Projects: LIFE Experiment: Shuttle & Phobos
Frequently Asked Questions
General FAQ
Experiment Size and Design
Planetary Protection
General FAQ:
Why are we trying to fly microorganisms to Phobos and back?
To test whether organisms can survive for years in deep space. We want to fly selected organisms in a simulated meteoroid -- a small canister on board the Russian Phobos-Sample Return mission-- over a three-year mission. LIFE (Living Interplanetary Flight Experiment) will test one aspect of transpermia, the hypothesis that life could survive space travel, if protected inside rocks blasted by impact off one planet to land on another. For example, could they make it from Mars to Earth? Organisms have never been tested to see if they could survive beyond the protection of Earth’s magnetosphere for multi-year periods.
What is the status of this experiment?
The LIFE experiment is inside the sample return capsule on the Phobos Sample Return spacecraft awaiting launch. It is being done in collaboration with the Space Research Institute and the Institute for Biomedical Problems of the Russian Academy of Sciences, Moscow State University, the ATCC (American Type Culture Collection), and the Institute for Aerospace Medicine in Germany. We are also working with the Lavochkin Association who will integrate the experiment in the spacecraft and fly the experiment. The Phobos Grunt mission is a project of the Russian space agency, Roskosmos. We are also on the lookout for other opportunities to fly on other deep-space return missions.
Why the Phobos Sample Return mission?
Until very recently (with the selection of OSIRIS-REx), the Phobos-Sample Return mission has been the only scheduled mission that will return to Earth from deep space, far beyond the protection of Earth’s magnetic field (see next question for more). It offers a rare opportunity for a return trip to interplanetary space for approximately 34 months. We are hoping to fly a similar experiment on other missions.
Couldn’t you just do this on an Earth orbiting spacecraft?
Earth’s magnetosphere, the area of influence of its magnetic field, protects near-Earth spacecraft (and any life that would be flying upon them) from the charged particle component of galactic cosmic radiation (GCR) and solar particle events (SPE). Sending biological samples through deep space is therefore a much better test of interplanetary survivability than sending the samples on a typical Earth-orbiting flight.
Has this type of experiment ever been done before?
Not with the combination of multi-year time periods and exposure beyond the protection of Earth’s magnetosphere. In this regard, European experiments called Biostak 1 aboard Apollo 16 and Biostak 2 on Apollo 17 carried biological samples outside the magnetosphere, but only for periods of many days. Since then, various European, Russian, and American biological survival experiments have flown in low-Earth orbit: Biostak 3, Biobloc, Advanced Biostak, the Long Duration Exposure Facility (LDEF), Biopan, Experiment Exobiologie, the Planetary Society’s Growth of Bacteria on Surfaces in Space (GOBSS), and Shuttle LIFE on STS 134. With the exception of GOBSS, which was recovered damaged after the Columbia STS-107 tragedy, these experiments have demonstrated that microorganisms and certain other classes of terrestrial life (such as plant seeds and fungus) are not destroyed by exposure to the space environment. Only two, however, flew outside of the magnetosphere, Biostak 1 for 11 days and Biostak 2 for 12 days. While other experiments flew for longer times (the LDEF exposed spore of the bacterium Bacillus subtilis to space for six years and some survived), they flew well within the Earth’s magnetosphere, so the radiation exposure was much lower than it would be during a Mars-Earth trajectory of similar duration.
Experiment Size and Design
What is the size of the experiment?
In order to fit within the sample return capsule (note that Phobos LIFE will not be in the actual canister containing Phobos samples for return), the Phobos LIFE biomodule is 56 mm in diameter with a maximum thickness of 18 mm. Mass, which had to be very low, is 88 grams for the entire bio-module. The current design is a short cylinder, looking much like a hockey puck, but smaller.
What are other current design constraints?
The bio-module has 30 small tubes (3 millimeters in diameter) for individual microbe samples. It also accommodates a native sample of bacteria -- derived from a desert region on Earth -- within a cavity 26mm in diameter. The Bio-module must be sealed to meet experimental validation requirements and to provide additional planetary protection. The requirement was that the module must also be able to withstand a single 4000g impact (as could occur in a hard landing on Earth -- the sample return capsule has no parachute) without the seals failing or the outer case fracturing. Also desired were simple means of recording radiation doses and temperature extremes during its flight and return to Earth.
What is the current engineering design of the Bio-module experiment, and what materials do you plan to use?
Our design is compact, rugged and simple. Maximum mass, sample requirements, resistance to seal failure and case breach were strict requirements controlling this design. We are using strong, lightweight materials, structural integration, and multiple sealing techniques. A preliminary design diagram is shown here and much more information on the design, materials, and rationale for those can be found on our current design page.
The LIFE biomodule, exploded view
Credit: The Planetary Society
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What organisms do you plan to fly and why?
We are flying representatives of all three domains of life: bacteria, eukaryota, and archaea. Most have been flown in near-Earth space on short missions. All have been studied extensively, most having their genomes sequenced, for example. Most are “extremophiles”: organisms resistant to one or more environmental factors such as radiation, high salt concentration, heat, etc. None of the microbes will be dangerous to humans. We are flying 10 individual organisms in 30 self-contained samples, i.e., each will be flown in triplicate for better science results. In addition, one native soil sample will be flown in its own self contained capsule. Learn more about all the Phobos LIFE organisms on our organisms page.
If any of the microbes survive, how will you know they are the same microbes you intended to send from Earth, rather than contaminants?
Some of the things under consideration to avoid this include:
- the multiple seals used in the canister
- separate sealed tubes for each biological sample within the canister
- impact and other testing to insure that the container won’t break at any time, including landing on Earth
- choosing unusual strains of each organism that you wouldn’t find as typical lab contaminants (e.g., on people’s hands, in sneezes, or in the labs while the samples are loaded)
- Sterilizing the canister before loading the biological samples
- Sterilizing the surface of the canister before unloading the biological samples
- Following standard sterility lab procedures to avoid contamination.
Planetary Protection:
Are any of the microbes being flown dangerous to humans?
No. None of the microbe strains being selected will be dangerous to humans
Could these microbes mutate in space and return as dangerous microbes?
Dangerous mutation is extremely improbable because we are sending only desiccated, inactive microbes without sources of nutrition and energy, and they will not be reproducing. To create evolutionarily successful mutations, an organism needs to reproduce. The development of evolutionarily successful mutations, good or bad, requires conditions favorable to microbial growth. In order to give the microbes maximum chance of surviving the trip, the LIFE experiment requires that the microbes travel in a desiccated, inactive, non-replicating state, the exact opposite of what’s needed to change a microbe gene pool in any meaningful way.
All our organisms will be non-pathogenic (do not cause disease). To change these benign organisms -- without the forcers of natural evolution and by random chance -- to generate dangerous and viable organisms is incredibly improbable.
Even with the very low probabilities, we will take great care with the samples and follow standard biological protocols to always err on the side of extreme caution. And, as in all aspects of this experiment, we will get external review of our analyses and plans.
Is it likely that this experiment could contaminate Mars with life, thus confusing future searches for life on Mars?
The short answer is that it is extremely unlikely. We emphasize this is a mission to Mars’ moon Phobos, not to the surface of Mars. Phobos LIFe fully complies with the COSPAR (Committee on Space Research of the International Council for Science) planetary protection guidelines aimed at preventing the contamination of Mars by introducing terrestrial life onto the surface of Mars. Orbital analyses indicate the probabilities of any kind of malfunction leading to the spacecraft hitting the Mars atmosphere are extremely small and well within the COSPAR guidelines. In addition, the LIFE biomodule itself is designed and tested to survive high impacts intact and sealed. Also, the organisms in Phobos LIFE are very well characterized, so even in a worst of the worst extremely unlikely case that they not only made it to the surface, ended up outside the biomodule, and somehow survived the harsh, ultraviolet bathed Martian surface environment, their DNA would be recognizable in future studies.
Mars meteoroid facts:
- About 1 Martian meteorite is thought to hit Earth every month.
- About a billion tons of Martian rock have landed on Earth since the solar system formed.
- About 30 Martian meteorites have been identified on Earth.
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