Recognising the threat of near-Earth objects (NEOs) to life on Earth, many projects have been developed worldwide with the aim of detecting potential impactors, most of which are focused on ground-based surveys. However, _20% of the Earth-threatening NEOs are estimated to be approaching Earth from the day-side, and are thus very difficult to detect using ground surveys. Over the last decade, several space-based capabilities have emerged in an effort to discover and catalogue NEOs in order to better quantify their risk of impact, yet little research has gone into dealing with imminent-impacting NEOs. The aim of this paper is to design a space mission that places a telescope in-orbit in order to detect and provide warning for Earth-impacting NEOs down to 20m in size, by determining the performance of both a visible and an infrared (IR) space-based telescope used in two mission candidates. The first mission candidate consists of a halo orbit about the artificial equilibrium point sub-L1 of the Sun-Earth (SE) system, which is displaced with respect to the classical L1 point, along the SE direction towards the Sun, through the use of solar-sail propulsion. As second mission candidate, three vertical Lyapunov orbits about the libration points L3, L4 and L5 of the Sun-Venus system are considered. A trade-off between detection rates and warning times is conducted to determine the most suitable space-based NEO survey system. It is concluded that an IR space-based telescope placed at the SE solar-sail displaced L1 point is the best option because of the long warning times obtained and the beneficial contribution to existing ground-based NEO surveys. A preliminary mission analysis is also performed to determine a solar-sail propelled transfer trajectory to the SE sub-L1 region, assuming a ride-share launch on ESA’s Euclid mission.
|Title of host publication||AAS/AIAA Astrodynamics Specialist Conference|
|Number of pages||20|
|Publication status||Published - 2020|
|Event||AAS/AIAA Astrodynamics Specialist Conference 2020 - virtual event|
Duration: 9 Aug 2020 → 12 Aug 2020
|Conference||AAS/AIAA Astrodynamics Specialist Conference 2020|
|Period||9/08/20 → 12/08/20|