Project Lyra: Sending a spacecraft to 1I/’Oumuamua (former A/2017 U1), the interstellar asteroid

Abstract

The first definitely interstellar object 1I/'Oumuamua (previously A/2017 U1) observed in our solar system provides the opportunity to directly study material from other star systems. Can such objects be intercepted? The challenge of reaching the object within a reasonable timeframe is formidable due to its high heliocentric hyperbolic excess velocity of about 26 km/s; much faster than any vehicle yet launched. This paper presents a high-level analysis of potential near-term options for a mission to 1I/'Oumuamua and potential similar objects. Launching a spacecraft to 1I/'Oumuamua in a reasonable timeframe of 5-10 years requires a hyperbolic solar system excess velocity between 33 to 76 km/s for mission durations between 30 to 5 years. Different mission durations and their velocity requirements are explored with respect to the launch date, assuming direct impulsive transfer to the intercept trajectory. For missions using a powered Jupiter flyby combined with a solar Oberth maneuver using solid rocket boosters and Parker Solar Probe heatshield technology, a Falcon Heavy-class launcher would be able to launch a spacecraft of dozens of kilograms towards 1I/'Oumuamua, if launched in 2021. An additional Saturn flyby would allow for the launch of a New Horizons-class spacecraft. Further technology options are outlined, ranging from electric propulsion, and more advanced options such as laser electric propulsion, and solar and laser sails. To maximize science return decelerating the spacecraft at 'Oumuamua is highly desirable, due to the minimal science return from a hyper-velocity encounter. Electric and magnetic sails could be used for this purpose. It is concluded that although reaching the object is challenging, there seem to be feasible options based on current and nearterm technology.

Project Lyra: Catching 1I/‘Oumuamua – Mission opportunities after 2024

“…As is clear from Hein et al [26], (a) and (b) conspire to allow a minimum total ΔV of around 18.3km/s with a launch in 2021. Figure 1 shows the long-term results for the total ΔV for this E-J-3SR-1I trajectory.…”

“…The original Project Lyra [26] paper discussed an Earth to Jupiter to 3 Solar Radii to 1I trajectory (E-J-3SR-1I), employing a Solar Oberth maneuver, launching in 2021. The favourable timing of this trajectory relies on:…”

“…The 3 solar radii perihelion distance for the Solar Oberth burn in [26], used in the previous Section's calculations was taken from the KISS architecture [29]. It seems reasonable to question whether this is an optimal value for the E-J-SO-1I trajectory, i.e.…”

“…Seligman and Laughlin [24] have previously concluded that missions to objects similar to 1I would be feasible but dependent on an early detection and early launch. Hein et al [25,26] have argued that a mission to 1I would be feasible, using existing and near-term technologies and a combination of a powered Jupiter flyby and a Solar Oberth maneuver. However, the optimal determined launch date between 2020 and 2021 is deemed to be very challenging from an engineering point of view, as the development of interplanetary spacecraft takes at least 5 and often more than 10 years.…”

Subsurface exolife

“…Hence, ceteris paribus , the flux from the nearest Type U planet would be 10 −5 −10 −6 lower than that of Enceladus unless we serendipitously discover such an object much closer to our planet. Another possibility in the future is to make use of small spacecraft powered by light-sail technology, along the lines of the recently announced Breakthrough Starshot project, 32 for carrying out flyby missions (Hein et al , 2017). A spacecraft travelling at 20% the speed of light might be able to reach the nearest type U planet in a span of ~ 1 yr.…”