. 2016 Oct 1;16(10):755–774. doi: 10.1089/ast.2015.1376

Table 1.

Science Traceability Matrix for a Microscopic Imager

Specific science goal	Observable	Performance requirement	Performance goal	Sample conditions	Volumes required
Detect cell-like objects	Microscopic image	0.8 μm resolution (motile terrestrial prokaryotes); limit of detection 10⁴ cells mL⁻¹ (10× more dilute than seawater) determined by xyz field of view	0.3 μm (nonmotile terrestrial prokaryotes); limit of detection 100 cells mL⁻¹	On slide/suspension in liquid	∼0.25 μL at 10⁴ mL⁻¹ density; ∼25 mL at 100 mL⁻¹ density at minimum performance requirement
Distinguish density of different objects	Measure Brownian motion	Velocity resolution ∼100 μm s⁻¹		Suspension in liquid; known temperature; viscosity measurement (useful not required)	Sufficient to have particles present
Detect structure in objects	Microscopic image	0.8 μm resolution	0.3 μm	Instrument dependent	Instrument dependent
Test for life	Detect motility of cell-like objects	Velocity resolution 2 μ s⁻¹, dynamic range up to ∼500 μ s⁻¹ motion/frame < ∼0.1 frame/frame	Velocity resolution <1 μ s⁻¹, frame rate >10 fps
	Feeding/Culture of cell-like objects	Evaporate 1 mL of sample, heat-sterilize, mix new culture in
	Chemotaxis	Supply inorganic agents
	Phototaxis	3 additional light sources (LED)	Varying wavelength sources
	Magnetotaxis	Electromagnet ∼2× ambient field of planet
	Detect specific cell components	Specific dye labeling with dyes for membrane, nucleic acid, protein OR downstream coupling to mass spectrometry	Additional panel of dyes targeting cell wall components, esterases, etc.	On slide with dyes added	Pre-concentrated sample of at least 1 mL (at 10⁴ mL⁻¹ concentrations) or 100 mL (for 100 mL⁻¹ concentrations)

The overall NASA goal is “Search for/detect life on Ocean Worlds or Mars.”