Suborbital Research Articles

Shared Metabolic Remodeling Processes Characterize the Transcriptome of Arabidopsis thaliana within Various Suborbital Flight Environments

Abstract The increasing availability of flights on suborbital rockets creates new avenues for the study of spaceflight effects on biological systems, particularly of the transitions between hypergravity and microgravity. This paper presents an initial comparison of the responses of Arabidopsis thaliana to suborbital and atmospheric parabolic flights as an important step toward characterizing these emerging suborbital platforms and their effects on biology. Transcriptomic profiling of the response of the Arabidopsis ecotype Wassilewskija (WS) to the aggregate suborbital spaceflight experiences in Blue Origin New Shepard and Virgin Galactic SpaceShipTwo revealed that the transcriptomic load induced by flight differed between the two flights, yet was biologically related to traditional parabolic flight responses. The sku5 skewing mutant and 14-3-3κ:GFP regulatory protein overexpression lines, flown in the Blue Origin and parabolic flights, respectively, each showed altered intra-platform responses compared to WS. An additional parabolic flight using the F-104 Starfighter showed that the response of 14-3-3κ:GFP to flight was modulated in a similar manner to the WS line. Despite the differing genotypes, experimental workflows, flight profiles, and platforms, differential gene expression linked to remodeling of central metabolic processes was commonly observed in the flight responses. However, the timing and directionality of differentially expressed genes involved in the conserved processes differed among the platforms. The processes included carbon and nitrogen metabolism, branched-chain amino acid degradation, and hypoxic responses. The data presented herein highlight the potential for various suborbital platforms to contribute insights into biological responses to spaceflight, and further suggest that in-flight fixation during suborbital experiments will enhance insights into responses during each phase of flight.

A Proposal of a Life-Cycle for the Development of Sounding Rockets Missions

Suborbital flight experiments, carried out through sounding rockets, have been employed for scientific and technological research since the beginning of the space age, in the late 1950s. In Brazil, sounding rocket campaigns have been carried out since 1965, when the Centro de Lançamento Barreira do Inferno (CLBI) began its operation, having the Instituto de Aeronáutica e Espaço (IAE) as the primary provider of vehicles. IAE has also provided vehicles for international programs, such as the TEXUS and MASER microgravity programs, implemented by the European Space Agency (ESA), with launching campaigns based in the European territory. To implement each Brazilian mission that uses IAE’s sounding rockets, a set of activities focused on mission objectives is planned and implemented. Although structured and executed quite similarly to a project, such sounding rocket campaigns do not have their complete life-cycle studied and formally described in phases, review meetings, management processes and verification and validation philosophy. In the present work, the attempt has been to characterize a sounding rocket mission as a project and then, based on European Cooperation for Space Standardization (ECSS) standards, propose a reduced life-cycle to develop such projects, tailored to meet Brazilian sounding rocket missions. The proposed life-cycle, adapted to Brazilian sounding rocket missions, is then compared with two other sounding rocket campaigns life-cycles: one from the European Programme for Life and Physical Sciences in Space and the other from the National Aeronautics and Space Administration (NASA) sounding rocket program. The study and availability of a framework for implementing and managing sounding rocket missions will improve the reliability of such endeavors and speed up their organization.

APL JANUS System Progress on Commercial Suborbital Launch Vehicles: Moving the Laboratory Environment to Near Space

Abstract Multiple private companies are building suborbital reusable launch vehicles possessing vastly different designs. Many of these companies originally focused on space tourism; however, revolutionary applications for scientific and engineering research as well as technology demonstrations and instrument development are emerging. The dramatic reduction in cost over traditional launch systems as well as a guaranteed (and rapid) safe payload return enable many new launch vehicle applications. These new capabilities will essentially move the laboratory environment up to the edge of space. To make use of these novel launch vehicles, the John Hopkins University Applied Physics Laboratory has established a Commercial Suborbital Program with a core system (JANUS) to support and enable many future suborbital missions. This program has already conducted six suborbital flight missions to establish vehicle interfaces and analyze the suitability and limits of each flight environment. Additionally, this program has also been selected by the NASA Flight Opportunities Program for five additional operational suborbital missions. Here we present the results of our completed missions as well as descriptions of future selected missions scheduled for 2021–2023.

Using Tapered Channels to Improve LAD Performance for Cryogenic Fluids: Suborbital Testing Results

Abstract Improvement of cryogenic fluid storage and transfer technology for in-space propulsion and storage systems is required for long-term space missions. Screened channel liquid acquisition devices (LADs) have long been used with storable propellants to deliver vapor-free liquid during engine restart and liquid transfer processes. The use of LADs with cryogenic fluids is problematic due to low temperatures associated with cryogenic fluids. External heat leaks will cause vapor bubbles to form within the LADs that are difficult to remove in the existing designs. A tapered LAD channel has been proposed to reliably remove vapor bubbles within the device without costly thrusting maneuvers or active separation systems. A model has been developed to predict bubble movement within tapered LAD channels, and subsequent ground testing was completed with a simulant fluid to provide model validation data. Suborbital microgravity testing of tapered LAD technology was recently completed with two different simulant fluids and demonstrated that the concept can passively expel vapor bubbles within the channel. Two additional suborbital flights have been funded to further develop this technology by investigating the performance of larger scale versions of the design.

From Space Tourism to Commercial Suborbital Travel

After several announcements last years, the recent successful flights with Jeff Bezos and Richard Branson as passengers have brought the space tourism topic back at the top of news headlines. Indeed, several projects have undergone incremental and careful development steps last years to ensure a sufficient reliability of such flights with passengers on board. The perfect re-entry of both the New Shepard system of Blue Origin and the Unity system of Virgin Orbit in July 2021 are now opening the path for commercial space tourism flights, with several hundreds of candidates having paid either substantial advance payments or even the total ticket price and a rising demand after these demonstrations. This evolution can be compared with the first flights in the aeronautical field starting in 1919, when, at the end of WW1, experienced pilots and proven (ex-military) planes were used to carry air tourists at short turn-around flights. This rapidly evolved a few years later in regular commercial Point-to-Point air traffic, with the first air connection Paris London Paris. We can easily forecast a similar evolution in suborbital transport of cargo and passengers after the first wave of space tourism. Similar as with the first aviation tourism, where passengers got a first sensation of flying and were then brought back to the starting point after a few minutes, suborbital space experience will soon evolve in so called pointto-point suborbital flights, covering intercontinental travel in 60-80 minutes in one go, which now takes up more than 21 hours, like a trip London-Sydney with one stopover. This article will focus on the feasibility of such development, focusing in the first place on the potential business case and the economic rationale. It will be demonstrated that for ‘time-poor, cash-rich’ people such suborbital intercontinental travel will be a viable option and a potential market.

Mathematical Simulation and Experimental Investigation of a Contactless Measuring Section in the Problem on High-Velocity Ballistic Flights

Mathematical Simulation and Experimental Investigation of a Contactless Measuring Section in the Problem on High-Velocity Ballistic Flights

Analysis Ballistic Flight and Design of Control System RKX200TJ/Booster at Rocket Booster and Climb Phases

The problem encountered while developing the RKX-200TJ/booster is the measurement of mass vehicle (center of gravity). The thrust line of the rocket booster does not coincide with the center of gravity can induce a pitch disturbance. By controlling the pitch parameter, the pitch disturbance phenomenon can be minimized. In this paper is presented the flight performance and dynamics analysis and the design of pitch and roll control system for RKX200TJ/booster during rocket booster and climb phase. The result indicates that the pitch disturbance can be reduced until decrease about 27% whereas roll angle ( ) can be damped at zero level ( ). Pitch angle ( ) can be maintained at angle 5° for climb phase. Although the one of moment arm case shows the static instability and uncontrollability during rocket booster phase, the control system can control vehicle the further phase. This simulation presented in X-Plane and Simulink. The PID controller is selected in control system design.

Simulated Hypergravity Activates Hemostasis in Healthy Volunteers.

BackgroundHypergravity may promote human hemostasis thereby increasing thrombotic risk. Future touristic suborbital spaceflight will expose older individuals with chronic medical conditions, who are at much higher thromboembolic risk compared with professional astronauts, to hypergravity. Therefore, we tested the impact of hypergravity on hemostasis in healthy volunteers undergoing centrifugation.Methods and ResultsWe studied 20 healthy seated men before and after 15 minutes under 3 Gz hypergravity on a long‐arm centrifuge. We obtained blood samples for hemostasis testing before, immediately after, and 30 minutes after centrifugation. Tests included viscoelastic thromboelastometry, platelet impedance aggregometry, endothelial activation markers, blood rheology testing, microparticle analyses, and clotting factor analysis. Exposure to hypergravity reduced plasma volume by 12.5% (P=0.002) and increased the red blood cell aggregation index (P<0.05). With hypergravity, thrombelastographic clotting time of native blood shortened from 719±117 seconds to 628±89 seconds (P=0.038) and platetet reactivity increased (P=0.045). Hypergravity shortened partial thromboplastin time from 28 (26–29) seconds to 25 (24–28) seconds (P<0.001) and increased the activity of coagulation factors (eg, factor VIII 117 [93–134] versus 151 [133–175] %, P<0.001). Tissue factor concentration was 188±95 pg/mL before and 298±136 pg/mL after hypergravity exposure (P=0.023). Antithrombin (P=0.005), thrombin‐antithrombin complex (P<0.001), plasmin‐alpha2‐antiplasmin complex (0.002), tissue‐plasminogen activatior (P<0.001), and plasminogen activator inhibitor‐1 (P=0.002) increased with centrifugation. Statistical adjustment for plasma volume attenuated changes in coagulation.ConclusionsHypergravity triggers low‐level hemostasis activation through endothelial cell activation, increased viscoelasticity, and augmented platelet reactivity, albeit partly counteracted through endogenous coagulation inhibitors release. Hemoconcentration may contribute to the response.

Beamline and Flight Comparisons of the ARMAS Flight Module With the Tissue Equivalent Proportional Counter for Improving Atmospheric Radiation Monitoring Accuracy

AbstractIonizing radiation at aircraft and commercial suborbital spaceflight altitudes is driven by space weather and is a health concern for crew and passengers. We compare the response functions of two radiation detectors that were exposed to four different ground‐based laboratory radiation fields as well as flown alongside each other on aircraft. The detectors were a tissue equivalent proportional counter (TEPC) and a Teledyne silicon micro dosimeter chip that was integrated into an Automated Radiation Measurements for Aerospace Safety Flight Module (ARMAS FM). Both detectors were flown onboard commercial and research aircraft. In addition, both detectors were exposed neutrons at the Los Alamos Neutron Science Center, protons at Loma Linda University Medical Center, 56Fe particles at the NASA Space Radiation Laboratory, and also a gamma radiation source at Lawrence Livermore National Laboratory. The response of each of these instruments as well as derived dosimetric quantities are compared for each radiation exposure and the ratio for converting ARMAS absorbed dose in silicon to an estimated absorbed dose in tissue is obtained. This process resulted in the first definitive calibration of the silicon‐based detector like ARMAS to TEPC. In particular, with seven flights of both instruments together, the ARMAS‐derived dose in tissue was then validated with the TEPC‐measured dose in tissue and these results are reported. This work provides a method for significantly improving the accuracy of radiation measurements relevant to human tissue safety using a silicon detector that is easy to deploy and can report data in real time.

Preliminary Study of Launch and Orbit of a CubeSat Using a Modified VSB-30 Launcher Vehicle

During the last decade, the world faced the mass insertion of small satellites in the space technology scenario. Every year, the number of micro and nanosatellites launched increases and gets more attention from players in the space market. Despite the lack of a national launcher, the Brazilian Space Program is known for some successful development in the last century, including its space assets, such as a privileged launch site near the equator, a family of flight proven and reliable sounding rockets for suborbital flights and microgravity experiments and universities with established small satellites programs. Thereby, the present work proposes a modification of the Brazilian VSB-30 sounding rocket in order to allow the launch and insertion in low Earth orbit (LEO) of small satellites fulfilling the gap of a national launcher. It also presents a CubeSat orbital decay simulation and orbital insertion simulation with the modified rocket launched from the Alcântara Launch Center as a matter of verifying the potential of national missions using this modified launcher.

A multi-spectral polarimetric imager for atmospheric profiling of aerosol and thin cloud: Prototype design and sub-orbital performance

We report on the development of a novel multi-spectral polarimetric imager for atmospheric remote sensing of aerosol and cloud properties. The instrument concept, called the Aerosol Limb Imager (ALI), is ultimately intended for satellite measurements from a low Earth orbit. It utilizes a coupling of a dual transducer acousto-optic tunable filter and a liquid crystal rotator to provide dual linear polarization observations over a wide spectral range covering 600 nm-1500 nm. In the limb, or side-viewing, geometry, these measurements provide the capability to resolve vertical and horizontal distributions of aerosol and cloud properties such as extinction coefficient, optical depth, and particle distribution parameters. Here, we present the design and performance of an ALI prototype. Lab characterization of the instrument is used to develop a mathematical instrument model to predict signal levels under various atmospheric conditions. Results from a sub-orbital flight of the ALI prototype on a stabilized high-altitude stratospheric balloon gondola are presented that show the first known polarimetric, multi-spectral images of the limb radiance. The signal levels obtained agree reasonably well with those predicted by the instrument model using radiative transfer calculations for typical atmospheric conditions.

Trajectory Estimation for Particles Observed in the Vicinity of (101955) Bennu

AbstractWe analyze the trajectories of 313 particles seen in the near‐Bennu environment between December 2018 and September 2019. Of these, 65% follow suborbital trajectories, 20% undergo more than one orbital revolution around the asteroid, and 15% directly escape on hyperbolic trajectories. The median lifetime of these particles is ∼6 hr. The trajectories are sensitive to Bennu's gravitational field, which allows us to reliably estimate the spherical harmonic coefficients through degree 8 and to resolve nonuniform mass distribution through degree 3. The particles are perturbed by solar radiation pressure, enabling effective area‐to‐mass ratios to be estimated. By assuming that particles are oblate ellipsoids of revolution, and incorporating photometric measurements, we find a median axis ratio of 0.27 and diameters for equivalent‐volume spheres ranging from 0.22–6.1 cm, with median 0.74 cm. Our size distribution agrees well with that predicted for fragmentation due to diurnal thermal cycling. Detailed models of known accelerations do not produce a match to the observed trajectories, so we also estimate empirical accelerations. These accelerations appear to be related to mismodeling of radiation pressure, but we cannot rule out contributions from mass loss. Most ejections take place at local solar times in the afternoon and evening (12:00–24:00), although they occur at any time of day. We independently identify ten ejection events, some of which have previously been reported. We document a case where a particle ricocheted off the surface, revealing a coefficient of restitution 0.57±0.01 and demonstrating that some apparent ejections are not related to surface processes.

Optimal control of propellant consumption during vertical lifting of rocket in homogeneous atmosphere using regularized solution of integral equation of the first kind

The article is devoted to the study of the optimal control of propellant consumption during vertical lifting of rocket in homogeneous atmosphere using regularized solution of integral equation of the first kind. The problem of lifting of a rocket into desired height along optimal trajectory in the view of minimal consumption of propellant leads to solving the set of differential and integral equations. Problem of optimal control of propellant consumption during lifting of rocket in homogeneous atmosphere is solved using regularized solution of integral equation of the first kind which is solution of corresponding Euler equation on discrete time net. Influence of the regularization parameter and some additional parameters on precision of discreted problem is investigated. Considered algorithm is summed up easily to the case of non-homogeneous atmosphere by introducing dependence of the ballistic coefficient on altitude of flight and to problem of putting spacecraft into determined orbit and suborbital flights by setting desired altitude and velocity and modifying of motion equations.

Machine Learning for 3D Particle Tracking in Granular Gases

Dilute ensembles of granular matter (so-called granular gases) are nonlinear systems which exhibit fascinating dynamical behavior far from equilibrium, including non-Gaussian distributions of velocities and rotational velocities, clustering, and violation of energy equipartition. In order to understand their dynamic properties, microgravity experiments were performed in suborbital flights and drop tower experiments. Up to now, the experimental images were evaluated mostly manually. Here, we introduce an approach for automatic 3D tracking of positions and orientations of rod-like particles in a dilute ensemble, based on two-view video data analysis. A two-dimensional (2D) localization of particles is performed using a Mask R-CNN neural network trained on a custom data set. The problem of 3D matching of the particles is solved by minimization of the total reprojection error, and finally, particle trajectories are tracked so that ensemble statistics are extracted. Depending on the required accuracy, the software can work fully self-sustainingly or serve as a base for subsequent manual corrections. The approach can be extended to other 3D and 2D particle tracking problems.

Sloshing and pressurization tests for membrane tank: Tests, validation and models

This paper presents recent 1:1 scaled tests results for sloshing, pressurization and evacuation behaviour in membrane tanks used for spacecrafts and satellites. The first 1:1 scale sloshing test setup evaluates fluid reaction forces for axial, lateral and spin excitations at different fill level. Evaluation and determination of sloshing forces during relevant flight phases is important for flight stability and GNC layout. The test evaluates the impact of pressure level, membrane position, acceleration level and excitation direction. Mathematical reaction force models for accelerated and ballistic flight phases are presented. The second 1:1 scale pressurization test setup shows the transient membrane position during Helium pressurization and evacuation at realistic flow rates. During launch in depressurized condition the mechanical impact on the membrane launch may be reduced in the membrane tank such that the membrane is supported by the tank wall and surrounded by vapour and dissolved gas below the membrane. The tests provide important information of the membrane state for drying, filling procedures and on-flight pressurizations effects. The membrane position during depressurization is dependent on fill level, vapour generation, dissolved gas amount in the test fluid and pressurization rate. The paper evaluates this evaporation and condensation effect below the membrane during the depressurization and repressurization process. Video recordings show the membrane position and gas state inside the membrane tank. In addition complementary test in a vacuum chamber are presented to support the analysis and allow optical observation from the outside.

Design of a Projectile-Borne Data Recorder Triggered by Overload

The projectile-borne data recorder is used to measure and record the position and attitude data of exterior ballistic flights, which experience high overload during the launching process. The navigation algorithm can be optimized by analyzing the data stored in the recorder. As the primary means of acquiring the navigation data, the micro inertial measurement unit (MIMU) is an inevitable part of the projectile equipment. However, its mechanical structure could hardly bear the high overload during operation. In view of the above problems, a novel projectile-borne data recorder triggered by overload is designed in this paper. The recorder could have the navigation system powered when the projectile leaves the barrel so as to activate the data recording of the high overload. Furthermore, the viability of the MIMU of the high overload is guaranteed through a specific way of system encapsulation. In the proposed design, the overload switch redundancy and the power supply redundancy were adopted to improve reliability. The proposed design is tested with practical experiments, and the results show that the proposed recorder could be effectively triggered by overloading, and the supply voltage is stable, which helps record reliable data for the projectile.

Patterns with Cold Atoms in a Square Optical Lattice

We consider coherent dynamics of cold atoms in a square optical lattice without interference between counter-propagating laser beams. The dynamics is treated within the framework of semi-classical approximation, taking into account a coupling between the atom internal and external degrees of freedom. The corresponding set of equations of motion has been found before to be regular or chaotic in dependence on the values of the control parameters, the detuning between the atomic transition and laser frequencies, and the atom recoil frequency. In this paper, we carry out numerical experiments on spreading of cold atomic clouds in the lattice under different values of the detuning, keeping the recoil frequency to be fixed. The distributions of atoms differ strongly providing a way to control atomic transport by tuning just a single control parameter called the detuning. It is possible to drive cold atoms through different regimes of translational motion, from regular ballistic flights to chaotic walking. A possibility to observe the effect of chaotic walking in real experiments is discussed.

Aerothermodynamics and thermal design for on-ground and in-flight testing of a deployable heat shield capsule

The article deals with the aerothermodynamic and thermal analysis of two technological demonstrators suitable for research activities on deployable heatshield entry capsules. Variable geometry bodies represent a formidable way to build low ballistic coefficient entry platforms able to limit convective heat fluxes, mechanical loads, and final descent velocity. These characteristics suggest several interesting applications for space missions such as to exploit those systems for human or large payloads landing on Mars. The main feature of the demonstrators is the umbrella-like deployable heatshield made of a flexible thermal protection system. In this framework, the work reports on the design analyses carried out for a flight and a ground demonstrator developed to prove, with suborbital flight and plasma wind tunnel test campaigns, several key technologies of the deployable heatshield. Several non-equilibrium three-dimensional flowfield simulations were performed to assess the aerothermal loading conditions expected for the demonstrators. Pressure and heat flux distributions on the deployable heatshield are provided and discussed. Finally, those surface loading conditions are set to feed a finite-element thermal analysis of the demonstrators, also detailed in the work.

The Portuguese Space Act: An Innovative Framework for Space Activities

This article examines Portugal’s legal and regulatory framework for space activities, including on authorization, pre-qualification, registration, liability and insurance. It analyses the choices made at both the national and regional levels, including in light of the country’s international obligations under the UN Space Treaties and the evolution of the space sector in matters such as small satellites, constellations of satellites, suborbital flights and space mining. It notes that the legal framework is business-friendly but that there are issues that require further clarification, a goal that will no doubt be achieved once launches from the future Azores spaceport begin. National Space Act, Regional Space Act, small satellites, constellation of satellites, Azores spaceport

Research on fast switching interception of the real target

In order to distinguish the decoy missile from the real in the middle of the ballistic missile flight, we proposed using image recognition and sliding-mode guidance in the kinetic energy interceptor terminal guidance phase. The paper set background on the kinetic energy interceptor in the middle course of ballistic missile flight. Due to the influence of the dummy target, the preset interception point is out of alignment and interceptors require terminal guidance adjustment. In this paper, two different global fast Terminal sliding modes are used to establish the intercept model equation. By simulink simulation comparison, it is found that the sliding mode guidance proposed in this paper can quickly and effectively switch interception orbit to hit the target.