Voyager 1 fires thrusters last used in 1980 – and they worked!

Ancient assembler code checked out and now probe’s mission can be extended

NASA’s announced that Voyager 1’s already-amazingly-long mission will probably be extended for an extra two or three years, thanks to a successful attempt to use thrusters that haven’t fired up since the year 1980.

As NASA announced last Friday, Voyager 1’s been using its “attitude control thrusters” (ACMs) for decades, to nudge the probe so that its antenna points at Earth and it can stay in touch.

While the ACMs work, since 2014 they’ve use more fuel than in the past. As Voyager 1 carries a finite quantity of fuel, thirsty thrusters are not welcome.

The probe does, however, have other thrusters – its “trajectory correction maneuver” (TCM) thrusters were last used as it passed Saturn, to help point Voyager 1’s instruments at the ringed gas giant. As the TCMs are mounted on the craft’s rear and Voyager doesn’t need a speed boost – it’s already doing 17.46 km/second – they’ve been left alone since 1980.

But Voyager’s masters felt the ailing ACMs meant it was worth trying to see if the TCMs could pick up the slack.

Testing that hypothesis was a job for software developers, as Jet Propulsion Laboratory chief engineer Chris Jones said “The Voyager flight team dug up decades-old data and examined the software that was coded in an outdated assembler language, to make sure we could safely test the thrusters.”

Helping things out was the fact that the same model of thruster used on Voyager 1 was later deployed on Cassini and Dawn probes, meaning NASA had experience with the hardware.

So last Tuesday, November 28th, the Voyager team told the far-off probe to fire the TCM thrusters. And late the next day – after a 38-hour radio round trip – they learned that they worked and did the job just as well as the ACMS.

“With these thrusters … we will be able to extend the life of the Voyager 1 spacecraft by two to three years,” said Suzanne Dodd, project manager for Voyager. She added that the Voyager team is so chuffed with the result, they may test the TCMs on Voyager 2, too, even though its ACMs continued to perform well.

Both Voyagers are powered by radioisotope thermoelectric generators, devices that can turn heat into electricity, but which also degrade over time. NASA plans to switch off the Voyagers’ instruments as their generators deplete, eventually leaving just the radios. Once even they stop working, the craft have enough momentum to keep sailing on into the Galaxy, complete with their golden records that attempt to explain humanity, until something nasty stops them.

HERE’S THE 411 ON THE EMDRIVE: THE ‘PHYSICS-DEFYING’ THRUSTER EVEN NASA IS PUZZLED OVER

Even if you don’t keep up with developments in space propulsion technology, you’ve still probably heard about the EmDrive. You’ve probably seen headlines declaring it the key to interstellar travel, and claims that it will drastically reduce travel time across our solar system, making our dreams of people walking on other planets even more of a reality. There have even been claims that this highly controversial technology is the key to creating warp drives.

These are bold claims, and as the great cosmologist and astrophysicist Carl Sagan once said, “extraordinary claims require extraordinary evidence.” With that in mind, we thought it’d be helpful to break down what we know about the enigmatic EmDrive, and whether it is, in fact, the key to mankind exploring the stars.

So without further ado, here’s absolutely everything you need to know about the world’s most puzzling propulsion device.

This article is periodically updated in response to news and developments regarding the EM Drive and the theories surrounding it.

A new, leaked NASA paper points to potentially working EmDrive

A leaked NASA paper obtained by the International Business Times via a post by a user on the NASA Spaceflight forums. The post was originally deleted by the forum’s moderators, however, the document has since been posted and remains currently viewable here. The paper is ostensibly the same that was discussed earlier in the year (reported below). The information in the paper clearly points to a working version of the EmDrive, and while it’s yet to be published, it is still set to run in the Institute of Aeronautics and Astronautics’ scientific journal, AIAA Journal of Propulsion and Power.

As discussed below, this is a massive step forward for the EmDrive and for those who believe in the theoretical technology. If the paper on NASA’s findings does in fact pass muster and see the light of day — which seems very likely — it’ll be a boon for further research and development of the EmDrive tech. This would open the door for continued study and tests, and may finally put humans on the road to fast, lightweight space travel.

An EmDrive paper has finally been accepted by peer review

Originally, this article pointed out that previous studies and papers on the EmDrive have either not been submitted, or passed peer review. Those days are in the past, however, given a NASA Eagleworks’ paper on the EmDrive test which has reportedly passed the peer review process and will soon be published by the American Institute of Aeronautics and Astronautics’ AIAA Journal of Propulsion and Power.

This is an important step for the EmDrive as it adds legitimacy to the technology and the tests done thus far, opening the door for other groups to replicate the tests. This will also allow other groups to devote more resources to uncovering why and how it works, and how to iterate on the drive to make it a viable form of propulsion. So, while a single peer-reviewed paper isn’t going to suddenly equip the human race with interplanetary travel, it’s the first step toward eventually realizing that possible future.

What is the EmDrive?

Simply put, the EmDrive is a conundrum. First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellantless propulsion system, meaning the engine doesn’t use fuel to cause a reaction. Removing the need for fuel makes a craft substantially lighter, and therefore easier to move (and cheaper to make, theoretically). In addition, the hypothetical drive is able to reach extremely high speeds — we’re talking potentially getting humans to the outer reaches of the solar system in a matter of months.

We’re talking potentially getting humans to the outer reaches of the solar system in a matter of months.

The issue is, the entire concept of a reactionless drive is inconsistent with Newton’s conservation of momentum, which states that within a closed system, linear and angular momentum remain constant regardless of any changes that take place within said system. More plainly: Unless an outside force is applied, an object will not move.

Reactionless drives are named as such because they lack the “reaction” defined in Newton’s third law: “For every action there is an equal and opposite reaction.” But this goes against our current fundamental understanding of physics: An action (propulsion of a craft) taking place without a reaction (ignition of fuel and expulsion of mass) should be impossible. For such a thing to occur, it would mean an as-yet-undefined phenomenon is taking place — or our understanding of physics is completely wrong.

How does the EmDrive “work?”

Setting aside the potentially physics-breaking improbabilities of the technology, let’s break down in simple terms how the proposed drive operates. The EmDrive is what is called an RF resonant cavity thruster, and is one of several hypothetical machines that use this model. These designs work by having a magnetron push microwaves into a closed truncated cone, then push against the short end of the cone, and propel the craft forward.

This is in contrast to the form of propulsion current spacecraft use, which burn large quantities of fuel to expel a massive amount of energy and mass to rocket the craft into the air. An often-used metaphor for the inefficacy of this is to compare the particles pushing against the enclosure and producing thrust to the act of sitting in a car and pushing a steering wheel to move the car forward.

While tests have been done on experimental versions of the drive — with low energy inputs resulting in a few micronewtons of thrust (about as much force as the weight of a penny) — The first peer-reviewed paper has only been recently accepted, and none of the findings from other tests have ever been published in a peer-reviewed journal. It’s possible some positive thrust results may have been caused by interference or an unaccounted error with test equipment. The fact that NASA Eagleworks’ paper has been reportedly accepted by peer review and will be published in AIAA Journal of Propulsion and Power does add quite a bit of legitimacy to these claims, however.

Although there’s been much skepticism regarding the EmDrive prior to the Eagleworks paper, it’s important to note that there’s been a number of people who have tested the drive and reported achieving thrust.

• In 2001, Shawyer was given a £45,000 grant from the British government to test the EmDrive. His test reportedly achieved 0.016 Newtons of force and required 850 watts of power, but no peer review of the tests verified this. It’s worth noting, however, that this number was low enough that it was potentially an experimental error.
• In 2008, Yang Juan and a team of Chinese researches at the Northwestern Polytechnical University allegedly verified the theory behind RF resonant cavity thrusters, and subsequently built their own version in 2010, testing the drivemultiple times from 2012 to 2014. Tests results were purportedly positive, achieving up yo 750 mN (millinewtons) of thrust, and requiring 2,500 watts of power.
• In 2014, NASA researchers, tested their own version of an EmDrive, including in a hard vacuum. Once again, the group reported thrust (about 1/1,000 of Shawyer’s claims), and once again, the data was never published through peer-reviewed sources. Other NASA groups are skeptical of researchers’ claims, but in their paper, it is clearly stated that these findings neither confirm nor refute the drive, instead calling for further tests.
• In 2015, that same NASA group tested a version of chemical engineer Guido Fetta’s Cannae Drive (née Q Drive), and reported positive net thrust. Similarly, a research group at Dresden University of Technology also tested the drive, again reporting thrust, both predicted and unexpected.
• Yet another test by a NASA research group, Eagleworks, in late 2015 seemingly confirmed the validity of the EmDrive. The test corrected errors that had occurred in the previous tests, and surprisingly, the drive achieved thrust. However, the group has not yet submitted their findings for peer review. It’s possible that other unforeseen errors in the experiment may have cause thrust (the most likely of which is that the vacuum was compromised, causing heat to expand air within it testing environment and move the drive). Whether the findings are ultimately published or not, more tests need to be done. That’s exactly what Glenn Research Center in Cleveland, Ohio, NASA’s Jet Propulsion Laboratory, and Johns Hopkins University Applied Physics Laboratory intend to do. For EmDrive believers, there seems to be some hope.

In mid-2016, a new theory was put forth by physicist Michael McCulloch, a researcher from Plymouth University in the United Kingdom, which may offer an explanation of the thrust observed in tests. McCulloch’s theory deals with inertia and something called the Unruh effect — a concept predicted by relativity, which makes the universe appear hotter the more you accelerate, with the heat observed relative to the acceleration.

McCulloch’s new theory deals with the unconfirmed concept of Unruh radiation, which infers that particles form out of the vacuum of space as a direct result from the observed heating of the universe due to acceleration. This theoretical concept largely fits into our current understanding of the universe and predicts the results of inertia we currently observe, albeit with one notable exception: small accelerations on the scale of about what has been observed while testing the EM Drive.

This acceleration comes as a result of the Unruh radiation particles, whose wavelengths increase as acceleration decreases. Unruh particles at different wavelengths would have to fit at either end of the EM Drive’s cone, and as they bounce around inside the cone, their inertia would change as well, which would ultimately result in thrust.

McCulloch’s theory is, admittedly, a bit difficult to parlay into succinct layman’s terms. If you’re curious and want to delve into further reading on the theory, you can read McCulloch’s entire paper discussing his theory here. The point here is that, should the Unruh Effect and Unruh Radiation be confirmed, it offers an entirely plausible explanation for the EM Drive’s seemingly heretofore impossible thrust observations. This will require further research and experimentation, and gives the propulsion system even more momentum for testing.

Implications of a working EmDrive

It’s easy to see how many in the scientific community are wary of EmDrive and RF resonant cavity thrusts altogether. But on the other hand, the wealth of studies raises a few questions: Why is there such a interest in the technology, and why do so many people wish to test it? What exactly are the claims being made about the drive that make it such an attractive idea? While everything from atmospheric temperature-controlling satellites, to safer and more efficient automobiles have been drummed up as potential applications for the drive, the real draw of the technology — and the impetus for its creation in the first place — is the implications for space travel.

Spacecraft equipped with a reactionless drive could potentially make it to the moon in just a few hours, Mars in two to three months, and Pluto within two years. These are extremely bold claims, but if the EmDrive does turn out to be a legitimate technology, they may not be all that outlandish. And with no need to pack several tons-worth of fuel, spacecraft become cheaper and easier to produce, and far lighter.

For NASA and other such organizations, including the numerous private space corporations like SpaceX, lightweight, affordable spacecraft that can travel to remote parts of space fast are something of a unicorn. Still, for that to become a reality, the science has to add up.

Shawyer is adamant that there is no need for pseudoscience or quantum theories to explain how EmDrive works. Instead, he believes that current models of Newtonian physics offer an explanation, and has written papers on the subject, one of which is currently being peer reviewed (separate from the Eagleworks paper). He expects the paper to be published sometime this year. While in the past Shawyer has been criticized by other scientists for incorrect and inconsistent science, if the paper does indeed get published, it may begin to legitimize the EmDrive and spur more testing and research.

Despite his insistence that the drive behaves within the laws of physics, it hasn’t prevented him from making bold assertions regarding EmDrive. Shawyer has gone on record saying that this new drive produced warp bubbles which allow the drive to move, claiming that this is how NASA’s test results were likely achieved. Assertions such as these have garnered much interest online, but have no clear supporting data and will (at the very least) require extensive testing and debate in order to be taken seriously by the scientific community — the majority of which remain skeptical of Shawyer’s claims. Hopefully, with this new peer reviewed paper, more EmDrive tests will be undertaken, helping elucidate just how this thing works.

Colin Johnston of the Armagh Planetarium wrote an extensive critique of the EmDrive and the inconclusive findings of numerous tests. Similarly, Corey S. Powell of Discovery wrote his own indictment of both Shawyer’s EmDrive and Fetta’s Cannae Drive, as well as the recent fervor over NASA’s findings. Both point out the need for greater discretion when reporting on such instances. Professor and mathematical physicist, John C. Baez expressed his exhaustion at the conceptual technology’s persistence in debates and discussions, calling the entire notion of a reactionless drive “baloney.” His impassioned dismissal echoes the sentiments of many others.

Shawyer’s EmDrive has been met with enthusiasm elsewhere, including the website NASASpaceFlight.com — where information about the most recent Eagleworks’ tests was first posted — and the popular journal New Scientist, which published a favorable and optimistic paper on EmDrive. (The editors later issued a statement that, despite enduring excitement over the idea, they should have shown more tact when writing on the controversial subject.)

Ten reasons why NASA’s James Webb Space Telescope will kick some cosmic butt

Here are ten amazing facts about the JWST that you might not have known.

James Webb Space Telescope

1. It’s as big as a tennis court

With a sunshield 22 metres (72 feet) in length, the size of a tennis court, and a mirror 6.5 metres (21 feet) wide the JWST, which is due to launch in October 2018, is over twice the size of the Hubble Space Telescope, making it the largest space telescope ever launched.

2. The mirrors are coated in a golf ball’s worth of gold

The JWST’s mirrors are covered in gold to optimise them for infrared light, with the gold further protected by a thin layer of glass. The thickness of this gold coating is 0.00001 centimetres across the 25 square-metre mirror’s surface, and in total the gold weighs 48.25 grams, roughly equivalent to the weight of a golf ball.

3. It’ll be about four times further from Earth than the Moon

The JWST will take about a month to reach a position 1.5 million kilometres (930,000 miles) from Earth known as Lagrange point 2, or L2. Here the telescope’s observations will be unhindered by Earth and the Moon although, if it malfunctions (as happened with Hubble), we currently have no way to go and fix it.

 

NASA is building the largest rocket of all time for a 2018 launch

Artist’s rendering of a blueprint of the completed Space Launch System. (NASA/MSFC)

NASA has worked on some inspiring interplanetary projects in the last few years, but few have been as ambitious as the simply-named Space Launch System, a new rocket that will be the largest ever built at 384 feet tall, surpassing even the mighty Saturn V(363 feet), the rocket that took humanity to the moon. It will also be more powerful, with20 percent more thrust using liquid hydrogen and oxygen as fuel. Last week, NASA announced that the Space Launch System, SLS for short, is on track to perform its first unmanned test launch in 2018. The larger goal is to carry humans into orbit around an asteroid, and then to Mars by the 2030s. After that, NASA says the rocket could be used to reach Saturn and Jupiter.

At the moment, even getting off the ground would be progress: since the retirement of the Space Shuttle in 2011, NASA has been left without any domestic capability to launch American astronauts into space; instead it has been purchasing rides for them aboard Russian Soyuz spacecraft at high cost. While SpaceX and other private companies are working furiously to provide their own human passenger spacecraft for travel into Earth’s orbit, NASA wants to go even further. The agency has begun testing models of the SLSand initial construction of some the major components. It says the first test flight will have an initial cost of $7 billion. The SLS will also be reusing some leftover parts from the inventory of the retired Space Shuttle, including its engines.

However, as with many large NASA projects, the SLS has already been delayed from an initial flight in 2017, and lawmakers in Congress, who must approve NASA’s budget, areconcerned about further delays and cost overruns. Whether NASA is able to keep the project on track remains to be seen, but at the moment, it’s all systems go. Check out the progress and promise in photos and conceptual illustrations below.

NASA engineers used a 67.5-inch model to test how environmental factors including wind and water would affect the rocket on the launchpad. (Credit: NASA/LaRC)

 

Artist’s rendering of the Space Launch System sitting on the launchpad at Kennedy Space Center in Cape Canaveral, Florida. (NASA/MSFC)

More awesome images here:

Source

Three newly discovered Earth-sized planets may be prime spot to hunt alien life

The artist’s impression provided by European Southern Observatory on May 2, 2016 shows an imagined view from the surface one of the three planets orbiting an ultracool dwarf star just 40 light-years from Earth that were discovered using the TRAPPIST telescope at ESO’s La Silla Observatory. (ESO/M. Kornmesser via AP)

CAPE CANAVERAL, Fla. –  Astronomers searching for life beyond our solar system may need to look no farther than a little, feeble nearby star.

A Belgian-led team reported Monday that it’s discovered three Earth-sized planets orbiting an ultra-cool dwarf star less than 40 light-years away. It’s the first time planets have been found around this type of star — and it opens up new, rich territory in the search for extraterrestrial life.

Because this star is so close and so faint, astronomers can study the atmospheres of these three temperate exoplanets and, eventually, hunt for signs of possible life. They’re already making atmospheric observations, in fact, using NASA’s Spitzer Space Telescope. The Hubble Space Telescope will join in next week.

Altogether, it’s a “winning combination” for seeking chemical traces of life outside our solar system, said Massachusetts Institute of Technology researcher Julien de Wit, a co-author of the study, released by the journal Nature.

The star in question — named Trappist-1 after the Belgian telescope in Chile that made the discovery — is barely the size of Jupiter and located in the constellation Aquarius.

Other exoplanet searches have targeted bigger, brighter stars more like our sun, but the starlight in these cases can be so bright that it washes out the signatures of planets. By comparison, cool dwarf stars that emit infrared light, like Trappist-1, make it easier to spot potential worlds.

University of Liege astronomers in Belgium — lead study authors Michael Gillon and Emmanuel Jehin — built the Trappist telescope to observe 60 of the nearest ultra-cool dwarf stars. The risky effort paid off, de Wit noted in an email.

“Systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology,” Gillon said in a statement. “So if we want to find life elsewhere in the universe, this is where we should start to look.”

The two inner exoplanets take between 1.5 and 2.4 days to orbit the Trappist-1 star. The precise orbit time of the third planet is not known, but it falls somewhere between 4.5 days and 73 days. That puts the planets 20 times to 100 times closer to their star than Earth is to our sun, Gillon noted. The setup is more similar in scale to Jupiter’s moons than to our solar system, he added.

Although the two innermost planets are very close to the star, it showers them with only a few times the amount of energy that Earth receives from our own sun. The third exoplanet farther out may receive significantly less of such radiation than Earth does.

The astronomers speculate the two inner exoplanets may have pockets where life may exist, while the third exoplanet actually might fall within the habitable zone — real estate located at just the right distance from a star in order to harbor water and, possibly, life.

Spitzer and Hubble should answer whether the exoplanets have large and clear atmospheres, according to de Wit. They also might be able to detect water and methane, if molecules are present.

Future observatories, including NASA’s James Web Space Telescope set to launch in 2018, should unearth even more details.

Gillon and his colleagues identified the three exoplanets by observing regular dips in the infrared signals emanating from the Trappist-1 star, some 36 light-years away. A single light-year represents about 6 trillion miles.

The astronomers conducted the survey last year using the Transiting Planets and Planetesimals Small Telescope, or Trappist. It’s considered a prototype for a more expansive European project that will widen the search for potentially habitable worlds to 500 ultra-cool stars. This upcoming project is dubbed Speculoos — short for Search for Habitable Planets Eclipsing Ultra-Cool Stars.

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The Curious Link Between the Fly-By Anomaly and the “Impossible” EmDrive Thruster

The same theory that explains the puzzling fly-by anomalies could also explain how the controversial EmDrive produces thrust.

About 10 years ago, a little-known aerospace engineer called Roger Shawyer made an extraordinary claim. Take a truncated cone, he said, bounce microwaves back and forth inside it and the result will be a thrust toward the narrow end of the cone. Voila … a revolutionary thruster capable of sending spacecraft to the planets and beyond. Shawyer called it the EmDrive.

 

 

Shawyer’s announcement was hugely controversial. The system converts one type of energy into kinetic energy, and there are plenty of other systems that do something similar. In that respect it is unremarkable.

The conceptual problems arise with momentum. The system’s total momentum increases as it begins to move. But where does this momentum come from? Shawyer had no convincing explanation, and critics said this was an obvious violation of the law of conservation of momentum.

Shawyer countered with experimental results showing the device worked as he claimed. But his critics were unimpressed. The EmDrive, they said, was equivalent to generating a thrust by standing inside a box and pushing on the sides. In other words, it was snake oil.

Since then, something interesting has happened. Various teams around the world have begun to build their own versions of the EmDrive and put them through their paces. And to everyone’s surprise, they’ve begun to reproduce Shawyer’s results. The EmDrive, it seems, really does produce thrust.
In 2012, a Chinese team said it had measured a thrust produced by its own version of the EmDrive. In 2014, an American scientist built an EmDrive and persuaded NASA to test it with positive results.

And last year, NASA conducted its own tests in a vacuum to rule out movement of air as the origin of the force. NASA, too, confirmed that the EmDrive produces a thrust. In total, six independent experiments have backed Shawyer’s original claims.

That leaves an important puzzle—how to explain the seeming violation of conservation of momentum.

Today we get an answer of sorts thanks to the work of Mike McCulloch at Plymouth University in the U.K. McCulloch’s explanation is based on a new theory of inertia that makes startling predictions about the way objects move under very small accelerations.

First some background. Inertia is the resistance of all massive objects to changes in motion or accelerations. In modern physics, inertia is treated as a fundamental property of massive objects subjected to an acceleration. Indeed, mass can be thought of as a measure of inertia. But why inertia exists at all has puzzled scientists for centuries.

McCulloch’s idea is that inertia arises from an effect predicted by general relativity called Unruh radiation. This is the notion that an accelerating object experiences black body radiation. In other words, the universe warms up when you accelerate.

According to McCulloch, inertia is simply the pressure the Unruh radiation exerts on an accelerating body.

That’s hard to test at the accelerations we normally observe on Earth. But things get interesting when the accelerations involved are smaller and the wavelength of Unruh radiation gets larger.

At very small accelerations, the wavelengths become so large they can no longer fit in the observable universe. When this happens, inertia can take only certain whole-wavelength values and so jumps from one value to the next. In other words, inertia must quantized at small accelerations.

McCulloch says there is observational evidence for this in the form of the famous fly by anomalies. These are the strange jumps in momentum observed in some spacecraft as they fly past Earth toward other planets. That’s exactly what his theory predicts.

Testing this effect more carefully on Earth is hard because the accelerations involved are so small. But one way to make it easier would be to reduce the size of allowed wavelengths of Unruh radiation. “This is what the EmDrive may be doing,” says McCulloch.

The idea is that if photons have an inertial mass, they must experience inertia when they reflect. But the Unruh radiation in this case is tiny. So small in fact that it can interact with its immediate environment. In the case of the EmDrive, this is the truncated cone.

The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust.

McCulloch puts this theory to the test by using it to predict the forces it must generate. The precise calculations are complex because of the three-dimensional nature of the problem, but his approximate results match the order of magnitude of thrust in all the experiments done so far.

Crucially, McCulloch’s theory makes two testable predictions. The first is that placing a dielectric inside the cavity should enhance the effectiveness of the thruster.

The second is that changing the dimensions of the cavity can reverse the direction of the thrust. That would happen when the Unruh radiation better matches the size of the narrow end than the large end. Changing the frequency of the photons inside the cavity could achieve a similar effect.

McCulloch says there is some evidence that exactly this happens. “This thrust reversal may have been seen in recent NASA experiments,” he says.

That’s an interesting idea. Shawyer’s EmDrive has the potential to revolutionize spaceflight because it requires no propellant, the biggest limiting factor in today’s propulsion systems. But in the absence of any convincing explanation for how it works, scientists and engineers are understandably wary.

McCulloch’s theory could help to change that, although it is hardly a mainstream idea. It makes two challenging assumptions. The first is that photons have inertial mass. The second is that the speed of light must change within the cavity. That won’t be easy for many theorists to stomach.

But as more experimental confirmations of Shawyer’s EmDrive emerge, theorists are being forced into a difficult position. If not McCulloch’s explanation, then what?

Ref: arxiv.org/abs/1604.03449 : Testing Quantized Inertia on the EmDrive

Explaining EmDrive, the ‘physics-defying’ thruster even NASA is puzzled over

Even if you don’t keep up with developments in space propulsion technology, you’ve still probably heard about the EmDrive. You’ve probably seen headlines declaring it the key to interstellar travel, and claims that it will drastically reduce travel time across our solar system, making our dreams of people walking on other planets even more of a reality. There have even been claims that this highly controversial technology is the key to creating warp drives.

These are bold claims, and as the great cosmologist and astrophysicist Carl Sagan once said, “extraordinary claims require extraordinary evidence.” With that in mind, we thought it’d be helpful to break down what we know about the enigmatic EmDrive, and whether it is, in fact, the key to mankind exploring the stars.

So without further ado, here’s absolutely everything you need to know about the world’s most puzzling propulsion device.

 

What is the EmDrive?

See, the EmDrive is a conundrum. First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellantless propulsion system, meaning the engine doesn’t use fuel to cause a reaction. Removing the need for fuel makes a craft substantially lighter, and therefore easier to move (and cheaper to make, theoretically). In addition, the hypothetical drive is able to reach extremely high speeds — we’re talking potentially getting humans to the outer reaches of the solar system in a matter of months.

We’re talking potentially getting humans to the outer reaches of the solar system in a matter of months. The issue is, the entire concept of a reactionless drive is inconsistent with Newton’s conservation of momentum, which states that within a closed system, linear and angular momentum remain constant regardless of any changes that take place within said system. More plainly: Unless an outside force is applied, an object will not move.

 

Reactionless drives are named as such because they lack the “reaction” defined in Newton’s third law: “For every action there is an equal and opposite reaction.” But this goes against our current fundamental understanding of physics: An action (propulsion of a craft) taking place without a reaction (ignition of fuel and expulsion of mass) should be impossible. For such a thing to occur, it would mean an as-yet-undefined phenomenon is taking place — or our understanding of physics is completely wrong.

How does the EmDrive “work?”

Setting aside the potentially physics-breaking improbabilities of the technology, let’s break down in simple terms how the proposed drive operates. The EmDrive is what is called an RF resonant cavity thruster, and is one of several hypothetical machines that use this model. These designs work by having a magnetron push microwaves into a closed truncated cone, then push against the short end of the cone, and propel the craft forward.

This is in contrast to the form of propulsion current spacecraft use, which burn large quantities of fuel to expel a massive amount of energy and mass to rocket the craft into the air. An often-used metaphor for the inefficacy of this is to compare the particles pushing against the enclosure and producing thrust to the act of sitting in a car and pushing a steering wheel to move the car forward.

While tests have been done on experimental versions of the drive — with low energy inputs resulting in a few micronewtons of thrust (about as much force as the weight of a penny) — none of the findings have ever been published in a peer-reviewed journal. That means that any and all purportedly positive test results, and the claims of those who have a vested interest in the technology, should be taken with a very big grain of skepticism-flavored salt. It’s likely that the thrust recorded was due to interference or an unaccounted error with equipment.

Until the tests have been verified through the proper scientific and peer-reviewed processes, one can assume the drive does not yet work. Still, it’s interesting to note the number of people who have tested the drive and reported achieving thrust:

• In 2001, Shawyer was given a £45,000 grant from the British government to test the EmDrive. His test reportedly achieved 0.016 Newtons of force and required 850 watts of power, but no peer review of the tests verified this. It’s worth noting, however, that this number was low enough that it was potentially an experimental error.
• In 2008, Yang Juan and a team of Chinese researches at the Northwestern Polytechnical University allegedly verified the theory behind RF resonant cavity thrusters, and subsequently built their own version in 2010, testing the drive multiple times from 2012 to 2014. Tests results were purportedly positive, achieving up yo 750 mN (millinewtons) of thrust, and requiring 2,500 watts of power.
• In 2014, NASA researchers, tested their own version of an EmDrive, including in a hard vacuum. Once again, the group reported thrust (about 1/1,000 of Shawyer’s claims), and once again, the data was never published through peer-reviewed sources. Other NASA groups are skeptical of researchers’ claims, but in their paper, it is clearly stated that these findings neither confirm nor refute the drive, instead calling for further tests.
• In 2015, that same NASA group tested a version of chemical engineer Guido Fetta’s Cannae Drive (née Q Drive), and reported positive net thrust. Similarly, a research group at Dresden University of Technology also tested the drive, again reporting thrust, both predicted and unexpected.
• Yet another test by a NASA research group, Eagleworks, in late 2015 seemingly confirmed the validity of the EmDrive. The test corrected errors that had occurred in the previous tests, and surprisingly, the drive achieved thrust. However, the group has not yet submitted their findings for peer review. It’s possible that other unforeseen errors in the experiment may have cause thrust (the most likely of which is that the vacuum was compromised, causing heat to expand air within it testing environment and move the drive). Whether the findings are ultimately published or not, more tests need to be done. That’s exactly what Glenn Research Center in Cleveland, Ohio, NASA’s Jet Propulsion Laboratory, and Johns Hopkins University Applied Physics Laboratory intend to do. For EmDrive believers, there seems to be some hope.

Implications of a working EmDrive

It’s easy to see how many in the scientific community are wary of EmDrive and RF resonant cavity thrusts altogether. But on the other hand, the wealth of studies raises a few questions: Why is there such a interest in the technology, and why do so many people wish to test it? What exactly are the claims being made about the drive that make it such an attractive idea? While everything from atmospheric temperature-controlling satellites, to safer and more efficient automobiles have been drummed up as potential applications for the drive, the real draw of the technology — and the impetus for its creation in the first place — is the implications for space travel.

Spacecraft equipped with a reactionless drive could potentially make it to the moon in just a few hours, Mars in two to three months, and Pluto within two years. These are extremely bold claims, but if the EmDrive does turn out to be a legitimate technology, they may not be all that outlandish. And with no need to pack several tons-worth of fuel, spacecraft become cheaper and easier to produce, and far lighter.
For NASA and other such organizations, including the numerous private space corporations like SpaceX, lightweight, affordable spacecraft that can travel to remote parts of space fast are something of a unicorn. Still, for that to become a reality, the science has to add up.

Shawyer is adamant that there is no need for pseudoscience or quantum theories to explain how EmDrive works. Instead, he believes that current models of Newtonian physics offer an explanation, and has written papers on the subject, one of which is currently being peer reviewed. He expects the paper to be published sometime this year. While in the past Shawyer has been criticized by other scientists for incorrect and inconsistent science, if the paper does indeed get published, it may begin to legitimize the EmDrive and spur more testing and research.

Spacecraft equipped with a reactionless drive could potentially make it to the Moon in just a few hours.

Despite his insistence that the drive behaves within the laws of physics, it hasn’t prevented him from making bold assertions regarding EmDrive. Shawyer has gone on record saying that this new drive produced warp bubbles which allow the drive to move, claiming that this is how NASA’s test results were likely achieved. Assertions such as these have garnered much interest online, but have no clear supporting data and will (at the very least) require extensive testing and debate in order to be taken seriously by the scientific community — the majority of which remain skeptical of Shawyer’s claims.

Colin Johnston of the Armagh Planetarium wrote an extensive critique of the EmDrive and the inconclusive findings of numerous tests. Similarly, Corey S. Powell of Discovery wrote his own indictment of both Shawyer’s EmDrive and Fetta’s Cannae Drive, as well as the recent fervor over NASA’s findings. Both point out the need for greater discretion when reporting on such instances. Professor and mathematical physicist, John C. Baez expressed his exhaustion at the conceptual technology’s persistence in debates and discussions, calling the entire notion of a reactionless drive “baloney.” His impassioned dismissal echoes the sentiments of many others.

Shawyer’s EmDrive has been met with enthusiasm elsewhere, including the website NASASpaceFlight.com — where information about the most recent Eagleworks’ tests was first posted — and the popular journal New Scientist, which published a favorable and optimistic paper on EmDrive. (The editors later issued a statement that, despite enduring excitement over the idea, they should have shown more tact when writing on the controversial subject.)

Clearly, the EmDrive and RF resonant cavity thruster technology have a lot to prove. There’s no denying that the technology is exciting, and that the number of “successful” tests are interesting, but one must keep in mind the physics preventing the EmDrive from gaining any traction, and the rather curious lack of peer-reviewed studies done on the subject. If the EmDrive is so groundbreaking (and works), surely people like Shawyer would be clamoring for peer-reviewed verification.

A demonstrably working EmDrive could open up exciting possibilities for both space and terrestrial travel — not to mention call into question our entire understanding of physics. However, until that comes to pass, it will remain nothing more than science fiction.

Read more: http://www.digitaltrends.com/cool-tech/emdrive-news-rumors/#ixzz41JSPv7jZ
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NASA’s real life Enterprise may take us to other star systems one day

Dr. Harold “Sonny” White is still working on a warp drive at NASA’s Johnson Space Center. His work is still in the experimental stage but that doesn’t mean he can’t imagine what the real lifeEnterprise ship would look like according to his math.

You’re looking at it right now.

..

 

This is the starship that may take us where no human has gone before. And it has me screaming like a little Klingon girl.

 

 

Concept 3D artist Mark Rademaker told io9 that “he worked with White to create the updated model, which includes a sleek ship nestled at the center of two enormous rings, which create the warp bubble.”

The updated model is the one you can see above, a variation of the original concept which, according to Dr. White, was rendered by Rademaker based on an idea by Matthew Jeffries, the guy who came with “the familiar Star Trek look.” This is the original warp drive spaceship concept:

Dr. White—whose daily life is working in future propulsion solutions for interplanetary travel in the near future, like ion and plasma thrusters—developed new theoretical work that solved the problems of the Alcubierre Drive concept, a theory that allowed faster-than-light travel based on Einstein’s field equations in general relativity, developed by theoretical physicist Miguel Alcubierre.

A spaceship equipped with a warp drive would allow faster-than-light travel by bending the space around it, making distances shorter. At the local level, however, the spaceship wouldn’t be moving faster than light. Therefore, warp drive travel doesn’t violate the first Einstein commandment: Thou shall not travel faster than light.

Not a fantasy, but real science

But Interstellar is just science fiction. Dr. White’s work at the Advanced Propulsion Theme Lead for the NASA Engineering Directorate is science. And while his department only gets peanuts compared to NASA’s budget (not to talk about the Pentagon’s) I find his words comforting:

Perhaps a Star Trek experience within our lifetime is not such a remote possibility.

See, Dr. White and his colleagues aren’t making a movie or coming up with 3D renders for the sake of it. They just don’t just believe a real life warp drive is theoretically possible; they’ve already started the work to create one:

Working at NASA Eagleworks—a skunkworks operation deep at NASA’s Johnson Space Center—Dr. White’s team is trying to find proof of those loopholes. They have “initiated an interferometer test bed that will try to generate and detect a microscopic instance of a little warp bubble” using an instrument called the White-Juday Warp Field Interferometer.

It may sound like a small thing now, but the implications of the research huge. In his own words:

Although this is just a tiny instance of the phenomena, it will be existence proof for the idea of perturbing space time-a “Chicago pile” moment, as it were. Recall that December of 1942 saw the first demonstration of a controlled nuclear reaction that generated a whopping half watt. This existence proof was followed by the activation of a ~ four megawatt reactor in November of 1943. Existence proof for the practical application of a scientific idea can be a tipping point for technology development.

The roadmap to the warp drive

According to Dr. White, this is a roadmap that they need to follow to achieve that final objective of rapid interstellar travel.

Every time I read that paragraph I smile—and these renders just make my smile so wide it looks stupid.

OK, Dr. White, you got our attention. Make it so.

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SpaceX’s new Dragon capsule could be the future of space travel

The new Dragon V2 spacecraft, revealed by Space X on Thursday

Thursday evening, SpaceX revealed an upgraded version of its Dragon spacecraft, capable of carrying up to seven people at a time.

The company hopes to use the 15-foot-tall capsule to carry astronauts to the International Space Station beginning in 2017.

THE COMPANY HOPES TO CARRY ASTRONAUTS TO THE SPACE STATION BEGINNING IN 2017

Its timing is impeccable. Currently, NASA relies entirely on Russia for transporting its astronauts to the station. But, last month, Russia threatened to revoke accessdue to tensions between the two countries. And a few days ago, NASA announced that its latest purchase of six round-trip tickets to the space station, good through 2017, will be its last. (The tickets cost $76.3 million each.)

That brings us to SpaceX, the private company started by Elon Musk (founder of PayPal and Tesla Motors) in 2002. Since May 2012, the company has been using a previous version of the Dragon spacecraft to carry cargo to the space station — as part of NASA’s long-term plan to have private US companies take over the basics of space transport.

The latest Dragon V2 has a few upgrades on the old one: it lands with thrusters, instead of crashing into the ocean with parachutes, is more fully reusable, and, of course, can carry people. SpaceX will begin testing the craft over the next few years, with its first peopled flights coming in 2016.

(SpaceX)

In terms of hardware, the new Dragon’s biggest upgrade is a set of 8 thrusters, which are powerful enough to slow down the capsule, allowing controlled landings on Earth.

The Dragon will also carry parachutes in case of an equipment failure, but if the thrusters are successful, they’d be a huge step forward in space flight, eliminating the need for parachute-aided crash landings for a capsule for the first time.

Many components of the current Dragon can be used for multiple flights, but the new landing method will, in theory, make the whole capsule rapidly reusable, going through ten flights before needing to be heavily serviced.

“You can just reload propellant and fly again,” Elon Musk said during the announcement. Additionally, the new spacecraft’s improved heat shield is designed to deteriorate less as it enters the atmosphere, allowing for a greater number of reuses.

SpaceX is trying to make every component of its space flight program as reusable as possible. It recently launched a version of the Falcon 9 rocket — which will put Dragon in space — with a first stage that can land on metallic legs, potentially allowing for easier retrieval and reuse.

“This is extremely important for revolutionizing access to space,” Musk said. “As long as we continue to throw away rockets and space craft, we will never have true access to space — it’ll always be incredibly expensive.”

It has room for seven people

(Djansezian/Getty Images)

The other chief upgrade of the Dragon is pretty obvious: it can carry people into space. But it goes further, outstripping Russia’s Soyuz rockets (which can transport three astronauts at a time) with a capacity of seven.

IT OUTSTRIPS RUSSIA’S SOYUZ ROCKETS, WHICH CAN TRANSPORT THREE ASTRONAUTS

SpaceX went with a minimalist aesthetic for the Dragon’s interior, putting nearly all the controls on touch screen panels that fold down during flight. It’s a far cry from the button-crammed cockpit of NASA’s space shuttle.

The craft also has a few other upgrades: it can dock autonomously with the International Space Station without needing to use the station’s robotic arm, and the Dragon’s trunk (which detaches before re-entry to the Earth’s atmosphere) will be wrapped in solar panels, instead of having them on arms that extend outward.

 

What does the Dragon mean for the future of space travel?

(SpaceX)

All in all, the debut of this upgraded spacecraft is a very good sign for US space travel, and couldn’t have come at a better time.

For years, Congress has appropriated less money for NASA’s Commercial Crew Program — created to fund the development of private space travel — than the $800 million requested annually.

THE DEBUT OF THIS UNGRADED SPACECRAFT COULDN’T HAVE COME AT A BETTER TIME

But the tensions with Russia seem to have added urgency to the goal. The transport won’t necessarily come via the Dragon capsule — less ballyhooed options like Boeing’s CST-100 crew capsule and Sierra Nevada’s Dream Chaser space plane are also in the running to win NASA’s contract — but the timely premiere of this craft can’t hurt. An upcoming NASA funding round will likely cut down the competition to one option, and SpaceX is clearly planning to win.

There are also intriguing signs that SpaceX envisions the Dragon being useful for future missions that go way beyond the space station. As Phil Plait points out, SpaceX’s press materials say the Dragon’s new thrusters will “enable the vehicle to land propulsively on Earth or another planet with pinpoint accuracy.”

Missions to Mars, of course, are still a long way off. But the 2017 target date for private US missions to the space station is quickly approaching. SpaceX’s progress — with both its Dragon capsule and other launch technologies — are making it look more likely that they’ll hit the deadline.

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‘Moon’ shots: Decades-old photos of Apollo training surface

Before Apollo astronauts went to the moon, they went to Hawaii to train on the Big Island’s lunar landscapes.

Now, decades-old photos are surfacing of astronauts scooping up Hawaii’s soil and riding across volcanic fields in a “moon buggy” vehicle.

The Pacific International Space Center for Exploration Systems, a Hawaii state agency, is displaying the photos at its Hilo headquarters. Rob Kelso, the agency’s executive director, found the images at the Johnson Space Center in Houston.

Astronauts from Apollo missions 13 through 17 trained in Hawaii as did some back up crews, Kelso said.

Some training was on Mauna Kea volcano, where glacial runoff crushed and refined rock into power. Astronauts also trained on recent lava flows.

Today, robots are tested on the Big Island for moon and Mars missions.

In recent years, engineers have tested technology to pull oxygen out of the island’s dirt, which is volcanic basalt like the Martian and lunar soil. Future missions could use this technology to extract oxygen from the land instead of taking it along. The oxygen could be used for breathing, to make fuel or for other purposes.

Kelso said scientists are also interested in testing robots at the Big Island’s lava tubes and lava tube skylight holes, which resemble similar formations recently spotted in high-definition images taken by satellites orbiting the moon, Mercury, Venus and Mars.

Lava tubes are tunnels made when lava forms a solid roof after flowing steadily in a confined area for hours. Skylight holes are formed when part of the tube breaks.

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