Mars Ion and Sputtering Escape Network 

(MISEN)

Rob Lillis1, Jeff Parker2, Shannon Curry1, Jordi Puig-Suari3, 

Christopher Russell4, Janet Luhmann1, David Brain5

1UC Berkeley Space Sciences Laboratory

2Advanced Space LLC

3Tyvak LLC

4UCLA Dept of Earth and Space Sciences

5University of Colorado, Boulder

Lunar and Planetary Science Conference,

March 18, 2017
Outline

• The Science Gap: why planetary aeronomy needs 

multi-point measurements.

• The MISEN Mission Concept for PSDS3

– Science Objectives

– Science Payload

– Mission Design/Architecture

– Mission ops & spacecraft

– Mission Team

NOTE: two other similar competing missions 

for SIMPLEX-II: some details omitted 
Plasma & magnetic field measurements in 

planetary environments: why do we care?

• Understand the structure, composition, variability and 

dynamics of planetary magnetospheres (e.g. MAVEN).
Plasma & magnetic field measurements in 

planetary environments: why do we care?

• Understand the structure, composition, variability and 

dynamics of planetary magnetospheres (e.g. MAVEN).

• Atmospheric Escape Processes: ion and sputtering escape are 

important for climate evolution of terrestrial planets

1 2

3

escape

Pickup Ion

Escape
1 2

Sputtering

Escape

3

Plasma & magnetic field measurements in 

planetary environments: why do we care?

• Understand the structure, composition, variability and 

dynamics of planetary magnetospheres (e.g. MAVEN).

• Atmospheric Escape Processes: ion and sputtering escape are 

important for climate evolution of terrestrial planets
A single measurement platform leaves 

major questions unanswered

a) spatial and temporal variations in escape fluxes cannot be distinguished 

b) responses of escape fluxes to changing solar wind conditions (~1 minute) 

can only be measured with a time-lag of an hour or (much) more 

c) global escape rate variability in response to space weather “storms” 

(much more common and intense in the early solar system) must be 

estimated (poorly) from a single orbit track. 

MAVEN’s precessing orbit
A Multi-spacecraft Revolution

Cluster II THEMIS

Van Allen Probes

Magnetospheric 

Multi-Scale (MMS)

• The same problem faced terrestrial space 

plasma physics in the 1980s, early 1990s.

• Single spacecraft couldn’t characterize plasma 

boundary dynamics.

• Multiple spacecraft allow the 3D, time-resolved 

measurements to create a realistic picture of 

the magnetosphere and how solar wind 

conditions affect it. 

• Similarly, multiple spacecraft are the next step 

in understanding the solar wind interaction with 

unmagnetized bodies like Mars.
• Science Objective: Characterize the magnitude, structure and 

variability and real-time response to changing solar wind 

conditions, of ion escape and precipitation at Mars.

MISEN Objective and Concept

• In-situ measurements of ions, 

electrons and magnetic field.

• Three smallsats: 

– elliptical orbits (~250 x 7000 km)

– Spaced in argument of periapsis, 

RAAN, and phased to ensure:

• upstream solar wind measurements 

>90% of the time.

• Simultaneous measurements of the 

different plasma regimes 

surrounding Mars.
Science Payload

M-MAG (MISEN Magnetometer)

• Developed by UCLA (C. Russell)

• Clone of Insight Mars 

magnetometer

• Two mounted on boom (90 cm) i.e. 

gradiometer configuration

• 0.3U, 144 g, 0.8 W per sensor

• ±8000 nT range

• 48 bits per readout up to 64 Hz

MESA (MISEN electrostatic analyzer)

• UCB/SSL heritage design, ion & 

electron analyzer

• 1.8 kg, 1.7 W.

• 4p FOV via spinning platform

• 22.5° x 6°, 3 eV-25 keV range

• DE/E = 18%

• Light-vs-heavy mass differentiation 

achieved through pulse height 

analysis.
Mission Design 1: Cruise

• Separate from primary on lunar or Earth-escape trajectory.

• Point Mission Design is for Psyche ride-share (launch 

08/2022).

• 15 month electric propulsion cruise to Mars rendezvous.

• Near-constant thrusting, no spinning.

• Regular DSN contacts.
Mission Design 2: Spiral Down to Science

• Match Mars’ orbit and cross its sphere of influence.

• Each spacecraft guided to its own orbital plane.

• Switch to Mars-centered Conops/Nav

s 

o 

Target: 

250 x 7000 km

• 11 months of spiraling

• End in science orbits

• Full instrument commissioning

~100,000 km

Each spacecraft 

approaches Mars in it

own plane, spiraling t

its own target orbit.
Mission Design 3: Science Orbits

• Elliptical orbits:

– High enough to ensure outward particles are escaping.

– Low enough to ensure inward particles are precipitating.
Mission Design 3: Science Orbits

• Elliptical orbits:

– High enough to ensure outward particles are escaping.

– Low enough to ensure inward particles are precipitating.

– RAANs, AoPs chosen so sufficient coverage of Mars’ different plasma 

regions is maintained as orbits precess over a 1-year primary mission. 

Orbits are stable, though will need ~monthly phasing maneuvers
Spin axis

Spacecraft Ops and architecture

Ops:

• Three axis stabilized until science orbit.

• Spinning at 16s period after that

• Ops are simple: data collection is ‘dumb’ and 

continues indefinitely 

• ~Weekly downlinks

Spacecraft:

• SC volume depends on launch point.

• Gimballed solar panels

• IRIS radio X or Ka-band

• MarCO style antenna
MISEN Study Team

UC Berkeley Space Sciences Lab

• PI: Rob Lillis

• Project Scientist: Shannon Curry

• Systems Engineering & 

Management: Dave Curtis

• Ion & electron analyzer: Davin 

Larson, Roberto Livi, Phyllis 

Whittlesley

• Science advisory: Janet Luhmann

UCLA Earth and Space Sciences

• Magnetometer: Chris Russell

• MHD modeling: Yingjuan Ma

Advanced Space LLC

• Mission Design & Navigation: 

Jeff Parker & Nathan Parrish

Tyvak LLC

• Spacecraft bus & subsystems: 

Jordi Suig-Puari, Angelo Lopez

University of Colorado Boulder

• Science advisory: David Brain
Summary

MISEN will: 

• Provide simultaneous multi-point measurements of 

the Martian plasma environment.

• Elucidate the real-time response of the this 

environment to solar wind changes & disturbances 

(CMEs, SEPs etc)

• Reveal for the first time the global structure of ion 

and sputtering escape and how and why it varies.

• Build on MAVEN’s legacy for a fraction of the cost.

THANK YOU to the PSDS3 Program! 
BACKUP SLIDES
Feasibility Study flowchart
A single measurement platform leaves 

major questions unanswered

a) spatial and temporal variations in escape fluxes cannot be distinguished 

b) responses of escape fluxes to changing solar wind conditions (~1 minute) 

can only be measured with a time-lag of an hour or (much) more 

c) global escape rate variability in response to space weather “storms” 

(much more common and intense in the early solar system) must be 

estimated (poorly) from a single orbit track. 

Credit: M. Marquette