Original | MATT WILLIAMS
Translate | Linvo
In October 2017, the interstellar visit "Oumuamua" passed through our solar system and left many mysteries. Not only is it the first interstellar object ever observed, but the limited data that astronomers get from its rush out of the solar system also leaves them scratching their heads. Even today, 5 years after the interstellar visitor flew over Earth, scientists still can't be sure of its truth and origin. In the end, the only way to get some real answers from it is to catch up with it.
Interestingly, there are already many proposals on the table for tasks that can do this. Take Project Lyra, for example, proposed by the Interstellar Institute (i4is) that will rely on advanced propulsion technology to merge with interstellar objects (ISOs) to study it. According to their latest research, if their mission concept is launched in 2028 and performs a complex Jupiter Olbers maneuver (JOM), it will be able to catch up with Oumuamua within 26 years.
On October 30, 2017, less than two weeks after the discovery of Oumuamua, the Interstellar Research Initiative (i4is) launched Project Lyra. The purpose of this study was to determine whether it would be feasible to use the latest current technology to meet the "Oumuamua" mission. Since then, the i4is team has conducted some research, considering the use of nuclear thermal propulsion (NTP) and a laser sailboat similar to breakthrough star-catching, a concept of interstellar missions designed to reach α Centauri within 20 years.
As they describe in their study, most of the previously proposed methods of using the latest technology to reach Oumomo require a "Solar Olbers Maneuver" (SOM). A perfect example is "Sundiver," which was proposed by Coryn Bailer-Jones, a researcher at the Max Planck Institute for Astronomy (MPIA). The concept is a light sail that relies on the radiation pressure of the sun to achieve a very high speed.
"The principle of the Olbers effect is that when you move fast enough relative to an object orbiting you, in the case of Sundiver, you get a boost," he said. "In your orbit, the closer you are to the sun, the faster you will be. Therefore, in order to take advantage of the Olbers effect, you need to be as close to the sun as possible. ”
At the heart of SOM and other Olbers-like approaches is a technique known as gravitational booster, which has been used to explore the solar system since the early 1970s. The technology requires harnessing the gravitational pull of three objects, including the spacecraft, a second object that provides "boost" (usually a large planet), and a central object that controls the spacecraft's path.
Adam Hibberd, a researcher at i4is and the lead author of a recent study on the Lyra Project, was a space engineer who developed the Best Interstellar Orbit software (OITS) before joining i4is. When Oumuamua was detected, he decided to use OITS and this ISO as the intended destination. After learning about the Lyra project, he quickly joined their research efforts.
THE SOM relies on three discrete velocity changes to leave the solar system. These include:
1, on the earth, increase the distance of the spacecraft far point (far point),
2, at the far point, slow down and approach the sun,
3) At perihelion, the spacecraft flies at the fastest speed to get extra boosts
Theodore Edelbaum discovered these three ways of working in 1959, although the term SOM seems to have been used. It is the best fuel for high-speed flight outside the solar system. When the ISO has passed through perihelion and is rapidly moving away from the sun, this is exactly what is needed to capture the ISO. ”
However, this theory does not take Jupiter into account. So, as a slight modification, if we slow down with the help of the second step, with the help of the reverse Jupiter gravity, then we can achieve less fuel escape. This is because SOM is very effective at generating high speeds, and it has been used for ISO research tasks. ”
To find an alternative to SOM, Hibbert and his colleagues considered taking a time-tested route that would incorporate Jupiter's powerful gravity. Part of the reason they do this is because of the inherent challenges posed by the sun's gravitational boost. While this exercise looks great on paper, it has never been performed before, so the Technical Readiness Level (TRL) rating is low.
The Interstellar Probe mission will be the furthest mission to date, surpassing the Voyager and New Horizons probes.
What's more, the question of how much heat occurs when the light sail reaches perihelion in the third step (between 3 and 10 solar radii). These issues were addressed in a recent NASA study of solar and space physics concepts called "Interstellar Exploration: A Journey through Interstellar Space for Man." The research was conducted for the 2023-2032 Decade Survey of Solar and Space Physics, which includes the concept of interstellar probes. Written in Appendix D2.2, the study explores thermal protection in the context of solar Olbers:
Unlike previous missions, where shield design is required at a given solar distance, the challenge for interstellar probes is to see how close a spacecraft can actually get to the sun. As the distance from the sun decreases, the angle of the umbra increases, and the size of the sunshade will increase significantly relative to the spacecraft.
"Because the initial design work could not include all the material design, fabrication, and testing limitations of the entire design, it seemed impossible to recommend a final safe solar distance based on the design."
As the Parker Solar Probe fully demonstrated, approaching the Sun requires a heat shield that can withstand extreme heat and radiation. In the case of Parker, its protective cover is about 2.44 meters in diameter and weighs about 72.5 kilograms. While the size and mass of the heat shields are not the same as the Lyra program, it's safe to say that the solar heat shields will bring a lot of extra mass to the light sails.
A group of laser sail spacecraft leave the solar system
As an alternative, Hibberd and his team recommended jupiter-Olbers Maneuver (JOM), which would be launched from Earth, then orbited Venus and Earth, performing a deep space orbit (DSM), spinning through the Earth again, and then using Jupiter's gravitational pull to get a gravitational boost. This is boosted by the abbreviation V-E-DSM-E-J, or more commonly V-E-E-GA - Venus, Earth, Earth, Gravitational Boost. As Hebbard points out, this strategy has several advantages over SOM, including:
It doesn't require a heavy heat shield or:
A) Additional travel distance from Jupiter to solar Olbers (approximately 5.2 AU)
B) Additional travel distance back into Jupiter's orbit
Both (A) and (B) require SOM time, while the Jupiter Orbers maneuver does not.
"JOM is a discovery, it's the key to the Lyra project, using state-of-the-art technology to find options because it essentially doesn't require any hardware or operation that hasn't been tried before, unlike SOM. However, despite the time savings due to the lack of need for items (A) and (B) above, the lower escape velocity generated by JOM means that the mission duration must be longer. ”
Another advantage hibberd and his team found was the spacecraft's speed of arrival, which would be much slower than som-dependent spacecraft — 18 km/s vs. 30 km/s. This will give the Lyra program spacecraft more time to analyze oumuamua's situation as it approaches and leaves. Based on the 2028 launch window, they determined that the light sails of the Lyra project will be able to catch up with "Oumuamua" in 2054.
"Considering that Oumuamua is the closest interstellar matter we can approach, the scientific rewards of this mission will be immeasurable." Due to the relatively low cost of the mission, humans can get their first glimpse of other galaxies in the middle of this century. What's more, it will be an opportunity to finally solve many of the problems raised by Oumuamua when it flew over the Earth historicly many years ago!
Is it a nitrogen iceberg? Is it aliens? Is it something completely different? If we handle it properly, by the middle of this century we will know the answers to all these questions!
original:
https://www.universetoday.com/154028/if-launched-by-2028-a-spacecraft-could-catch-up-with-oumuamua-in-26-years/