Reusable Launch Vehicle Technology Research Articles

A novel cable-net buffer device for recovering reusable launch vehicle: Design, dynamic modeling, and performance analysis

At present, reusable launch vehicle technology (RLV) has become a research hotspot in the aerospace field and one of the major development trends in this industry. With reference to the aircraft carrier’s arresting cable technology, this paper puts forward a novel cable-net buffer device for recovering the first stage of launch vehicle. The device can transfer load through a cable-pulley mechanism, and then complete the first stage recovery by losing the kinetic energy and gravitational potential energy of the first stage through hydraulic dampers and preloaded counterweights. In order to analyze the performance of this cable-net buffer device, the finite element software ABAQUS is adopted to establish a rigid-flexible coupling dynamic model. In this model, the cable-pulley mechanism is simulated by connector and shell elements, the damping force of the hydraulic dampers by VUAMP subroutine, and the preloaded counterweights by mass point. And then, performance evaluation indexes of this buffer device are proposed in this paper. Meanwhile, the dynamic simulation, using the established dynamic model, is carried out under different device design parameters and working condition parameters. On the one hand, the simulation results show that the tower span and damping force have remarkable effects on the buffer performance. On the other hand, among all working condition parameters, only the fall point deviation has a significant effect on the buffer performance, but this effect is less than that of the design parameters. Finally, combing the dynamic model and the surrogate model technique, this paper obtains feasible boundaries of design parameters of the device for the subsequent detailed design of it. Researches in this paper will provide new ideas for the development of RLV.

Mission Profile Analysis of Point-to-Point Rocket Cargo Transportation System Using Trajectory Optimization

This paper proposes new concepts for the point-to-point rocket cargo transportation system (RCTS). The RCTS is a transportation system that can deliver cargo anywhere on Earth in an hour using reusable launch vehicle technologies. As a fundamental study of global transportation on Earth, we especially address the mission profiles for short-range transportation within hundreds of kilometers using small rocket engines, which are intended for logistics transportation within neighboring countries or domestic transportation in a country. Two mission profiles of the RCTS are introduced, and the flight phases of each concept are explained in detail. The trajectory optimization problem of the RCTS is formulated based on the mission profiles, incorporating the flight constraints, boundary conditions, and an objective function that aims to maximize the payload ratio. The explicit-guidance is employed during the landing burn phase to enhance the convergence of the optimization problem by expanding the feasible region. The coevolutionary augmented Lagrangian method, one of the evolutionary algorithms, is utilized to obtain the solution for the trajectory optimization problem. The optimal trajectory and state variables are presented through numerical simulations. Additionally, parametric studies are performed to determine the payload mass trend of the RCTS. The trajectory optimization results are summarized to provide an analysis and comparison of the proposed mission profiles.

Analysis of the development of reusable launch vehicle technology

Nowadays, with the development of the space technology and the maturity of traditional launch vehicle technology, there are sufficient foundations for the research of higher-level space vehicles. As space vehicles gradually enter the commercial market, the demand for better cost control and higher carry capacity has been put forward. The recovery and reuse of space vehicles, especially launch vehicle, often means higher resource utilization and effective cost control, which has unprecedented advantages in business mode. Many countries and organizations have shown concern about the reusable vehicles. In order to facilitate the further research of reusable rocket technology, this article summaries the research and developments of reusable vehicles over the years and sorts out the overall scheme and key technologies of it. In particular, in view of the successful case of Falcon 9, this article analyses the commercialization experience of SpaceX reusable rockets and its business model. This article may offer a reference for the reusable rocket technology development.

Stability analysis and flight control design of the winged reusable launch vehicle ReFEx

The German Aerospace Center (DLR) is currently studying different technologies for reusable launch vehicles (RLVs) to evaluate and compare their benefits. The project CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss-back Operations) investigates a VTVL (vertical takeoff, vertical landing) concept. In the DLR project ReFEx (reusability flight experiment), in the context of which this paper is presented, a winged VTHL (vertical takeoff, horizontal landing) concept is investigated to develop the key technologies for future winged RLV applications, culminating in a flight experiment to demonstrate the capability of controlled autonomous return flight from supersonic to subsonic speeds. In this paper, analysis of stability and controllability is used on a three-dimensional envelope of points to derive a suitable flight corridor for the re-entry. Second, a controller concept based on inversion of the rotational equations of motion is derived. The validity of the presented controller concept is shown on a preliminary level via comparison of open-loop and closed-loop dynamics at two representative flight points and a time simulation which includes a segment of the planned mission.

Guidance command generation and nonlinear dynamic inversion control for reusable launch vehicles

Future launch vehicle concepts and technologies for expendable and reusable launch vehicles are currently investigated by the DLR research projects Akira and X-tras. In particular, the winged Liquid Fly-back Booster concept Lfbb based on an LOX/LH2 propellant combination for vertical takeoff and vertical landing (VTVL), as well as the delta-winged horizontal takeoff and horizontal landing (HTHL) concept Aurora based on an LOX/Kerosene propellant combination are considered in these projects. Because of the complexity and risks involved in on-line trajectory optimization, off-line reference trajectories are still considered important for tracking purposes. In that sense, the goal of this paper is to investigate an off-line and general-purpose guidance and control (G&C) architecture for preliminary studies of reusable launch vehicles. This is done by using trajectory optimization combined with Modelica models for the generation of optimal guidance commands, and then trajectory tracking is performed by means of inner-loop feedback controls in terms of nonlinear dynamic inversion with prescribed desired dynamics. We showcase the advantages of this baseline G&C architecture in terms of early stability and controllability aspects during the preliminary design studies of an example configuration of a reusable launch vehicle investigated in the context of the research projects above mentioned.

Multidisciplinary modeling and simulation framework for launch vehicle system dynamics and control

Future concepts and key technologies for reusable launch vehicles are currently investigated by the DLR project AKIRA, focusing on vertical takeoff and horizontal landing (VTHL), as well as horizontal takeoff and horizontal landing (HTHL) concepts. Dedicated developments of multidisciplinary frameworks for launch vehicle modeling and preliminary design optimization have been presented in the relevant literature. These activities are often performed by several independent and discipline-specific tools; such an approach can only account for limited interactions of the involved disciplines with the overall system dynamics.Therefore, the objective of this paper is to focus on a multidisciplinary launch vehicle dynamics modeling, guidance, and control framework to support reusable launch vehicle design activities at DLR while taking into account the highly interconnected disciplines involved and changing environmental conditions. The modeling framework is based on the object-oriented, multidisciplinary, and equation-based modeling language MODELICA. Dedicated 3-DOF and 6-DOF model implementations, covering the kinematics and dynamics formulation, environmental effects, aerodynamics, and propulsion models are presented.Within this framework, a method to obtain a direct connection between 3-DOF and 6-DOF models is shown. This is done by considering results from the trajectory optimization package ‘trajOpt’ in combination with nonlinear 6-DOF inverse models obtained automatically by MODELICA. Angular rates and resulting moments can be retrieved by this intermediate 6-DOF modeling approach for subsequent controllability studies. We discuss some of these benefits in terms of nonlinear flight control simulations for an HTHL reusable launch vehicle concept.

Research Progress of Key Technologies for Typical Reusable Launcher Vehicles

In recent years, driven by space X and other commercial companies, the requirement of low cost and fast response to transport, reusable launch vehicle technology is attracting the world’s attention. Aerospace agencies in various countries have stepped up research and made some progress in the related technologies of reusable launch vehicles. The development of reusable launch vehicle has become an important direction of space development in the future. First, the development status of reusable vehicles, the Space Shuttle Mode, the Falcon-9 Mode, the Launch Mode on board, and the Airborne Aircraft Mode, are introduced. Second, the structure design, the propulsion system, the recycling scheme, the thermal protection system and the launch costs of each mode is analyzed. Third, some related development suggestions are put forward in terms of the carrier configuration, the design of recycling scheme, the choose of propulsion system and the thermal protection system for reusable launch vehicle designer.

An Overview of Reusable Launch Vehicle Technology Demonstrator

After the successful operationalization of Polar Satellite Launch Vehicle and Geo Synchronous Launch Vehicle, the Indian Space Research Organisation is in the process of developing Reusable Launch Vehicle technologies to achieve low-cost access to space. Towards this programme, a winged body configuration was conceived, which can fly at subsonic, supersonic and hypersonic Mach number regime, re-enter into the earth’s atmosphere and simulate the landing manoeuvre. The aerodynamic design, analysis and wind-tunnel testing, aerothermal and structural design, analysis and testing were carried out. Suitable solid motor with slow burn rate propellant was developed. Mission design, guidance and control schemes were implemented. In order to meet the above objectives, certain technologies and infrastructure were developed. The entire subsystems were integrated and a large number of flight measurements were made in the maiden successful flight of Reusable Launch Vehicle Technology Demonstrator in May 2016. The flight measurements and flight performance indicated that the design philosophy, testing schemes and approaches followed are in order, thus providing confidence to proceed to the next logical step in the development of Reusable Launch Vehicle Technologies.

Mission Design and Performance of RLV-TD

Renewed interest in re-usable launch vehicles has led to the evolution of technology demonstration concepts, where the prime objective is to demonstrate new technologies at reduced cost and shorter turnaround time. This article presents details of both ascent and descent mission design of a low-cost Reusable Launch Vehicle Technology Demonstration (RLV-TD) programme. The technology demonstrator vehicle is boosted to hypersonic Mach number using a solid booster. During ascent phase, the vehicle was flown in a gravity turn trajectory to minimize structural loads on it. In the descent phase, an optimum angle of attack profile as a function of Mach number was computed to limit dynamic pressure, load factor and achieve vehicle trim with minimum control surface deflection. The mission design parameters were evaluated using Monte Carlo analysis utilizing six degrees of freedom simulations. Comparison of actual flight performance with pre-flight prediction is also made this article. Flight performance exhibits close match with the pre-flight predictions.

Integrated Electrohydraulic Control Actuation System with Centralized Power Plant for the Reusable Launch Vehicle Technology Demonstrator

An electrohydraulic control actuation system for actuating eight aerodynamic control surfaces of the two-stage technology demonstrator of the Indian reusable launch vehicle (RLV-TD) was developed, validated by extensive testing in various test beds, simulation runs and flight proven in the RLV-TD HEX-01 mission flight on 23 May 2016. A centralized hydraulic power generating unit (HPU) was used for powering the eight actuators located in two stages. The network of plumbings and control components of this actuation system were required to be laid out over the entire length and breadth of the vehicle measuring 17 m in length, to distribute the hydraulic power to all the actuators. The hydraulic actuation system had to work for the longest ever duration of 833 s for an Indian launch vehicle. Many challenges arose due to a single HPU for two stages, long complex network of plumbings, longest ever operating duration, thermal issues, second-stage structure resembling an aircraft, limited occupancy for operations at the launch pad, limited power source, etc. Necessary provisions were incorporated in the design to successfully overcome them. This article describes the development of the control actuation system.

The SpaceX Effect

Abstract Space Exploration Technologies Corporation (SpaceX) had demonstrated its reusable launch vehicle technology by recovering and reusing the core stage of its Falcon 9 launch vehicles. SpaceX believes reusable launch vehicles will enable its vision of colonizing Mars. This had unleashed pricing competition as SpaceX had begun offering low-cost access to space. Rival launch service providers, although contentious of SpaceX business model, are planning to introduce reusable launch systems into their product mix. This article offers a survey of such launch service providers from 4 distinct geographical regions with varying degrees of public-to-private ownership and catering to different requirements. The study conveys that regardless of these variables, reusability is fast becoming the norm of the launch vehicle industry. Interestingly, managers of these programs do not shy from admitting that Elon Musk and SpaceX are influential factors in their decision-making. The article argues that the space indus...

Special Theme: India’s Reusable Launch Vehicle Technology Demonstrator: The Future of Space Transportation System

Special Theme: India’s Reusable Launch Vehicle Technology Demonstrator: The Future of Space Transportation System

Design, Analysis and Qualification of Elevon for Reusable Launch Vehicle

Reusable launch vehicle technology demonstrator is configured as a winged body vehicle, designed to fly in hypersonic, supersonic and subsonic regimes. The vehicle will be boosted to hypersonic speeds after which the winged body separates and descends using aerodynamic control. The aerodynamic control is achieved using the control surfaces mainly the rudder and the elevon. Elevons are deflected for pitch and roll control of the vehicle at various flight conditions. Elevons are subjected to aerodynamic, thermal and inertial loads during the flight. This paper gives details about the configuration, design, qualification and flight validation of elevon for Reusable Launch Vehicle.

Quality Assurance and T&E of Inertial Systems for RLV Mission

This work describes the quality assurance and Test and Evaluation (T&E) activities carried out for the inertial systems flown successfully in India’s first reusable launch vehicle technology demonstrator hypersonic experiment mission. As part of reliability analysis, failure mode effect and criticality analysis and derating analysis were carried out in the initial design phase, findings presented to design review forums and the recommendations were implemented. T&E plan was meticulously worked out and presented to respective forums for review and implementation. Test data analysis, health parameter plotting and test report generation was automated and these automations significantly reduced the time required for these activities and helped to avoid manual errors. Further, T&E cycle is optimized without compromising on quality aspects. These specific measures helped to achieve zero defect delivery of inertial systems for RLV application.

Instrumentation and Baseband Telemetry for RLV-TD HEX Mission

In this work, the salient requirements and features of the baseband telemetry system used in Reusable Launch Vehicle—Technology Demonstrator Hypersonic Experiment mission are discussed. The configuration of the overall system, subsystem components and their features are described in brief. The unique requirements of the telemetry system, when compared to that in a conventional launch vehicle, by way of a large number of temperature and strain measurements that enable the assessment of structural integrity and mission performance in re-entry mission, are dealt with, along with the system configuration to cater to these. Subsequently, two new units have been described—Strain Data Acquisition Unit and Multiplexed Data Acquisition Unit that were inducted specifically to cater to strain measurements using strain gauges and temperature measurements using thermocouples respectively. The optimized subsystem configurations for these units are described and their field performance during flight is analyzed. This work further discusses a novel method of data recovery for those measurements affected by the baseline offset shift caused by the presence of a chassis voltage and poor isolation of sensor to chassis.

Global atmospheric response to emissions from a proposed reusable space launch system

AbstractModern reusable launch vehicle technology may allow high flight rate space transportation at low cost. Emissions associated with a hydrogen fueled reusable rocket system are modeled based on the launch requirements of developing a space‐based solar power system that generates present‐day global electric energy demand. Flight rates from 104 to 106 per year are simulated and sustained to a quasisteady state. For the assumed rocket engine, H2O and NOX are the primary emission products; this also includes NOX produced during reentry heating. For a base case of 105 flights per year, global stratospheric and mesospheric water vapor increase by approximately 10 and 100%, respectively. As a result, high‐latitude cloudiness increases in the lower stratosphere and near the mesopause by as much as 20%. Increased water vapor also results in global effective radiative forcing of about 0.03 W/m2. NOX produced during reentry exceeds meteoritic production by more than an order of magnitude, and along with in situ stratospheric emissions, results in a 0.5% loss of the globally averaged ozone column, with column losses in the polar regions exceeding 2%.

Technology Engineering: The Concurrent Development of Space Transportation Systems and Technology

:This article develops and presents a technology engineering framework for the selection, development, and insertion of space transportation technologies concurrent with the systems engineering of the space transportation system(s) in which the technology will eventually be employed. The technology engineering framework developed and presented in this article draws on existing systems engineering processes, tools, and methods; takes into account the differences between systems engineering and technology engineering; and accounts for the high degree of interaction required between the concurrent technology and system development programs. The components of this technology engineering framework are discussed, and the major steps in the technology engineering process are outlined. An investigation is also conducted into facilitating the implementation of key portions of the framework using a state-of-the-art relational computer database referred to as the Reusable Launch Vehicle (RLV) Technology Database (RTDB). This database is demonstrated to provide an invaluable tool to collect, manipulate, analyze, document, and disseminate technology-related information, including previous research results, key technical parameters and characteristics, technology readiness levels, relationships to other technologies, costs, and potential barriers and risks.

NASA's Integrated Space Transportation Plan — 3 rd generation reusable launch vehicle technology update

NASA's Integrated Space Transportation Plan (ISTP) calls for investments in Space Shuttle safety upgrades, second generation Reusable Launch Vehicle (RLV) advanced development and third generation RLV and in-space research and technology. NASA's third generation launch systems are to be fully reusable and operation by 2025. The goals for third generation launch systems are to reduce cost by a factor of 100 and improve safety by a factor of 10,000 over current systems. The Advanced Space Transportation Program Office (ASTP) at NASA's Marshall Space Flight Center in Huntsville, AL has the agency lead to develop third generation space transportation technologies. The Hypersonics Investment Area, part of ASTP, is developing the third generation launch vehicle technologies in two main areas, propulsion and airframes. The program's major investment is in hypersonic airbreathing propulsion since it offers the greatest potential for meeting the third generation launch vehicles. The program will mature the technologies in three key propulsion areas, scramjets, rocket-based combined cycle and turbine-based combination cycle. Ground and flight propulsion tests are being planned for the propulsion technologies. Airframe technologies will be matured primarily through ground testing. This paper describes NASA's activities in hypersonics. Current programs, accomplishments, future plans and technologies that are being pursued by the Hypersonics Investment Area under the Advanced Space Transportation Program Office will be discussed.

X-33 Experimental Aeroheating at Mach 6 Using Phosphor Thermography

The goal of the NASA Reusable Launch Vehicle (RLV) technology program is to mature and demonstrate essential, cost effective technologies for next generation launch systems. The X-33 flight vehicle presently being developed by Lockheed Martin is an experimental Single Stage to Orbit (SSTO) demonstrator that seeks to validate critical technologies and insure applicability to a full scale RLV. As with the design of any hypersonic vehicle, the aeroheating environment is an important issue and one of the key technologies being demonstrated on X-33 is an advanced metallic Thermal Protection System (TPS). As part of the development of this TPS system, the X-33 aeroheating environment is being defined through conceptual analysis, ground based testing, and computational fluid dynamics. This report provides an overview of the hypersonic aeroheating wind tunnel program conducted at the NASA Langley Research Center in support of the ground based testing activities. Global surface heat transfer images, surface streamline patterns, and shock shapes were measured on 0.013 scale (10-in.) ceramic models of the proposed X-33 configuration in Mach 6 air. The test parametrics include angles of attack from -5 to 40 degs, unit Reynolds numbers from 1x106 to 8x106/ft, and body flap deflections of 0, 10, and 20 deg. Experimental and computational results indicate the presence of shock/shock interactions that produced localized heating on the deflected flaps and boundary layer transition on the canted fins. Comparisons of the experimental data to laminar and turbulent predictions were performed. Laminar windward heating data from the wind tunnel was extrapolated to flight surface temperatures and generally compared to within 50 deg F of flight prediction along the centerline. When coupled with the phosphor technique, this rapid extrapolation method would serve as an invaluable TPS design tool.

Reusable launch vehicle technology program

Industry/NASA reusable launch vehicle (RLV) technology program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low-cost program. This paper reviews the current status of the RLV technology program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion, and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight tests. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost-effective, reusable launch vehicle systems.