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 heat shield 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 near-term technology.

• The paper demonstrates a feasible mission to intercept 1I/'Oumuamua by utilizing gravitational assists such as Jupiter flybys and solar Oberth maneuvers.
• The study employs detailed trajectory analyses, outlining DeltaV requirements of 33–76 km/s over mission durations of 5–30 years.
• The paper explores integrating current technologies, including Falcon Heavy-class launchers and advanced heatshield systems, to enable in-situ interstellar research.

Feasibility Study of a Mission to Interstellar Object 1I/’Oumuamua: Analysis and Prospects

The study presented in the paper investigates the feasibility of launching a spacecraft to intercept the interstellar object 1I/’Oumuamua, leveraging current and near-term technologies. Discovered in 2017, 1I/’Oumuamua exhibited a heliocentric hyperbolic excess velocity of approximately 26 km/s, posing a formidable challenge for any prospective mission originating from Earth. This velocity far surpasses that of any spacecraft sent from the solar system to date, including Voyager 1.

Trajectory and Mission Design

The paper's trajectory analysis juxtaposes various mission timelines and their respective velocity requirements, specifying a range between 33 to 76 km/s for hyperbolic solar system excess velocity to complete the mission within 5 to 30 years. The study concludes that achieving a mission within this timeframe is plausible through several potential trajectories including a powered Jupiter flyby and solar Oberth maneuver. Utilizing a Falcon Heavy-class launcher and incorporating heatshield technology from the Parker Solar Probe are crucial parts of the proposed mission architecture, enabling a launch as early as 2021, with an additional Saturn flyby considered to enhance spacecraft mass capabilities.

Technological Solutions and Constraints

The study explores a multitude of propulsion options, from conventional chemical propulsion to advanced proposals such as laser electric propulsion, solar sails, and magnetic sails, which have yet to be fully developed or operationalized. For practical scenarios with current technologies, the focus remains on gravitational assists and high-deliverable DeltaV maneuvers using large-scale boosters. For instance, the Oberth maneuver close to the sun illustrates how gravitational potential can be exploited to generate significant velocity increases.

Key architecture analysis reveals that, employing gravitational assists such as a Jupiter flyby, allows for minimizing propulsion requirements, thus deploying larger payloads. Plans also include the use of solar sails and laser sails, potentially augmented by Project Starshot infrastructure for swift response to future interstellar objects. Nevertheless, these options await further technological maturity.

Science and Technological Implications

The scientific motivation for visiting 1I/’Oumuamua lies in the unprecedented opportunity to directly study material originating from outside the solar system. In-situ observation would address unresolved issues like the object's elongated shape, non-gravitational acceleration, and composition that spectroscopic analysis suggests bears similarities with Trans-Neptunian objects.

From a technological perspective, a successful mission could catalyze advancements in spacecraft velocity capabilities and mission planning. Existing systems like NASA's Space Launch System and SpaceX's Falcon Heavy are poised to exceed previous limits, though significant challenges remain in spacecraft mass, thermal protection during solar approaches, and communication capabilities over interstellar distances.

Conclusion and Future Directions

The research delineates feasible pathways for intercepting 1I/’Oumuamua using available or near-term technologies, highlighting both the scientific value and technical challenges inherent in such a mission. The study encourages further exploration of non-conventional propulsion methods and distributed sensing architectures as integral elements of future interstellar exploration strategies. The potential for craft with mission styles akin to swarm robotics enables flexible approaches to elusive cosmic phenomena. Future work within Project Lyra aims to refine mission concepts and select the most promising strategies for interstellar research endeavors.