Search arXivSearch

arXiv · 2302.07659

Project Lyra: Catching 1I/'Oumuamua Realistically with a Jupiter Encounter and Imminent Propulsion Options

Abstract

Any missions to catch 1I/'Oumuamua have the daunting challenge of generating higher hyperbolic excess speeds than the interstellar object's own, i.e. $>$ 26.3 $kms^{-1}$ with respect to the Sun. To accomplish this task using chemical propulsion, previous papers have investigated a Solar Oberth manoeuvre and alternatively a Jupiter Oberth, these options requiring a thrust from the chemical rocket at perihelion/perijove respectively, points at which the available velocity increment ($ΔV$) results in maximum augmentation of the kinetic energy of the spacecraft. In this paper we unravel the specifics of a mission requiring a JOM or optionally a passive Jupiter encounter, i.e. with no thrust, the latter having so far not been addressed by Project Lyra. Whereas the previous papers were feasibility studies, this paper delves into what would be achievable with a Jupiter encounter (without any preceding gravitational assists from the inner planets), using currently available off-the-shelf solid and liquid rocket stages and assuming the NASA Space Launch System Block 2 can be deployed. Optimal Launch dates are found to lie in the years 2030, 2031 and 2032 with resulting mission durations of around 30-40 years, depending on the particular number and combination of stages exploited. Payload masses to 'Oumuamua of 860kg can readily be accomplished with a duration of 43 or so years, assuming a Centaur D and STAR 48B combination, the latter booster being ignited at perijove. On the other hand if two Centaur Ds are utilised instead of just one, retaining the STAR 48BV for the JOM, 35 years are evinced for the same mass. Furthermore, for lower payloads of $\sim{100}$kg, the flight duration can be cut accordingly to 31 years, with the additional benefit of requiring no burn at Jupiter.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Adam Hibberd. 2023-02-15. Project Lyra: Catching 1I/'Oumuamua Realistically with a Jupiter Encounter and Imminent Propulsion Options. https://arxiv.org/abs/2302.07659

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Bridging magnetothermal winds and photoevaporation to model discs dispersal

Protoplanetary disc dispersal is driven by two processes usually modelled separately: photoevaporative and magnetohydrodynamic (MHD) disc winds. Global simulations indicate that in the inner disc these are not distinct outflows but a single magnetothermal wind. We assemble a closed-form, two-phase model that respects it. A single-field-line wind, whose base is fixed by the irradiated temperature and penetration column, supplies the launch and feeds a secular evolution, with photoevaporation convolved on as a sink. The flux closure $B_z\proptoΣ^q$ is self-limiting: for $q\le1/2$ depletion alone cannot demagnetise the disc, so dispersal requires independent flux loss, parameterised by the magnetic Reynolds number $\mathcal{R}_m$. Integrating the coupled system yields two regimes. Efficient flux loss ($\mathcal{R}_m\lesssim1$) lets the magnetisation front recede by over an order of magnitude and opens a photoevaporative gap. Flux retention ($\mathcal{R}_m\gg1$) drives the front outward, sustains accretion, and defers dispersal by $\approx2.7$~Myr. Deriving the base from stellar irradiation instead of prescribing it, we find that the cold-launch approximation is valid during the early stages of disc evolution: anchoring the base at plasma equipartition ($β_{\rm base} \sim 1$) confines irradiation's influence on the magnetic lever arm to the magnetothermal annulus, decoupling the peak accretion rate from the incident flux. Both regimes clear the disc inside-out, through either a photoevaporatively amplified cavity wall or an expanding magnetothermal front.

astro-ph.EP

Faithful Neural Embeddings for 3D Exoplanet Climate Modeling

With the rapid advancement of telescopes like JWST and Ariel, there is an urgent need for efficient 3D climate models to interpret observations of exoplanet atmospheres. Traditional 3D general circulation models (GCMs) are computationally intensive, prompting the development of machine learning (ML) emulators to accelerate simulations. Recent work, such as that by Plaschzug et al. 2026 \cite{plaschzug2026accelerating}, uses a dense neural network (DNN) to predict local gas temperatures and winds from input parameters, including local gas pressure, spatial coordinates (longitude and latitude), and global temperature. However, this model relies on predicting individual temperature values (points) at specific grid points, which can be limited by the resolution and constraints of the training grid. In this work, we investigate a couple of alternative frameworks based on latent-space representations of local gas temperature ($\text{T}_{\text{gas}}$) to obtain a faithful, low-dimensional representation of these profiles. This represents the first step toward developing a latent space regression model, offering a structurally cohesive alternative to the existing point-wise prediction method \cite{plaschzug2026accelerating}. By capturing the optimal embedding space of atmospheric data, our proposed framework can produce simulated profiles while maintaining computational efficiency, making it suitable for large-scale exoplanet ensemble studies.

astro-ph.EP

Some challenges for the long-term survival of Naiad, Neptune's innermost moon

The Naiad-Thalassa 73:69 mean-motion resonance implies these moons have co-existed for $\gtrsim$1 Gyr, raising the question of how they survived to the present day. We examine three challenges to Naiad's long-term survival: tidal disruption, heliocentric bombardment, and runaway collisional erosion by planetocentric debris. We constrain Naiad's internal strength requirements from its nominal density and shape, compute present-day impact rates on Neptune's inner moons from heliocentric bombardment, and use $N$-body simulations to model the fate of ejecta produced by non-disruptive impacts. First, Naiad's nominal density of ${\sim}0.8\text{ g cm}^{-3}$ and elongated shape suggest it cannot be held together by self-gravity alone, implying a cohesive strength of $\gtrsim10$ kPa to avoid tidal disruption, although this constraint is relaxed if Naiad has a higher density of ${\gtrsim}1.3\text{ g cm}^{-3}$. Second, we show that Naiad may have been disrupted in the last 1 Gyr by heliocentric bombardment, although this depends sensitively on the size-frequency distribution of Kuiper Belt objects at small sizes and on Naiad's catastrophic disruption threshold, both of which are poorly constrained. Third, and most notably, we find that even small, non-disruptive impacts can trigger runaway collisional erosion by planetocentric debris on extremely short timescales. Avoiding this ``sesquinary catastrophe'' requires that Naiad has a collisional strength of at least several MPa, which is difficult to reconcile with being a reaccumulated ``rubble pile'', leftover from the capture of Triton and the subsequent cataclysm of Neptune's primordial satellite system. Together, these results suggest that Naiad may be a physically unusual object among small ring-moons -- possibly a largely coherent, monolithic fragment -- and that our understanding of Neptune's inner satellite system leaves much to be explained.

astro-ph.EP