Project HOME: Hydroponic Operations for Mars Exploration

This study considers the challenges NASA, SpaceX, and other private companies will face in the approaching two decades when sending astronauts on missions to Mars. The longest exploration is planned to take place in the 2030\u27s, sending a crew of, at minimum, four astronauts to Mars for a year of research. The research conducted is assisting NASA, SpaceX, and alike companies ways to grow a complete diet on a planet that does not receive enough sunlight. Agriculture in enclosed and buried structures on Mars will enable astronauts to conduct extended surface exploration missions. The researchers evaluated a deep-water culture indoor hydroponics system to grow Moringa oleifera (M. oleifera), a nutrient- and antioxidant-rich plant with leaves containing all nine essential amino acids. After initial aquaponics growth and 3 prior harvests, the lighting intensity was set to 590 W/m^2 in a twelve hour on/off cycle, in normal indoor atmosphere. This simulates an ambient light collection and reflection system on Mars illuminating an insulated, pressurized underground chamber for agriculture. All plants (N = 32) were harvested 17 times over a 9 month period at regular intervals, when plant heights reached an average of 0.9 m. Consumable leaf yield averaged 0.18 dry g per plant per day. Data suggest M. oleifera as a perennial hydroponic crop is possible under reduced illumination, and is a candidate food source for Mars explorers. Preliminary research has expanded to utilizing natural light, five additional plants, three more hydroponic systems, and solar power. Currently a solar powered eight by twelve- foot greenhouse is being used to hydroponically grow Goji Berries, Moringa, Bamboo, Kale, Chia, and Sweet Potatoes. When these foods are combined they contain a complete necessary set of amino acids, vitamins, minerals, fiber, carbohydrates, and nutrients for a balanced human diet. The plants receive 590 W/m^2 by utilizing a shade cloth over the entire greenhouse and the solar panels. In conclusion, the report states that NASA and alike companies will obtain valuable stepping stones in future missions to Mars by maximizing the growth of superfoods with utilization of natural light, and a focus on a hydroponics system as the farming method for space

The Penguin: a Low Reynolds Number Powered Glider for Station Keeping Missions

The Penguin is a low Reynolds number (approx. 100,000) remotely piloted vehicle (RPV). It was designed to fly three laps indoors around two pylons in a figure-eight course while maximizing loiter time. The Penguin's low Reynolds number mission is an important one currently being studied for possible future flights in the atmospheres of other planets and for specialized military missions. Although the Penguin's mission seemed quite simple at first, the challenges of such low Reynolds number flight have proven to be quite unique. In addition to the constraint of low Reynolds number flight, the aircraft had to be robust in its control, highly durable, and it had to carry a small instrument package. The Penguin's flight plan, concept, performance, aerodynamic design, weight estimation, structural design, propulsion, stability and control, and cost estimate is detailed

Calculation of the photoionization with de-excitation cross sections of He and helium-like ions

We discuss the results of the calculation of the photoionization with de-excitation of excited He and helium-like ions Li$^{+}$ and B$^{3+}$ at high but non-relativistic photon energies $\omega$. Several lower $^{1}S$ and $^{3}S$ states are considered. We present and analyze the ratios $R_{d}^{+\ast}$ of the cross sections of photoionization with de-excitation, $\sigma_{(d)}^{+\ast}(\omega)$, and of the photo-ionization with excitation, $\sigma ^{+\ast}(\omega)$. The dependence of $R_{d}^{+\ast}$ on the excitation of the target object and the charge of its nucleus is presented. Apart to theoretical interest, results obtained can be verified using such long living excited state as $2^{3}S$ of He.Comment: 10 pages, 6 table

On the role of shake-off in single-photon double ionization

The role of shake-off for double ionization of atoms by a single photon with finite energy has become the subject of debate. In this letter, we attempt to clarify the meaning of shake-off at low photon energies by comparing different formulations appearing in the literature and by suggesting a working definition. Moreover, we elaborate on the foundation and justification of a mixed quantum-classical ansatz for the calculation of single-photon double ionization

Quasi-one-dimensional Bose gases with large scattering length

Bose gases confined in highly-elongated harmonic traps are investigated over a wide range of interaction strengths using quantum Monte Carlo techniques. We find that the properties of a Bose gas under tight transverse confinement are well reproduced by a 1d model Hamiltonian with contact interactions. We point out the existence of a unitary regime, where the properties of the quasi-1d Bose gas become independent of the actual value of the 3d scattering length. In this unitary regime, the energy of the system is well described by a hard rod equation of state. We investigate the stability of quasi-1d Bose gases with positive and negative 3d scattering length.Comment: 5 pages, 3 figure

Quantitative Study of Magnetotransport through a (Ga,Mn)As Single Ferromagnetic Domain

We have performed a systematic investigation of the longitudinal and transverse magnetoresistance of a single ferromagnetic domain in (Ga,Mn)As. We find that, by taking into account the intrinsic dependence of the resistivity on the magnetic induction, an excellent agreement between experimental results and theoretical expectations is obtained. Our findings provide a detailed and fully quantitative validation of the theoretical description of magnetotransport through a single ferromagnetic domain. Our analysis furthermore indicates the relevance of magneto-impurity scattering as a mechanism for magnetoresistance in (Ga,Mn)As.Comment: 5 pages, 4 figures; v2: missing references included, figures recompressed to improve readabilit