CORDIS - EU research results

Smart propulsive device for controlled satellite decommissioning and reentry.

Periodic Reporting for period 2 - D3 (Smart propulsive device for controlled satellite decommissioning and reentry.)

Reporting period: 2016-12-01 to 2018-05-31

There are about 750,000 objects larger than 1cm originated by human activities in outer space. Out of all these “space bullets”, only 17,000 are traceable and catalogued, and just about 1,250 are controllable active satellites. All other objects are uncontrolled with high risk to collide with other operational satellite, making space activities unsustainable and risky: if the satellites launched in orbit are not disposed quickly at the end of their mission, the possibility of chain collisions could become real. For example, one Iridium satellite was destroyed by a defunct Russian Cosmos satellite in 2009, causing shutdown of Motorola telecommunication network and costing millions of dollars to the Company. Over the next years the probability of the satellites failure due to collision with fragments has been predicted to grow incrementally, jeopardizing the space activities and their profitability.

The success rate of current disposal practices is only around 50%, making them insufficient and inefficient solutions. It has been recognized through many different studies that a minimum viable removal efficiency has to be at least 90% to keep the debris population at a steady value and to guarantee the conduction of space activities under an acceptable risk.

There are a number of different collision scenarios in orbit: for instance, a satellite that has reached end-of-life can collide with another operational satellite; or a satellite that has become uncontrollable by a major malfunction can jeopardize the functioning of a constellation of satellites; or a large number of smaller debris can threat satellites operating in the space.

Beyond the direct damage caused by the loss of a satellite or the interruption of a service, there are also indirect damage such as political frictions between the States where the colliding satellites were certificated or launched from.
Furthermore, collisions with people or assets on ground – although the probability is still fairly low - can occur as a consequence of the uncontrolled re-entry of defunct satellite from low-Earth orbits. If the satellite is larger than 500kg, some of the components (e.g. propellant tanks, reaction wheels, lens, etc.) can survive the tremendous heat and fall into the Earth, posing at risk people and assets. For instance, a large metal object (4.5m long and 1.2m wide) fallen from the sky into a jade mining area in north Myanmar in November 2016, disturbing people lives. The events of space debris on the Earth could also present a political risk, particularly in case when a satellite includes sensitive or strategic payloads.

The overall objectives are to complete and launch the down-scaled version of the D3 (D-SAT mission) demonstrating the feasibility of a safe, quick and direct decommissioning of a satellite in space through a dedicated device; update the decommissioning system requirements and design according to customers’ feedback; develop and CMMI certify the Control & Command software; and implement Manufacturing, Assembly, Integration and Test (MAIT) process.
In the first 12 months of the project the SME beneficiary focused on the updates of D3 decommissioning device requirements and specifications, optimization of a Command and Control Unit, development of a Critical Software and preparation for D-SAT mission. D-SAT satellite was qualified for space, D3 Requirements and Specifications were updated, D3 Control and Command Software Specifications were updated, and the preliminary architectural design of D3 Critical Software was reviewed.

In the second period, D-Orbit completed the design, manufacturing and testing of D3 hardware as well as the design, coding, validation and verification of D3 software. The Company defined manufacturing and testing processes and developed an internal project/product management system as well as space mission control platform. D-Orbit completed a space mission, validating the preparation process for the mission, its execution and management, as well as the D3 operation in space. The Company was successfully certified for a CMMI-DEV Level 3. All deliverables and milestones were successfully achieved.
D3 is an independent, smart device based on solid propellant technology optimized for decommissioning manoeuvres. Installed on satellites or launcher upper stages before launch, D3 removes them from orbit quickly, safely, and directly at end-of-life or in case of failure. D3 is fully compliant with international space debris regulations, enabling operators of constellations to maintaining their operational orbits free from uncontrolled satellites, and reducing collision risk. Depending on the configuration, D3 can perform quick re-entry for LEO satellites, re-orbiting to graveyard orbit for MEO and GEO satellites.

D3 device is designed to generate economic savings to satellite operators in terms of direct and indirect costs:
- direct costs related to: the complexity of the end-of-life manoeuver (dedicated team, residual propellant estimation in the tanks, etc.); fuel for decommissioning that could extend the life of the satellite (up to 6 months, convertible in extra-revenues); satellite monitoring effort (negligible with D-Orbit system); increased price of the insurance premium.
- indirect costs related to: bad image and reputation as a consequence of improper decommissioning (especially felt by GEO operators); liability for interrupting some other operators’ services in case of collision with other satellites; environmental cost of leaving a piece of garbage uncontrolled.

D3 enables a safe and quick satellite re-entry to a well-defined area safe away from human population or a successful re-orbit MEO and GEO satellite into graveyard orbit, ensuring no risks for other space vehicles or people and assets on the Earth.
D3 decommissioning device