1. The MAss Spectrometer for Planetary EXploration (MASPEX)
Tim Brockwell, Hunter Waite and Mark Libardoni
Department of Space Science and Engineering
Southwest Research Institute, San Antonio, TX
10th International Planetary Probe Workshop
San Jose, CA - June 2013

2. Roadmap Introduction to MASPEX
Operational and Performance Characteristics
Mating MASPEX with GC×GC
Proposed Flight Missions
Questions and Discussions

3. MASPEX Overview Areas of enhanced performance include:
MASPEX is a next generation spectrometer with significantly improved performance over existing instruments
Areas of enhanced performance include:
Extended mass range (>1000 amu) for heavy organic molecules
Enhanced mass resolution (>30,000 M/dM) for critical isotopes
Enhanced dynamic range (109 in a 1s period) for high S/N
Improved sensitivity (better than 1ppt with cryo) for rare noble gases
High throughput (>5000 samples/s) for rapid descent probes

4. MASPEX Built on MB-TOF Backbone
Analyzer development has mainly concentrated on:
Improved mechanical tolerance of the ion optics.
Titanium and ceramic construction of mirror elements and strong back.
Mass relieving of the major portions of the ion optics.
Vibration testing of the analyzer with mass models of the ion source
and detector.
Generation-1
Generation-2 with orthogonal ion source
Generation-3

5. Development of Multi-Bounce Time of Flight (MBTOF)
Numerical simulations of ion trajectories showing focusing of multi-bounce ion packets.
R(N) = NTo/2(Dt+NdT)
40cm & < 8kg
Third generation MBTOF has successfully undergone vacuum and vibration tests.

6. MBTOF ION OPTICS Detector Drift tube Ion Source Reflectron-2
Ion Bunchers
used to modify the focal lengths
of the mirrors for stable ion motion
Reflectron-1

7. Bulk Resistive Ceramic Mirrors
Conventional
Lab Reflectron
Test fit. Ceramics when fired turn black

8. Dual Pickoff Detector Development
Fast < 2 ns FwHM response time
Low timing jitter
Can be baked to 300 degree C
High dynamic range >10^5
Fast recovery time ( no current “sag”) after large multiple ion events.
Rugged
Tested in a radiation environment
Magnet B
Original Concept
Two-stage dual pickoff detector

9. MBTOF Performance
Simulations demonstrate resolution using line shapes obtained in the lab. Performance allows MBTOF to separate isotopologues of CH4 and H2 in order to determine hydrogen and helium abundances.
Survey Resolution
m/∆m = 1800
m/∆m = 513
3He HD H3
Low Resolution
signal (counts)
High Resolution
m/∆m = 10,200
m/∆m = 5968
13CH4
CH3D
13CH2D

10. MBTOF Performance (Survey Mode)
Window
number
Low mass
High mass 1
2.0
2.8 2
4.0 3
5.7 4
8.0 5
11.4 6
16.1 7
22.8 8
32.3 9
45.8 10
64.8 11
91.7 12
129.9 13
183.9 14
260.4 15
368.7 16
522.1 17
739.3
Survey Mode Tiles
(6000 resolution)
Lab data

11. Separation of CO from N2 M/DM = 13,500
MBTOF Performance (High-Resolution Mode)
M/DM = 3000
Separation of CO from N2 M/DM = 13,500

12. Performance Overview Resolution Sensitivity Spatial Resolution
D/H ratio in water is important for formation conditions of the Galilean satellites (H217O and HD16O : 12,283)
Sensitivity
Noble gases and trace organic species provide information about the formation and habitability. Using a cryo-trap in addition to a storage source enables ppb level organic materials to be measured
Spatial Resolution
The requirement to observe spatial features as small as 400km of orbital track need high scan rates to collect the data. MASPEX can operate at 5kHz across full mass range

13. Stand Alone Missions for MASPEX
The versatility of the instrument allows application adaptability for multiple missions:
Europa Jupiter System Mission (EJSM)
Jupiter Icy Moons Explorer Missions (JUICE)

14. MACE – Mars Lander Proposal
GC×GC
TOFMS
Pyrolysis

15. Comprehensive Two-Dimensional Gas Chromatography (GC×GC)
1st Dimension Column-Long (non-polar)
2nd Dimension Column - Short (polar)
Connected via a Modulator
Benefits
Large available peak capacity
Increased detectibility
Structured chromatograms
1D Text
2D Plot
3D View

16. Commercial Modulator Performance

17. GC×GC Hardware Development
The Modulator is the heart of a GC×GC
Requires LN2 or other media
Requires large amount of Carrier Gas (valve based)
Goal is to build a modulator that requires no cryogenic media, requires no external compressed gas and can effectively modulate from nC1 – nC100

19. Resistive Heating Modulator
Cooling Lines
O-ring
Modulator Housing
Insulating Sleeve
Modulator Support
Retaining Cap
Thermal Modulator
Libardoni, et al

20. 2-Stage Resistive Heating
Two-Stage modulator evaluation
Qualitative and quantitative studies
Two-Stage will eliminate sweep through
Libardoni, et al

21. 2-Stage Resistive Heating
C6 – C20 Alkane mixture 5 10 15 20 25 30 35
W1/2 – 32 ms
Time (s)
Time (min)
Libardoni, et al

22. 2-Stage Resistive Heating
Two-Stage Modulator Design
Cross Section of Modulator
Thermodynamic Modeling
Isometric View of Thermal Modulator
SMARTMod Modulator Assembly
Power Supply and Electronics

23. GC×GC-MBTOF

24. GC-MS Performance

25. GC×GC-TOF of Murchison

26. GC×GC-TOF of Oreugil

27. GC×GC-TOF of Tholin sample
Time (sec)
pyrrole
methyl pyrrole
dimethyl pyrrole
trimethyl pyrrole
tetramethyl pyrrole
Time (sec)

28. Multi-bed Trap GC×GC-MS

29. Laser Thermal Desorption

30. MASPEX Summary
Together these advanced capabilities will provide future missions with enhanced science return not previously available
Some examples:
PRIME: Exceptional resolution and sensitivity will allow unique determinations of noble gas isotopic ratios and ratios of stable isotopes in major volatiles, which are key to understanding solar system formation.
Saturn Probe: High sample throughput provides precise measurements of noble gases and key volatiles during rapid descent. Again, these are critical for understanding solar system evolution.
Mars 2020 Rover: Mating of MASPEX with GC×GC will deliver unparallel results for the determination of organics
Return to Titan and Enceladus : Identity of large organic molecules and chiral characteristics used to identify biological activity and enable the search for life.

31. Acknowledgements
Southwest Research Internal Research Funding (Grant #R8223)
NSF, NASA, JPL – Director’s Funding
University of Michigan
Department of Atmospheric Oceanic and Space Science
Department of Chemistry
Tim Brockwell
Hunter Waite
Mark Libardoni
Greg Miller
Keith Pickens
Dave Young
Ryan Blase