The problem of optimal guidance of a low-altitude skid-to-turn vehicle is considered. In particular, the skid-to-turn vehicle is both guided and controlled using a recently developed computational optimal guidance and control method that employs hp Gaussian quadrature collocation. First, this recently developed method is used to re-solve the optimal control problem on a shrinking horizon at constant

An experimental test campaign was conducted for a rotating detonation rocket engine (RDRE) using gaseous oxygen and RP-2 at operating pressures of 3–18 atm. The copper chamber outer wall was instrumented with embedded thermocouples to provide insight into heat-flux levels for various locations in the chamber at numerous operating conditions and wave topologies. Results were compared to throat-level

This Paper presents the feasibility of estimating the mass of an asteroid by tracking a number of probes ejected from a host spacecraft during a flyby. The probes are designed to fly by at a much closer distance to the asteroid than the host spacecraft, which lowers the risk of endangering the overall mission. The motion of these probes is perturbed due to the target asteroid’s mass, and by tracking

A performance analysis for aerocapture at Uranus and Neptune is presented and considers entry corridor width, peak deceleration, peak heat rate, total heat load, and the effect of postcapture orbit on the design parameters. Aerocapture mass benefit vs chemical capture is also quantified. Design relationships are found that can be used in flight system sizing for future studies involving aerocapture

Identifying the optimal design of a new launch vehicle is most important because design decisions made in the early development phase limit the later performance of the vehicles and determine the associated costs. Reusing the first stage via retropropulsive landing increases the complexity even more. Therefore, an optimization framework for partially reusable launch vehicles is developed, which enables

Journal of Spacecraft and Rockets, Ahead of Print.

High-speed laminar-to-turbulent transition over blunt bodies is relevant to a variety of aerodynamic applications. Experiments have observed that beyond a critical value of the nose radius the initially downstream movement of transition location is reversed. Linear stability and receptivity analyses have been unsuccessful at predicting this reversal. The current Paper uses a random forcing approach

DESTINY+ is a medium-class interplanetary mission, selected by the Japan Aerospace Exploration Agency for potential launch windows in the first half of 2020s. The mission will demonstrate innovative spacecraft subsystem technologies, including a new type of ion engine for future missions. The mission will also collect scientific data through high-speed flyby observations and dust measurements from

Entry flight performance is assessed for single-stage discrete-event drag-modulation trajectory control on Mars with two different real-time guidance algorithms: a heuristic velocity trigger and numerical predictor–corrector. Three degree-of-freedom simulation and Monte Carlo techniques are used to determine flight performance across a range of mission and vehicle design parameters. Trends are identified

Journal of Spacecraft and Rockets, Ahead of Print.

The deflecting asteroid by dusting (DAD) mission addresses the challenges of deflecting a potentially hazardous asteroid (PHA) that has a large probability of impacting Earth. It is an innovative and mass-minimalist approach to exploit PHAs by using the dusting deflection method. This conceptual design is developed based on an asteroid space duster, which is a space miner that is equipped with dust

Imaging cameras are cost-effective sensors for spacecraft navigation. Image-driven techniques to extract the target spacecraft from its background are efficient and do not require pretraining. In this paper, we introduce several image-driven foreground extraction methods, including combining the difference of Gaussian-based scene detection and graph manifold ranking-based foreground saliency generation

This analysis estimates collision risks between tracked satellites based on the statistically expected collision rate N˙c and number of collisions Nc, which are closely related to the collision probability Pc. For isolated encounters, Nc equals Pc. For multi-encounter interactions, Nc can exceed Pc and is significantly easier to approximate semi-analytically. Estimating Nc requires integrating the

Spin stabilization is a commonly used form of passive attitude control for spacecraft. The use of ball-in-tube dampers has been studied extensively for oblate spacecraft. It is widely known from classic rigid-body dynamics that, in the presence of energy dissipation, pure spin is stable only when performed about the axis associated with the maximum central principal moment of inertia. In this study

Spacecraft commonly use multilayer insulation (MLI) on fixed panels and bodies to assist with thermal management of the system. This paper describes the design of an origami pattern that allows MLI to be used on deployable structures, specifically telescoping booms. Origami patterns have well-defined fold lines that provide predictable compression and extension of the MLI, which allows for high compression

This paper describes an algorithm obtained by merging a recursive star-identification algorithm with a recently developed adaptive singular-value-decomposition-based estimator of the angular-velocity vector (QuateRA). In a recursive algorithm, the more accurate the angular-velocity estimate is, the quicker and more robust to noise is the resultant recursive algorithm. Hence, combining these two techniques

The increasing capabilities of the CubeSat platform have led to growing interest in performing more complex commercial and science missions with these miniature spacecraft. In particular, electric propulsion provides unprecedented mission ΔV and enables ambitious but low-cost Earth missions as well as lunar, asteroid, and interplanetary exploration. As a case study, a 6 U (where U represents a 10×10×10

This paper discusses the analysis of the UHF (401 MHz) plasma-induced communications blackout (and brownout) experienced by the Mars InSight spacecraft during its entry, descent, and landing (EDL) phase into the Martian atmosphere on 26 November 2018. The UHF relay links from InSight to the Mars Reconnaissance Orbiter and to the Mars Cube One A and Mars Cube One B CubeSats suffered a period of about

A nonlinear dynamic modeling method for solar-sail mast under solar load is proposed in this paper. To further predict accurately the dynamic behaviors of solar-sail masts, nonlinear dynamic equation considering nonlinear geometric parameters and nonlinear strain of the mast is acquired by absolute nodal coordinate formulation. The absolute nodal coordinate formulation (ANCF) is improved by introducing

Chamber pressure, as it develops during rocket combustion, strongly correlates with many of the internal motor ballistic properties, including combustion stability, fuel regression rate, and mass flow. Chamber pressure is also an essential measurement for calculating achieved thrust coefficient and characteristic velocity. Because of the combustion environment hostility, sensing chamber pressure with

Water vapor plumes emanating from the geyser vents at Enceladus’s south pole area invite the possibility of direct access to the subsurface liquid reservoir to acquire pristine biological material if it exists. Any descending lander adapted for plume localization is required to not only explore the icy plume environment during its descent, but it must also infer the location of the landing target—the

This study focused on the hierarchical modular approach to assembling space structures, which can be scaled up to increasingly larger sizes. This approach is based on dividing a large space structure into multiple modules, each with homogeneous automatic assembly functions. Hence, the overall structure can have diverse shapes and functions depending on the arrangement of modules, regardless of the

The problem of performance optimization of a skid-to-turn vehicle is studied. The objective is to minimize the time required to steer the vehicle from an initial state at a nonzero altitude to a ground target state subject to constraints on altitude and crosstrack. A performance index is designed that enables the vehicle to fly at a constant low altitude for as long as possible while performing a bunt

Journal of Spacecraft and Rockets, Volume 58, Issue 1, Page 4-5, January 2021.

Journal of Spacecraft and Rockets, Volume 58, Issue 1, Page 1-3, January 2021.

This paper addresses the problem of singularity avoidance in a four-control-moment-gyroscope cluster as used for the attitude control of a satellite. A global search algorithm is developed that adjusts the null motion added upon the singularity robust inverse steering law. Its principal characteristic is that it uses global information gathered from the whole maneuver, compared to most conventional

A feasibility study related to the scale-up of solid fuel with multiport was performed using the regression rate equation derived from a laboratory-scale hydrogen peroxide (H2O2) hybrid rocket using a single-port solid fuel. First, a 250-N-class hybrid rocket using a single-port solid fuel was designed and experiments were conducted to derive the regression rate equation. Based on the derived equation

This paper introduces a guidance strategy for spacecraft proximity operations, which leverages deep reinforcement learning, a branch of artificial intelligence. This technique enables guidance strategies to be learned rather than designed. The learned guidance strategy feeds velocity commands to a conventional controller to track. Control theory is used alongside deep reinforcement learning to lower

The multidimensional geometric effects within the heat shield of the Stardust sample return capsule are studied over its reentry trajectory, using a material response solver. The solver models material charring, conductive heat transfer, surface energy balance, pyrolysis gas transport, and orthotropic material properties in three dimensions. The material response of the heat shield is computed using

The understanding of rocket plume–surface interaction on planetary bodies will drive safer and more sustainable exploration missions. To that end, the average plume-induced erosion rate of the Mars InSight lander during its powered descent was estimated at 60.4 kg/s. The volume of material displaced and final form of the site were reconstructed photogrammetrically using postlanding images captured

Hypersonic International Flight Research Experimentation 5 (HIFiRE-5) is a hypersonic flight-test experiment designed to investigate the aerothermodynamics of a 3-D geometry. The vehicle is an elliptic cone with a 2:1 aspect ratio and 2.5 mm nose radius. The HIFiRE-5b achieved a Mach number of 7.7–7.9 and freestream unit Reynolds number of 5⋅106/m to 50⋅106/m during descent. Heat flux was calculated

Many low-Earth-orbit constellations consist of multiple small satellites that are launched together in batches, and which make use of differential atmospheric drag for subsequent deployment and phasing. Depending on the initial altitude, this process can potentially take many months, or even years, to complete, and satellite altitudes can only ever be decreased, potentially affecting mission lifetimes

This paper describes a method for characterizing the 1–3 mm low Earth orbit (LEO) debris environment using satellite perturbation data (unexpected, sudden orbital movements not attributable to other sources), evidenced by changes in Global Positioning System position, temporary breaks in communication links, and other methods. This technique is used to point out a potential overprediction of risk in

Liquid-propellant slosh occurrence in spacecraft continues to introduce instability-induced failures. Current mechanical models are insufficient in predicting differences in slosh frequencies for varying tank structure flexibilities. This paper is focused on 3-D high-fidelity computational simulation of sloshing in liquid-filled tanks under dynamic loads using the arbitrary Lagrangian–Eulerian method

The InSight mission landed on the surface of Mars on 26 November 2018. The InSight system performance met all design requirements, although several performance metrics fell near the boundaries of the predictions. The peak deceleration was high, the overall timeline was short, and the landing site was uprange and crossrange from the target. This paper describes the reconstruction of the entry, descent

Journal of Spacecraft and Rockets, Ahead of Print.

Journal of Spacecraft and Rockets, Ahead of Print.

The harsh environment of Venus poses a significant challenge for the design of lightweight surface probes. The authors investigated isogrid-stiffened spherical shells produced by additive manufacturing. A Ti-6Al-4V, 1.12-m-diam lightweight structural shell capable of surviving a Venus surface environment was designed and assessed via analytical methods and finite element modeling. Subscale components

Journal of Spacecraft and Rockets, Ahead of Print.

ZURAM is an ablative carbon–phenolic thermal protection material, developed by the DLR, German Aerospace Center (DLR) in cooperation with the Institute of Space Systems, University of Stuttgart. In addition to building up a basic competence in the sector of ablative thermal protection materials, an objective of the development was to provide a nonclassified ablative material for university research

For a returnable hypersonic cruise vehicle, the whole trajectory design is strongly coupled to the cruise state. To deal with the coupling relationship, a bilevel trajectory optimization problem is proposed in this paper. The upper level is for single-objective optimization of the whole trajectory, whereas the lower level is to conduct multiobjective optimization of the cruise flight. Based on the

The concept of reducing environmental impact from a launch vehicle after the emergency cutoff of the liquid-propellant engine is proposed. A key component of the proposed concept is an onboard propellant gasification system, installed on the rocket blocks of the launch vehicle. The onboard propellant gasification system performs forced gasification of the propellant residues in the tanks of the launch

Recent successful recovery techniques for rockets require that rockets maintain a vertical configuration with zero vertical and lateral velocities; otherwise, landings may fail. To relax this requirement, a new active-arresting system (inspired by the arresting gears used on aircraft carriers) is proposed herein to achieve a robust landing, even if the rocket deviates from the target position or has

The objective of the Boundary Layer Transition (BOLT) flight experiment is to investigate the hypersonic boundary-layer transition mechanisms on a low-curvature concave surface with a swept leading edge at Mach numbers between five and seven. This shall be achieved during a captive-carry flight experiment on an S31/Improved Orion sounding rocket. The BOLT project is coordinated by the U.S. Air Force

Journal of Spacecraft and Rockets, Ahead of Print.

The anomalous spin of the Huygens probe on Titan is simulated with a simple model, which is also applied to the (also anomalous) spin history from a terrestrial parachute drop test. The model considers two parameters: a “setting angle,” which defines an equilibrium spin rate for a given descent speed, and a coefficient, which defines how quickly the probe spin changes to reach that equilibrium. The

Subcentimeter debris has been proven to cause significant damage to Earth-orbiting spacecraft sensors and subsystems; however, they are currently undetectable using ground-based radar and optical methods. Orbital debris will produce plasma density solitary waves, or solitons, due to their electrical charge, which propagate along the debris velocity vector, with amplitudes within the range of detectability

A new approach for folding the Yoshimura cylinder is proposed in this study. The proposed concept is based on a reconfiguration process involving a cylindrical structure with the Yoshimura pattern and the bellows fold pattern. Static analyses are conducted to confirm the effectiveness of the proposed folding methodology. A special case of folding is observed that does not create wrinkles in the fully

This paper presents a parallel-structured Newton-type guidance law for the missile guidance problems. In the proposed approach, the modified Chebyshev–Picard iteration is used to approximate the dynamic equations, by which the continuous-time guidance problem is transcribed into a sequence of discrete-time subproblems, and both serial and parallel computing can be supported. The subproblems can then

This Paper uses Reinforcement Meta-Learning to optimize an adaptive integrated guidance, navigation, and control system suitable for exoatmospheric interception of a maneuvering target. The system maps observations consisting of strapdown seeker angles and rate gyroscope measurements directly to thruster on/off commands. Using a high fidelity six-degree-of-freedom simulator, this Paper demonstrates

Landing on celestial bodies typically includes a free fall to the body surface and requires energy dissipation. Landing sites can exhibit many uncertainties, especially in surface parameters. Therefore, robustness is required irrespective of variations in landing conditions. Conventional mechanisms, such as shock absorbers or airbags, have repeatedly achieved safe landings; however, they are not reusable

Gauging propellant fuel of spacecraft in outer space has been an issue, because their liquid fuels tend to float, slosh, adhere to the tank walls, and form bubbles under low-gravity conditions. For this reason, conventional fuel gauging techniques may not be an accurate way of gauging the fuel in space. In this paper, we report a flexible monolithic printed assembly of electrocapacitive volume tomography

This paper proposes a metallic spring root hinge to effectively stow and deploy a collapsible and rollable tubular carbon fiber reinforced polymer (CFRP) boom. The proposed hinge consists of two half-cylindrical parts with narrowed regions and a hole. One of the ends of the hinge is fixed to a hub with the circular cross section, and the other end that is connected to the boom is flattened with the

Journal of Spacecraft and Rockets, Ahead of Print.

Image-based terrain relative navigation is expected to play an important role in the safe operation of upcoming lunar exploration missions. This work provides a detailed treatment of how visual odometry direction-of-motion measurements may be constructed using images from a monocular camera and without the need of an onboard map of the lunar surface. Substantial care is required to achieve best-possible

Chip scale atomic clocks (CSACs) have the potential to provide CubeSat missions with precision timekeeping capabilities to support onboard radiometric tracking, reducing dependence on ground support. This work considers a baseline orbit determination (OD) scenario for a low-Earth-orbit CubeSat, with one-way radiometric measurements made onboard using a CSAC as the timing reference. Methods for simulating

With upcoming heavy and superheavy lift rockets targeted for launch in 2021, a new class of payloads can be launched into low Earth orbit. This paper presents a design for a space station capable of being lifted by a single Blue Origin New Glenn vehicle. Once assembled on orbit, it contains more than twice the pressurized volume of the International Space Station (ISS). The pressurized volume of traditional

Future space missions, such as return from Mars, will require entry speeds of the order of 15 km/s. These harsh conditions are dominated by radiative heat flux and have large modeling uncertainties related to radiative coupling, such as precursor radiation and ablation radiation coupling. These conditions have also never been tested in a flight scenario and have limited ground testing data available

Materials used in the fabrication of landers for Venus exploration need to be carefully selected to assure functional durability throughout anticipated prolonged future mission durations in the harsh conditions that include 460°C and 9.2 MPa pressure with supercritical CO2 and trace corrosive gases. Previous work has shown the adverse effects that trace quantities of the atmospheric sulfide and halogen

This study investigates the effects of single, double, and multi-protrusion on the performance of a hybrid rocket with two different L/D ratio motors, mainly 12.5 and 18. Wax and gaseous oxygen were used as fuel and oxidizer, respectively. It has been observed from studies that the performance of a hybrid rocket is sensitive to the number of protrusions and their locations within the motor. Between