C. Colombo

M. Trisolini

Y. Tsuda

English

Archivio istituzionale della ricerca - Politecnico di Milano

Credit: NASAA mission concept for in-orbit particle collection around asteroidsMirko Trisolini1, Camilla Colombo1, Yuichi Tsuda21 Department of Aerospace Science and Technology, Politecnico di Milano2 Institute of Space and Astronautical Science (ISAS) / Japan Aerospace Exploration Agency (JAXA).2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECBackground Increasing interest in asteroid exploration and sample collection missions Recent missions JAXA’s Hayabusa2 Created an artificial crater on Ryugu via a small carry-on impactor Collected samples via touch and go mechanism with sampler horn NASA’s OSIRIS-REx Sample collection on Bennu via touch and go using the TAGSAM arm NASA’s DART and ESA’s Hera Asteroid deflection technology demonstrationCredits: JAXA Credits: NASACredits: NASA208/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECBackground Starting from the heritage of Hayabusa2, we propose a new concept for in-orbit sample collection Why an alternative approach? Complementary to already existing methodologies Potential implementation in challenging environmental conditions preventing landing or touch down Hazardous terrain features Fast rotating asteroidMission concepts for sample collectionA kinetic impactor generates a crater and its ejectaThe spacecraft collects the ejecta resulting from the impactThis diagram has been designed using resources from Flaticon.com308/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECPreliminary mission concept Assessment of mission feasibility and principal mission driversMain building blocksAssessing the risk for the                 spacecraftUnderstanding operationalrequirements and constraintsEstimating the amount ofcollectable samplesIdentifying possiblecollection strategies408/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Collection strategies may exploit hovering of the spacecraft in specific locations Also orbiting solutions may be investigatedPossible collection strategiesxHovering above the asteroid’s surfaceHovering in suitable locations around the asteroid508/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroidWe can then estimate the flux of particles on a given surfaceThe surface can represent the collection area of the instrumentThe flux will be dependent on the spacecraft position and orientation relative to the impact pointEstimating the amount of collectable samplesxHovering in suitable locations around the asteroid608/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroidWe can then estimate the flux of particles on a given surfaceThe surface can represent the collection area of the instrumentThe flux will be dependent on the spacecraft position and orientation relative to the impact pointEstimating the amount of collectable samples Sample the ejecta distribution Propagate the samples and the representative fragments We store the propagation at specific snapshots in time708/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroidWe can then estimate the flux of particles on a given surfaceThe surface can represent the collection area of the instrumentThe flux will be dependent on the spacecraft position and orientation relative to the impact pointEstimating the amount of collectable samples Discretise the space around the asteroid with aspherical grid Estimate the fragments density and speed inside each spherical bin𝜌𝜌(𝑟𝑟,𝛼𝛼, 𝛿𝛿) =∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖 𝑟𝑟,𝛼𝛼, 𝛿𝛿Δ𝑉𝑉(𝑟𝑟,𝛼𝛼, 𝛿𝛿) =𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑟𝑟 𝑜𝑜𝑜𝑜 𝑜𝑜𝑟𝑟𝑓𝑓𝑓𝑓𝑁𝑁𝑁𝑁𝑛𝑛𝑓𝑓𝑓𝑓𝑆𝑆𝑆𝑆𝑁𝑁𝑟𝑟𝑆𝑆𝑆𝑆𝑓𝑓𝑆𝑆 𝑁𝑁𝑆𝑆𝑛𝑛 𝑣𝑣𝑜𝑜𝑆𝑆𝑁𝑁𝑁𝑁𝑁𝑁𝒗𝒗 𝑟𝑟,𝛼𝛼, 𝛿𝛿 =∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖 𝑟𝑟,𝛼𝛼, 𝛿𝛿 ⋅ 𝒗𝒗𝑖𝑖∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖(𝑟𝑟,𝛼𝛼, 𝛿𝛿)808/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroidWe can then estimate the flux of particles on a given surfaceThe surface can represent the collection area of the instrumentThe flux will be dependent on the spacecraft position and orientation relative to the impact pointEstimating the amount of collectable samples Discretise the space around the asteroid with a spherical grid Estimate the fragments density and speed inside each spherical bin𝜌𝜌(𝑟𝑟,𝛼𝛼, 𝛿𝛿) =∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖 𝑟𝑟,𝛼𝛼, 𝛿𝛿Δ𝑉𝑉(𝑟𝑟,𝛼𝛼, 𝛿𝛿) =𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑟𝑟 𝑜𝑜𝑜𝑜 𝑜𝑜𝑟𝑟𝑓𝑓𝑓𝑓𝑁𝑁𝑁𝑁𝑛𝑛𝑓𝑓𝑓𝑓𝑆𝑆𝑆𝑆𝑁𝑁𝑟𝑟𝑆𝑆𝑆𝑆𝑓𝑓𝑆𝑆 𝑁𝑁𝑆𝑆𝑛𝑛 𝑣𝑣𝑜𝑜𝑆𝑆𝑁𝑁𝑁𝑁𝑁𝑁𝒗𝒗 𝑟𝑟,𝛼𝛼, 𝛿𝛿 =∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖 𝑟𝑟,𝛼𝛼, 𝛿𝛿 ⋅ 𝒗𝒗𝑖𝑖∑𝑖𝑖 𝑛𝑛𝑓𝑓𝑖𝑖(𝑟𝑟,𝛼𝛼, 𝛿𝛿)908/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroid We can then estimate the flux of particles on a given surface (impact rate) The surface can represent the collection area of the instrument, AEstimating the amount of collectable samples ?̇?𝜂𝑠𝑠𝑠𝑠 𝑟𝑟,𝛼𝛼, 𝛿𝛿 = 𝜌𝜌 𝑟𝑟,𝛼𝛼, 𝛿𝛿 ⋅ (𝒗𝒗 𝑟𝑟,𝛼𝛼, 𝛿𝛿 − 𝒗𝒗𝑠𝑠𝑠𝑠 | ⋅ 𝐴𝐴Computation of the flux in a spherical bin𝒗𝒗𝑟𝑟𝑟𝑟𝑟𝑟1008/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Use of a methodology borrowed from the space debris field Consists of computing distribution of the particles density and speed around the asteroid We can then estimate the flux of particles on a given surface (impact rate) The surface can represent the collection area of the instrument, A We repeat the procedure for each of the bins crossed by the spacecraft Estimate the total impactsEstimating the amount of collectable samples 𝑁𝑁𝑖𝑖𝑖𝑖𝑖𝑖 ≅ ∑𝑡𝑡=1𝑁𝑁𝑇𝑇 ?̇?𝜂𝑠𝑠𝑠𝑠𝑡𝑡 𝑟𝑟𝑡𝑡,𝛼𝛼𝑡𝑡, 𝛿𝛿𝑡𝑡 ⋅ Δ𝑇𝑇𝑡𝑡Spacecraft trajectory passing through the spherical binsTime interval between consecutive spacecraft positions1108/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysisExample Target Asteroid Ryugu Sand-like material  negligible strength Impact location (synodic frame) α = 200° δ = 10° Impactor U = 2 km/s m = 2 kg Normal impact Particle distribution Size range between 10 μm and 1 cm Speed range: up to the escape speed of the asteroidEstimating the amount of collectable samples1208/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Assume now we want estimate the impact rate on a hoveringspacecraft The S/C occupies a fixed position in the synodic frame The S/C is approximated with a sphere of 1 m2 cross-sectionEstimating the amount of collectable samplesExamples of hovering points1308/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Assume now we want estimate the impact rate on a hoveringspacecraft The S/C occupies a fixed position in the synodic frame The S/C is approximated with a sphere of 1 m2 cross-sectionEstimating the amount of collectable samplesExamples of hovering pointsImpact rate and cumulative impactsImpact rate by particle size range1408/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysisImpact rate by particle size range1508/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysisPreliminary collection trajectory design The particle fluxes around the asteroid can be exploited to design a collection trajectory We can create trajectory waypoints the spacecraft should pass to improve the collection The waypoints can be selected as the location of maximum cumulative flux in a given time span1608/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysisPreliminary collection trajectory design The particle fluxes around the asteroid can be exploited to design a collection trajectory We can create trajectory waypoints the spacecraft should pass to improve the collection The waypoints can be selected as the location of maximum cumulative flux in a given time span Example trajectory for an impact on Ryugu Total manoeuvre time of 24 hours Minimum distance from the asteroid surface of 300 m avoids crashing on the asteroid Maximum distance from the centre of the asteroid of 6 km  Minimum time between snapshots of 1 hourWaypoints selection example. The black line is a spline interpolation to represent a possible trajectory.1708/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Once generated the waypoints, we need to control the spacecraft motion across them We utilise a higher-order sliding mode control1between the waypoints Control problem definition Hayabusa2-like spacecraft Mass of 600 kg Cross-section of 25 m2 Maximum thrust of 20 N Attitude motion not consideredTrajectory controlTop: 3D trajectory of the spacecraft following a sliding-mode controlLeft: Position of the spacecraft as function of time1 Furfaro, 2015, Hovering in Asteroid Dynamical Environments Using Higher-Order Sliding Control, JGCD.1808/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECEjecta collection analysis Once generated the waypoints, we need to control the spacecraft motion across them We utilise a higher-order sliding mode controlbetween the waypoints Control problem definition Hayabusa2-like spacecraft Mass of 600 kg Cross-section of 25 m2 Maximum thrust of 20 N Attitude motion not considered We can finally compute the number of collectable particles by the spacecraft along this trajectory (1 m2 cross-section)Impact rate estimateImpact rate (blue) and cumulative number of impacts (orange) intime, along the specified trajectory. Notice the oscillations of theimpact rate as a result of the change of particle flux due to thechange in velocity of the spacecraft during the manoeuvres.1908/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECConclusions and future work Possible collection strategies have been explored for in-orbit sample collection Collection in the anti-solar direction for particles mainly affected by SRP Collection exploiting the location of re-impacting particles Future efforts will also consider particles orbiting for a longer period A methodology has been presented to estimate the collectability of samples in orbit The methodology is statistical in nature Further analyses to study its sensitivity will be performed The understanding of the sensitivity to impact uncertainties is under analysis E.g.: impact angle, target properties This methodology is integrated with the design and control of a collection trajectory to maximise the collection Introduction of operational constraints (e.g., eclipse periods, communication windows, etc.) is under consideration2008/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTECCredit: NASAThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 896404 - CRADLEA mission concept for in-orbit particle collection around asteroidsmirko.trisolini@polimi.itwww.linkedin.com/in/mirkotrisolini/www.researchgate.net/profile/Mirko-TrisoliniMirko Trisolini, Camilla Colombo, Yuichi Tsuda Visit the project websitewww.cradle.polimi.itAssessing the risk for the spacecraft Preliminary analysis of risk from ejected particles Compute the critical diameter using Ballistic Limit Equations (BLEs) Assuming normal impact on a 1 mm single-wall structure in Aluminium alloyRisk areaParticle diameter greater than the critical diameterPotential damage to the spacecraftEstimated number of dangerous particles2208/11/2022 2nd International Stardust Conference, 7-11 November 2022, ESA, ESTEC

A mission concept for in-orbit particle collection around asteroids

https://re.public.polimi.it/bitstream/11311/1223981/2/TRISM04-22.pdf

A mission concept for in-orbit particle collection around asteroids

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Politecnico di Milano