Status of Europa Mission Descope Studies

Curt Niebur and Joan Salute NASA Headquarters

PSS Meeting December 21, 2011

Background

• In March 2011 the Planetary Decadal Survey recommended JEO (Jupiter Europa Orbiter) as the “second highest priority Flagship mission” relative to MAX-C, based on “pragmatic reasons associated with the spending profiles.”

– JEO’s “cost as currently designed is so high that both a decrease in mission scope and an increase in NASA’s planetary budget are necessary to make it affordable.”

• The mission opportunity (cost, schedule, LV, etc.) for Europa is not defined.

• NASA is evolving the Europa mission concept as a consequence of the Decadal Survey recommendations and the current environment to craft credible, flexible concepts that are responsive to an array of budgetary and programmatic outcomes

– DS recommended that “NASA should immediately undertake an effort to find major cost reductions for JEO, with the goal of minimizing the size of the budget increase necessary to enable the mission.”

– DS also insisted that study results undergo independent review – NASA must match the concept(s) and technologies under development

to the likely mission opportunity 2

Post-Decadal Study Goal and Guidelines

• Intent of study is to define and validate a set of minimum concepts that demonstrate missions exist at the lower end of the cost spectrum that still provide significant science return

• Key study guidelines include: – The primary science objective is Europa and the EJSM/JEO science

content is expected to be descoped – Concepts represent the minimum science missions that are at or very

near the acceptable science “floor” below which the mission concept is not worth pursuing at the cost estimate

– Cost target of $1.5B (excluding LV); reliability of cost estimate takes precedence over target

– Small, revitalized SDT to define scientific objectives, measurements, and priorities to match the mission concepts

– A review of the cost and technical results of the studies will be conducted by a board independent of the study team and Aerospace Corp.

– Study and independent review reports are due in May 3

Science Goal, Objectives, and Themes Modified and Simplified from JEO

• Goal: Explore Europa to investigate its habitability

• Objectives: Themes: – Ocean: Characterize the extent of the ocean

and its relation to the deeper interior

– Ice Shell: Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange

– 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

Water

Organic Chemistry Energy

Three Ingredients For

Habitability

4

Europa Mission Concepts

• Last spring the SDT deconvolved JEO into a fly-by element and an orbiter element, each of which accomplish standalone compelling science

– Orbiter mission concept: Geophysical measurements to characterize the ocean that can be achieved only from Europa orbit

– Flyby mission concept: Remote measurements to study Europa’s ice shell, composition, and geology that can be accomplished via multiple flybys (~35)

– These concepts were developed over the summer and are quite mature

• Recently NASA requested a third concept, a Europa lander, be investigated under the same guidelines as the orbiter and fly-by missions

– Lander mission concept: in situ measurements on Europa’s composition and seismology to determine its internal structure

• Orbiter and lander concepts were presented to OPAG in October to assess their science content 5

Orbiter description

• 1.5 year non-science jovian tour followed by 30 days in ~100 km near-polar orbit around Europa

• 5 instruments operating simultaneously requiring 20.2 kg (incl. 6.2 kg shielding), 27.3 W, 134 kbps

– Radio science – Laser altimeter – Magnetometer – Langmuir probe – Mapping camera

• 4 ASRGs plus battery • Total ionizing dose of 1.5 Mrad1

• 2.3 km/s delta-V capability • Robust margins on mass (43%) and

power (39%) • Disposal onto Europa surface,

sterilized (DHMR) spacecraft

6

Radio Subsystem

Magnetometer

Laser Altimeter & Mapping Camera on gimbaled platform

Langmuir Probe (x2)

1 Behind 100 mil Al

Flyby description

• 34 Europa flybys over 28 months (25 @ 100 km CA, 5 @ 25 km CA)

• 4 instruments requiring 84.8 kg (incl. 28.7 kg shielding), 112.5 W, 32 Gb/flyby

– Ice Penetrating Radar – Shortwave Infrared Spectrometer – Topographical Imager – Ion & Neutral Mass Spectrometer

• 4 ASRGs plus battery • Total ionizing dose of 2.0 Mrad1

• 1.6 km/s delta-V capability • Robust margins on mass (50%) and

power (39%) • Disposal onto Ganymede surface,

sterilized (DHMR) spacecraft

7

Ice Penetrating Radar

Shortwave Infrared

Spectrometer

Topographical Imager

1 Behind 100 mil Al

Ion & Neutral Mass

Spectrometer

Technical Review

• An independent technical review chaired by Scott Hubbard was held Nov. 15, 2011, for the orbiter and flyby mission concepts. Key conclusions:

– No show stoppers. Creative approach to cost and risk reduction. – Both concepts satisfied existence proof test to meet science

requirements within approximate cost constraints. • Flyby mission likely yields greater science return than orbiter mission

– Two most significant technical risks impact both concepts: • ASRG performance, availability, and 238Pu availability • Instrument detectors experience high radiation loads, investment

needed to ensure sensor performance • Identical technical review will be held for lander in March • Aerospace Corp. to perform independent Cost and

Technical Evaluation on all three mission concepts in mid- 2012

8

Backup Slides

9

Europa Science Definition Team 2011-2012

• Fran Bagenal Univ. Colorado Plasma • Amy Barr Brown Univ. Geophysics • Bruce Bills JPL Geophysics • Diana Blaney JPL Composition • Don Blankenship Univ. Texas Ice shell • Will Brinckerhoff GSFC Astrobiology • Jack Connerney GSFC Magnetometry • Kevin Hand JPL Astrobiology • Tori Hoehler Ames Astrobiology • Bill Kurth Univ. Iowa Plasma • Melissa McGrath MSFC Atmosphere • Mike Mellon SWRI Ice Physics • Jeff Moore Ames Geology • Bob Pappalardo JPL Chair / Study Scientist • Louise Prockter APL Deputy / Geology • Dave Senske JPL Deputy / Geology • Everett Shock ASU Geochemistry • David Smith MIT Geophysics

10

Science Traceability for Orbiter Mission

11

Goal Objective Investigation Model Instruments Theme

W C E

Expl

ore

Euro

pa to

inve

stig

ate

its h

abita

bilit

y

Oce

an

Characterize the extent of the ocean and its relation to the deeper interior.

O.1 Determine the amplitude and phase of gravitational tides.

Radio subsystem, Laser altimeter ✓

O.2 Determine Europa's magnetic induction response.

Magnetometer, Langmuir probe ✓

O.3 Determine the amplitude and phase of topographic tides.

Laser altimeter, Radio subsystem ✓

O.4 Determine Europa's rotation state. Laser altimeter, Mapping camera ✓

O.5 Investigate the deeper interior. Radio subsystem, Laser altimeter, Magnetometer, Langmuir probe

✓ ✓

Geo

logy

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

G.1

Determine the distribution, formation, and three-dimensional characteristics of magmatic, tectonic, and impact landforms.

Mapping camera, Laser altimeter

✓ ✓

Themes: W= Water, C = Chemistry, E = Energy

Science Traceability for Flyby Mission

12

Goal Objective Investigation Model Instr. Theme

W C E

Expl

ore

Euro

pa to

inve

stig

ate

its h

abita

bilit

y

Ice

Shel

l

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

I.1 Characterize the distribution of any shallow sub- surface water and the structure of the icy shell.

Radar sounder, Topo. Imager ✓ ✓

I.2

Search for an ice-ocean interface.

Radar sounder, Topo. Imager ✓ ✓

I.3 Correlate surface features and subsurface struc-ture to investigate processes governing material exchange among the surface, ice shell, and ocean.

Radar sounder, IR spectrometer,

Topo. imager ✓ ✓ ✓

I.4 Characterize regional and global heat flow variations.

Radar sounder ✓ ✓

Com

posi

tion

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.

IR spectrometer, INMS ✓ ✓

C.2 Determine the role of Jupiter's radiation environ-ment in processing materials on Europa.

IR spectrometer, INMS ✓ ✓

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

IR spectrometer, INMS ✓ ✓

Geo

logy

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

G.2 Determine sites of most recent geological activity, and characterize high science interest localities.

Topo. Imager

✓ ✓ Themes: W= Water, C = Chemistry, E = Energy

Mapping Camera Coverage for Orbiter Mission

13

Coverage after one cycle (11 days)

Laser Altimeter Coverage for Orbiter Mission

14

Europa Ground Tracks for Flyby Mission

15

Instrument Coverage for Flyby Mission

16

S/W IR Spec. - Low Res

S/W IR Spec. – High Res

Ice Penetrating Radar

Topographic Imager