Oumuamua was the first interstellar object to be observed passing through the Solar System. It was discovered in 2017. The unusual shape of Oumuamua, its lack of coma and the fact it changed its trajectory, all led to many theories about its origin. Could it have been a hydrogen-iceberg that was exhibiting outgassing or an extraterrestrial solar sail (sorry, folks, not likely). Oumuamua moved too fast and was not able to be seen in time to give us a clear view.Oumuamua may have lost his chance, but we might be able to be prepared for the next interstellar visitor. It is possible to design and build a spacecraft that could capture such an object in a matter of seconds. Experts have suggested the idea of an interstellar interceptor. NASA's Innovative Advanced Concepts program has provided funding for research into such a concept. How would an interceptor like this work?A new paper was released on ArXiv June 27th. It explores one possible mission design. The proposal is based on the NIAC study and suggests combining solar sail technology with space probe miniaturization to make them smaller and lighter.Solar sails are a viable propulsion system, as demonstrated by the JAXAs IKAROS probe of Venus and the Planetary Society's ongoing LightSail 2 project on Earth orbit. The Jet Propulsion Laboratory demonstrated the use of CubeSats for interplanetary missions in 2018. Two CubeSats were sent by the Jet Propulsion Laboratory, named Mars Cube One (MarCO–a and MarCO–b), to support InSight's journey to the red planet. They worked like a charm.Combining solar sails with CubeSats can be an effective tool for exploration.The paper suggests that an interstellar object could be intercepted by a solar-sailing CubeSat. It could be launched in advance and parked in orbit around the Sun, where it would quietly wait for its discovery. This vehicle would allow for different mission designs. For example, a five-year mission could quickly catch up to an interstellar object and beam back to Earth the same data we did not get from Oumuamua. A similar spacecraft, however, could also carry out a sample-return mission if it was given a longer period of time, say ten years.Artist's impression of Oumuamua, the first interstellar comet/asteroid. This rare object was discovered by Pan-STARRS 1 telescope at Hawaii on 19 October 2017. Credit: ESO/M. KornmesserThe ability of solar sails to handle heat is one of the most difficult engineering problems for such a mission. The interceptor will have to travel closer to the Sun than previous solar sail tests. These usually use aluminum coated in Kapton. This material may be able to survive within 0.15AU of the Sun without melting. However, it will need to be shielded from control mechanisms and other spacecraft systems while not adding to its mass. If the sail is too heavy, it will not be able catch up to the target.This interceptor spacecraft is very valuable. Although we have only seen two interstellar objects, it is likely that they pass by constantly. We will be able to find them with better telescopes that are coming online in the next decade. However, they move quickly and don't stay there for very long. A fast response interceptor spacecraft will be our best hope of success if we want to get up close to an interstellar object.Find out more:Darren Garber and Louis D. Friedman. Artur Davoyan, SlavaG. Turyshev. Nahum Melamed. John McVey. Todd F. Sheerin. A Fast Response Mission. Rendezvous with an Interstellar Object.John Ballentine is the photographer of the featured image.
