Project Lyra develops concepts for reaching interstellar objects such as 1I / 'Oumuamua and 2I / Borisov with a spacecraft, based on near-term technologies. But what is an interstellar object?
On October 19th 2017, the University of Hawaii’s Pan-STARRS 1 telescope on Haleakala discovered a fast-moving object near the Earth, initially named A/2017 U1. It is now designated as 1I/’Oumuamua. This object was found to be not bound to the solar system. It has a velocity at infinity of ~26 km/s and an incoming radiant (direction of motion) near the solar apex in the constellation Lyra. Due to the non-observation of a tail in the proximity of the Sun, the object does not seem to be a comet but an asteroid. More recent observations from the Palomar Observatory indicate that the object is reddish, similar to Kuiper belt objects. This is a sign of space weathering.
When will such an object visit us again? End of 2019, a second interstellar object, 2I/Borisov was discovered, which is a comet. As 1I/‘Oumuamua and 2I/Borisov are the nearest macroscopic samples of interstellar material, the scientific returns from sampling the object are hard to overstate. Detailed study of interstellar materials at interstellar distances are likely decades away, even if Breakthrough Initiatives’ Project Starshot, for example, is vigorously pursued. Hence, an interesting question is if there is a way to exploit this unique opportunity by sending a spacecraft to 1I/’Oumuamua to make observations at close range.
To answer these questions, the Initiative for Interstellar Studies, i4is, announced Project Lyra on the 30th October 2017. The goal of the project is to assess the feasibility of a mission to 1I/’Oumuamua, 2I/Borisov and other potential interstellar objects, using current and near-term technology and to propose mission concepts for achieving a fly-by or rendezvous. The challenge is formidable: 1I/’Oumuamua has a hyperbolic excess velocity of 26 km/s, which translates to a velocity of 5.5 AU/year. It will be beyond Saturn’s orbit within two years. This is much faster than any object humanity has ever launched into space. Compare this to Voyager 1, the fastest object humanity has ever built, which has a hyperbolic excess velocity of 16.6 km/s. As 1I/’Oumuamua is already on its way of leaving our solar system, any spacecraft launched in the future needs to chase it. The challenge to reach the object could stretch the current technological envelope of space exploration.
After days of intense work, we have published some preliminary results on the 8th November 2017 for reaching the object within a timeframe of a few decades. The paper was published on arXiv. Subsequently, our arXiv paper created a surge of media articles, which can be found below.
A revised version of the paper "Project Lyra: Sending a spacecraft to 1I/’Oumuamua (former A/2017 U1), the interstellar asteroid" has been accepted by the journal Acta Astronautica and has been published on the 7th of January 2019.
In the paper, we demonstrate that missions to 'Oumuamua are feasible with current and near-term technologies (Falcon Heavy or Space Launch System launcher, solid rocket motors, and Parker Solar probe heat shield), with an optimal launch date in 2021. However, this launch date would be too soon for developing a dedicated spacecraft, something that usually takes 5 to 10 years for an interplanetary mission.
Hence, in January / February 2019, our team has worked on potential missions after 2024, leaving enough time for spacecraft development. The results have been published on arXiv on the 14th of February. In this paper, titled "Project Lyra: Catching 1I/'Oumuamua - Mission Opportunities After 2024", we show that missions to 'Oumuamua are possible with current and near-term technologies much later than 2021, with opportunities coming up in 2030, 2033, and even later dates. Trip times are 17 and 16 years, respectively, with arrival dates in 2047 and 2049.
A third paper, "Sending a Spacecraft to Interstellar Comet C/2019 Q4 (Borisov)" has been published on the 13th of September 2019 on arXiv, about two weeks after the discovery of 2I/Borisov.
We conclude that a mission to 'Oumuamua and Borisov are feasible, not only technologically, but also from a spacecraft development perspective.
Project Lyra Publications
Hibberd, A., Hein, A.M., Eubanks, T.M., 2019. Project Lyra: Catching 1I/'Oumuamua - Mission Opportunities After 2024. arXiv preprint arXiv:1902.04935.
Hein, A.M., Perakis, N., Eubanks, T.M., Hibberd, A., Crowl, A., Hayward, K., Kennedy III, R.G. and Osborne, R., 2019. Project Lyra: Sending a spacecraft to 1I/’Oumuamua (former A/2017 U1), the interstellar asteroid. Acta Astronautica, Volume 161, August 2019, Pages 552-561.
Hein, A. M., Perakis, N., Long, K. F., Crowl, A., Eubanks, M., Kennedy III, R. G., & Osborne, R. (2017). Project Lyra: Sending a Spacecraft to 1I/'Oumuamua (former A/2017 U1), the Interstellar Asteroid. arXiv preprint arXiv:1711.03155.