Astrobiology Exposure and Micrometeoroid Capture Experiments (Tanpopo) - 07.11.18

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The Astrobiology Exposure and Micrometeoroid Capture Experiments (Tanpopo) is the first astrobiology experiment performed on the International Space Station (ISS) Kibo Exposed Facility (EF), to test key questions of the “panspermia” hypothesis, a theory for the origin of life and their transport among celestial bodies. In a small pallet called “ExHAM” installed onto the handrail of the Kibo EF, blocks of low density-solid material called “aerogel” are exposed and later retrieved, that captures impacting solid microparticles, such as organic-bearing micrometeoroids and possible terrestrial particles in low Earth orbit, for assessing the possibility of interplanetary transport of life and its precursors. Terrestrial, extremophile microbes, and astronomical organic compounds are also exposed in space for evaluation of their survival and alterations, and are studied in laboratories upon return to Earth.
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Information Pending

The following content was provided by Hideyuki Watanabe, and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA).
Experiment Details


Principal Investigator(s)
Akihiko Yamagishi, Ph.D., Tokyo University of Pharmacy & Life Sciences, Tokyo, Japan

Shin-ichi Yokobori, Ph.D., Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
Hajime Yano, Ph.D., Japan Aerospace Exploration Agency, Sagamihara Kanagawa, Japan
Hirofumi Hashimoto, Ph.D., JAXA, Institute of Space and Astronautical Science, Sagamihara Kanagawa, Japan

Tsukuba Space Center, Tsukuba, Ibaraki, Japan
Kawasaki Heavy Industries, LTD., Kagamihara, Gifu, Japan

Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)

Sponsoring Organization
Japan Aerospace Exploration Agency

Research Benefits
Scientific Discovery, Space Exploration

ISS Expedition Duration
March 2015 - September 2015; April 2017 - February 2018

Expeditions Assigned

Previous Missions

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Experiment Description

Research Overview

  • The origin of life is one of the most profound scientific quests to be challenged in this century. It is unclear if terrestrial life originated on Earth, or in other parts of the solar system. On the other hand, it is known that “life precursors”, or complex organics, have been discovered in molecular clouds, nearby young stars, and inside meteorites and cosmic dust, reaching earth by way of asteroids and comet impacts. So far it has not been proven if life may also be transported onboard meteoroids or other celestial bodies. Astrobiology Exposure and Micrometeoroid Capture Experiments (Tanpopo) tests the possibility for terrestrial microbes to survive in space for long durations of time, such as for interplanetary transport. Additionally, tests are performed to determine whether extraterrestrial organic compounds can reach earth in pristine states inside micrometeoroids, and how they are altered in outer space.
  • By analyzing captured micrometeoroids in the aerogel panels, it is possible to find what kinds of life precursors can be transported to earth from primitive bodies in the solar system. By discovering impacting microparticles of terrestrial origin into the aerogel panels, it is possible to test for terrestrial microbes that may be present in low earth orbit altitudes. By evaluating retrieved samples of exposed terrestrial microbes, it can be shown that some species of these microbes may be able to survive in space for the duration of interplanetary transport.
  • This research contributes better understanding of the sources of life precursor organic compounds needed for the origin of terrestrial life. This research also gives insight into whether some terrestrial microbes are capable of surviving in space long enough for interplanetary transport to other celestial bodies. The impact of this research can be potentially a paradigm shift of both working theories of the origin of life and public perception of life in our solar system.


The Astrobiology Exposure and Micrometeoroid Capture Experiments (Tanpopo) consists of the following 6 subjects:
  1. Life evolved on earth about 4 billion years ago. Before the evolution of life, organic compounds needed to be accumulated on the earth surface. One of the major sources of the organic compounds are found on micrometeorites, which are captured on blocks of aerogel. Aerogel is a soft inorganic material designed to capture small particles with high velocity. Micrometeorite particles captured on the aerogel blocks are to be analyzed for the presence of organic compounds upon return to earth.
  2. Organic compounds on micrometeorites are exposed to the space environment before return to earth. The organic compounds may be modified by the environment. Several organic compounds that are expected to be present on micrometeorite are exposed to the space environment to test for the modifications in the chemical structure.
  3. Some research groups have done sampling experiments at high altitude using balloons and aircraft. Microbes were isolated, suggesting the possible migration of microbes from the ground to high altitudes. This part of the investigation tests for the possibility for terrestrial microbe detection at the ISS orbital altitude. Micro-particles in aerogel are microbiologically analyzed, under a fluorescence microscope in the presence of the DNA specific fluorescence pigment.
  4. Terrestrial microbes may escape from the earth gravity due to the processes of volcanic eruptions, thunderstorms, meteorite impacts, and electromagnetic fields around the earth. These microbes may possibly travel to other planets. This part of the investigation tests for the survival of some species of microbes in the space environment. Analysis for the survival of microbes is carried out upon return to earth.
  5. The micro-particles captured by aerogel include artificial particles, also known as space debris. The number, sizes, direction of the orbit, approximate velocities of the captured particles are recorded to gain additional information about space debris at ISS orbital altitudes.
  6. The aerogel used in the Tanpopo experiment is specially designed to capture particles moving at high velocity. The density of the upper part of the aerogel block is less than 0.01g/cubic cm. The lower part of the aerogel block is about 0.03g/cubic cm. The upper layer is expected to capture particles with less alteration form the heat production, while the lower layer is designed to stop particles with higher energy. Performance will be tested while testing the above experiments.

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Space Applications
Space debris is a real, existing threat to a sustainable space program. Tanpopo captures sub-milimeter sized space debris, which are impossible to be observed by remote sensing, in the entire duration of exposure operations of Tanpopo. The aerogel panels are potentially useful for other particle capture experiments. Monitoring the mechanical thermometer can provide a new, economical option of visual monitoring of temperature just outside of spacecraft.

Earth Applications
The origin of terrestrial life is a fundamental question in science. The results from Tanpopo may be able to provide important clues to answer some of major questions, such as whether organic compounds were transported from outer space before the origin of terrestrial life, and whether life may migrate through interplanetary space.

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Operational Requirements and Protocols

Number of experiment:  3 rounds.
Duration of 1 round of experiments:  about 1 year.
Number of experimental apparatus (Sample Aerogel Panels):
- 17 Sample Aerogel Panels for 1 round of experiments 51 Sample Aerogel Panels in total. (Sample Trays).
- 3 Sample Trays and 3 Control Sample Trays.

Handling care:
Front surface of the Sample Aerogel Panels should not be touched by anything.
Containers of Sample Aerogel Panel should not be shocked.
Front surface of the Sample Trays should not be hit by hard objects.
ExHAM should be attached in the indicated direction toward the direction of ISS movement.

Downlink of data (Non real time):
- Video recorded data of the thermometer.
- Date of position and direction of ISS during the experiments.
- Temperature and pressure data in the storage site of the SAP and ST.

Return of samples:
- 17 Sample Aerogel Panels, 1 Sample Tray and 1 Control Sample Tray for 1 round of experiment.

Launch operation:  Tanpopo Assembly (TA) is contained in TBD number of containers and placed right side up to avoid the possibility of aerogel falling down from Capture Panel and samples from Exposure Panel.
Transport of TA from Dragon and in ISS:  Aerogel is fragile material; special care not to shock the container.
Attachment of ExHAM on Airlock Table:  ExHAM is attached on the Airlock Table.
Attachment of TA on ExHAM:  TA taken out from the TA containers.  9 Capture Panels and 3 Exposure Panels are attached to the indicated sites on ExHAM. 3 Control Exposure Panels are kept inside of the container and stowed at the assigned place.
Removal of the covers of each Capture Panel:  Front surface of each Capture Panel is protected by plastic film from possible contamination during the transport.  The film is detached by the ISS crew after the attachment of all of the Capture Panels on ExHAM. 
Photo taking of the TA on ExHAM:  Photographs of 5 faces of ExHAM excluding The Airlock Table side is taken to record the secure attachment and the direction of each Capture Panel and Exposure Panel regarding the direction of ExHAM.
Transfer of ExHAM through the Airlock and attachment of ExHAM on a Handhold:  ExHAM is transferred through Airlock, and is detached from the Airlock Table with the combination of Main Arm and Small Fine Arm.  ExHAM is attached on an assigned Handhold.
Special care should be taken not to touch the surface of the TA by the Robotic arms.  Special care to not hit the surface of TA by other object should be also taken.
Video camera recording of Mechanical Thermometer:  During the duration of exposure experiment, at the designated time and duration, Mechanical Thermometer is recorded by designated video camera.
Retrieval of ExHAM and transport ExHAM through the Airlock: After the designated duration of time, ExHAM is retrieved from the Handhold by Robotic Arms, and transported through the Airlock into JEM PM. 
Special care should be taken not to touch the surface of TA by Robotic Arms.  Special care not to hit the surface of TA by other objects should be also taken.
Photo taking of the TA on ExHAM: photographs of 5 faces of ExHAM excluding the Airlock Table side should be taken to record the appearance of each Capture Panel and Exposure Panel on ExHAM.
Attachment of Covers:  Aluminum Cover (AC) is attached in front of the Capture Panel by an ISS crew.  Special care not to touch at the front surface of Capture Panel should be taken during the operation.
Detachment of Capture Panel and storage:  All of Capture Panel are detached from ExHAM and stored in Capture Panel containers.  The Capture Panel containers are stowed at the assigned area until the transfer back to the ground.
Detachment of Exposure Panel:  One of the attached Exposure Panel, the specific one assigned, is detached from ExHAM. Exposure Panel is stored in Exposure Panel container and stowed at the assigned area until the transfer back to the ground.
Transfer back to the ground:  Containers of 9 Capture Panels, a Container of Exposure Panels, and a Reference Panel are transferred back to the ground by the vehicle to be determined.

Attachment of Capture Panel on ExHAM:  New Capture Panels are taken out from the TA containers.  New 9 Capture Panels are attached to the indicated sites on ExHAM. Reference Panel(s) is (are) kept inside of the container and stored at the assigned place.
Following steps are the same as the FIRST ROUND OPERATION

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Results Publications

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Ground Based Results Publications

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ISS Patents

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Related Publications

    Kawaguchi Y, Yokobori S, Hashimoto H, Yano H, Tabata MJ, Kawai H, Yamagishi A.  Investigation of the interplanetary transfer of microbes in the Tanpopo Mission at the exposed facility of the International Space Station. Astrobiology. 2016 May; 16(5): 363-376. DOI: 10.1089/ast.2015.1415. PMID: 27176813.

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Related Websites

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image Image courtesy of JAXA.
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