Speaker
Description
It is well-known that nowadays economy and society are highly dependent on the use of space and space applications: climate monitoring, weather forecast, transportation, communications, financial exchanges, etc. It is also known that, since the beginning of the space era the number of objects in orbit has continuously increased, with the orbital debris (abandoned stages, fragments from collisions and explosions, defunct satellites,…) outnumbering the operational satellites and hindering their missions. Moreover, in the last years, with the decrease in the cost of the access to space and the deployment of the so-called mega-constellations, the launches have increased to a rate never seen before.
The situation is such that, as stated in the last “ESA’s Annual Space Environment Report”, “Even in case of no further launches into orbit, it is expected that collisions among the space debris objects already present will lead to a further growth in space debris population. Based on these findings, among others, there is a growing consensus that stricter space debris mitigation and practices need to be implemented globally, and, eventually, remediation might need to be considered”.
In a nutshell: On top of mitigating the creation of new debris and improving the tracking and characterisation of the existing ones, there might be a need to remove the debris already in-orbit. Several approaches are possible, ranging from the remove of a sensitive number of small pieces of debris between 1cm and 10cm using various technologies, to the controlled / uncontrolled re-entry of the most dangerous large debris objects in orbit. Each approach has its own pros and cons and should be deeply analysed and considered, and probably a combination of several would be the right solution.
SENER Aerospace & Defence, as a pioneer engineering company in the design of satellites technology and equipment for the space exploration, is committed to contribute to the long-term sustainability of the space environment, not only for the success of the industry, but as a moral responsibility to preserve the space environment for ensuring the exploration, science and innovation in benefit of the future generations.
Therefore, with the aspiration to contribute to the fulfilment of the UN Long Term Sustainability Guidelines (e.g., B.8 and D.2) by governments and international institutions and keeping in mind the Space Debris Mitigation Guidelines (e.g., limit the long-term presence of spacecraft and launch vehicle orbital stages in LEO and GEO), SENER considers that a viable option to contribute to the remediation of space debris would be the development of a reusable “Cleaning Vehicle” attached to a container provided with several grasping mechanisms and de-orbiting devices. The “Cleaning Vehicle” would be able to manoeuvre to different orbits within the LEO region, identifying and capturing large debris objects by means of the grasping mechanisms, attached to them a de-orbiting device, release the object and manoeuvre to the next target. Once the container has depleted the grasping and de-orbiting mechanisms, it would de-orbit itself and a new container can be launched and docked to the “Cleaning Vehicle” to continue its mission.
SENER is a leading company in the development of mechanism for space, as well as in GNC. Therefore, several projects run at SENER would be relevant for the development of the concept. In the next paragraphs, grouped by element of the “Cleaning Vehicle” and the container, these projects are summarised:
1. Rendezvous and capture GNC:
- SENER has been exploiting its capabilities to develop rendezvous and docking GNC systems, applied and further developed in the frame of the In-Orbit Logistics Proof Of Concept 1 ESA programme (POC1). The SENER rendezvous GNC is based on the use of onboard optimized guidance built on the SENER convex optimization toolbox (SOTB), and on in house developed collaborative visual navigation algorithms. Internal R&D activities are in progress to test in a robotic facility the rendezvous guidance and navigation and further mature the GNC algorithms in preparation of forthcoming POC1 phases. The rendezvous GNC has been designed in co-engineering with SIROM mechanical experts (see bullet 2), to ensure compliance with capture requirements, and provide inputs for SIROM evolution taking into account GNC needs and limitations. This concept could be used by the “Cleaning Vehicle” in case of collaborative targets (i.e. satellites designed with SIROM interfaces on-board)
- Under an ESA contract part of the Studies, Technology and Evolution Preparation Programme for the ISS, the Automatic Servicing Vehicle for ISS Surveilling (ASVIS) system was conceived as an unmanned vehicle operating outside ISS from an external Base Platform located on one of the platforms available for external payloads. ASVIS is an operative system for providing services to ISS such as: inspection at different ranges (both periodical and on-demand) and support for EVA.
Figure 1. ASVIS System Concept
- SMART-OLEV was based on a purpose designed and built spacecraft to mechanically dock with a client satellite’s zenith face using its liquid apogee engine nozzle and launch vehicle interface ring. Neither electrical nor any other connections (e.g. fluid) connections are necessary to perform the on-orbit servicing except the mechanical link through the nozzle. SMART-OLEV would take-over attitude and orbit control functions for the client satellite allowing the client to continue to operate the other functions on the communication satellite as normal. In this way valuable geostationary hardware and orbital slots can be maintained and secured in a very cost-effective manner SMART-OLEV will be controlled before and during docking from a dedicated Operations Control Centre (OCC). After docking, SMART-OLEV control may be transferred to the client’s OCC if desired. Within SMART-OLEV SENER was responsible for some of the main subsystems and tasks like the GNC subsystem, the RCS subsystem and the camera image processing that would be relevant for the rendevouz phase of the “Cleaning Vehicle” and could be used in the case of non-collaborative target (i.e. no dedicated interface for the capturing/docking available)
Figure 2. SMART-OLEV in docked configuration
2. Grasping of the object and attachment of the de-orbit mechanism:
- ADR clamping system, SENER was responsible for concept of a clamping system for the active debris removal (ADR) missions in frame of e.Deorbit activity led by Airbus. The clamping mechanism is responsible for catching a satellite to be removed from the orbit in order to allow to do so.
For the activity, various clamping scenarios were studied, aiming defining the suitable area (Interface) at a spacecraft to be caught by the clamping system. Final decision considered clamping on the Launch Adapter Ring (LAR) as the most suitable choice.
The mechanism is composed by the clamp driven by a motor with a gear. The motor is also coupled with a brake to maintain the position and force of the clamps. In addition, there is also a spindle driven rotational degree of freedom allowing adjustment of the mechanism in respect to the LAR.
- SIROM, already mentioned in the previous bullet, is a robotic interface that can be used both in orbital and planetary applications. As a robotic interface, SIROM integrates four different functionalities in a single mechanism: mechanical, data, electrical and fluids.
SIROM is one of the key “building blocks” developed for the European Union in the frame of PERASPERA, a project aiming to deliver enabling technologies and demonstrate autonomous robotic systems for on-orbit satellite servicing and planetary exploration.
SIROM was developed in the first Call of PERASPERA (2016-2019) by a project consortium coordinated by Sener Aeroespacial.
SIROM was successfully tested in a final orbital scenario by means of robotic devices, performing several test maneuvers, in AIRBUS DS (Bremen) and DLR.
In EROSS, project of the second Call of PERASPERA (2019-2021), Sener Aeroespacial has developed an integrated SIROM product combining the mechanics and flight compatible electronics, resulting in a simple and compact mechanism. SIROM is also being applied in other projects such as: MIRROR (ESA project), PERIOD (third PERASPERA Call) and currently in EROSS IOD (late PERASPERA call).
In addition, SENER Aeroespacial is coordinating a new Horizon Europe project, called ORUBOAS where SIROM is applied to a new concert of smart ORU (Orbital Replacement Unit).
SIROM videos:
https://youtu.be/uwpm_SOnYE8
https://youtu.be/fO-iVjy4voA
3. De-orbiting device: E.T.PACK-Fly is an EIC Project funded by the European Innovation Council with 2.5 M€. The main goal of E.T.PACK-F is to prepare a Ready-to-Fly (TRL 8) deorbit device based on ElectroDynamic Tether (EDT) technology. ETPACK-Fly will deploy 500 meters of thin aluminum tape in space and circulate up to 500mA of current collecting electrons from the earth plasma. Thanks to Lorentz drag the 24kg spacecraft will deorbit from 600 km altitude orbit in less than 100 days without using propellant. The E.T.PACK-Fly mission has been selected in the frame of the CASSINI IOD/IOV program to fly in 2025. The team of the project includes Universidad Carlos III de Madrid, the University of Padova, the Technical University of Dresden and Rocket Factory Augsburg.
Of course, all these development would be applicable also to other ADR concepts than the “Cleaning Vehicle” and SENER is open to collaborate in other visions/misions to ensure the long-term sustainability of the orbital environment.
