The goal of this project is to develop and flight test a novel, low cost/risk deorbiting device based on a 25-m squared Solar Sail with a total mass (including the satellite platform) of 3 kg. The approach will be to modify Solar Sail deployment technology for use as a satellite and/or rocket upper stage deorbiting system. The effectiveness of such deorbiting device is predicted to be high at altitudes lower than 900 km for minisatellites (20 to 500 kg) if deorbiting time constraints of 25 years are being considered. Recent studies show an increasing probability of collisions between intact spacecraft and debris. If no countermeasures are taken, the number of debris particles will grow with a growth rate in the order of up to 5% per year. The historical practice of abandoning spacecraft and upper stages at the end of mission life has resulted in 8,500 tones of space debris in low earth orbit. The uncontrolled growth of the space debris population has to be avoided in order to enable safe operations in space for the future. However, reviews by panels of independent international experts have repeatedly failed to identify a single plan which is both technically feasible in the near-term and economically viable.
The consortium will design and develop a state of the art deorbiting system for LEO satellites and upper stages with a mass less than 500 kg. The deorbiting system will be deployed after the useful time of the satellite/upper stage and will be used to remove/deorbit the object from its orbit within 25 years as required by Space Agency recommendations. An example of the kind of impact this project can have is that if one assumes that all satellites and upper stages with a mass < 500 kg launched after 2013 to 2020 would hypothetically carry the proposed deorbiting system developed by the DEOBRIT-SAIL team space, debris (> 10 cm) will be reduced by 70%.
Making space for new satellites with the help of solar sails
Abandoned decommissioned satellites and upper stages of multi-stage rockets are a growing threat to in-service spacecraft. EU-funded scientists are developing a mini solar sail for drag deorbiting to solve the problem.
Uncontrolled growth of orbiting space debris poses an increasing risk to present and future space missions. EU-funded scientists working on the project 'De-orbiting of satellites using solar sails' (DEORBIT SAIL) are providing a low-cost and effective deorbiting solution.
The system is designed as a 3U CubeSat of less than 500 kg, where a CubeSat or cubic satellite has dimensions 10 x 10 x 10 cm3 and the 3U version has one dimension of 30 cm. It is targeted for the deorbiting of space objects in low Earth orbit (LEO), the region up to around 2,000 km above the Earth. The DEORBIT SAIL system is expected to be useful for drag deorbiting up to 1 000 km and for deorbiting with solar radiation pressure above that height.
Based on modified solar sail technology, the solution comes in the form of a 4 x 4 m square consisting of 4 triangles supported by 4 relatively stiff structural booms. Deorbiting will be accomplished by drag on the deployable sail. The device will be complete with altitude determination and control as well as a communications link to a ground station.
During the previous year, scientists manufactured and tested both payload sub-systems, namely the deployable sail and the attitude and control system. Considerable effort has been devoted to the volume requirement in which the electronics, sail and booms must be accommodated. Having successfully tested the three-axis control system, the boom deployment system and the large cantilevered deployable solar panels, the team is now designing the flight model. Researchers anticipate launch of the DEORBIT SAIL satellite and orbital operations which will enable data collection and optimisation of final designs.
Recent estimates suggest that over 1 000 satellites will be launched in the next 9 years. Together with their launch vehicles, they represent a potential market of 2,000 eventual deorbiting devices.
Space law is imposing strict regulations on end-of-life obligations for satellite operators. DEORBIT SAIL is thus expected to make an important contribution to the competitiveness of satellite manufacturers and operators in addition to its obvious benefits in terms of protecting valuable space assets for all.