Laser sail spacecraft coming to Oumuamua, the interstellar asteroid. Credit: Maciej Rebisz
In October 2017, the interstellar object Oumuamua passed through our Solar System, leaving a lot of questions in its wake. Not only was it the very first object of its kind ever to be observed, but the restricted information astronomers gotten as it shot out of our Solar System left them all scratching their heads.
Surprisingly enough, there are lots of propositions on the table for objectives that might do just that. Think About Project Lyra, a proposal by the Institute for Interstellar Studies (i4is) that would depend on sophisticated propulsions innovation to rendezvous with interstellar objects (ISOs) and study them. According to their newest study, if their mission concept released in 2028 and performed a complicated Jupiter Oberth Manoeuvre (JOM), it would be able to capture up to Oumuamua in 26 years.
On October 30th, 2017, less than two weeks after Oumuamua was found, the Initiative for Interstellar Studies (i4is) inaugurated Project Lyra. The purpose of this principle study was to determine if a mission to rendezvous with Oumuamua was possible using near-term or existing technologies. Ever since, the i4is team has conducted research studies that thought about capturing up with the ISO utilizing nuclear-thermal propulsion (NTP) and a laser sailcraft, similar to Breakthrough Starshot– an interstellar mission concept for reaching Alpha Centauri in 20 years.
As they describe in their research study, most of the formerly proposed approaches for reaching 1I/ Oumuamua utilizing near-term technologies call for a Solar Oberth Maneuver (SOM). A perfect example is the “Sundiver,” a proposition made by scientist Coryn Bailer-Jones of limit Planck Institute for Astronomy (MPIA). As he explained to Universe Today in a previous short article, this principle depends on the Suns radiation pressure to acquire a really high velocity with a light sail.
” The concept of the Oberth result is to apply your increase when you are moving fastest relative to the body you are orbiting, which is the Sun when it comes to the Sundiver,” he said. “The closer you are to the Sun in your orbit, the faster you will be. So to make the most of the Oberth result, you require to get as close to the Sun as possible.”
At the heart of the SOM and other Oberth maneuvers is a strategy referred to as a Gravity Assist, which has been used to explore the Solar System because the early 1970s. This technique involves using the gravitational force of 3 bodies, consisting of the spacecraft, a 2nd body that provides the “assist” (normally a large planet), and the central body about which the spacecrafts path is being managed.
When Oumuamua was identified, he chose to utilize OITS with this ISO as the intended destination. After finding out about Project Lyra, he joined them and their research efforts soon later.
Artists impression of the Project Lyra lightsail probe rendezvousing with an interstellar things (ISO). Credit: i4is
As he described to Universe Today by means of email, the Solar Oberth Maneuver (SOM) counts on three discrete modifications in velocity (aka. impulses) to exit the Solar System. These consist of:
In October 2017, the interstellar things Oumuamua passed through our Solar System, leaving a lot of questions in its wake. As they describe in their study, most of the previously proposed approaches for reaching 1I/ Oumuamua utilizing near-term technologies call for a Solar Oberth Maneuver (SOM). Whats more, theres the concern of how much heating will take place as the spacecraft achieves perihelion throughout action 3 (between 3 and 10 solar radii)., the study addresses thermal security in the context of a Solar Oberth Maneuver:.
As the Parker Solar Probe amply shows, getting close to the Sun needs a heat shield that can handle the extreme heat and radiation.
At Earth, to increase the spacecrafts fathest range from the Sun (aphelion),.
At aphelion, to slow down and fall in near to the Sun,.
When the spacecraft is travelling at it fastest to get an extra boost, at the closest point to the Sun (perihelion).
” This 3-impulse circumstance was found by Theodore Edelbaum in 1959, although the term SOM appears to have actually stuck. It is fuel-optimal for creating high speeds out of the solar system. This is precisely what is required to capture an ISO when the ISO has actually passed perihelion and is receding rapidly from the sun.”.
” However, this theoretical setup disregards Jupiter. Thus as a slight modification to this, if we decrease in action 2 with the assistance of a reverse Jupiter gravitational assist, then we can achieve escape with even less fuel. It is because the SOM is so effective at producing high speeds that it has actually been utilized to research missions to ISOs.”.
Searching for options to a SOM, Hibbert and his coworkers thought about using a reliable route that would incorporate Jupiters effective gravitational pull. Part of their motivation for this was the fundamental difficulties a solar gravity assist maneuver presents. While this maneuver looks fantastic on paper, it has never been performed prior to and therefore has a low Technology Readiness Level (TRL) ranking.
The Interstellar Probe objective would be the farthest-reaching objective to date, overtaking the Voyager and New Horizons probes. Credit: NASA/JHUAPL.
Whats more, theres the problem of just how much heating will happen as the spacecraft achieves perihelion during step 3 (between 3 and 10 solar radii). These issues were resolved in a recent NASA Solar and Space Physics idea research study entitled “Interstellar Probe: Humanitys Journey to Interstellar Space.” This research study was performed for the Solar and Space Physics 2023– 2032 Decadal Survey, which consisted of (to name a few) ideas for an interstellar probe. In Appendix D2.2., the study addresses thermal defense in the context of a Solar Oberth Maneuver:.
” Unlike earlier objectives, where a shield style was needed for a given Sun range, the Interstellar Probe challenge is to see how near the Sun a spacecraft can reasonably get. As the solar distance reduces, the umbra angle boosts and the size of the guard, relative to the spacecraft, grows considerably.
” Because a conceptual design effort can not include all the product design, fabrication, and testing restrictions of the full design, the final recommendation of allowed Sun distance is made based on where the style seems to be moving from really tough to difficult.”.
As the Parker Solar Probe amply demonstrates, getting close to the Sun needs a heat guard that can handle the extreme heat and radiation. When it comes to Parker, that protect measures about 2.44 meters (8 feet) in size and weighs practically 72.5 kg (160 pounds). While the size and mass of a heat shield for Lyra would not equal, its a reasonable bet that a solar heat guard would result in a great deal of extra mass for the lightsail.
A swarm of laser-sail spacecraft leaving the Solar System. Credit: Adrian Mann.
As an alternative, Hibberd and his team suggested a Jupiter Oberth Manoeuvre (JOM), which would launch from Earth, swing around Venus and Earth, conduct a Deep Space Maneuver (DSM), visit Earth again, then receive a Gravity Assist utilizing Jupiters gravitational pull. This is summarized by the acronym V-E-DSM-E-J, or the more commonly used V-E-E-GA– Venus, Earth, Earth, Gravity Assist. As Hibberd showed, this maneuver would have numerous benefits over a SOM, amongst them:.
” [It] would not need a heavy heat guard and likewise would not require: a) An additional travel distance from Jupiter to the Solar Oberth of around 5.2 huge systems (au), [and] b) A more travel back to around Jupiters orbit of an extra 5.2 au. Both (a) & &( b )would take some time for a SOM which would not be needed for a Jupiter Oberth Manoeuvre.”.
” JOM is a discovery which is key to the remit of Project Lyra to find options using present or near-term technology as essentially it does not need any hardware or manoeuvres which have actually not been attempted in the past, unlike the SOM. Nonetheless, regardless of the conserving in time from not needing (a) & & (b) above– the lower escape speeds created by the JOM imply the mission duration should be longer.”.
Another advantage Hibberd and his group determined was the arrival speed of the spacecraft, which would be much slower than one counting on a SOM– 18 km/s (64,800 km/h; 40,265 miles per hour) vs. 30 km/s (108,000 km/h; 67,108 miles per hour). This would provide the spacecraft more time to analyze Oumuamua throughout approach and departure. Based upon a launch window of 2028, they figured out that a Project Lyra spacecraft would have the ability to catch up to Oumuamua by 2054.
Considered that Oumuamua is the closest piece of interstellar material available to us, the scientific returns for a rendezvous mission would be immeasurable. For the reasonably low expense of a rendezvous objective, humanity might get its very first look of what goes on in other star systems by mid-century. More to the point, it would be an opportunity to finally resolve the numerous concerns Oumuamua raised when it made its historic flyby of Earth years ago!
Was it something else totally? If we play our cards right, we will know the answers to all of these concerns by mid-century!
Originally published on Universe Today.