General Atomics Blitzer Railgun

In 2007, building upon knowledge gained under an Office of Naval Research (ONR) Innovative Naval Prototype contract, GA initiated development of the Blitzer™ system using internal funds to accomplish two major objectives:

  • Demonstrate the technical maturity of tactically relevant railgun technologies in a proving-ground environment.
  • Generate interest in the viability of smaller Electromagnetic (EM) gun systems for use in a broader set of missions, including integrated air and missile defense (IAMD)

GA accomplished both of these objectives by demonstrating the launcher and power system technologies to full design levels in 2009 during testing with non-aerodynamic rounds, followed by testing of aerodynamic rounds during the fall of 2010.

The tests demonstrated the integration and capabilities of a tactically relevant EM Railgun launcher, pulsed power system, and projectile. The projectiles were launched by Blitzer at Mach 5 with acceleration levels exceeding 60,000 gee, and exhibited repeatable sabot separation and stable flight.

The Vegetable Garden on the International Space Station

The latest crop harvested from the Garden on the International Space Station is Mizuna lettuce. The lettuce was returned to Earth for scientific research, aboard the Discovery shuttle in April 2010.

The greenhouse, first sent up in 2002, has been used for 20 plant growth experiments so far. Now, a second unit has been added, and the lettuce crop was the first experiment to test different conditions side by side.

For many years, the experiments have sought to confirm Earth side results which show that minimizing water usage and salt accumulation would lead to healthier crops. During this experiment, two different root growth mediums were used. One was the traditional root pack used on all the previous tests. The second was the new and improved root pack, with slow release fertilizer. The hypothesis was that the slow release would help reduce salt intake.

Science is sometimes best when things go wrong.

Mizuna Lettuce
Mizuna Lettuce On ISS
Image Credit: NASA

For some reason, the sensor controlling the watering in the first (traditional) module failed. This resulted in “over-watering” the plants. The results were surprising, but microgravity has held many surprises for scientists. First, the seeds that got “too much” water sprouted quicker and developed leaves twice as fast as the second (improved) module. The second surprise was that the plants grown in the slow release fertilizer in the second module had more salt accumulation than the plants in the first module.

The results suggest that plants in space need a larger volume of water and a faster rate of fertilizer than they do under normal gravity. Shane Topham, an engineer with Space Dynamics Laboratory at Utah State University in Logan, said that “the conservative water level we have been using for all our previous experiments may be below optimal for plant growth in microgravity”.

Overall, the garden experiments have four objectives:

  • Can the crops grown in space be consumed safely
  • What microorganisms grow on the plants, and how do you prevent or minimize microorganisms in the modules prior to launch
  • How do you clean and sanitize the crops after they are harvested
  • What conditions optimize the production of crops in microgravity

One additional objective of the experiments is to measure the non-nutritional benefits (stress relief, etc.) that crew members experience working with plants in space. Growing and tending to the crops provides comfort and relaxation to the crew. On a long voyage, this activity may contribute to the success of the mission.

Lada Module
A view of the Russian BIO-5 Rasteniya-2/Lada-2 (Plants-2)
plant growth experiment located in the Zvezda Service Module
on the International Space Station (ISS).
Image Credit: NASA

Sprouts
A close up view of sprouts on the Russian Lada-2 experiment.
Image Credit: NASA

Peas
A view of peas growing in the Russian Lada-2 plant growth experiment.
Image Credit: NASA

Bloom
A close up view of a bloom on the Russian Lada-2 plant growth experiment.
Image Credit: NASA

NASA – ISS Science Success – Part II

Part I, Part II, Part III

In Part I, we looked at “Technology Development for Exploration” and “Physical Sciences in Microgravity” aboard the International Space Station from NASA’s report on “International Space Station Science Research Accomplishments During the Assembly Years: An Analysis of Results from 2000-2008”.

The major areas of research from the report include:

  • Technology Development for Exploration
  • Physical Sciences in Microgravity
  • Biological Sciences in Microgravity
  • Human Research Program
  • Observing the Earth and Educational Activities
  • Science from International Space Station Observations

Here in Part II, we will highlight research from “Biological Sciences in Microgravity” and “Human Research Program”.

ISS
International Space Station. Credit: NASA Image

Biological Sciences in Microgravity

For long term human occupation of the Solar System, production of food and reproduction in microgravity are key research arenas.

Thale cress (Arabidopsis thaliana) is a model system in plant biology studies and has been studied aboard the ISS in a series of tests over three Expeditions (2, 4, and 5). The studies used the Advanced Astroculture apparatus, a commercially sponsored payload that “provided precise control of environmental parameters for plant growth, including temperature, relative humidity, light, fluid nutrient delivery, and CO2 and ethylene concentrations” (p 83).

Results included successful germination, growth to maturity and production of seeds. Both plant and seed tended to be slightly bigger than ground results. Seed germination rates were similar to ground germination, and no major morphological differences were noted. Additional results have not been released.

The Avian Development Facility (ADF) is designed to study embryogenesis in microgravity (the ADF can carry bird eggs, fish, plants, insects, or cells in its sample containers.). “During its flight on space shuttle mission STS-108 to the ISS, the ADF housed two investigations: the Development and Function of the Avian Otolith System in Normal and Altered Gravity Environments (ADF-Otolith) and the Skeletal Development in Embryonic Quail on the ISS (ADF-Skeletal) investigations” (p 81). It has been suggested that absence of gravity can affect embryo development. Changes in inner ear development has been observed before, and the Otolith experiments showed that inner ear bones from quail embryos are larger than those found in controls on Earth. Additional analysis is being conducted. Below are images from the experiment showing differential development.

Fused Otoconial Ear Bones
Credit: NASA Image.

The ADF-Skeletal experiments were designed to begin determining the molecular and cellular biology of bone formation and loss.

Osteocalcin levels in the day 12 embryos showed no effect from space flight. However, day 7 and day 12 embryos direct mineralization quantitative studies have not been reported. Second, space flight embryos had a reduced level of collagen-synthesizing activity compared to the ground control specimens. Final analyses and publication of results are pending.

Other Biological experiments include:

  • Biomass Production System – “Multiple criteria were used to evaluate BPS technology; nearly all of the performance requirements (plant health, temperature and humidity control, atmospheric composition control, nutrient and water delivery, lighting, data acquisition of CO2 levels, water use, biofouling) were met successfully (Iverson et al. 2003). While researchers noted a few performance parameters required additional work (e.g., elevated temperatures of the root zones), these indicators were identified and documented, and will be built in to the design modification. Overall the BPS hardware performed as expected, and may provide a viable use in the development for regenerative life support systems for future spacecraft development.” (p 85)
  • Cellular Biotechnology Operations Support System. CBOSS is intended to grow three-dimensional clusters of cells in microgravity. Cell lines in the experiments included: Renal Cortical Cells, for study of Kidney disorders; Colin Carcinoma Cells, testing three-dimensional growth in microgravity affecting signaling pathways and gene expression as cells differentiate into the two major colonic cell lines; Ovarian Tumor Cells, involved three-dimensional development and associated cell cycle kinetics, proteins and oncoproteins; three additional cell lines were studied. Significant problems with preservation and air/liquid interface bubbles were encountered. (p 90-92)
  • Effect of Space Flight on Microbial Gene Expression and Virulence (Microbe). The Microbe experiment was performed in Sep 2006 during the STS-115/12A mission to the ISS; it tested three microbial pathogens; Salmonella typhimurium, Pseudomonas aeruginosa, and Candida albicans. Initial data from S. typhimurium showed that a total of 167 genes were expressed differently in flight when compared with ground controls. The data indicate that bacteria respond to the microgravity environment with widespread alterations of gene expression (process by which DNA is made into a protein), alterations in microbial morphology (shape and form of microbes), and increased virulence (disease-causing potential) (p 97-98)
  • Multigenerational Studies of Thale Cress. Samples were returned to Earth for analysis by the investigator team in Apr 2008. Final results of the investigation are pending data analysis of the returned samples. (p 99)

Human Research Program

Areas under investigation include:

  • Bone and Muscle
  • Cardiovascular and Respiratory Systems
  • Immune, Neurological, and Vestibular Systems
  • Behavior and Performance Studies
  • Radiation Studies

The Anomalous Longterm Effects in Astronauts’ Central Nervous System (ALTEA) hardware is designed to measure particle radiation in the space environment, and determine how this radiation impacts the CNS of the crew. “Preliminary data that were compiled from three Expeditions, are currently in being fully analyzed. A long run of dosimetry data was collected during Expeditions 13 and 14; including definable particle and solar events. During Expedition 13, the visual stimulator malfunctioned, resulting in a loss of data from this instrument. During Expedition 14, variable results were obtained from different crewmembers. Overall, the crew reported a lower frequency of light flash events than expected; this was anecdotally attributed to a lack of dark adaptation. The astronauts did perceive a higher rate of light flashes in their sleeping quarters.” (p 115)

The Bonner Ball Neutron Detector (BBND), which was developed by the Japan Aerospace Exploration Agency (JAXA), was used inside the ISS to measure the neutron energy spectrum. It consisted of several neutron moderators enabling the device to discriminate neutron energies up to 15 mega electron volts (MeV). (p 116)

Effect of Prolonged Space Flight on Human Skeletal Muscle. Muscle biopsy evaluated changes in calf muscle function over long-duration space flights (30 to 180 days). “Preliminary results were presented at the 2004 American Physiological Society Intersociety Meeting: Integrative Biology of Exercise in three abstracts. Summarizing data that were collected from the first five subjects, microgravity produced a 47% decrease in the peak power of postflight muscle fiber samples compared to preflight muscle fiber samples. This decrease was due to the combined effects of reduced fiber size and a decline in the size of the myofibrils that make up the fiber”. (p 118)

Commercial Biomedical Test Module-2 (CBTM-2) examined the effectiveness of an experimental therapeutic in preventing muscle loss in mice that were exposed to microgravity. This was the first time that an experimental therapeutic for muscle loss was investigated in space; an important and significant step in developing a more effective countermeasure to microgravity induced muscle changes. (p 122)

Other human space flight related studies include:

  • Space Flight Induced Reactivation of Latent Epstein-Barr Virus (EBV). “The decreased cellular immune function that is experienced by astronauts in space flight is likely caused by a combination of the microgravity environment and the stresses that are associated with a mission. With longer-duration missions, it is hypothesized that latent viruses are more likely to be reactivated, placing the crew at risk of developing and spreading infectious illnesses and jeopardizing the mission. Preliminary studies of astronauts have shown increased EBV shedding”. (p130)
  • Effects of Altered Gravity on Spinal Cord Excitability. (p 135)
  • Behavioral Issues Associated with Isolation and Confinement. (p 140)
  • Incidence of Latent Virus Shedding During Space Flight. “The observed decrements in the immune response resulting from space flight may allow increased reactivation of the same herpes viruses, and may increase the incidence and duration of viral shedding. Such a result may increase the concentration of herpes viruses in the spacecraft.” (p 141)
  • Renal Stone Risk During Space Flight.(p 149)
  • Stability of Pharmacotherapeutic and Nutritional Compounds. Pharmaceuticals have been observed to degrade in microgravity in as short a period as 20 days. (p 152)
  • Subregional Assessment of Bone Loss in the Axial Skeleton in Long Term Space Flight. (p 154)
  • Surface, Water, and Air Biocharacterization (SWAB) – A Comprehensive Characterization
    of Microorganisms and Allergen in Spacecraft. (p 156)
  • Effect of Microgravity on the Peripheral Subcutaneous Veno-Arteriolar Reflex in Humans. (p 159)

Part I, Part II, Part III

NASA – ISS Science Success – Part I

Part I, Part II, Part III

ISS
International Space Station. Credit: NASA Image

It now appears likely that the mission of the International Space Station (ISS) will be continued through 2020 (See the Augustine Scenarios). And following NASA’s announcement in September of the release of the report on “International Space Station Science Research Accomplishments During the Assembly Years: An Analysis of Results from 2000-2008”, now would be a good time to look back on the scientific accomplishments so far, and to look ahead. Because NASA’s report is 250 pages in length, we will digest it in small pieces.

The major areas of research include:

  • Technology Development for Exploration
  • Physical Sciences in Microgravity
  • Biological Sciences in Microgravity
  • Human Research Program
  • Observing the Earth and Educational Activities
  • Science from International Space Station Observations

Following launch of the Russian Zarya module in 1998, and before human occupation began in 2000, several experiments were conducted:

  • Protein Crystal Growth – Enhanced Gaseous Nitrogen Dewar (PCG-EGN)
  • Commercial Generic Bioprocessing Apparatus: Kidney Cell Gene Expression (CGBA-KCGE) and Synaptogenesis in Microgravity (CGBA-SM)
  • Incidence of Latent Virus Shedding During Space Flight (Latent Virus)
  • International Space Station Acoustics Measurement Program (ISS Acoustics)

One of the most exciting results reported from ISS research is the confirmation that common pathogens change and become more virulent during space flight, performed in September 2006. This has important implications for extended human missions. It is also a target for additional research.

During the time covered by this report, steady growth in publications associated with ISS research has occurred, as shown in the graph to the right.

What have been the major research results in each of the six areas discussed in the report?

Technology Development for Exploration

One of the most important concerns of any space based operation has to be air quality. Therefore, the experiments with the “Analyzing Interferometer for Ambient Air” (ANITA) instrument will prove crucial to future explorers. “ANITA was calibrated to simultaneously monitor 32 gaseous contaminants (including formaldehyde, ammonia, and carbon monoxide (CO)) at low as parts per million levels in the ISS atmosphere. The hardware design—a quasi on-line, fast-time resolution gas analyzer—allowed air quality to be analyzed in near real time.”

Cumulative ISS Publications
Credit: NASA Image

As an example of the importance of these capabilities, the report notes that “ANITA was used in mid 2008 to detect a Freon leak (Khladon 218) from the Russian air conditioner, and to monitor the timeline of Freon concentrations with CDRA operations and shuttle docking. The ANITA data helped to determine that the zeolite bed in the CDRA was not effective in scrubbing the Freon leak, but that diluting the ISS air after the docking with the shuttle substantially reduced the level of Freon” (p18).

Other research topics include:

  • The Active Rack Isolation System (ARIS), which protects equipment by absorbing the shock of motion before it can affect an experiment.
  • The Smoke and Aerosol Measurement Experiment (SAME), which is planned to gather particulate size information on ISS. It is known that fires in microgravity produce smoke particles that are larger than on Earth. Being able to distinguish between smoke and other particles on ISS is important.
  • “The elastic memory composite hinge (EMCH) experiment provided test data on new materials that will further space hardware technology. This technology may eliminate the need for highly complex deployment mechanisms by providing a simpler, lightweight alternative to mechanical hinges. EMCH builds on the previous space shuttle experiment, lightweight flexible solar array hinge (LFSAH) that was flown on STS-93” (p 22).
  • “The In-SPACE Soldering Experiment (ISSI) is another payload that was rapidly developed after the Columbia accident to provide a lowmass experiment using hardware already on board station. It was designed to promote understanding of joining techniques, shape equilibrium, wetting phenomena, and micro-structural development in space” (p 23).

Physical Sciences in Microgravity

While Technological Development is important for space exploration, pure research also has a place on the ISS. Protein crystal growth, fluid physics and materials science are being researched:

  • The Advanced Protein Crystallization Facility (APCF) can support three crystal-growth methods: liquid-liquid diffusion, vapor diffusion, and dialysis. In the vapor diffusion method, a crystal forms in a protein solution as a precipitant draws moisture in a surrounding reservoir. In the dialysis method, salt draws moisture away from the protein solution via a membrane separating the two and forming crystals. Initial analysis of the crystals that were returned from station supports the findings of earlier APCF flights: comparative crystallographic analysis indicates that space-grown crystals are superior in every way to control-group crystals that are grown on Earth under identical conditions (p 47).
  • The Binary Colloidal Alloy Test hardware supported “three investigations in which ISS crews photographed samples of colloidal particles (tiny nanoscale spheres suspended in liquid) to document liquid/gas phase changes, growth of binary crystals, and the formation of colloidal crystals that were confined to a surface. Colloids are small enough that in a microgravity environment without sedimentation and convection, they behave much as atoms. By controlling aspects of colloidal mixtures, they can be used to model all sorts of phenomena” (p 49).
  • Protein Crystal Growth-Enhanced Gaseous Nitrogen (PCG-EGN) was designed to produce crystals of various biological compunds. Also, some 500 student preparations were made as part of an education program to teach students about crystallization, crystallography methods and the impact of crystallography on medicine and biotechnology. A significant number of crystallization were successful. Indeed, some of the results produced better data than could be obtained in Earth bound efforts (p 69).

Sometimes, “no” is just as important as “yes”.

Researchers have found that it is possible to grow high-quality protein crystals in the weightlessness of LEO, where gravitational forces will not distort or destroy a crystal’s delicate structure.

The goal of the Dynamically Controlled Protein Crystal Growth (DCPCG) experiment was to control and improve the crystallization process by dynamically controlling the elements that influence crystal growth.

DCPCG was the first flight test of an apparatus that was designed to control the crystal growth process by controlling the rate of evaporation. The apparatus worked on orbit, and crystals were grown for the test proteins; however, the investigators determined that the growth could have been better. The same apparatus was used in extensive testing on the ground. Researchers tested a selection of protein solutions, including insulin (a hormone that is produced by the pancreas to regulate the metabolism and use of sugar), serum albumin, and lysozyme (an enzyme that attacks bacteria) and found that a slower evaporation rate yielded better results than a more rapid evaporation rate. While the results of the ground tests were published, the DCPCG experiment investigators did not seek to publish any structures from crystals grown in orbit.

What’s Ahead

In 2008, the European Space Agency’s (ESA’s) Columbus and Japanese Aerospace Exploration Agency’s Kibo scientific modules joining NASA’s Destiny Laboratory. Further, in 2009, the number of crew members increased from three to six. This means that a lot more time is available for research in the future.

New experiments aboard the ISS include a broad range of science, as follows:

  • Coordinated human research experiments that collaborate with International Partners’ science objectives and activities, including shared baseline data collection and in-flight sampling, with the goal of understanding integrated causes and effects of changes in the human body.
  • Research using new science racks, including the fluids integrated rack (FIR), the combustion integrated rack (CIR), and materials science research rack (MSRR), will enable new experiments exploring combustion, fluid behavior, and heat-dependent crystallization patterns in metal alloys.
  • Exploration Technology Development will build from early experiments on materials exposure, smoke generation, liquid fuel management, and environmental monitoring.
  • The new Window Observation Research Facility (WORF) will provide capabilities to support remote sensing instruments, enabling Earth Science research that will, for example, document crop health and test the utility of blue-green bands for ocean research.

Part I, Part II, Part III