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 first object of its kind ever to be observed, but the limited data astronomers obtained as it shot out of our Solar System left them all scratching their heads. Even today, almost five years after this interstellar visitor made its flyby, scientists are still uncertain about its true nature and origins. In the end, the only way to get some real answers from ‘Oumuamua is to catch up with it.
Interestingly enough, there are many proposals on the table for missions that could do just that. Consider Project Lyra, a proposal by the Institute for Interstellar Studies (i4is) that would rely on advanced propulsions technology to rendezvous with interstellar objects (ISOs) and study them. According to their latest study, if their mission concept launched in 2028 and performed a complex Jupiter Oberth Manoeuvre (JOM), it would be able to catch up to ‘Oumuamua in 26 years.
On October 30th, 2017, less than two weeks after ‘Oumuamua was detected, the Initiative for Interstellar Studies (i4is) inaugurated Project Lyra. The purpose of this concept study was to determine if a mission to rendezvous with ‘Oumuamua was feasible using current or near-term technologies. Since then, the i4is team has conducted studies that considered catching up with the ISO using nuclear-thermal propulsion (NTP) and a laser sailcraft, similar to Breakthrough Starshot – an interstellar mission concept for reaching Alpha Centauri in 20 years.
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As they describe in their study, most of the previously proposed methods for reaching 1I/’Oumuamua using near-term technologies call for a Solar Oberth Manoeuvre (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 article, this concept relies on the Sun’s radiation pressure to obtain a very high velocity 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, which is the Sun in the case of the Sundiver,” he said. “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 a Gravity Assist, which has been used 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 the “assist” (typically a large planet), and the central body about which the spacecraft’s path is being controlled.
Adam Hibberd, a researcher with the i4is, was the lead author of this latest Lyra study (titled “Project Lyra: A Mission to 1I/’Oumuamua without Solar Oberth Manoeuvre.”) Before joining i4is, Hibberd was an aerospace engineer who developed the Optimum Interplanetary Trajectory Software (OITS). When ‘Oumuamua was detected, he decided to use OITS with this ISO as the intended destination. After finding out about Project Lyra, he joined them and their research efforts shortly afterward.
Artist’s impression of the Project Lyra lightsail probe rendezvousing with an interstellar object (ISO). Credit: i4is
As he explained to Universe Today via email, the Solar Oberth Maneuver (SOM) relies on three discrete changes in velocity (aka. impulses) to exit the Solar System. These include:
At Earth, to increase the spacecraft’s fathest distance from the Sun (aphelion),
At aphelion, to slow down and fall in close to the Sun,
At the closest point to the Sun (perihelion) when the spacecraft is travelling at it fastest to get an extra boost
“This 3-impulse scenario was discovered by Theodore Edelbaum in 1959, although the term SOM seems to have stuck. It is fuel-optimal for generating high speeds out of the solar system. This is precisely what is needed to catch an ISO when the ISO has passed perihelion and is receding quickly from the sun.”
“However, this theoretical setup disregards Jupiter. Thus as a slight modification to this, if we slow down in step 2 with the help of a reverse Jupiter gravitational assist, then we can achieve escape with even less fuel. It is because the SOM is so efficient at generating high speeds that it has been used to research missions to ISOs.”
Looking for alternatives to a SOM, Hibbert and his colleagues considered using a time-tested route that would incorporate Jupiter’s powerful gravitational pull. Part of their motivation for this was the inherent challenges a solar gravity assist maneuver presents. While this maneuver looks great on paper, it has never been executed before and therefore has a low Technology Readiness Level (TRL) rating.
The Interstellar Probe mission would be the farthest-reaching mission to date, overtaking the Voyager and New Horizons probes. Credit: NASA/JHUAPL
What’s more, there’s the issue of how much heating will take place as the lightsail achieves perihelion during step 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 Solar and Space Physics 2023–2032 Decadal Survey, which included (among others) concepts for an interstellar probe. In Appendix D2.2., the study addresses thermal protection in the context of a Solar Oberth Maneuver:
“Unlike earlier missions, where a shield design was needed for a given Sun distance, the Interstellar Probe challenge is to see how close to the Sun a spacecraft can realistically get. As the solar distance decreases, the umbra angle increases and the size of the shield, relative to the spacecraft, grows significantly.
“Because a conceptual design effort cannot include all the material design, fabrication, and testing limitations of the full design, the final recommendation of allowable Sun distance is made based on where the design seems to be moving from very difficult to impossible.”
As the Parker Solar Probe amply demonstrates, getting close to the Sun requires a heat shield that can handle the extreme heat and radiation. In the case of Parker, that shield measures about 2.44 meters (8 ft) in diameter and weighs almost 72.5 kg (160 lbs). While the size and mass of a heat shield for Lyra would not be identical, it’s a fair bet that a solar heat shield would result in a lot of additional mass for the lightsail.
A swarm of laser-sail spacecraft leaving the Solar System. Credit: Adrian Mann
As an alternative, Hibberd and his team recommended a Jupiter Oberth Manoeuvre (JOM), which would launch from Earth, swing around Venus and Earth, conduct a Deep Space Maneuver (DSM), swing by Earth again, then receive a Gravity Assist using Jupiter’s 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 indicated, this maneuver would have several advantages over a SOM, among them:
“[It] would not require a heavy heat shield and also would not need: a) An extra travel distance from Jupiter to the Solar Oberth of around 5.2 astronomical units (au), [and] b) A further travel back to around Jupiter’s orbit of an additional 5.2 au. Both (a) & (b) would take time for a SOM which would not be required for a Jupiter Oberth Manoeuvre.”
“JOM is a discovery which is key to the remit of ‘Project Lyra’ to find options using ‘current or near-term technology’ as essentially it does not require any hardware or manoeuvres which have not been tried before, unlike the SOM. Nevertheless, despite the saving in time from not requiring (a) & (b) above – the lower escape speeds generated by the JOM mean the mission duration must be longer.”
Another advantage Hibberd and his team identified was the arrival speed of the spacecraft, which would be much slower than one relying on a SOM – 18 km/s (64,800 km/h; 40,265 mph) vs. 30 km/s (108,000 km/h; 67,108 mph). This would give the Project Lyra spacecraft more time to analyze ‘Oumuamua during approach and departure. Based on a launch window of 2028, they determined that a Project Lyra lightsail would be able to catch up to ‘Oumuamua by 2054.
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Given that ‘Oumuamua is the closest piece of interstellar material accessible to us, the scientific returns for a rendezvous mission would be immeasurable. For the relatively low cost of a rendezvous mission, humanity could get its first glimpse of what goes on in other star systems by mid-century. More to the point, it would be a chance to finally resolve the many questions’ Oumuamua raised when it made its 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 of these questions by mid-century!
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
