Project Lyra: A Mission to 1I/'Oumuamua without Solar Oberth Manoeuvre (2201.04240v1)

Abstract: To settle the question of the nature of the interstellar object 1I/'Oumuamua requires in-situ observations via a spacecraft, as the object is already out of range of existing telescopes. Most previous proposals for reaching 1I/'Oumuamua using near-term technologies are based on the Solar Oberth Manoeuvre (SOM), as trajectories without the SOM are generally significantly inferior in terms of lower mission duration and higher total velocity requirement. While the SOM allows huge velocity gains, it is also technically challenging and thereby increases programmatic and mission-related risks. In this paper, we identify an alternative route to the interstellar object 1I/'Oumuamua, based on a launch in 2028, which does not require a SOM but has a similar performance as missions with a SOM. It instead employs a Jupiter Oberth Manoeuvre (JOM) with a total time of flight of around 26 years or so. The efficacy of this trajectory is a result of it significantly reducing the $\Delta$V to Jupiter by exploiting the VEEGA sequence. The total $\Delta$V of the trajectory is 15.8 $kms^{-1}$ and the corresponding payload mass is 115 kg for a SLS Block 1B or 241 kg for a Block 2. A further advantage of the JOM is that the arrival speed relative to 1I/'Oumuamua is approximately 18 $kms^{-1}$, much lower than the equivalent for the SOM of around 30 $kms^{-1}$.

• The paper proposes an alternative mission trajectory to 1I/'Oumuamua using a Jupiter Oberth Manoeuvre (JOM) and VEEGA gravity assists, significantly reducing delta-V requirements and technical risks compared to Solar Oberth Manoeuvre (SOM) approaches.
• Numerical results using OITS demonstrate mission feasibility for a 2028 launch and 26-year flight, enabling payload masses up to 241 kg depending on the launch vehicle.
• This JOM-based approach reduces technical risk and cost by eliminating the need for advanced heat shields, increasing payload capacity for scientific instruments compared to SOM designs.

Analysis of "Project Lyra: A Mission to 1I/'Oumuamua without Solar Oberth Manoeuvre"

The paper "Project Lyra: A Mission to 1I/'Oumuamua without Solar Oberth Manoeuvre," presents an alternative mission design to reach the interstellar object 1I/'Oumuamua using a Jupiter Oberth Manoeuvre (JOM) instead of the commonly proposed Solar Oberth Manoeuvre (SOM). This approach addresses the technical challenges and risks associated with executing a SOM, while maintaining comparable mission performance.

Overview of the Proposed Methodology

The authors propose a trajectory that bypasses the need for a SOM by leveraging gravity assists from Venus, Earth, and Jupiter, in combination with a Deep Space Manoeuvre (DSM). This trajectory is denoted as V-E-DSM-E-J (VEEGA), and is proposed for a launch in 2028, reaching 1I/'Oumuamua in 2054. The total delta-V requirement for this trajectory is significantly reduced to 15.8 km/s compared to those necessitating a SOM, which typically involve complex near-solar maneuvers and require substantial spacecraft heat shielding. The Jupiter Oberth Manoeuvre results in an arrival speed relative to 'Oumuamua of 18 km/s, considerably lower than the 30 km/s typical of SOMs.

Numerical Results

The mission design is rigorously calculated using the Optimum Interplanetary Trajectory Software (OITS) with Non-Linear Programming optimizers NOMAD and MIDACO for trajectory optimization. A key mission scenario with a 26-year flight duration constraint demonstrates the feasibility of the proposed approach. For a mission duration of this extent, the cumulative delta-V applied, including gravity assists and the DSM, enables a payload mass of 115 kg with a Space Launch System (SLS) Block 1B launch, or 241 kg with SLS Block 2. This payload capability supports significant scientific instrumentation for in-situ analysis of 1I/'Oumuamua.

Implications and Future Considerations

The proposed JOM-based mission architecture presents several implications:

1. Technical Feasibility: Eliminating the requirement for a SOM removes the necessity to develop new heat shield technologies, reducing both development risk and cost. This can be vital in realizing near-term interstellar mission endeavors.
2. Increased Payload Capacity: The absence of a large heat shield enables higher payload masses, allowing for more comprehensive scientific payloads essential for in-depth analysis of 'Oumuamua's composition and properties.
3. Mission Risk Management: The strategy mitigates risks associated with precisely navigating a SOM, which demands high-precision thrust vector control near the Sun.
4. Comparable Duration: Despite the longer mission time (26 years), the trajectory still supports timely scientific returns within the operational lifespan of scientific instruments.

Challenges and Limitations

The primary challenges of this mission architecture include:

1. Rarer Launch Windows: The intricate gravity assist sequence requires precise alignment of celestial bodies, potentially limiting window opportunities.
2. Extended Mission Duration: A 26-year mission timeline demands highly durable spacecraft systems and raises considerations for long-term mission management.

Conclusion

This paper presents a compelling alternative to SOM-based mission profiles for reaching interstellar objects, particularly 1I/'Oumuamua, by leveraging a JOM and gravity assists within the solar system. This approach reduces the technical and financial barriers to engaging in interstellar exploration and opens new frontiers for scientific discovery, while also highlighting the need for continued advancements in spacecraft longevity and deep-space navigation. The scientific community can look forward to implementing such innovative mission designs as part of future interstellar exploration initiatives.