PTScientists is bringing down the cost of exploration and building reusable space infrastructures so more people benefit from access to space - because space belongs to everyone.
ALINA is designed to be compatible with all major commercial launch vehicles (including SpaceX’s Falcon 9, and ISRO’s PSLV), allowing invaluable flexibility when contracting a launch. This means that customers can...
optimization methods and related modelling related to spacecraft design
Opening speech of the 7th ICATT conference by Dr. J. Bals from DLR
Key note speech by ESA about the exploration of the Moon
Future launch vehicle concepts and technologies for expendable and reusable launch vehicles are currently investigated by the DLR research 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...
This work presents the new set of equations of motion incorporated in ASTOS release 9.3.
The new implemented feature, based on DCAP multibody software, provides the building blocks to simulate a complete launcher scenario considering vehicle flexibility, sloshing effects, stages separation, engine pressure oscillations and complex aerodynamic loads distribution.
The interaction between...
For numerous years, CNES Flight Dynamics teams have made freely available some astrodynamics tools and libraries as MSLIB library. Nevertheless, these tools, essentially coded in Fortran language needed different versions of compilation depending on used platforms (Solaris, Linux, Windows …) which didn’t ease its installation and therefore limit their dissemination. Some years ago, CNES...
Poincare is a modular trajectory design tool based on a catalog of three-body science orbits and a differential corrector to compute connecting transfer arcs between orbits in multi-body systems. Poincare attempts to offer a unified approach, i.e., an "all-in-one" integrated search within one interface and setup in MONTE (JPL's signature astrodynamic computing platform) The Science Orbit...
Human activity in the space has caused the growth of a very large population of resident space objects (RSO). More than 19,000 objects are currently catalogued by 18th SPCS (former JFSCC) with sizes starting around 10 centimetres in LEO and around 1 metre in GEO. Space debris has nowadays become a very important thread to space operations as high-risk collisions are predicted daily between...
Space objects catalog maintenance demands an accurate and fast orbit determination (OD) process to cope with the ever increasing number of observed space objects. The development of new methods, that answer the two previous problems, becomes essential.
Presented as an alternative to numerical and analytical methods, the Draper Semi-analytical Satellite Theory (DSST) is an orbit propagator...
As it’s known that our Sun rises always in the east and sets in the west, similarly, all the stars in the sky also rise in the east and set in the west. But day time, due to sun's brightness, we would not able to see the stars in the sky. Apart from this, there are many other parameters that restrict the observation these celestial objects. A few of those are : Time period of rising and...
In this paper, a mathematical model was developed to design and optimize interplanetary trajectories that include gravity assist. The method of patched conics and a solver of the Lambert problem transfers are used to cast the space trajectory design process as an optimization problem, subsequently solved by using MATLAB. This model has been tested to provide an overview of the processes...
Safe de-orbiting and increasing the life-time of satellites by on-orbit servicing (OOS) will be of high importance in future spaceflight. The rendezvous and docking/berthing (RvD/B) phase is one of the most complex and critical parts of on-orbit servicing and debris removal missions. Several missions and developments have been started like the Restore-L mission of NASA, the RSGS (Robotic...
Preliminary design of artificial satellite missions commonly relays on the use of simplified models that comprise the bulk of the dynamics. In the case of the gravitational potential, the amplitude of long-term oscillations of the orbital parameters is roughly one order of magnitude larger than the short-period oscillations. Because of that, dealing with just the few more relevant zonal...
In the context of future Human Spaceflight exploration missions, Rendezvous and Docking (RVD) operational activities are mandatory and critical for the assembly and maintenance of cislunar structures [1]. The Orion spacecraft is expected to handle cargo delivery and crew exchange missions that will all require RVD. Despite extensive experience in Low Earth and Low Lunar Orbits, no operational...
It is possible to design heliocentric transfers to Mars culminating in ballistic capture and, with an impulsive-thrust strategy, these have already been studied, but were found to be less fuel-efficient and longer-lasting than Hohmann transfers. The objective of the present work is to investigate the characteristics of Earth-Mars low-thrust transfers to ballistic capture.
Small spacecraft are...
Extended abstract
The present international cooperation scenario for robotic and human space exploration is focusing on mission architectures that revolve around building and exploiting a crew-tended cis-lunar space station, known as Lunar Orbital Platform-Gateway. Candidate orbits for this vehicle are the near rectilinear halo orbits (NRHO). Therefore, the capability to inject in NRHO...
This paper presents the analysis of a low-thrust rendezvous mission to a target non-Keplerian orbit of the circular restricted three body problem (CR3BP) in the Earth-Moon system. The dynamical characteristics of this system are revisited, and some non-Keplerian orbits (e.g., L1 halo orbits, NRO and L2 halo orbits) have been simulated to study their suitability for a rendezvous mission....
The tentative position of the next habitable space station could be a southern L2 Near Rectilinear Halo Orbit (NRHO) of the Earth Moon System. To bring crew and cargo to the station, a safe and efficient rendezvous methodology has to be established. However, a significant body of work remains to be done on the design of the rendezvous procedure between halo orbits. Given fixed start and end...
The support from JSpOC to current collision avoidance operations is priceless. As a result, most satellite owners and operators have signed with USSTRATCOM an SSA Data Sharing agreement and have Orbital Data Requests in place in order to have access to JSpOC conjunction assessment and collision avoidance support services.
JSpOC issues CDM messages in case an upcoming conjunction is detected....
The existence of families of solar-sail displaced libration point orbits in the Earth-Moon system has recently been demonstrated. These families originate from complementing the dynamics of the classical Earth-Moon circular restricted three-body problem with a solar-sail induced acceleration. The addition of this acceleration makes the problem non-autonomous, but by constraining the orbital...
Recent mission and system studies conducted for the European Space Agency have involved the design of transfers targeting Earth-trailing or Earth-leading heliocentric operational orbits, in a 1:1 resonance with Earth.
Airbus is currently leading two such studies on behalf of the European Space Agency: the Lagrange (Space Weather) mission targeting the Sun-Earth L5 Lagrange Point, and the LISA...
See the pdf file attached.
As French National Space Agency, CNES is in charge of monitoring safety requirements for people and property related to space operation as defined in French Space Operation Act (FSOA). To evaluate these requirements, and in particular to be able to assess the compliance with safety threshold, CNES has developed its own tools, DEBRISK and ELECTRA. DEBRISK software computes the ablation of the...
The European Union is now developing a federated SST system composed of existing sensors and operations centres in Europe through the EU SST Support Framework. Potential future architectures are also being evaluated for the development of new future sensors, including both radar and telescope sensors and both tracking and surveillance sensors. This brings the need to analyse the performances...
The design of space missions is generally driven by severe requirements on the Delta-v budget. Navigation is also becoming more and more challenging, asking for the satisfaction of stringent conditions characterized by unprecedented accuracy. As a consequence, an increased complexity in the trajectory design is needed, ultimately leading to employing high-fidelity models already in the early...
A renewed vision to send humans beyond Low Earth Orbit (LEO) has given rise to a whole range of studies proposing different destinations and operational orbits for a new crew-tended space station; referred here as Deep Space Gateway (DSG). Near Rectilinear Halo Orbits (NRHO) have been identified as one of the most promising destinations for a DSG, due to the combination of both dynamical...
One of the deliverables of the ReDSHIFT H2020 project will be a software tool available to the scientific community and the public via a web-based interface. The ReDSHIFT software is thought as a tool for spacecraft operators, space agencies and research institution to design the end-of-life of any Earth-based mission and to study the interaction with the space debris environment.
In this talk...
The execution of precision landing missions applicable for future Mars missions (in particular, Sample Return Missions and Human Missions) is a major technical challenge that will require the adoption of a set of technologies that have not yet been demonstrated in flight.
In the scope of an ongoing ESA activity related to the development of advanced navigation techniques for pinpoint landing...
The continuing development of solar-sail technology in combination with the rising interest in a mission to the Sun-Earth $L_5$ point for heliophysics and the search for Trojan asteroids, raises the question of using solar sailing as the primary propulsion method to enable such a mission. This paper therefore investigates a range of solar-sail transfers to the $L_5$ point, departing from...
We consider the problem of optimal low-thrust spacecraft geostationary orbit (GEO) insertion from initial circular orbit with 800 km height and 51.6 degrees inclination. Minimal time for electric propulsion insertion of considered nuclear powered heavy spacecraft [1] is about 117 days. Significant amount of this time (~90 days) the spacecraft spends in regions with harsh space radiation...
Online optimization and trajectory planning are key aspects of autonomous deep space missions. Taking into account individual target criteria, such as time or energy optimality, any spacecraft maneuver can be traced back to a general problem definition of the form "move the spacecraft from its initial state to a desired final state, while considering a dynamic model and avoiding collisions"....
LOTNAV has been for 10 years the ESA reference tool in the design of finite-thrust and ballistic interplanetary spacecraft trajectories and the preliminary assessment of navigation and guidance issues on the computed trajectories. Within DEIMOS Space LOTNAV has recently undergone a considerable update effort to enhance its modularity and flexibility to extend its applicability to new...
ELECTRO: a SW tool for the ELECtric propulsion TRajectory Optimization
Low-thrust orbit transfers are becoming increasingly attractive thanks to the mass savings they offer and the maturity of electric propulsion technology. For this reason, there is an interest in developing fast, but still reliable trajectory optimisation methods that can be applied in the preliminary phase of the design of...
MODHOC (Multi Objective Direct Hybrid Optimal Control) is a toolbox for the design, optimisation and trade off study of space systems and missions.
It solves general nonlinear multi phase optimal control problems, automatically computing a well spread set of optimal trade off solutions. In addition, it is able to handle discrete optimisation parameters.
In order to do so, MODHOC combines a...
Traditionally, GTO to GEO transfers using chemical propulsion consist in optimising a rather limited number of manoeuvres. The compliance with the satellite platform and operational constraints are then guaranteed by the launch window design. On the contrary, low-thrust transfers of GEO satellites require very long thrust phases. The complex satellite platform and operational constraints...
An algorithm for the computation of distant retrograde orbits is presented. It is based on the computation of an approximate analytical solution of the restricted three body problem in the Hill problem approximation that provides accurate estimations of two basic design parameters. Notably, these parameters can be used for the computation of initial conditions of orbits that are periodic on...
Preliminary design of artificial satellite missions commonly relays on the use of simplified models that comprise the bulk of the dynamics. In the case of the gravitational potential, the amplitude of long-term oscillations of the orbital parameters is roughly one order of magnitude larger than the short-period oscillations. Because of that, dealing with just the few more relevant zonal...
The history of the creation of the Draper Semi-analytical Satellite Theory (DSST) started at the Computer Sciences Corporation, with support from the NASA Goddard Space Flight Center (GSFC), in the early 1970s. Then, its development continued at the Draper Laboratory in the 1980s and 1990s. Since 2001, some enhancements to the DSST have been achieved by the technical staff at the Massachusetts...
Commercial and scientific satellites located in Geostationary Equatorial Orbit (GEO) that are not placed there by the launch vehicle are often injected in a parking orbit. They are transferred therefrom to GEO using their own on-board propulsion system. The classical strategy relies either on Chemical Propulsion (CP) or Electrical Propulsion (EP). The former guarantees very short transfer...
Low-thrust propulsion and gravity assists maneuvers are both well known to provide sig- nificant benefits in terms of required propellant mass for interplanetary trajectories. However, the propellant reduction achieved with low-thrust engines, when compared to their chemical counterparts, comes at the cost of a higher transfer time.
Therefore, the design and optimization of interplanetary...
The Eumetsat GEO fleet has successfully performed its orbital determination using ranging-only data from three different ground-based tracking stations. Data from two different ground stations is used for each of the satellites. For more than 15 years, these results have been used for manoeuvre planning, after manoeuvre calibration and collision risk assessment. Since June 2018, an effort has...
Bi-lateral discussions between NASA and the European
Space Agency identified the orbiter element as a promising
European-led contribution to a future international Mars Sample
Return campaign. Airbus recently completed the Mars
Sample Return Architecture Assessment Study on behalf of
ESA, with the objective to identify and quantify candidate
mission architectures. The paper describes the...
This paper presents Astrodynamics.jl an open source framework for high-performance, interactive orbital mechanics implemented in the Julia programming language. The implementation language was chosen based on previous work that demonstrated that it is possible to bridge the performance gap between compiled and dynamic programming languages by using Just-in-time (JIT) compilation and was...
Modern space missions often require a large velocity increment, which leads to the need to use main electric propulsion systems with a high value of the specific impulse to reduce the mass of the active propellant and increase the mass of spacecraft in target orbits.
To improve the efficiency of space transportation operations, optimization of the low-thrust trajectories is required....
The plethora of spacecraft simulation software tools is an indispensable part of modern spacecraft design processes. The continual increase in complexity of spacecraft missions and maneuver design, dynamical and kinematic design verification and post-launch telemetry analysis all heavily rely on software simulation tools. This simulation ability provides engineers with the tools to increase...
Formalized and internationally supported space debris mitigation guidelines have been in place for several decades. Since 2010, the International Organization for Standardization (ISO) has published a comprehensive set of space system engineering standards aimed at mitigating space debris. These standards and guidelines reflect the common requirements and practices around the globe and are...
JSatOrb is an ISAE-Supaero's software tool dedicated to orbital calculation and designed for pedagogical purposes, with professional level features outputs.
It has been initiated to find a soft which would fill the gap between local teachers developed tools and professional tools, exploiting state of the arts
algorithms concerning space mechanics calculus. Even if current provided open source...
Sails and electrodynamic tethers have been proposed as passive devices to deorbit dead satellites. Their implementation in satellites would diminish very much their deorbiting time, typically down to a few years, as opposed to several decades. However, they would also increase very much the collision cross section of the said satellites, which would therefore increase the probability of...
Several multi-satellite mission architectures in Low Earth Orbits (LEO) as formation-flying, spacecraft clusters and active debris removal ask for accurate modeling of the relative motion between objects in neighboring orbits. The closer the region of interaction, the higher the level of autonomy the Guidance Navigation and Control (GNC) system may require to accomplish the mission’s tasks....
In the frame of the European GNSS Evolution Programme (funded by ESA), Deimos Space studied, designed and developed a stochastic simulator with the objective of computing and trading-off different constellation replenishment plans, that are able to guarantee a given service availability of satellite constellations, for any satellite constellation (GNSS, Satcom, etc).
During the first phase of...
TUDAT (TU Delft Astrodynamics Toolbox) is an open-source, general astrodynamics toolbox, with a focus on numerical state propagation, that has been under development by staff and students of the Astrodynamics and Space Missions (AS) section of Delft University of Technology (TUD). Since early 2015, the software has been hosted as a [github repository][1] and is freely available under the BSD-2...
While modern trajectory calculation and optimization tools are very effective, sometimes it is still useful to manually find an orbit for e.g. a necessary initial guess, or simply in order to understand the size and shape of the orbit.
A simple Visual Orbit Design (VOD) tool was created that allows changing orbit parameters such as apogee, perigee, delta-V given at a point, etc. while...
