The monitoring of microorganisms will be an important part of a mission to Mars. Microbial monitoring equipment will be needed to look for the presence of microorganisms on the planet, to confirm that planetary protection measures are working, to monitor the health of plants, bioreactors and humans living in a habitat and to monitor the performance of the life support systems that will keep them alive during their stay on Mars. Coordinating the different microbial monitoring needs during the early days of mission planning, can provide NASA with equipment that could meet more than one need while also providing complementary analysis options, which can enhance the research capabilities. The early coordination between the different NASA groups that will need microbial monitoring equipment on the surface of Mars, could also make the mission more affordable, as development of the needed equipment could be potentially cost shared

Birmele, M. N.

Castro, V. A.

Jan, D. L.

Ott, C. M.

Roberts, M. S.

Roman, M. C.

Venkateswaran, K. J.

NASA Technical Reports Server

MICROBIAL MONITORING CHALLENGES AND NEEDS FOR MARS APPLICATIONS.  M. C. Roman1, 
C. M. Ott2, V. A. Castro3,  M. N. Birmele4, M. S. Roberts4, K. J. Venkateswaran5 and D. L. Jan5 
1NASA/Marshall Space Flightg Center (NASA/MSFC, Mailcode ZP31, Huntsville, AL 35812), 2NASA/Johnson 
Space Center (Mail Code SF211, 2101 NASA Parkway, Houston, TX 77058), 3NASA/Johnson Space Center (En-
terprise Advisory Services, Inc. JSC Microbiology Laboratory c/o Wyle 1290 Hercules, Houston, TX 77058), 
4NASA/Kennedy Space Center (ESC Team QNA Mail code: ESC-24 KSC, FL 32899) and 5Jet Propulsion Labora-
tory (JPL 4800 Oak Grove Drive Pasadena, CA 91109-8099). 
 
 
Introduction:  The monitoring of microorganisms 
will be an important part of a mission to Mars.  Micro-
bial monitoring equipment will be needed to look for 
the presence of microorganisms on the planet, to con-
firm that planetary protection measures are working, to 
monitor the health of plants, bioreactors and humans 
living in a habitat and to monitor the performance of 
the life support systems that will keep them alive dur-
ing their stay on Mars.  Coordinating the different mi-
crobial monitoring needs during the early days of mis-
sion planning, can provide NASA with equipment that 
could meet more than one need while also providing 
complementary analysis options, which can enhance 
the research capabilities.  The early coordination be-
tween the different NASA groups that will need mi-
crobial monitoring equipment on the surface of Mars, 
could also make the mission more affordable, as de-
velopment of the needed equipment could be potential-
ly cost shared. 
Challenges and Needs:  Humans have been ex-
ploring space for more than 50 years. For all those 
years, microorganisms have accompanied both manned 
and un-manned spacecraft and cargo. Microorganisms 
that are commonly found on Earth easily adapt to 
space environments or mutate to survive in very harsh 
conditions. Their presence in spacecraft and cargo has 
caused problems in areas like crew health, life support 
systems performance, and degradation of material in 
the cabin. Other sources of the microbial burden in a 
spacecraft include experimental animals, plants, sup-
plies, food, and water.  Humans that had contact with 
the spacecraft before and during the mission are the 
chief contributors (about 95% of recovered organisms) 
to the microbial populations in the cabin.. The sterili-
zation of the spacecraft that will host humans in long 
duration missions would be a difficult and costly oper-
ation that will not provide a long-term solution to the 
microbial colonization of the vessels. As soon as a 
human is exposed to the spacecraft, microorganisms 
will start populating the new environment.   
 
During early NASA missions the microbial popula-
tion of spacecraft, cargo (including water/food) and 
crew was carefully monitored before and after all 
flights using ground analysis. To minimize the risk of 
contaminating Earth with microorganisms from the 
lunar surface, even the crew was quarantined after 
missions. The vehicle was disinfected before the 
launch, but microbial control in the cabin during the 
mission was minimal. When the Space Shuttle pro-
gram started to take humans to space, the inside of the 
vehicle was carefully disinfected before each flight and 
the microbial population of the crew was once again 
investigated before and after the mission. Microbial 
control inside the Space Shuttle was improved, but 
areas like air filtration needed to be improved. Apollo 
and Space Shuttle missions were short duration mis-
sions, compared to the current missions to the Interna-
tional Space Station (ISS). Microbial monitoring of the 
short duration missions was accomplished by returning 
samples to the ground; no in-flight monitoring capabil-
ities were required. As mission duration increases, 
disinfection of the crew cabin is more challenging be-
cause the spacecraft is not returned to the ground, like 
the ISS. The risk from the microbial load to hardware 
and crew also increases. Microbial monitoring aboard 
the ISS is limited to microbial enumerations. For mi-
crobial identification, samples have to be returned to 
the ground for analysis. 
 
To ensure that pathogenic microorganisms are min-
imized to the extent possible in spaceflight, preventive 
measures are taken. For instance in the International 
Space Station, there are HEPA (or equivalent) filters in 
the air regeneration system to remove particulates and 
microorganisms, relative humidity is reduced, and ma-
terials are carefully selected. In addition, in-flight 
monitoring of the air, surfaces, and water are conduct-
ed, as well as routine housekeeping and inspections. 
Due to the potential for health impacts on the crew and 
for degradation of air, water supplies, and equipment, 
it is important to address fundamental issues surround-
ing the sources and risks of pathogenic microorgan-
isms in spacecraft.    
 
Mitigation of the microbial population risk to the 
crew, vehicle and life support systems involves several 
different strategies that will include controlling the 
microbial load (in numbers and diversity) and monitor-
ing. Controlling the microbial population load includes 
https://ntrs.nasa.gov/search.jsp?R=20120015291 2019-08-30T22:14:51+00:00Z
careful disinfection of all surfaces and controlling the 
crew temperature and humidity to prevent condensa-
tion. Active and aggressive control of the microbial 
population is a very important risk mitigation tool for a 
long duration mission. To meet planetary protection 
obligations integrated system technologies to protect 
human life from alien microorganisms (should they 
exist) and to shield engineering systems from bio-
corrosion are required. In addition, assurance of com-
pliance with evolving standards for planetary protec-
tion (both forward and backward contamination) relat-
ing to the human exploration of Mars is essential. Fi-
nally, a sound technical basis is needed to determine 
whether the inadvertent shedding of bio-contaminants 
from human explorers can be minimized to such a de-
gree that the search for life can continue in an unob-
structed, meaningful manner. Then there is the in-
creased need to grow food for long duration human-
associated missions due to limited resupply options. 
Monitoring plants and crops, especially the wet rooting 
environment, for microbes is required to ensure a safe 
and palatable food source. To accomplish that goal, a 
real time integrated system is required to identify and 
characterize human associated pathogens that may be 
introduced into a plant growth system and become a 
potential cause of food-borne illness. Previous micro-
biological analyses of edible crops grown in a variety 
of plant growth chambers have shown that the num-
bers on some crops exceeds the current microbiologi-
cal standards. A tool is needed to evaluate the effec-
tiveness of post-harvest sanitizing methods to reduce 
microbial numbers including potential pathogens and 
monitor critical control points in the cultivation and 
food preparation processes.  
 
Automated microbial monitoring can be used as 
part of a comprehensive risk mitigation strategy in 
long duration missions. It can provide the crew with a 
way of regularly characterizing the microbial popula-
tion inside the cabin. During nominal conditions, a 
baseline database can be acquired and stored.  When/if 
conditions deteriorate, the crew will be able to monitor 
the effectiveness of remediation activities or watch for 
the off-nominal condition to stabilize. Off-the-shelf 
automated microbial monitoring systems that provide 
semi-quantification and identification of the microbial 
population are currently available. This kind of analy-
sis can provide the crew with a way to know what kind 
of microorganisms they are dealing with and help ex-
pedite the remediation process tailored to the species 
responsible for the problem. Although it appears that 
no technology from those currently available repre-
sents a “catch-all solution” to the needs of long term 
spaceflights, several technologies offer significant ad-
vantages over the current practice.  
 
At least some of the technologies available, when 
optimized for the special needs and conditions of 
spacecraft, such as challenges like; sample collection 
and preparation, partial gravity, cross contamination, 
disinfection of the systems between samples, calibra-
tion, expendables, biohazard waste generation, library 
of unknown organisms, can represent robust and cost-
effective means to assess the health of the crew and the 
environment. A key deliverable would be an integrated 
microbial monitoring system, validated in a terrestrial 
Mars analog environment and ready for deployment on 
a human mission. Such a system is essential for mis-
sions to comply with requirements to avoid harmful 
contamination and thereby facilitate human explora-
tion. The proposed integrated microbial monitoring 
system will bolster confidence in, and lend support to, 
planetary protection efforts, hardware reliability, and 
sustained crew health. By forewarning human explor-
ers of any significant fluctuations in microbial burden, 
the system allows the crew to take immediate actions 
to significantly diminish any threat to crew health, or 
deterioration of the habitation module resulting from 
bio-corrosion. In addition, the advancement of enu-
meration and identification capabilities would provide 
the ability to provide a daily assessment of systems 
and increase risk mitigation respectively.  
 
In an effort to reformulate the Mars Exploration 
Program, NASA will need to evaluate microbial moni-
toring challenges and mitigation strategies. The high 
risk potential for microbial contamination and biofilm 
formation is a safety, crew health, planetary protection, 
food source, and hardware hazard with costly conse-
quences. The first line of defense during long duration 
missions would be to develop microbial control meth-
ods and then focus on microbial monitoring as a miti-
gation strategy. Current microbial monitoring practices 
in spacecraft rely on relatively slow, manual, highly 
consumable processes which are then reliant upon 
earth analysis. The utilization of currently available 
hardware with advanced analytical options for space-
flight environmental monitoring will be crucial for 
furthering human exploration to Mars.  
 


Microbial Monitoring Challenges and Needs for Mars Applications

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server