Lab-on-a-Chip Application Development-Portable Test System - Exploration (LOCAD-PTS-Exploration) - 01.09.14
Science Objectives for Everyone Lab-on-a-Chip Application Development-Portable Test System - Exploration (LOCAD-PTS-Exploration) is a handheld device for rapid detection and quantification of biological substances onboard the International Space Station (ISS). LOCAD-PTS-Exploration shall test procedures onboard the ISS that will ultimately support scientific activities during the human exploration of the moon and Mars. It will mark the first time that external surfaces of a spacecraft have been sampled for biological material during extra-vehicular activity (EVA), followed by analysis within the cabin environment. This type of procedure shall be required during future exploration missions to monitor and restrict the transfer of biological material from Earth to other planets.
Science Results for Everyone
Earth invades Mars! To prevent that, future missions must monitor and restrict transfer of Earth’s biological material to other planets. This investigation tested procedures to sample external spacecraft surfaces during Extra-Vehicular Activity (EVA) for potential biological contamination. Samples were analyzed with a handheld device and compared to preflight tests. The fungal marker glucan was found on gap spanners, the fabric straps between handrails. While these molecules pose no apparent problem to the International Space Station (ISS), they could hitch a ride to Mars and interfere with life search experiments there. Results will help design contamination control strategies for future planetary exploration.
Charles River Endosafe, Charleston, SC, United States
Marshall Space Flight Center, Huntsville, AL, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
October 2008 - April 2009
Previous ISS Missions
LOCAD-PTS Exploration is a new investigation for space research and has evolved from the existing LOCAD-PTS flight project.
- Lab-on-a-Chip Application Development-Portable Test System - Exploration (LOCAD-PTS-Exploration) seeks to understand the process by which biological material is transferred from Earth to space during human space exploration, and to test procedures for the crew to monitor that biological material while in space.
- LOCAD-PTS-Exploration will specifically analyze biological material on the external surfaces of the Starboard 6 (S6) Truss, an ISS element to be launched on flight STS-119/15A. The S6 Truss shall be analyzed on the ground at the Space Station Processing Facility (SSPF) at Kennedy Space Center, and then again following docking to the ISS.
- Analysis of biological material in space shall be performed with the LOCAD-PTS device currently onboard the International Space Station (ISS).
- The crew will sample the external surfaces of the S6 truss in space during the EVA for installation (the palm of the extravehicular mobility unit (EMU) spacesuit glove will come into contact with the same sites previously analyzed on the ground). The palm of the EMU glove shall be swabbed before and after EVA for S6 Truss installation. This will test an in space method to sample external surfaces of a spacecraft in space, and evaluate potential biological contamination introduced between SSPF storage and flight.
While there are no planetary protection or contamination issues for space flight to low Earth orbit (LEO), the current process by which spacecraft are processed before launch, transferred to the pad and then launched follows a similar pattern to be expected for exploration missions to the Moon and Mars. It is this process, by which terrestrial microbial contamination can be transferred from Earth to space, that shall be investigated by the Lab-on-a-Chip Application Development-Portable Test System - Exploration (LOCAD-PTS-Exploration) experiment.
During this experiment, surface samples shall be taken from the handrails of the Starboard 6 (S6) Truss segment (the final set of solar arrays to be launched to the ISS) along the EVA primary path to be used for S6 installation. Surfaces within the Space Station Processing Facility (SSPF) at Kennedy Space Center shall also be analyzed. All surfaces shall be analyzed at 3 months before launch (L-3 months), and if possible at L-1 months. Following launch of the S6 Truss on flight STS-119/15A, the same handrails shall be sampled again onboard the ISS, during an EVA and analyzed onboard the ISS with LOCAD-PTS.
The data obtained with LOCAD-PTS-Exploration shall feed forward to support exploration missions and help determine appropriate forward contamination requirements for human space exploration of the lunar and Martian surface; both for spacecraft external surfaces and processing facilities.
This experiment makes use of a unique opportunity, before assembly of the ISS is complete, to analyze an ISS element (S6 Truss) before and after flight, and feed forward the data and procedures evaluation to support the human exploration of the Moon and Mars.
The data obtained with LOCAD-PTS-Exploration shall serve as a foundation for planetary protection procedures performed during the human exploration of the Moon and Mars. The extent to which human space exploration transfers biological material to other planets is currently unknown. This study seeks to understand this process and test procedures that can be developed further on the Moon in preparation for the human exploration of Mars, where a key scientific objective will be to search for biological material indigenous to Mars and to differentiate it from that found on Earth.
The procedures used in this study to detect biological material in the hostile environment of space have many other applications for similar tests performed in extreme environments on Earth. These include the investigation of hyperthermophiles (organism that thrives in extremely hot environments from 60 degrees Celsius and higher) in active volcanic craters and fumeroles (opening in Earth's crust which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide); the detection of lethal viral outbreaks; the exploration of deep sea flora and fauna by deep divers on the ocean floor; and the evaluation of biological attacks in a military or civilian situation.
The LOCAD-PTS unit will interface to an ISS UOP for power. A swabbing unit has been designed for sampling surfaces, dissolving the sample with water, and delivering precise volumes of sample to the LOCAD-PTS cartridge for analysis. Crewmembers will use this device to swab the surface of the EMU spacesuit glove before and after the EVA to install the S6 Truss. LOCAD-PTS-Exploration results taken before and after the EVA will be compared to the data collected from the S6 Truss before launch in the SSPF. Results from the analyses will be digitally recorded and downloaded from ISS to ground. No sample return is necessary.
Preflight in the SSPF surface samples from the S6 Truss handrails shall be collected with the LOCAD-PTS-Exploration swab unit and swatch material (this material is used to manufacture the palms of each EMU spacesuit glove). A swab unit is currently used onboard the ISS to take surface samples within the cabin environment as part of the existing LOCAD-PTS flight project. It consists of a pipette, attached directly to a cartridge containing ultra-clean endotoxin-free water, which is in turn attached to a swab tip made from endotoxin-free Dacron material. In this configuration, it can be used to swab a surface. The surface area of each swab shall be approximately 25cm2; the same area as currently swabbed on the ISS as part of the LOCAD-PTS investigation.
Inflight it is not possible to use the standard LOCAD-PTS swabbing method to sample the S6 Truss surfaces during the EVA. Therefore an alternative method is required. This method shall utilize the EMU spacesuit glove palm, made of smooth RTV silicone material, as the swab device. The on-orbit protocol shall consist of a swab of an EMU spacesuit palm before and after EVA to install the S6 Truss. The time of swabbing before and after EVA should be performed as close as possible to EVA for S6 Truss installation (within the constraints of inflight operations) to avoid contamination of the glove by other sources. One swab shall be performed on each glove palm (left and right). Each swab shall consist of an approximately 25cm2 surface area of the palm and be analyzed subsequently with LOCAD-PTS.
If possible, both left and right EMU glove palms should be cleaned briefly with a benzalkonium (BZK) wipe prior to the pre-EVA swab. BZK wipes are used routinely onboard ISS to clean surfaces. Tests performed on EMU glove palms at Johnson Space Center showed that approximately 5-minutes is required for the RTV silicone surface to dry following application of a BZK wipe; therefore this wipe should be performed at the beginning of procedures (e.g. during experiment set-up).
LOCAD-PTS-Exploration preflight tests of the S6 Truss were performed in the Space Station Processing Facility (SSPF) at NASA Kennedy Space Center on October 27, 2008 and December 9, 2008. Approximately fifteen surface sites were chosen on the S6 Truss for sampling and analysis, based upon the likelihood those sites would be contacted by mission specialists during Extravehicular Activity (EVA) 1 of the STS-119 mission to the ISS. Sample sites were distributed throughout the S6 Truss, on the Integrated Equipment Assembly (IEA) and the Long Spacer.
During each preflight test, surface samples were taken by swab and contact slide methods. Contact slides are gel culture media, which are applied to a surface, and allowed to incubate for 3 - 5 days to see if any colonies grow. These colonies are counted as Colony Forming Units (CFUs). The swabs were analyzed immediately with LOCAD-PTS and results logged within 15 minutes.
The S6 Truss was extremely clean, biologically speaking. No endotoxin was detected at any surface site. However, glucan, a fungal marker, was found at some sites, especially gap spanners. Gap spanners are fabric straps that span the gap between handrails to assist movement of EVA crew. In many ways, fabric creates a more hospitable environment for any microorganism. It is expected that even if potential fungi or bacteria on these gap spanners (or any S6 truss surface) dies following exposure to the space environment, the molecules that make up their cell walls (e.g., endotoxin, glucan, lipoteichoic acid) may remain. The presence of these molecules on the external surface of the ISS poses no apparent problem, but the same molecules could hitch a ride on the external surface of a spacecraft carrying humans to Mars and may potentially interfere with experiments designed to search for life on the Martian surface. By understanding this process on the ISS and developing procedures to monitor biological contamination onboard, we shall be able to prepare for human exploration beyond low Earth orbit (LEO).
A microbial survey of the SSPF, a building that is the last stop on Earth for all ISS modules/elements transported to space by the Space Shuttle was also performed. Test sites included locations such as air vents (especially adjacent to the S6 Truss), floors and doors. Included in the analysis was the large west door of the SSPF high bay through which every ISS module and element enters and leaves. In general, the SSPF is a clean environment, maintained by the SSPF staff at Class 100,000 conditions. Elevated readings were found mainly at just two locations: air in-flow vents and footpads (sticky pads placed at the steps leading to each module platform). In many ways, this is a good sign and an indication that these vents and pads are doing their job and keeping dust away from ISS modules and the SSPF environment.
The S6 Truss was launched aboard Space Shuttle Discovery (STS-119) on March 15, 2009. Following five days in orbit, the S6 Truss was installed onto the ISS on Flight Day 5 (March 19, 2009) during Extravehicular Activity (EVA) 1. EVA crewmember 1 (EV1) was Steve Swanson and EVA crewmember 2 (EV2) was Richard Arnold. ISS Flight Engineer, Sandy Magnus performed swabs of the right-hand glove of both EV1 and EV2, both before and after EVA 1. Both swabs were performed in the Equipment Lock of the US Airlock Quest. The post-EVA swabs were performed prior as both EV1 and EV2 came through the hatch, before EVA crew touched any surface within the Equipment Lock. The four swabs were stored, dry and packaged in a sterile bag, until analysis with LOCAD-PTS on Flight Day 7 (March 21 2009).
Analysis showed that the absolute level of glucan on spacesuit gloves on orbit was low, especially when compared with other surfaces within the Station. The EVA crew contacted many sites on the S6 truss that tested high for glucan in the SSPF (e.g., gap spanners). Interestingly, rather an increase in glucan on the gloves from pre-EVA to post-EVA, there was a 50 percent decrease. This might be due to glucan on the S6 Truss (detected before launch) being destroyed after a few days in space, and to glucan on the spacesuit glove (detected pre-EVA) detaching during EVA. These insights will help design contamination control strategies for the human exploration of the Moon and Mars (Jake Maule, "LOCAD-PTS-Exploration: Updated Results" Email to Judy Tate-Brown, ISS Program Science Team Lead. 24 Mar. 2009).
Ground Based Results Publications
Eigenbrode J, Benning LG, Maule JG, Wainwright NR, Steele A, Amundsen HE. A field-based cleaning protocol for sampling devices used in life-detection studies. Astrobiology. 2009; 9(5): 455-465.
Maule JG, Fogel M, Steele A.Detection of human and bovine collagen in early holocene bone and teeth with antibody microarray. Astrobiology. 2005; 5(2): 289.
Morris HC, Monaco LA, Steele A, Wainwright NR. Setting a standard: the limulus amebocyte lysate assay and the assessment of microbial contamination on spacecraft surfaces. Astrobiology. 2010 Oct; 10(8): 845-852. DOI: 10.1089/ast.2009.0446.
- Lab-on-a-Chip Application Development-Portable Test System Home Page
- Science@NASA - ISS Spacewalkers Test Planetary Protection Concept
- LOCAD-PTS Tests on Desert-RATS and Arctic Mars Svalbard Analogue Expeditions (AMASE)
The LOCAD-PTS Reader, cartridge (below Reader) and swabbing unit (to the right). These three components are all that is required to collect a surface sample, dissolve and analyze it to obtain quantitative levels of endotoxin, Beta-glucan and lipoteichoic acid. Image courtesy of NASA, Marshall Space Flight Center.
+ View Larger Image
Dr. Jake Maule tests EVA procedures in a Mark III lunar prototype spacesuit in the Arctic with JPL Cliffbot during the NASA-funded Arctic Mars Analog Svalbard Expedition (AMASE) in 2006. Human-robot interactions combined with portable biochemical analysis, such as enabled by LOCAD-PTS, shall be required to monitor contamination during exploration missions. Image courtesy of Kjell Ove Storvik, AMASE.
+ View Larger Image
Spacesuit glove and LOCAD-PTS Swab Unit, showing: A, RTV silicone material on fingertips and palms; B, swab tip; C, water cartridge; D, Swab Unit; and E, the fabric gauntlet thermal micrometeoroid garment (TMG). Image courtesy of Jake Maule.
+ View Larger Image
LOCAD-PTS-Exploration collaborator Karissa West (Charles River Laboratories, Charleston, SC) analyzes S6 Truss swab samples on-site in the Space Station Processing Facility (SSPF) at NASA Kennedy Space Center in December 2008. The Long Spacer of the S6 Truss can be seen in the background. The S6 truss has been stored in the SSPF since 2002, following arrival in a Super Guppy aircraft. Image credit: Jake Maule.
+ View Larger Image
A swab is performed on the Gap Spanner on the S6 Truss in the Space Station Processing Facility (SSPF) at NASA Kennedy Space Center in December 2008. Gap Spanners are fabric straps that span the distance between handrails to help EVA crewmembers move around the truss. Preflight tests with LOCAD-PTS showed that fabric surfaces contain much higher levels of biological material than smooth, metal surfaces, such as handrails. Image credit: Erin Mulholland and Lane Dellwo, NASA Kennedy Space Center.
+ View Larger Image
LOCAD-PTS Exploration principal investigator Jake Maule tests the Extravehicular Mobility Unit (EMU) gloves at NASA Johnson Space Center. This test was performed in the EVA and Crew Systems glovebox. The internal pressure of the glovebox was reduced to approximately 10 psi, creating a +4.7 psi differential pressure experienced by EVA crew on orbit. The palms of each glove were tested for biological materail with LOCAD-PTS before and after handling of the Pistol Grip Tool (PGT), a device used by EVA crew to perform maintenance and repair tasks on orbit. Image credit: Amy Ross, EVA and Crew Systems, NASA Kennedy Space Center.
+ View Larger Image
LOCAD-PTS-Exploration principal investigator Jake Maule swabs the Handrail 2095 (gold color) of the S6 Truss in the Space Station Processing Facility (SSPF) at NASA Kennedy Space Center in December 2008. Handrails are smooth metal surfaces and relatively free of biological material. Ten to fifteen handrails were chosen for analysis based upon their likelihood of being used during EVA 1 of STS-119. Image credit: Erin Mulholland and Lane Dellwo, NASA Kennedy Space Center
+ View Larger Image
LOCAD-PTS Lead Flight Operations Engineer Dan Gunter (left) and LOCAD-PTS Project Scientist Jake Maule (right) talk to astronaut Suni Williams aboard the ISS during Expedition 14. Gunter and Maule have supported each LOCAD-PTS session on console at the Payload Operations and Integration Center (POIC) at NASA Marshall Space Flight Center in Huntsville, Alabama. Image credit: NASA Marshall Space Flight Center.
+ View Larger Image
Video screen shot of ISS Expedition 18 Flight Engineer Sandy Magnus , as she swabs the spacesuit glove of Extravehicular Activity (EVA) crewmember Richard Arnold in the Equipment Lock, following EVA 1 on Flight Day 5 of STS-119.
+ View Larger Image
Video screen shot of ISS of Expedition 18 Flight Engineer Sandy Magnus gets ready to swab the spacesuit gloves of Extravehicular Activity (EVA) crewmembers Steve Swanson and Richard Arnold, following EVA 1 on Flight Day 5 of STS-119.
+ View Larger Image
Operation of LOCAD-PTS swabbing unit to swab the room temperature vulcanizing (RTV) silicone palm of a spacesuit during simulated surface extravehicular activity (EVA) at Meteor Crater, Arizona, as part of NASA's Desert Research and Technology Study (RATS) in September 2005. This study will prepare for biological monitoring activities on the lunar surface, to understand the process by which human activities contaminate a lunar/planetary surface, in preparation for the human exploration of Mars, where a key scientific objective will be the search for life. Image courtesy of Jake Maule.
+ View Larger Image