Laser TOF-MS instrumentation for planetary missions - Harsh ...

Laser TOF-MS instrumentation 

for planetary missions 

Will Brinckerhoff, Cari Corrigan, Tim Cornish, Scott Ecelberger, Anita Ganesan 

(JHU/APL); Tim McCoy, Ed Vicenzi (Smithsonian NMNH); Paul Mahaffy (NASA/GSFC) 

W. B. Brinckerhoff (JHU/APL) et al. 

5 th Workshop on Harsh Environment Mass Spectrometry, September 22, 2005

Outline 

1. Some missions and their objectives 

2. General features of miniature LD-TOF-MS 

3. LAMS 

4. DS-TOF 

5. Tower TOF 

6. Sample handling and vacuum stuff 

7. Other LDMS projects 

8. Acknowledgements 



Example Planetary Missions 

• Mars rovers and sample returns 

• Asteroids 

• Comets 

• Jovian satellites, Venus, Titan, 

other moons 



Mars 

Goals: Understand Mars’ history; figure out how similar 

Mars was to Earth and how it diverged; locate water, 

organics, other chemicals, resources; find life (or lack) 

Conditions: Atmosphere ~ 7 Torr CO 2 and cold! 

• Mars Exploration Rovers (MER) - operating 

• Phoenix Mars Scout (2007) 

• Mars Science Laboratory (2009) 

• ExoMars 

• Astrobiology Field Laboratory 

• Mars Sample Return 



Asteroids 

Goals: Relate asteroids to solar and planetary 

compositions to understand solar system formation; 

link meteorite and asteroid classes; search for 

organics, water, metals; determine internal structure 

Conditions: Hard space vacuum; thermal gradients 

• NEAR (Eros) 

• Hayabusa (Itokawa) 

• Dawn (Vesta and Ceres) 

• Future landers / sample returns 



Comets 

Goals: Relate comets to asteroids and KBOs; determine 

if comets supplied water and pre-biotic organics to 

Earth; inventory cometary chemical and organic 

composition; determine internal structure, dynamics 

Conditions: Hard vacuum; thermal gradients; vents (!) 

• Giotto; Vega1, 2; Sakigake; Suisei (Halley) 

• DS-1 (Borelly) 

• Stardust (Wild 2) 

• Deep Impact (Tempel 1) 

• Rosetta (Churyumov-Gerasimenko) 

• Future landers / rendezvous / CSSR / CNSR 



In Situ Astrobiology at Comets 

Murchison 

1 mm 

“Extreme Close-Up” of a comet nucleus? 



High-Mass Organics 

Refractory organics with m >> 100 Da comprising insoluble organic matter (IOM): 

• encode formation processes and timescales (aromatic / aliphatic) 

• associate with key ISM organics (amino acids, nucleobases, sugars) 

• dominate the organic fraction of comet nuclei (as they do in c-chondrites) 

All Carbon 

Inorganic 

Organic 

Elemental Carbonates, etc. SOM (Free) IOM (MM) 

Volatile (Py) 

Refractory (nonPy) 



Outer Planetary Satellites 

Europa 

Titan 

• Ocean? 

• Life? 

• Ice chemistry 

is key goal 

• Surface vs 

subsurface 

• Radiation 

• Fissure 

upwellings 

• Lander w/drill 

• Hard mission! 

• Seas! 

• “Pre-biotic” 

chemistry 

• Atmospheric 

density is high 

• Long-term goal: A 

mobile lander (or 

aerobot/lander) 

equipped with a 

mass spec! 

• Expensive but not 

so difficult to do. 



Miniature LD-TOF-MS 

• Relatively speaking, laser TOF-MS can be miniaturized without 

extensive performance degradation compared to laboratory 

instruments, and instrument complexity is quite low. 

• With carefully designed gridless ion optics, a low-noise detector 

assembly, and a nonlinear “ideal” reflectron, one can achieve 

surprisingly high mass resolution and low detection limits with 

straightforward prompt LDI from unprepared samples. 

The reflectron corrects TOF dispersion: ions with same m/z but different 

energies arrive at the detector simultaneously. A nonlinear reflectron 

focuses LA and LD ions (wide KE band) as well as organic product ions. 



LAMS 

• 1064 nm Qsw pulses < 10 mJ @ 1 Hz or less 

• No sample preparation or contact needed 

• Elemental and isotopic analysis 

• Elemental LODs to ppmw in bulk phase 

• Probe on fine scales (spot size 10-100 µm) 

• Complementary to Pyr-GCMS & other methods 

40 

16 O 

24 Mg 

26 Mg 

28 Si 

Allende 

40 Ca 

30 

25 Mg 

27 Al 

20 

(Mg 2+ ) 

29 Si 

10 

12 C 

30 Si 

23 Na 

32 S 

39 K 

44 Ca 

0 

13 C 

40 Ca 2+ 

42 Ca 

10 20 30 40 

m/z (amu/e) 



BHVO-2 Basalt Standard 

10 2 

10 1 

K/Ca 

Fe 

Ca 

10 3 Powder/Si 

[Si] 

[Fe] 

Ca 

O 

Cation Ratio (Measured) 

10 0 

10 -1 

10 -2 

10 -3 

10 -4 

10 -5 

10 -6 

100x 

Glass 

1x 

Powder 

0.01x 

Pellet 

Co 

Cs...Nd 

Zn 

Cu 

Ni 

Cr 

P 

V 

Rb...Nb 

Mn 

10 -4 10 -3 10 -2 10 -1 10 0 10 1 

Na 

Fe 

Fe 

Mg 

Ti 

Cation Ratio (Given) 

Al 

Ca 

Ca 

O 

O 

Pellet/Si 

Glass/Si 

y = x 

Powder/Fe 

Pellet/Fe 

Glass/Fe 



JSC Mars-1 Simulant 

rRSC Unground 

10 2 O 

Fe 

10 1 

Ca 

10 0 

Na 

Ti 

Mn 

P 

Al 

K/Ca 

Mg 

10 -1 

10 -2 

10 -2 10 -1 10 0 10 1 10 2 

rRSC Fine Ground 



Meteorites 

10 15 20 25 30 35 40 45 50 55 60 65 70 

150 

100 

50 

32 S 

54 Fe 

(a) ALH83100 

58 Fe+ 58 Ni 

60 Ni 

Pentlandite 

(FeNiS) Grain 

0 

150 

(b) ALH83100 

100 

24 Mg 

28 Si 

40 Ca 

56 Fe 

Dark Matrix 

50 

23 Na 

0 

150 

16 O 

(c) Allende 

100 

50 

0 

(Mg 2+ ) 

12 C 

52 Cr 

10 15 20 25 30 35 40 45 50 55 60 65 70 

m/z (amu/e) 





DS-TOF 

• 355 or 337 nm pulses < 10 8 W cm -2 (1 - 20 Hz) 

• Unprepared chips or powders, mounted on 

insertion probe and held at +5 kV 

• Monolithic nonlinear reflectron 

• Double-sided detector system 

• Organic and elemental analysis capabilities 

• Refractory organic LODs in low ppbw range 

• Probe on fine scales (spot size

LD-TOF-MS of Allende Matrix 

12 

10 

8 

6 

4 

4.0 

3.5 

3.0 

2.5 

2.0 

1.5 

Phenanthrene 

m/z 178 

C 14 H 10 

Chrysene 

Benzo(a)pyrene 

Probe 4.76 kV 

Higher Fluence 

Coronene 

m/z 252 

m/z 228 

C 18 H 12 

C 16 H 10 450 500 550 600 650 700 750 800 850 

C 20 H 12 

m/z 300 

C 24 H 12 

2.0 

Pyrene 

1.8 

1.6 

1.4 

m/z 202 

~ 50 µm 

100 µm 

Craters 

Allende NMNH 3529 

Probe 6.37 kV 

Lower Fluence 

100 150 200 250 300 350 400 450 500 550 600 

m/z (Da) 



Allende High Mass Organics 

• High-mass (m/z > 300 Da) signal in Allende consistent 

with previous LDMS and other observations of known 

macromolecular IOM in C-chondrite acid residues 

(Becker et al. 1997, Kissin et al. 2003). 

• Particular pattern may be due to sequence of sodiated 

and potassiated parent compounds. Major adduct 

steps are ∆m/z = 28 Da (dimethyl, C 2 H 4 , CH 2 N, etc.) 

• Possible parent PAH @ 428 Da (octacene or equiv.) 

• Prompt LDI PAH ratios do not match REMPI ratios 

(Plows et al. 2003, Elsila et al., 2004). 

Bold = detected m/z; 

Non-bold = inferred m/z 



Tower TOF 

• Normal incidence desorption at 266, 355, or 

1064 nm with New Wave Tempest 

• Lateral postionization at 235 – 390 nm with 

doubled Opotek Vibrant 

• Unprepared samples mounted on XYZ stage 

using custom bellows assembly with 13 mm 

lateral and 25 mm vertical travel 

• Instrument and samples are vertical 

• Samples are at electrical ground; flight tube 

biased to negative voltage 

• No pre- or post-acceleration grids 

• Sensor about 50% size of DS-TOF 

• Goal: elemental and organic chemical imaging 

at resolutions ~ 50 µm 

• Still under development 



“Flight-Scale” TOF-MS 

ion extraction 

lens 

laser focus 

point 

Focusing 

System 

Vacuum 

Chamber 

detector 

assembly 

ion 

reflectron 

~ 7.5 cm 

Imager 

Light Path 

Ion 

Reflectron 

MCP-R 

MCP-L 

Detector 

Assembly 

Instrument Tray/ 

SMS Interface 

Extraction Lens 

Sample 

Position 

Sensor is ~ 50% size of DS-TOF prototype, and mounts on 450CF flange. Flight 

model bundles laser and microscopic imager in common optical system. 



TOF-on-a-flange, out 



TOF-on-a-flange, in 



Sample Handling and Vacuum Stuff 

High-resolution in situ chemical imaging 

• xyz sample manipulation system developed 

in collaboration with Honeybee Robotics 

• examine location of organics in meteorites 

Other Honeybee Robotics Collaborations 

• MSL Sample Acquisition/Sample Handling 

and Processing (SA/SPaH) system 

• Precision subsampling systems 

Vacuum Issues (Mars) 

• Method 1: (“brute force”) Acquire samples; 

use vacuum seals/valves; pump out. 

• Method 2: (“relax requirements”) Sample 

and/or ionize at ambient pressure; draw into 

dynamically-pumped MS; consider designs 

that tolerate higher operating pressure. 

• Evaluating current generation of Creare mini 

TMD pumps (to be flown in SAM on MSL) 



• A planned ESA Mars rover mission 

• Launch: Plan 2011 (2013?) 

• Strong exobiology orientation 

• Distinguish ExoMars from MSL 

– Exobiology payload 

– 2 m drill 

• Instrument payload nominally 

selected through 2-year process 

• Includes combo LD-GC-EI-ITMS 



Acknowledgements 

Collaborators and Co-workers: G. Managadze, A. 

Cheng, D. Harpold, H. Niemann, S. Gorevan, D. 

Yucht, R. Cotter, D. Glavin, L. Becker, D. Stepp, F. 

Gick, N. Tyris, A. Kritharis 

Funding: NASA PIDDP, ASTID, MIDP, ASTEP, and 

Exobiology programs; JHU/APL internal support 



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