Spacecraft could catch up with interstellar object ‘Oumuamua in 26 years – if launched by 2028
In October 2017, the interstellar object ‘Oumuamua passed through our solar system, leaving many questions in its wake. Not only was it the first such object ever observed, but the limited data astronomers got as it exited our solar system left them all scratching their heads. Even today, nearly five years after the flyby of this interstellar visitor, scientists are still unsure of its true nature and origins. In the end, the only way to get real answers from ‘Oumuamua is to catch him.
Interestingly enough, there are plenty of proposals on the table for missions that could do just that. To consider Project Lyraa proposal from Institute for Interstellar Studies (i4is) which would rely on advanced propulsion technology to encounter and study interstellar objects (ISO). According to them latest studyif their mission concept was launched in 2028 and performed a complex Jupiter Oberth Maneuver (JOM), it would be able to catch up to ‘Oumuamua in 26 years.
October 30and, 2017, less than two weeks after the detection of Oumuamua, the Initiative for Interstellar Studies (i4is) inaugurated the Lyra project. The purpose of this concept study was to determine if a rendezvous mission with ‘Oumuamua was feasible using current technologies or in the short term. Since then, the i4is team has conducted studies that envisioned catching up with ISO using nuclear-thermal propulsion (NTP) and a sailboat lasersimilar to Revolutionary Starshot – a concept of an interstellar mission to reach Alpha Centauri in 20 years.
As they describe in their study, most of the previously proposed methods for achieving 1I/’Oumuamua using short-term technologies require a Oberth’s Solar Maneuver (SOM). A perfect example is the “sundiver», a proposal made by researcher Coryn Bailer-Jones of the Max Planck Institute for Astronomy (MPIA). As he described to Universe Today in a previous postthis concept is based on the radiation pressure of the Sun to obtain a very high speed with a light sail.
“The principle of the Oberth effect is to apply your boost when you are moving fastest relative to the body you are orbiting, i.e. the Sun in the case of the Sundiver,” he said. he declares. “The closer you are to the Sun in your orbit, the faster you will be. So, to take advantage of the Oberth effect, you need to get as close to the Sun as possible.
At the heart of the SOM and other Oberth maneuvers is a technique known as Gravity Assistused to explore the solar system since the early 1970s. This technique involves using the gravitational force of three bodies, including the spacecraft, a second body that provides “assistance” (usually a large planet), and the central body around which the trajectory of the spacecraft is controlled.
i4is researcher Adam Hibberd was the lead author of this latest Lyra study (entitled “Project Lyra: A mission to 1I/’Oumuamua without Solar Oberth Maneuver. Before joining i4is, Hibberd was an aerospace engineer who developed Optimal Interplanetary Trajectory (OITS) software. When ‘Oumuamua was detected, it decided to use OITS with this ISO as its intended destination. After discovering Project Lyra, he joined them and their research efforts soon after.
As he explained to Universe Today via email, the Solar Oberth Maneuver (SOM) relies on three discrete changes in velocity (aka pulses) to exit the solar system. These include:
- On Earth, to increase the spacecraft’s furthest distance from the Sun (aphelion),
- At aphelion, slow down and get closer to the Sun,
- At the closest point to the Sun (perihelion) when the spacecraft is moving fastest to get an extra boost
“This 3-pulse scenario was discovered by Theodore Edelbaum in 1959, although the term SOM seems to have stuck. It is optimal in terms of fuel to generate high speeds from the solar system. This is precisely what is needed to catch an ISO when the ISO has passed perihelion and is rapidly moving away from the sun.
“However, this theoretical configuration does not take into account Jupiter. So, as a slight modification, if we slow down in Stage 2 using reverse gravity assist from Jupiter, then we can escape with even less fuel. It is because the SOM is so effective at generating high speeds that it has been used for research missions to ISOs.
Looking for alternatives to a SOM, Hibbert and his colleagues considered using a proven route that would incorporate Jupiter’s powerful gravitational pull. Part of their motivation for this was the challenges inherent in a solar gravity assist maneuver. Although this maneuver looks great on paper, it has never been performed before and therefore has a low Technology readiness level (TRL).
Additionally, there is the question of how much heating will take place when the spacecraft reaches perihelion during stage 3 (between 3 and 10 solar radii). These issues were addressed in a recent NASA Solar and Space Physics Concept Study titled “Interstellar Probe: Humanity’s Journey to Interstellar Space.” This study was conducted for the Decadal Survey of Solar and Space Physics 2023-2032, which included (among other things) concepts for an interstellar probe. In Appendix D2.2., the study addresses thermal protection in the context of a Solar Oberth Maneuver:
“Unlike previous missions, where a shield design was needed for a given solar distance, the challenge for the interstellar probe is to see how realistically close a spacecraft can get to the Sun. As the solar distance decreases, the challenge The shadow angle increases and the size of the shield, relative to the spaceship, increases dramatically.
“Because a conceptual design effort cannot include all of the design, manufacturing, and materials testing limitations of the complete design, the final recommendation of allowable solar distance is based on where the design appears to pass. from very difficult to impossible.”
As the Parker Solar Probe amply demonstrates that getting closer to the Sun requires a heat shield capable of withstanding extreme heat and radiation. In the case of parker, this shield measures approximately 2.44 meters (8 feet) in diameter and weighs almost 72.5 kg (160 pounds). Although the size and mass of a heat shield for Lyra is not identical, it’s a safe bet that a solar heat shield would result in a lot of extra mass for the light sail.
As an alternative, Hibberd and his team recommended a Jupiter Oberth Maneuver (JOM), which would launch from Earth, swing around Venus and Earth, perform a Deep Space Maneuver (DSM), swing back to Earth. , then would receive a Gravity Assist using Jupiter. gravitational attraction. This is summarized by the acronym VE-DSM-EJ, or more commonly used VEE-GA – Venus, Earth, Earth, Gravity Assist. As Hibberd pointed out, this maneuver would have several advantages over a SOM, including:
“[It] would not require a heavy heat shield, nor would it need: a) An additional travel distance from Jupiter to Solar Oberth of about 5.2 astronomical units (au), [and] b) A further trip to Jupiter’s orbit by an additional 5.2 AU. (a) and (b) would take time for a SOM that would not be needed for a Jupiter Oberth maneuver.
“JOM is a discovery that is critical to the mission of ‘Project Lyra’ to find options using ‘current or near-term technology’ because it requires essentially no hardware or maneuvers that have not been tried before, unlike the SOM: Nevertheless, despite the time saved by not requiring (a) and (b) above – the lower escape speeds generated by the JOM mean that the duration of the mission must be longer.
Another advantage identified by Hibberd and his team was the spacecraft’s arrival speed, which would be much slower than that relying on a SOM – 18 km/s (64,800 km/h; 40,265 mph) versus 30 km/s s (108,000 km/h). h; 107,108 km/h). This would give the spacecraft more time to scan ‘Oumuamua during approach and departure. Based on a 2028 launch window, they determined that a Project Lyra spacecraft would be able to catch up to ‘Oumuamua by 2054.
Given that ‘Oumuamua is the closest piece of interstellar material we have access to, the scientific payoff from a rendezvous mission would be immeasurable. For the relatively low cost of a rendezvous mission, humanity could get its first glimpse of what’s happening in other star systems by mid-century. Specifically, it would be a chance to finally resolve the many questions raised by ‘Oumuamua during her historic flyby of Earth years ago!
Was it a nitrogen iceberg? Was it aliens? Was it something else entirely? If we play our cards right, we will know the answers to all these questions by the middle of the century!
Originally published on Universe today.