Jesús Gil-Fernández

European Space Agency | ESA · TEC-ECN

The goal of the activity On-ground Validation of Debris Removal Technologies, ORCO, has been to investigate and mature the complex couplings between the different control systems (GNC including image processing and robotics) for autonomous rigid capture between an active chaser vehicle and a cooperative/non-cooperative target, and derive the requir...

Extending life or repairing damaged on-orbit assets is not only a very attractive economic option for satellite operators as it could potentially increase margins for commercial services or increasing delivered value of scientific missions, but it would also help reducing the number of debris objects in space. These types of servicing missions pose...

Our knowledge of the internal structure of asteroids is, so far, indirect – relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling of formation and evolution. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape asteroid internal structures?...

In the frame of NEO exploration and planetary defence, the two-part AIDA mission is currently studied by NASA and ESA. Being composed of a kinetic impactor, DART (NASA), and by an observing spacecraft, AIM (ESA), AIDA has been designed to deliver vital data to determine the momentum transfer efficiency of a kinetic impact onto a small body and the...

The situation of orbital debris is becoming more and more a worldwide concern for the safe operations of space assets. In this context, retiring orbital debris (and extending life or repairing damaged on-orbit assets) is very attractive to satellite operators as it could potentially decrease mission risks, increase margins for commercial services o...

ESA has been developing on-board Guidance, Navigation, and Control technologies for characterization, sample-return, and deflection missions to asteroids and comets (Rosetta, Don-Quijote, Marco-Polo, AIM). GNC systems have been prototyped for all mission phases, from early detection until landing. The GNC technologies are based on vision-based navi...

An autonomous GNC system for descent and landing (DL) on Phobos is being developed by GMV under several ESA contracts. The GNC system is based on advanced algorithms and European navigation sensors. Lessons learned from ROSETTA have been incorporated in the definition of the ground operations and performances. In addition, previous results from har...

Integrated GNC (iGNC) is an activity aimed at designing, developing and validating the GNC for autonomously performing the rendezvous and capture phase of the Mars sample return mission as defined during the Mars sample return Orbiter (MSRO) ESA study. The validation cycle includes testing in an end-to-end simulator, in a real-time avionics-represe...

Over the last few years, GMV has placed a remarkable e�ort in validating di�erent components of the GNC system for Lunar exploration. The Guidance Navigation and Control (GNC) system, in autonomous landing, is the key technology in order to achieve a precise, soft and safe landing. GMV has been involved in many projects in the frame of ESA, nationa...

Robotic exploration missions to small bodies require advanced technologies. One enabling technology is the Guidance, Navigation Control (GNC) system. The requirements on the GNC for these missions are very demanding. Cost shall be minimized, reducing the sensor suite. Tight orbital and landing performances are required. Furthermore, robustness is f...

ESA's Automated Transfer Vehicle (ATV-1) performed a cont rolled destructive re-entry on Monday 29 September 2008. It broke up at an altitude of ~75 km with the remaining fragments falling into the Ocean. To observe and characterise the events occurring during the re- entry, a joint ESA/NASA multi-instrument aircraft observation campaign was perfor...

NASA Deep Space 1 mission proved an autonomous low-thrust guidance method based on linearization of the terminal state in terms of a certain parameterization of the thrust profile. The optimal guidance and control methods presented for the mission focused on closed-form algorithms as in Deep Space 1 autonomous guidance, with special emphasis on the...

A study was conducted to introduce new transformation that reduced the computational time and increased the radius of convergence of the two-point boundary value problem (TPBVP) solution process. The low-thrust interplanetary transfer problem was formulated as an optimal control problem and only the first-order optimality conditions were considered...

High-speed intercept missions, which include kinetic impactors and nuclear penetration devices, may be required to mitigate the threat from a near-Earth object. Various guidance laws, including the pulsed proportional navigation (PPN) guidance and advanced predictive guidance, are examined for the autonomous terminal-phase guidance and control of a...

Several space agencies are currently studying plans for returning humans to the Moon; ESA and the European industry, in particular, are conducting preliminary studies for the CSTS (Crew Space Transportation System) program. One of the scenarios under analysis involves a rendezvous between the crew transportation vehicle and the lunar lander (or a p...

Manned missions to asteroids are gaining momentum due to scientific, exploration and outreach reasons. Human-related constraints pose stringent requirements on the mission design. A feasibility analysis is presented for missions launching between 2020 and 2050. The system constraints are derived from on-going ESA and NASA developments, leading to t...

Analysis of low thrust missions needs efficient methods to compute optimal trajectories with no a priori knowledge of the thrusting structure. The thrust-constrained, final mass maximization is reduced to a two-point boundary value problem. This problem is solved in two steps. First, the initial guess is constructed with a systematic search on a un...

The studied type of Crew Transfer Vehicle (CTV) is basically a modified ATV and a capsule for the crew. The emergency trajectories of the CTV consist of a propelled exo-atmospheric arc and the re-entry of the capsule only. The starting point is a failure in the Ariane5 EPC (Étage Principal Cryotechnique) after the Launch Escape System (LES) has bee...

Solar sails are currently being studied and developed as alternate propulsion vehicles that can provide high velocities. Their ability to reflect photons coming from the sun on a large lightweight reflective surface enables many unique space science missions. One such mission is the GeoSail mission, for which the aim is the study of Earth's magneto...

The design of a low-cost spacecraft to impact on a small, faint Near Earth Object (NEO), poses major challenges. This paper focuses on the terminal phase of such impact mission, analyzing the capability of autonomous Guidance, Navigation and Control (GNC) systems to compensate the deviations in the impact point to achieve a successful collision. Th...

Transportation systems able to support the future human exploration of the Moon are currently under investigation in Europe. These systems must ensure a safe return of the crew for a variety of contingency scenarios, including the loss of ground-based navigation. Optical measurements may be used to support on-board autonomous navigation for these c...

A new hybrid direct-indirect optimization algorithm is presented to compute the minimum-time transfer between two orbits, including the phasing with a desired spacecraft. Very-low thrust means several hundred revolutions to perform the large change in orbital elements. The optimal control solution of the fast-evolution problem combined with a direc...

We expose the rationale and methods that our team used to design the trajectory presented to the subject competition, and discuss our results. We identified a candidate EEVEEJSA trajectory that was comprised of (1) a priming EEV phase, (2) a VEE tour to prepare the departure to Jupiter, and (3) a EJSA phase that ended with an almost head-on collisi...

CX-OLEV is a commercial mission aimed to extend the operational life of geostationary telecommunications satellites by supplying them propulsion, navigation and guidance services. Under SENER's contract and ESA's supervision, GMV designed the CX-OLEV ground guided rendez-vous (RV) approach. The starting point of the RV phase between CX-OLEV and the...

A new hybrid direct/indirect optimization algorithm is presented to compute the minimum-time transfer from GTO to GEO, including phasing with desired SC. Very-low thrust results in several hundreds of revolutions to perform the large change in orbital elements. The optimal control solution of the fast-evolution problem combined with a direct method...

The objectives of ExoMars are to inject an orbiter around Mars and to land a rover on the surface to look for possible traces of life. During the first stages of the feasibility analysis, the mass margin of the orbiter was very small for a direct transfer in the Soyuz/Fregat scenario. An analysis of the combined use of lunar swing-bys and the Sun g...

This paper presents the application to certain arcs of the SMART-1 trajectory of a low-thrust guidance scheme designed for autonomous interplanetary missions. An analysis and post-process of the reference trajectory is done previous to the simulations to have a situation representative of an interplanetary environment. The algorithm to compute the...

Several techniques have been developed to obtain optimum trajectories with low-thrust propulsion. However, few low-thrust guidance schemes have been investigated to fly the reference optimum trajectories. The guidance algorithm successfully employed in the DeepSpace1 mission was the first approximation through the presented guidance schemes, valid...

In recent years, many interplanetary trajectories have been designed taking advantage of electric engines. These engines are more efficient in terms of fuel consumption than classical chemical thrusters due to the higher specific impulse, but they give lower thrust magnitude. Several techniques have been developed to obtain optimum trajectories wit...

The paper presents some design details of a GNC sys tem for a lunar landing mission requiring soft precision landing and safe place landing. Soft prec ision landing means landing in a specific location with a precision better than 200m (3σ value) (radius of the landing circle) and a veloci ty compatible with a soft landing system: -2.5 m/s vertical...

The design of a low-cost impactor SC, targeting a small, faint NEO, poses major challenges. One of the most demanding problems refers to the capability of the autonomous GNC to compensate the deviations affecting the impact point in order to achieve a successful collision. During the terminal phase, the autonomous GNC must use the information of th...