the formation and three-dimensional characteristics of magmatic,

tectonic, and impact landforms.

• Objectives are prioritized, and Investigations are prioritized within

each Objective

• Bold: Recent SDT edits to ensure plumes are explicit

Pre-Decisional — For Planning and Discussion Purposes Only

Reconnaissance Traceability Matrix

Pre-Decisional — For Planning and Discussion Purposes Only 3/4/14

Goal Objective Investigation

Char

acte

rize

Saf

e an

d S

cien

tifi

call

y C

om

pel

ling

Sit

es f

or

a F

utu

re L

ander

Mis

sion t

o E

uro

pa

Lan

din

g S

afet

y

Assess the distribution of surface hazards, the load-bearing capacity of the surface, the structure of the subsurface, and the regolith thickness.

SL.1 Determine the distribution of blocks and other roughness elements

within a potential landing site at scales that represent a hazard to

landing.

SL.2 Determine the distribution of slopes within a potential landing site over

baselines relevant to a lander.

SL.3 Characterize the regolith cohesiveness and slope stability within

a potential landing site.

SL.4 Determine the regolith thickness and whether subsurface layering is

present within a potential landing site.

Sci

enti

fic

Val

ue

Assess the composition of surface materials, the geologic context of the surface, the potential for geologic activity, the proximity of near surface water, and the potential for active upwelling of ocean material.

SV.1 Characterize the composition and chemistry of potential landing sites

with an emphasis on understanding the spatial distribution and

degradation state of endogenically derived compounds.

SV.2 Characterize the potential for recent exposure of subsurface ice

or ocean material vs. degradation of the surface by weathering and

erosion processes and provide geologic context for potential landing

sites.

SV.3 Characterize the potential for shallow crustal liquid water beneath or

near potential landing sites.

SV.4 Characterize anomalous temperatures (that are significantly out of

equilibrium with expected nominal diurnal cycles) indicative of current

or recent upwelling or outgassing at or near potential landing sites.

9

• Prioritization is at the measurement level

• Bold: Recent edits to make plumes explicit

Model Payload

10

Magnetometer &

Langmuir Probes sensing ocean salts

Gravity Science confirming an ocean

Topo Imager alien landscape in 3D

IR Spectrometer chemical fingerprints

Ice-Penetrating

Radar plumbing the ice shell

Neutral Mass

Spectrometer sniffing the atmosphere

Ice & Ocean

Composition

Geology


Reconnaissance

Imager preparing for future landing

Thermal

Imager preparing for future landing

Reconnaissance

Notional Europa Flyby


Comprehensive Surface Coverage Globally Distributed Regional Coverage by Model Instruments

12

Infrared Spectrometer

Ice Penetrating Radar

Topo Imager (alt. ≤4000 km)

Ground Tracks

Pre-Decisional — For Planning and Discussion Purposes Only. 3/4/14

Reconnaissance at High Resolution Topo Imager, Recon Camera, SWIRS (E6 Flyby)

Recon Camera stereo pairs SWIRS

hi-res

“bowties”

Topo Imager

Coverage

Pre-Decisional — For Planning and Discussion Purposes Only 13 3/4/14

Thrace

Thera

Current Europa Clipper Spacecraft

Configuration

14

Langmuir Probe

Magnetometers

Ice Penetrating Radar antenna

(17.5 m)

Pressurant

Tanks MMRTG (baseline)

Sun Sensors 3m High Gain Antenna

Surface Mapping Instruments • Thermal Imager

• Shortwave IR Spectrometer

• Topographic Imager

• Recon Camera

Neutral Gas Mass Spectrometer

Vault

Reaction Wheel

Thruster Cluster Magnetometer Boom

(10.0 m) Launch Vehicle Separation Interface

Thermal

Control

Radiator

Heat

exchangers

.

1.16m

5.85m


“The United States shall develop and use space nuclear power systems

where such systems safely enable or significantly enhance space

exploration or operational capabilities.”

National Space Policy of The United States of America

June 28, 2010

Solar Option

Pre-Decisional — For Planning and Discussion Purposes Only 3/4/14 15

• Planetary protection (PP) requires the avoidance of “harmful contamination” of

the target body, during the “period of biological exploration”.

• Since the early 1960s, consensus international policy (COSPAR) has provided

constraints for the probability of contamination at the 1x10-4 per mission level.

Planetary Protection

16

• Based on available knowledge of Mars, the Viking landers were system sterilized to adhere to NASA’s policy, adopted from COSPAR.

• Knowledge gained by Viking then allowed relaxation of the PP requirements to the present MSL-era “spore” based approach.

Viking

Terminal

Sterilization

• Based on available knowledge of Europa, Clipper needs to be sterilized to

TBD level to achieve the same 1x10-4 probability of contamination.

• Specifically, anticipated as a Planetary Protection Category III mission, Clipper would have

the principal planetary protection requirement of demonstrating a <1x10-4 probability of

contaminating a sub-surface Europan ocean.

For Planetary Protection, Europa is today where Viking was in the 1970’s


Present Coverage in Plumes Region 13F7-A21 Trajectory


Plume High Phase Opportunities 150° ≤ f ≤ 180°


Sun Direction 315° – 45°

45° – 135°

135° – 225°

225° – 315°

Europa True Anomaly

• Many Clipper orbits afford

excellent geometry for

observations of putative

plumes

• This permits an effective

fly-through and sampling

campaign to be designed

once Clipper is at Jupiter

Achieving Decadal Science

“The first step in understanding the potential of the outer solar

system as an abode for life is a Europa mission with the goal of

• Confirming the presence of an interior ocean,

• Characterizing the satellite’s ice shell, and

• Enabling understanding of its geologic history”

Composition Geology Ice Shell Ocean

– The Planetary Decadal Survey, 2011

19 Pre-Decisional — For Planning and Discussion Purposes Only 3/4/14

“We continue to support the Europa Clipper mission as a scientifically

compelling, technologically feasible and fiscally responsible approach to

exploration of Europa. The Europa Clipper mission meets the requirements of

the 2013-2022 Decadal Survey: it will accomplish flagship-worthy science by

investigating Europa and its subsurface ocean, a potential habitable zone.”

– Outer Planets Assessment Group (OPAG), 2013

Achieving Decadal Science

“Flagship-class missions historically

have a greatly enhanced science

return compared to smaller

missions—the whole is greater

than the sum of the parts—so the

higher cost of a flagship mission

compared to a New Frontiers-class

mission is well justified. Europa

remains the highest priority for

satellite exploration, and a Europa

mission deserves sufficient

resources to realize its

phenomenal scientific potential.

Therefore, a Europa mission should

take precedence over smaller

missions to outer solar system

targets during the next decade.” The Planetary Decadal Survey


Backup

3/4/14 21

Radiation Modeling: GIRE2

22

1.40E+05

3.32E+05

3.64E+05

5.64E+05

9.71E+05

1.07E+06

1.35E+06

1.48E+06

1.63E+06

1.70E+06

2.08E+06

2.00E+05

4.60E+05

5.05E+05

7.71E+05

1.31E+06

1.44E+06

1.84E+06

2.01E+06

2.22E+06

2.31E+06

2.82E+06

1.50E+05

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

11/9/

27

2/17/28

5/27/28

9/4/2

8

12/13/2

8

3/23/29

7/1/2

9

10/9/

29

1/17/30

4/27/30

8/5/30

11/13

/30

2/21/31

6/1/3

1

9/9/3

1

12/18/3

1

3/27/32

TOTA

LDOSE

13-F7GIRE(100milAl,SphericalShell)

13-F7GIRE2(100milAl,SphericalShell)

13-F7GIRE2(BehindVault)

Switch-flip

COT-1 N

on-R

esonant

Tra

nsfe

r

Petal Rotation

COT-2

COT-4 COT-3

Pum

p D

ow

n,

Cra

nk U

p

Pum

p U

p,

Avoid

Sola

r C

onju

nction

Non-R

esonant

Tra

nsfe

r

Transfer to Europa Science


Previous modeling used

GIRE1. GIRE2 model

extends out past L=16 to

L=25 and addresses several

concerns with the original

Divine/GIRE model.

3/4/14

11F5-A21 / 13F7-A21 Comparison Quick Look

Pedal Plot Comparison

SWIRS Coverage Comparison

Radiation Dose Comparison

8.92E+04

4.87E+05

6.61E+05

1.34E+06

1.86E+06

2.06E+06

7.23E+04

3.04E+05

5.03E+05

9.20E+05

1.30E+06

1.44E+06

1.66E+06

2.08E+06

0.00E+00

2.50E+05

5.00E+05

7.50E+05

1.00E+06

1.25E+06

1.50E+06

1.75E+06

2.00E+06

2.25E+06

1

17

33

49

65

81

97

113

129

145

161

177

193

209

225

241

257

273

289

305

321

337

353

369

385

401

417

433

449

465

481

497

513

529

545

561

577

593

609

625

641

657

673

689

705

721

737

753

769

785

801

817

833

849

865

881

897

913

929

945

961

977

993

1009

1025

1041

1057

1073

1089

1105

1121

1137

1153

1169

1185

1201

1217

1233

1249

1265

1281

TID(rads)

Time-of-FlightFrom(1dayincrements)

11F5 13F7

Gravity Science

Performance

Pre-Decis ional — For Planning and Discussion Purposes Only 3/4/14 23

11F5 13F7 11F5 13F7

11F5

13F7

Gravity Science Concept

• Gravity Science measurement

made concurrently with other flyby

observations

• Two-way, coherent, carrier only

radio link to Earth through medium

gain fan beam antennas

• Nadir spacecraft pointing requires

sequenced switching through

several antennas to maintain lock

with Earth

• Doppler measurement made by

Earth-based DSN Radio Science

Receiver

24

Forward

Fanbeam -Y

Fanbeam

-Z

Fanbeam

3/4/14 Pre-Decisional — For Planning and Discussion Purposes Only

Gravity Science Performance Model Simulation of k2 Uncertainty Through the Mission

• 2-fanbeam configuration; No ESA tracking

• Baseline: 3-element fanbeam; No ESA tracking

• 2-fanbeam configuration plus ESA tracking for

(E18, E22) provides ~ 20% margin

• Best 3-fanbeam configuration plus ESA

tracking for (E18, E22) provides ~ 36% margin

Baseline


Requirement: k2 uncertainty < 0.05

New Orbital Tour Design Baseline 13F7-A21

• Last OPAG meeting, introduced a new tour design under

consideration that improved flyby coverage and lighting

– Utilizes a more TID effective strategy (at the cost of time-of-flight) to

reach the Europa sub-Jovian hemisphere science phase

– Enables more Europa flybys, 45 (over 3.5 yr) vs. 32 (over 2.5 yr), for

approximately the same TID

• 37 flybys of 100 km or less

• Nine Callisto and four Ganymede flybys used for Europa positioning

– Tour developed for November 2021 Atlas launch

• In principle, similar tour can be created for any opportunity

– Team working updated tour, which decreases solar eclipse durations

• 13F7-A21 is now the current Pre-Project baseline tour

– Project Science is continuing to evaluate the tour

– Started to consider implications of the Europa plume discovery


Solar Power Feasibility Review August 2, 2013

• Review covered all mission aspects (not just the solar array)

– Chaired by the NASA power system Technical Fellow

– External panel with expertise across all spacecraft system disciplines

• Review board major findings:

– Solar power is feasible for the mission however there are risks to retire, all within

manageable engineering

– No new technology needed

– Numerous mission risks identified and considered (by the Project team)

• Primary risk is cold temperature combined with radiation

– The project risk management and mitigation plan is valid and realizable

• Actions since review:

– Board Chair briefed the NASA Planetary Science Division

– Continue to baseline MMRTG

– Initiated a risk reduction task of combined radiation and cold temperature testing

• Expect final results late next year

– Removed ASRG from option space

• Revisit MMRTG vs solar power trade next year


Major Risk Reduction Tasks

3/4/14 28

• Approximately 25% of project funding is being directed to risk

reduction activities

• Radiation

– CFC-11 testing

– Materials testing

– Attitude determination

sensor evaluation

– Pressure transducer

development

– EEE parts testing

– Radiation and plasma

model update

• Planetary Protection

– Vapor phase hydrogen peroxide

sterilization evaluation

– dry heat microbial reduction

implementation approaches

• Solar Feasibility

– Solar array cold

survivability testing

– Solar array radiation testing and

electrostatic discharge evaluation

• Mission

– High energy density battery cell characterization

– Time trigger Ethernet characterization

– Autonomous navigation


MMRTG vs. Solar Power Vehicle Comparison

MMRTG Solar Power Solar Power

Compatibility

Dual-Mode

Propulsion

Bi-propulsion Lower freezing

temperature of bi-

propellant reduces

Solar array and

battery mass

Magnetometer

separate

boom

Magnetometer

on end of

solar array

Location on array

reduces spacecraft

mass

Langmuir

probe on

MMRTG heat

shield

Langmuir

probe at end

of solar arrays

Location required to

provide Langmuir

probe visibility

45% mass

margin

40% mass

margin

Solar array and

battery heavier than

MMRTGs


Tracking Changes Between Two Power

Sources

“Orbit-in-the-Life” of Europa Clipper


Example shown for a 14-day

transfer, which is the shortest

duration transfer between

subsequent Europa flybys for

the current tour (13F7).

Representative Europa Flyby

31

• Repetitive, Simple Science

Operations Plan

• Instrument performance

parameters

• Instrument on / off times

• Compression ratios

• Designed for simultaneous

instrument operations

• Instrument deck remains

nadir fixed below 28,000 km

• Collected data returned

during next 30 days

• Prioritized

• Often much sooner

• Another flyby may occur

before full data return

3/4/14 Pre-Decisional — For Planning and Discussion Purposes Only

Mission Plan

Launch 21 Nov 2021

Jupiter Arrival 4 Apr 2028

Science Tour 45 Europa Flybys

Primary Mission End Oct 2031

Science

Objective Description

Ice Shell &

Ocean Characterize the ice shell, subsurface water & surface-ice-ocean interface.

Composition Understand the habitability of Europa's ocean through composition and

chemistry.

Geology Understand the formation of surface features, including sites of recent or

current activity, and characterize high science interest localities.

Recon Characterize Safe and Scientifically Compelling Sites for a Lander Mission

to Europa

Model Payload

Acronym Instrument

Flo

or

IPR Ice Penetrating Radar

SWIRS Shortwave Infrared

Spectrometer

TI Topographical Imager

NMS Neutral Mass

Spectrometer

Site

Se

lection

Recon Reconnaissance

Camera

Thermal Thermal Imager

Ba

se

line

LP Langmuir Probe

GS Gravity Science

Europa Clipper Concept Overview


Notional Instrument Locations

Configuration meets

all Field-of-view

requirements for

notional instruments


Neutral Mass

Spectrometer (NMS)

Langmuir Probes (x2)

Gravity Science

Fanbeam Antennae (x2)

Ice Penetrating Radar

Antennae

Magnetometers (x2)

Shortwave Infrared Spectrometer

Reconnaissance Camera

Thermal Imager

Topographic Camera

33 3/4/14

Notional Payload Accommodations

• Multiple standard interface types: TTE,

SpaceWire, ICC/ITC, UART, 1553

– Rate buffering required if payload data

rate is above these standards

• Bulk data storage provided: 128 Gb

• Compression trade study in progress

• Telemetry formatting provided by spacecraft

• Synchronizing and time stamping provided

by spacecraft

• Remote electronics hosted in radiation vault

(≤150 krad) on thermal loop

• For nadir mounted instruments: thermal loop

available to source/sink heat

Accommodations being defined for

possible AO supporting documents

Interface Name PHY Type Data Rate

(max.) Data Rate (25% max. allocation)

1553 Shared common physical interface

800 Kbps 200 Kbps

ICC/ITC P2P/LVDS 8 Mbps 2 Mbps

UART P2P/422/LVDS

1 Mbps 250 Kbps

TTE P2P/802.3 1 Gbps 250 Mbps

SpaceWire P2P/LVDS 400 Mbps 100 Mbps

Radiation Vault for

remote instrument

electronics

Instrument Deck on

Nadir pointing side Pre-Decisional — For Planning and Discussion Purposes Only

34 3/4/14

SLS Assessment Status

35 3/4/14

Atlas V 551

2021 VEEGA Trajectory

(6.37 year flight time)

SLS

2022 Direct-to-Jupiter Trajectory

(2.73 year flight time)

* Launch dates shown are the optimal launch dates, not the open of a launch period

Launch (14-Jun-2022)

JOI (4-Mar-2025)

Jupiter

Orbit

Launch

(21-Nov-2021) EGA-2

(24-Oct-2025)

EGA-1

(24-Oct-2023)

JOI

(4-Apr-2028)

VGA

(14-May-2022)

Baseline Trajectory

Jupiter

Orbit

• SLS would enable a shorter time of flight,

eliminates two Earth flybys and thermal

considerations for a Venus gravity assist

• Current earliest launch opportunity is

with SLS Block-1 vehicle in June of 2022

– Time of flight to Jupiter is 2.7 years

– Mass capability 4,800 kg

• Same as Atlas launch in November

2021 with Venus-Earth-Earth gravity

assist trajectory (which has 6.5 yr

time of flight)

• Tour after Jupiter orbit insertion is the

same for both vehicles

• The project will maintain dual launch

capability through CDR

Team continues to work with Marshall to assess this

option


Documents

Europa Clipper March 2014