Science
If Launched by 2028, a Spacecraft Could Catch up With Oumuamua in 26 Years – Universe Today
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.
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.
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.
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.
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.
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!
Further Reading: arXiv
Science
SpaceX sends 23 Starlink satellites into low-Earth orbit
|
April 23 (UPI) — SpaceX launched 23 Starlink satellites into low-Earth orbit Tuesday evening from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida.
Liftoff occurred at 6:17 EDT with a SpaceX Falcon 9 rocket sending the payload of 23 Starlink satellites into orbit.
The Falcon 9 rocket’s first-stage booster landed on an autonomous drone ship in the Atlantic Ocean after separating from the rocket’s second stage and its payload.
The entire mission was scheduled to take about an hour and 5 minutes to complete from launch to satellite deployment.
The mission was the ninth flight for the first-stage booster that previously completed five Starlink satellite-deployment missions and three other missions.
Science
NASA Celebrates As 1977’s Voyager 1 Phones Home At Last
|
Voyager 1 has finally returned usable data to NASA from outside the solar system after five months offline.
Launched in 1977 and now in its 46th year, the probe has been suffering from communication issues since November 14. The same thing also happened in 2022. However, this week, NASA said that engineers were finally able to get usable data about the health and status of its onboard engineering systems.
Slow Work
Fixing Voyager 1 has been slow work. It’s currently over 15 billion miles (24 billion kilometers) from Earth, which means a radio message takes about 22.5 hours to reach it—and the same again to receive an answer.
The problem appears to have been its flight data subsystem, one of one of the spacecraft’s three onboard computers. Its job is to package the science and engineering data before it’s sent to Earth. Since the computer chip that stores its memory and some of its code is broken, engineers had to re-insert that code into a new location.
Next up for engineers at NASA’s Jet Propulsion Laboratory in California is to adjust other parts of the FDS software so Voyager 1 can return to sending science data.
Beyond The ‘Heliopause’
The longest-running and most distant spacecraft in history, Voyager 1, was launched on September 5, 1977, while its twin spacecraft, Voyager 2, was launched a little earlier on August 20, 1977. Voyager 2—now 12 billion miles away and traveling more slowly—continues to operate normally.
Both are now beyond what astronomers call the heliopause—a protective bubble of particles and magnetic fields created by the sun, which is thought to represent the sun’s farthest influence. Voyager 1 got to the heliopause in 2012 and Voyager 2 in 2018.
Pale Blue Dot
Since their launch from Cape Canaveral, Florida, aboard Titan-Centaur rockets, Voyager 1 and Voyager 2 have had glittering careers. Both photographed Jupiter and Saturn in 1979 and 1980 before going their separate ways. Voyager 1 could have visited Pluto, but that was sacrificed so scientists could get images of Saturn’s moon, Titan, a maneuver that made it impossible for it to reach any other body in the solar system. Meanwhile, Voyager 2 took slingshots around the planets to also image Uranus in 1986 and Neptune in 1989—the only spacecraft ever to image the two outer planets.
On February 14, 1990, when 3.7 billion miles from Earth, Voyager 1 turned its cameras back towards the sun and took an image that included our planet as “a mote of dust suspended in a sunbeam.” Known as the “Pale Blue Dot,” it’s one of the most famous photos ever taken. It was remastered in 2019.
Science
NASA hears from Voyager 1, the most distant spacecraft from Earth, after months of quiet
|
CAPE CANAVERAL, Fla. (AP) – NASA has finally heard back from Voyager 1 again in a way that makes sense.
The most distant spacecraft from Earth stopped sending back understandable data last November. Flight controllers traced the blank communication to a bad computer chip and rearranged the spacecraft’s coding to work around the trouble.
NASA’s Jet Propulsion Laboratory in Southern California declared success after receiving good engineering updates late last week. The team is still working to restore transmission of the science data.
It takes 22 1/2 hours to send a signal to Voyager 1, more than 15 billion miles (24 billion kilometers) away in interstellar space. The signal travel time is double that for a round trip.
Contact was never lost, rather it was like making a phone call where you can’t hear the person on the other end, a JPL spokeswoman said Tuesday.
Launched in 1977 to study Jupiter and Saturn, Voyager 1 has been exploring interstellar space – the space between star systems – since 2012. Its twin, Voyager 2, is 12.6 billion miles (20 billion kilometers) away and still working fine.
-
Health16 hours ago
Remnants of bird flu virus found in pasteurized milk, FDA says
-
Art22 hours ago
Mayor's youth advisory council seeks submissions for art gala – SooToday
-
Health20 hours ago
Bird flu virus found in grocery milk as officials say supply still safe
-
Investment20 hours ago
Taxes should not wag the tail of the investment dog, but that’s what Trudeau wants
-
News21 hours ago
Peel police chief met Sri Lankan officer a court says ‘participated’ in torture – Global News
-
Art22 hours ago
An exhibition with a cause: Montreal's 'Art by the Water' celebrates 15 years – CityNews Montreal
-
Media16 hours ago
Vaughn Palmer: B.C. premier gives social media giants another chance
-
Art20 hours ago
Penetang couple 'saddened' after complaint forces folk art removal – MidlandToday