He had never been to the east of the Mississippi. After arriving at the Massachusetts Institute of Technology in 1975, he found himself on a journey to the edge of the Solar System. He ended up in the office of Herbert Bridge, a giant figure in space science who oversaw the cloak-and-dagger effort to dismantle and ship Harvard University's cyclotron to New Mexico for the Manhattan Project. McNutt was invited by Bridge to work on a detector for the epic mission to the outer planets that started in 1977. I asked if I could sign up before you changed your mind.
One of NASA's greatest scientific successes, the veteran wants to use his passion project to launch his own project. Interstellar probe is a $3.1 billion mission to pick up a scientific gauntlet that the two Voyager probes threw down a decade ago. Many beliefs about the Solar System's outer limits have been upended by the beguiling observations of the spaceship. A lot of our preconceptions didn't work out.
Some prominent researchers claim that the probes haven't made it to space yet because of the bounds of the heliosphere. The matter won't be settled by going out from Earth's perch. It's the only way to see what our fishbowl looks like. A space physicist at the University of Michigan says that modern instruments are needed. Interstellar probe would be a revolution.
He needs to convince his peers. A community exercise led by the National Academies of Sciences, Engineering, and Medicine will set the field's priorities for the next decade. Next month, the panel will begin to deliberate and make a decision by the year's end. It would take a lot of work to get NASA's support for a probe that would lift off in 2036. It would be possible for it to rendezvous with Jupiter and sling the probe towards the stars. In half the time it took, it arrived.
Chinese scientists are working on a mission that could be launched at the same time. Jim Bell is a planetary scientist at Arizona State University. There is a space race to the edge of the solar system.
McNutt and his colleagues face a challenge in selling a mission that will last at least 50 years. There are experts on space weather who can wreak havoc on satellites and power grids. Pontus Brandt, a space physicist at APL, says that people are overly scared that one big project will suck out all the funding for the rest of the science. Merav Opher is an astronomer at Boston University. If we keep funding just space weather, it will be foolish.
This first hurdle may be a problem for theVoyager on steroids. Bell doesn't have a stake in the project Opher says that McNutt is a great champion. Bell believes that McNutt's mentoring abilities will be important. He says that you need to think beyond your own lifetime.
McNutt has a passion for science fiction and has been pursuing interstellar space for a long time. Robert Heinlein's Time for the Stars was a novel that sought to explain a mind-bending aspect of Albert Einstein's special theory of relativity. In the novel, a teenager with telepathy joins an expedition to search for planets around other stars and spends four years on a spaceship that can travel at close to light-speed. His identical twin was 71 years old. McNutt, who was 16 at the time, came up with an idea for a project for the Fort Worth, Texas, science fair. He created a prototype spaceship from poster board, wood, and glue.
The administrators at the school were interested in preventing kids from dropping out, but he and several fellow students petitioned for a physics course. After World War II, Wernher von Braun, a former Nazi rocket scientist, moved to the US and became the chief architect of NASA's Moon program. Von Braun was speaking at Texas Christian University and McNutt was on a student panel that posed questions. Von Braun was asked if NASA had a plan to put humans on Mars. Von Braun said that wasn't in the cards. He said that the space agency would concentrate on robotic probes. McNutt says he was really annoyed. I was wondering what the hell was wrong with you.
McNutt came away from the encounter with von Braun with a determination to become a space scientist. He majored in physics at Texas A&M University and had a knack for math. He vividly remembers his visit to mission control at the JPL when he was a junior member of the team. The first images of Io, Jupiter's flamboyantly colorful volcanic moon, were shown on TV. It resembled a rotting orange or a pizza pie. I thought it was gorgeous.
There were revelations about the mysterious outer planets. The probes continued to go. The heliopause was thought to be reached by either one or both by the early 2000s. The fact that the probes were designed to investigate Jupiter's powerful magnetosphere was the reason for the excitement. The information you can get from the voyager is primitive. The fact that we were able to get something was better than nothing.
When the solar wind first starts to weaken as it is buffeted by the gas and dust of the Solar System, there is a big surprise. There were 94AU from Earth 3 years earlier. The average distance between Earth and the sun is 150 million kilometers. The inability to measure the slowing of the solar wind was caused by the failure of its detector. The wind was expected to decrease from 1.2 million kilometers per hour to 300,000 kilometers per hour. The wind speed was 540,000 km per hour. People were going through the shock of the abortion. The man says it.
It was odd that the shock was 10AU closer to Earth than it was to the other side. At a conference in Switzerland, a member of the team broke the news, and everyone was confused. What could be the physics behind the asymmetricality?
Researchers are pushing NASA to build the Interstellar Probe, which would explore the Sun and the outside of the solar system. It would follow in the footsteps of the first two Voyagers. The probes crossed the heliopause ten years ago. If a heavy lift rocket is launched in 2036, it will take less than a year to leave the heliosphere.
*One astronomical unit (AU) is 150 million kilometers, the average distance between the Sun and Earth.
The heliosphere is the Sun’s zone of influence, a bubble inflated by charged particles in the solar wind.
Buffeted by neutral gas and dust that penetrate the heliosphere, the solar wind drops from supersonic to subsonic speeds here.
At this boundary, the solar wind is stopped by plasma in the interstellar medium. Cosmic rays and energetic neutral atoms should become more prevalent. Magnetic field directions should also shift, although this has not been detected.
When the interstellar wind slows suddenly to subsonic speeds, a shock wave analogous to the termination shock can form. But some studies suggest the Solar System is not moving fast enough to create one.
In the classic picture, the heliosphere is shaped like a comet—squashed in the direction of the Sun’s orbit around the Galaxy. But data from NASA’s Cassini mission point to a spherical shape, whereas other models suggest it may be lobed, like a croissant.
Like Voyager, IP would measure magnetic fields, plasma flux, and cosmic rays. It would also bring new tools such as a dust analyzer. Transmissions would be much faster. “It’s like comparing a rotary telephone from 1935 to an iPhone 13,” says project leader Ralph McNutt.
Sometime in the next 2000 years, the Sun is expected to leave a local cloud of gas and dust. After that, it may enter the G cloud. If it is denser, it would squash the protective magnetic bubble of the heliosphere, potentially exposing the Solar System to a barrage of cosmic rays.
The models ignored the magnetic fields of the heliosphere below the ecliptic. The solar wind was assumed to be a steady gale. The Sun's 11-year cycle of magnetic activity is one of the reasons why the probes reached the shock at different distances.
The weakness of the termination shock was explained by the findings of other planetary probes such as the Cassini spaceship. There is a better understanding of pickup ionized atoms, neutral atoms that become ionized when they encounter the solar wind or the sun's ultraviolet radiation. Voyager wasn't able to measure pickup ion. These are the center of the place. The wind did not slacken as much as was predicted because pickup ion riders gained enough energy to cross the shock.
The heliosheath is where the Solar System plows through space as the solar wind continues to diminish. The heliosheath was seen as the thinskin of the heliosphere. The sheath needs to be thicker with a stronger solar wind. The solar wind would travel farther before stopping at the heliopause, where the hot, dense plasma of our heliosphere gives way to the cold, dense space of the outside world.
The picture was hard to confirm without a working detector. The probe left the heliosphere in August of 2012 and was declared to have left in early 2013. The case was made because of a drop in higher energy solar wind ion and a rise in Cosmic rays. The heliopause is almost the same distance from the Sun as it was six years ago, suggesting that the heliopause is sensitive to solar variations. The woman says that it was amazing.
Data didn't add up. The Sun's magnetic field is twisted by the Sun's rotation. The solar wind should have changed the direction of the magnetic field as it moved across the heliopause. It was basically the same way from the Sun. The people that know the theory are confused.
Fisk thinks it's a sign the probes haven't reached space. In the 1 March issue of The Astrophysical Journal, he and colleague George Gloeckler propose that the two planets are still in the heliosheath, where they have encountered two magnetic fields. He says that the physics change dramatically when you account for that. The solar wind's magnetic field appears to have dissipated over much greater distances than earlier models had suggested. Opher doesn't see a scenario where Voyager is still in the heliosphere.
Regardless of who is right, scientists find the space station's strange quirks irresistible. Fisk said thatVoyager didn't give them the answers they were looking for. A team of 45 people, including Fisk and Opher, collaborated to flesh out a mission concept. Nobody had done the engineering for the interstellar mission, which has been contemplated by scientists for half a century. The group's 498-page report was released in December.
The Oberth maneuver is an idea that was settled by the mission concept study. The heat shield needed for the probe to pass so close to the sun would add too much mass and risk, so the team decided to use a different heat shield. If the launch is on a heavy lift rocket with a rare third and fourth stage, you wouldn't get there any quicker. The first launch of NASA's Space Launch System could take place this summer as the agency contemplates sending astronauts back to the moon. He's put out feelers to the private companies about a ride on one of their rockets. After Jupiter's gravity boost, the IP should peak at speeds of more than 7AU per year.
The Interstellar Express mission would send probes in opposite directions, one towards the nose of the heliosphere and the other towards its tail. Wang Chi is the director-general of the National Space Science Center of the Chinese Academy of Sciences. The third probe was supposed to launch on a path that would take it away from the heliosphere. The technical challenges are difficult and the probe is on ice. A journey of a thousand miles begins with a single step. First, we should make the probes successful.
The Chinese team hold their cards close to their vest, but McNutt thinks the missions are synergistic. He wants the merrier. You will learn a lot about what is happening out there if you get different cuts through the heliospheric structure.
APL has a concept report that shows how science can be tackled. There is a suite of four detectors that measure particles across a broad energy spectrum. Alice Cocoros is a physicist at APL. Better detection of pickup ion may be the most important capability, with space physicists just starting to appreciate the unheralded role they play at the heliosphere.
Another blind spot could be cured by a dust detector. We don't know how much dust gets into the solar system or how it interacts with the solar wind. The cloud of dust leftover from the formation of the Solar System can be seen on the map. The shape of the dust could be used to refine formation models, but they are not known because they have only been taken from inside the cloud.
There is an unobscured view of the extragalactic background light, the sum of all radiation produced since the big bang. In the 1 March issue of The Astrophysical Journal, the mission team reported on the discovery of a mystery when it observed a patch of dark sky and recorded more visible light than the current census of galaxies can explain. The EBL's absolute brightness could be determined for the first time with the right instruments.
In the tradition of other far-ranging probes, the IP could look back at home once it was in the stars. The image of the whole heliosphere would be captured instead of the pale blue dot. McNutt says that he can solve the problem using a camera that captures a nightscape of neutral atoms in the heliosheath. The high-energy ENAs are showing. The simulations show that once you get above 50 keV, you can see the shape of the heliosphere. He said it would be the most expensive picture in history.
The Interstellar Boundary Explorer, or IBEX, was put into space by NASA in 2008 in a bus tire-sized craft. The first all-sky map of ENAs in the outer heliosphere was captured by the ENA cameras. A region just beyond the heliopause may be the location of the "great circle in the sky". In 2036, the probe would be shot through the ribbon.
IBEX data supports the idea of a comet-shaped heliosphere with a tail extending two to three times farther into space than the nose. Modeling suggests that the heliosphere is more rounded on one side than it is on the other. NASA plans to launch the Interstellar Mapping and Acceleration Probe (IMAP) in the year 2025. IMAP will bring a lot to the party. He says that the most revealing ENA map will be provided by IP once it exits the heliosphere.
After the probe reaches the stars, the science wouldn't stop. Opher says that the idea of the solar system being hurtle through the clouds of gas and dust in the center of the Milky Way is a game-changing idea. These clouds are probably remnants of stellar nurseries, wellsprings of hydrogen that collapsed under gravity to form stars. Physicists have created a cloud atlas of the area. It appears to be a child's sketch, but that's all we have.
The Local Interstellar Cloud is the solar system's home for the past 60,000 years. We will plunge into the G cloud in the next 2000 years if the transition hasn't already begun. We don't know what's going to happen next The denser and colder a cloud is, the more wind strength it has. That could cause the Sun to lose its magnetism.
The outer reaches of the heliosphere are where 75% of the rays coming from come from. Life forms would be exposed to an intense radiation environment if the next cloud squeezed the heliosphere.
Around the time early hominids began to pick up stone tools, there was evidence of a similar event. He says to let that bother you for a second. Scientists have found iron-60 in samples dating from 2 million to 3 million years ago. Iron-60 isn't found naturally on Earth, it's forged in the stars Either a nearby supernova blasted the heliosphere with iron dust or the heliosphere flew through a dense cloud filled with iron-60 from a previous supernova. We had a full blast of galactic Cosmic rays and interstellar matter for a long time. The temperature of nearby electrons could be taken with the help of a wave antenna. The blast paths of past supernovae may be marked by hot regions.
Even if the probe falls into alien hands, the team is thinking big in other ways. There is a golden record filled with music and voices. If an extraterrestrial IT department could figure out how to read the digital version, it would likely be an updated version of the thumb drive.
The space agency would need to convince Congress that the Star Trekkian emissary is worth the price tag in order to get it. The team is eager to put their sales hats back on after their recent success. There are many missions under our belt. The under budget was $100 million.
APL is trying to breed the next generation of scientists. That's right, literally. According to Cocoros, 13 babies were born during the concept design study. She is pregnant with a girl in November. She probably makes 14. Cocoros was used as a bridge between scientists and engineers as they tried to find an instrument that would meet key science objectives without being too fat. She enjoyed being the glue in the middle of the project.
McNutt is seen as a mentor by cocoros. I really like him. He will tell you a story if you ask him a question. She said it was a novel. He has a lot of knowledge in his APL office which is cluttered with items from his life. His brain is similar to his. There are piles and piles of VHS tapes.
With future leaders waiting in the wings, McIntyre hopes his push for the stars will be approved. He says they don't want to kick the can down the road more than it already is. This is a trip that has been in the making for a long time.
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