Planetary Defence Projects and Core Activities

APOPHIS MISSION STUDY

The asteroid (99942) Apophis will have a very close encounter with Earth on Friday, 13 April 2029. The minimum distance between the asteroid and Earth will be less than 40 thousand kilometres (within the geostationary orbit distance) and it will be visible to the unaided eye. Having such a large asteroid (which might in the far future become a danger to Earth) pass by so close to the Earth provides a unique opportunity to study it. The Apophis study spacecraft, named “Satis”, will be based on the M-ARGO mission concept currently being implemented via ESA’s General Support Technology Programme. The data acquired by Satis will be extremely valuable both for the purpose of Planetary Defence and for potential future asteroid mining activities (known as In-situ Resource Utilisation ISRU).

The mission is planned for launch in April 2028 and would arrive in orbit in February 2029. It is planned to be launched with a CubeSat carrier as co-passenger to GTO or on a ride share to Lagrangian point 2 - L2.

M-ARGO (led by GomSpace with Politecnico di Milano) is a stand-alone 12-unit CubeSat capable of rendezvous with Near Earth Objects, lowering the cost of entry of deep space missions by an order of magnitude, demonstrating miniaturised European technologies currently including high specific impulsive electric propulsion, an X-Band deep space transponder with reflectarray high gain antenna, high power steerable solar array and a cold gas reaction control system.

NEAR-EARTH OBJECT SURVEY SYSTEM

ESA’s Near-Earth Object (NEO) Survey System will add two complimentary new building blocks to ESA’s global NEO observation network, already consisting of TBT-1 (Cebreros), TBT-2 (La Silla), Flyeye-1 (Monte Mufara) and partner telescopes:

* An ESA’s second #2 Flyeye telescope featuring a fully revised design that incorporates new technologies and improvements to the Flyeye concept as well as the usage of novel technologies in the optical domain (e.g. free-form optics and optical fibres), new sensors, and new manufacturing methods. Telescope is going to be located in the southern hemisphere in order to complement the surveys performed by Flyeye #1 on the northern hemisphere.

* The Telescope Array, will complement the existing survey and follow-up capabilities by deploying an array of telescopes split across a reduced number of sites around the globe. The telescopes, which are expected to be in the ‘1 m class’ range, will be also able to perform characterisation observations. The project envisages the integration of modern and readily available ‘commercial of-the-shelf’ elements for telescopes, cameras and detectors, domes, mounts, control systems, and any other elements/equipment/tools required to complete the array solution (i.e. calibration, environmental conditioning, meteorological stations, remote tools, maintenance & support, etc.).

The array solution is meant to be fully scalable, allowing to start deployment and operations with a reduced subset of elements, and grow in size depending on the available funding. Potential adoption of synthetic tracking techniques (powered by modern scientific CMOS sensors) in addition to traditional survey strategies is also envisioned.

The adopted solution will be based on the outputs of an ongoing internal design study, which not only addresses the technical and architectural challenges, but also evaluates the application of novel commercial approaches for its implementation (I.e. "turn-key" solutions, multiple use of facilities, etc.), in line with ESA’s strategic objectives.

The many industrial opportunities from this will allow the NEO Survey System to become a cooperation between many ESA member states. Both blocks are expected to be deployed in 2028.

NEOMIR

The primary goal of NEOMIR (Near-Earth Object Mission in the Infra-Red) will be to act as an early warning system that will detect and characterise any asteroid coming from the direction of the Sun that cannot be monitored from the ground. An initial study to assess the feasibility of NEOMIR mission has been conducted by ESA's Concurrent Design Facility (CDF). The study focused on defining a mission that would complement NASA's NEO Surveyor mission. The US-funded mission is focused to fulfil the US Congress mandate to discover 90% of the NEOs bigger than 140 m, thus it is designed to find the larger NEO population.

NEOMIR will be placed at “L1”, the first Lagrange point located between the Sun and Earth. It should detect near-Earth objects with diameters of 20 metres and larger at least three weeks in advance of potential Earth impact, using a high-performance infrared detector. It would observe as close as 30º from the Sun and with a revisit time of few hours, so to avoid missing any asteroid passing in its field of regard. A half-meter telescope providing a large corrected focal plane is required, as are two IR channels covering the wavelength bands of 5 to 10 µm waveband. A mixed passive and active cooling system is envisaged.

There is currently no European industry capable of providing the required performance regarding the detectors and associated electronics (application-specific integrated circuit, ASIC). Therefore, further industrial R&D projects to fill this gap are recommended for Period 2. The requirements will be to deliver a similar performance as the NEO Surveyor detectors, i.e. Teledyne's HxRG, that which are in use in the (NASA/)ESA missions JWST (NIRSpec), Euclid (NISP) and Ariel, although at shorter wavelengths (1-5 µm).

Nevertheless, the details of the mission are currently being fleshed out and it is planned to be launched around 2030 with an Ariane 6-2 rocket.

Planetary Defence Core

The top-level objectives for Planetary Defence Core in the next Space Safety Period 2 are grouped into three main areas: Observations, Data Assessment and Mitigation activities.

Objectives of the Planetary Defence Core:

* Continued operation and enhancement of ESA’s near-Earth object observation network and an upgrade of the telescopes’ software and hardware.

* The Near-Earth Object Coordination Centre (NEOCC) will use machine learning to provide reliable detection of objects in ground-based observations and to link observations to existing objects.

* Adaptation of virtual reality for remote telescope maintenance and real-time flexible tasking for telescopes.

* Support the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG) including the implementation of information processes for emergency response agencies.

* Increase the involvement of the Planetary Defence segment in space missions.

* Fulfil modern security standards.

In the observation area of activities, the possibility studies of European contribution to radar observation are ongoing. Europe has high potential to expand capabilities and could add strong transmitting capabilities and contribute to an international planetary radar facility. For this purpose, a detailed feasibility study will be performed, followed by the implementation of prototype observing capabilities at an existing radar facility and the development of software for imaging. First studies indicate that an upgrade of the so-called DSS-63 Antenna at Robledo, close to Madrid, would be the most promising candidate. Other activities are focused on operations of ESA telescopes - Flyeye, Test-Bed Telescopes, OGS Tenerife. Upgrade of the telescope’s hardware and software in planned within the upcoming Space Safety Programe Period 2, also the ESEC (Site Equipment Controller) will be expanded to support all assets.

Other activities that are envisaged as information provision for Planetary Defence Core are as follows, enhancing orbit determination and impact monitoring with new algorithms, adding fidelity (e.g. include higher order dynamical terms, ensuring that ESA’s software can cope with artificial satellites), provide proper ephemerides service, update the priority list and coordinate with the EU-funded NEOROCKS (Near Earth Rapid Observation, Characterisation and Key Simulations) activity, coordinate physical properties handling with EU-funded activities, contribute to a European hot-redundant element to the Minor Planet Centre (funded by EU). A service to ensure that NEO observations are not ‘contaminated’ with artificial objects will be expanded; the existing NEO population model has to be expanded to smaller sizes, and a mission opportunity tool has to be produced.

On top of standard hardware and software maintenance, advanced new technologies have to be introduced for improving information provision, including AI techniques, and in particular use machine-learning for NEOs for reliable detection of objects in ground-based observations and linking observations to existing objects, virtual reality for remote telescope maintenance, real-time flexible tasking for telescopes and study the possibilities for a ‘Digital Twin’ of the NEO population.

The Hera mission will get closer to its target asteroid. This will require activities within the Planetary Defence team to ensure that the resulting data can be properly analysed and applied. The impact effects

tool will have to be expanded e.g. for ocean impacts and to cover larger impactor cases. Additional hydrodynamic simulations will need to be run to fill the complete parameter space of expected impacts. Communications and outreach activities will be reinforced, with training of journalists and emergency response entities considered an important activity.