Showing papers by "Paul A. Abell published in 2022"
DOI•
TL;DR: Hera as discussed by the authors is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October and rendezvous in late 2026 December with the binary asteroid (65803) Didymos and its moon, Dimorphos, which will be impacted by NASA's DART spacecraft on 2022 September 26 as the first asteroid deflection test.
Abstract: Hera is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October. It will rendezvous in late 2026 December with the binary asteroid (65803) Didymos and in particular its moon, Dimorphos, which will be impacted by NASA’s DART spacecraft on 2022 September 26 as the first asteroid deflection test. The main goals of Hera are the detailed characterization of the physical properties of Didymos and Dimorphos and of the crater made by the DART mission, as well as measurement of the momentum transfer efficiency resulting from DART’s impact. The data from the Hera spacecraft and its two CubeSats will also provide significant insights into asteroid science and the evolutionary history of our solar system. Hera will perform the first rendezvous with a binary asteroid and provide new measurements, such as radar sounding of an asteroid interior, which will allow models in planetary science to be tested. Hera will thus provide a crucial element in the global effort to avert future asteroid impacts at the same time as providing world-leading science.
24 citations
TL;DR: In this article , the authors discuss the most relevant forces acting on ejecta once decoupled from Dimorphos surface and highlight various software packages used to dynamically simulate ejecta under the action of those forces.
Abstract: We overview various efforts within the DART Investigation Team’s Ejecta Working Group to predict the characteristics, quantity, dynamical behavior, and observability of DART impact ejecta. We discuss various methodologies for simulation of the impact/cratering process with their advantages and drawbacks in relation to initializing ejecta for subsequent dynamical propagation through and away from the Didymos system. We discuss the most relevant forces acting on ejecta once decoupled from Dimorphos’s surface and highlight various software packages we have developed and used to dynamically simulate ejecta under the action of those forces. With some additional software packages, we explore the influence of additional perturbing effects, such as interparticle collisions within true N-body codes and nonspherical and rotating particles’ interplay with solar radiation pressure. We find that early-timescale and close-proximity ejecta evolution is highly sensitive to some of these effects (e.g., collisions) while relatively insensitive to other factors. We present a methodology for turning the time-evolving size- and spatially discretized number density field output from ejecta simulations into synthetic images for multiple platforms/cameras over wide-ranging vantage points and timescales. We present such simulated images and apply preliminary analyses to them for nominal and off-nominal cases bracketing realistic total mass of ejecta and ejecta cumulative size–frequency distribution slope. Our analyses foreshadow the information content we may be able to extract from the actual images taken during and after the DART encounter by both LICIACube and Earth-vicinity telescopes.
9 citations
TL;DR: Hera as discussed by the authors is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October and rendezvous in late 2026 December with the binary asteroid Didymos and its moon, Dimorphos, which will be impacted by NASA DART spacecraft on 2022 September 26 as the first asteroid deformation test.
Abstract: Hera is a planetary defense mission under development in the Space Safety and Security Program of the European Space Agency for launch in 2024 October. It will rendezvous in late 2026 December with the binary asteroid ( 65803 ) Didymos and in particular its moon, Dimorphos, which will be impacted by NASA ’ s DART spacecraft on 2022 September 26 as the fi rst asteroid de fl ection test. The main goals of Hera are the detailed characterization of the physical properties of Didymos and Dimorphos and of the crater made by the DART mission, as well as measurement of the momentum transfer ef fi ciency resulting from DART ’ s impact. The data from the Hera spacecraft and its two CubeSats will also provide signi fi cant insights into asteroid science and the evolutionary history of our solar system. Hera will perform the fi rst rendezvous with a binary asteroid and provide new measurements, such as radar sounding of an asteroid interior, which will allow models in planetary science to be tested. Hera will thus provide a crucial element in the global effort to avert future asteroid impacts at the same time as providing world-leading science.