SpaceJibe

December 6, 2017

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

Filed under: Cool, Gadgets, Outer Solar System, Space Exploration, Space Ships — bferrari @ 7:06 pm

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

voyagers_position

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Chris Jones said “The Voyager flight team dug up decades-old data and examined the software that was coded in an outdated assembler language, to make sure we could safely test the thrusters.”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.

July 7, 2017

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

Filed under: Cool, Gadgets, Space Exploration, Space Ships — bferrari @ 8:04 pm

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.)

September 19, 2016

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

Filed under: Cool, Inner Solar System, Mars, Military, Space Exploration, Space Ships — bferrari @ 8:54 am
Artist's rendering of a blueprint of the completed Space Launch System. (NASA/MSFC)

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)

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)

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

June 23, 2016

NASA reveals the X-57, its electric plane project

Filed under: Cool, Gadgets, Military, Space Ships — bferrari @ 2:57 pm

1466451753763Artist’s concept of the X-57. (NASA Langley/Advanced Concepts Lab, AMA, Inc.)

 

An electric plane project is in the works at NASA, and the new aircraft is called the X-57. It’s an initiative the space agency hopes will demonstrate that electric-powered aviation can be environmentally friendly, quiet, and quick.

Made out of a modified Italian-designed plane, the X-57 will have a skinny wing with a total of 14 battery-powered motors, and because it won’t run on gas, it won’t produce exhaust from burnt fossil fuels. NASA said that having multiple small engines means the X-57 will need less energy to cruise at a speed of 175 mph.

And while traditional fuel-burning airplanes need to cruise slower than their maximum speed to be the most fuel-efficient, the space agency says that that isn’t the case with an electric-powered plane.

Related: Solar Impulse 2 attempts fuel-free trans-Atlantic flight

The “X” designation in the plane’s name places it the tradition of experimental aircraft, with the first, the X-1, the name of the plane that broke the sound barrier in 1947 at the hands of Chuck Yeager.

“With the return of piloted X-planes to NASA’s research capabilities – which is a key part of our 10-year-long New Aviation Horizons initiative – the general aviation-sized X-57 will take the first step in opening a new era of aviation,” Charles Bolden, the NASA administrator, said in a statement.

Related: Hang glider aims to break long-distance flight record

The space agency may in fact make more than one aircraft in the program. “As many as five larger transport-scale X-planes also are planned as part of the initiative,” NASA says. The plane is also called Maxwell, named after James Clerk Maxwell, a vanguard in the study of electromagnetism.

The power of clean energy in aviation is in the spotlight lately, as the sun-powered aircraft Solar Impulse 2took off from New York’s Kennedy airport at 2:30 a.m. EDT Monday, on a daring trip across the Atlantic Ocean— the latest leg of a record-breaking solar-powered journey around the world meant to showcase the power of renewable energy.

Source

April 21, 2016

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.

em-drive-640x640

 

 

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

February 26, 2016

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

roger-shawyer-satellite-propulsion-research-ltd

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.

em-drive-640x640

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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December 26, 2015

China Just Flew This Gigantic Airship To the Edge Of Space

Filed under: Gadgets, Life, Military, Space Ships — bferrari @ 6:54 pm

The technology could have communications and military advantages for China.

China just flew a 250-foot airship to near the top of the Earth’s atmosphere. The solar-powered behemoth can stay airborne for half a year and requires no fuel to get it more than 12 miles into the air—just fill it with helium and let it go; the sun powers it once it reaches its cruising altitude.

Airships predate airplanes, but have been largely supplanted by them. However, they remain superior for pretty much anything that doesn’t require the speed of a jet engine. They can hang around for months, they can carry large payloads, and they can fly way higher than most planes, because an airplane’s wing runs out of air to support it at such high altitudes.

This last property might be the reason China is testing the Yuanmeng airship. During its estimated two-day trial, the airship launched from Xilinhot, Inner Mongolia, bristling with communications gear—”data relays, high-definition observation and spatial imaging” equipment—says the Chinese People’s Daily. The sedentary nature of the airship allows it to sit up at the edge of space and watch. It can surveil the ground, and it can also act as a base station to command fleets of military planes. In a pinch, the Yuanmeng airship could act as a stand-in for communications satellites.

Popular Science speculates on China’s plans for the technology:

Operating higher in near space means that the Yuanmeng would have constant line of sight over a hundred thousand square miles—an important requirement for radar and imaging. Increased sensor coverage means increased warning time against stealthy threats such as cruise missiles, giving Chinese forces a greater opportunity to detect and shoot down such threats. It would also be harder for fighters and surface-to-air missiles to attack near space objects.

They’re not perfect though. The People’s Daily spoke to Yu Quan of the Chinese Academy of Engineering, who told them that “The biggest challenge for the near-space airship is the big temperature difference in the day and night.” Because the airship is so close to space, it experiences space-like extremes of weather as it is baked by the sun and then frozen by the night.

Airships can solve many problems. In much the same way that regular oceangoing ships carry huge loads of goods from continent to continent, airships are also good for transporting goods. Even smaller airships can carry loads of 50 tons. And perhaps they could even replace passenger airplanes as providers of low-cost air travel. They might not be as fast, but they could be a lot more comfortable.

November 25, 2015

Blue Origin makes historic reusable rocket landing in epic test flight

Filed under: Cool, Earth, Inner Solar System, Moon, Space Ships — bferrari @ 10:38 am

Go AMAZON Go !

blueorigin_launch_web

The private spaceflight company Blue Origin just launched itself into the history books by successfully flying and landing a reusable rocket.

Powered by the company’s own BE-3 engine, the rocket kicked off the launchpad on Nov. 23 at 11:21 a.m. Central Time, carrying the New Shepard space vehicle. The stunning feat was captured in an amazing test flight video released by the company.

Shortly after liftoff, the rocket separated from the vehicle. In the past, a spent rocket would fall back to Earth like a stone, having completed its one and only flight.

But Blue Origin’s rocket didn’t fall aimlessly back to Earth; instead, it was guided toward a landing pad, where it re-ignited its engines, hovered briefly above the ground and finally touched down softly on the pad, remaining upright and intact. This soft landing means the rocket can be used for more flights, which Blue Origin and other companies have said will significantly drive down the cost of spaceflight. [See more photos of Blue Origin’s epic test flight]

No other agency or company has successfully landed a reusable rocket before.

“Rockets have always been expendable. Not anymore,” stated a blog post on the company’s website, written by founder Jeff Bezos, the billionaire who also founded Amazon.com. “Now safely tucked away at our launch site in West Texas is the rarest of beasts, a used rocket. This flight validates our vehicle architecture and design.”

Blue Origin’s New Shepard capsule reached a maximum altitude of 329,839 feet and a speed of Mach 3.72, meaning 3.72 times the speed of sound, or about 2,854 mph, according a press release.

The release also laid out the details of the rocket booster landing. The rocket’s physical design first helped it to glide back toward the launch pad. Closer to the ground, the vehicle’s eight “drag brakes” reduced its terminal speed to 387 mph. Additional fins on the outside of the vehicle “steered it through 119-mph high-altitude crosswinds to a location precisely aligned with and 5,000 feet above the landing pad,” the release stated.

Finally, the BE-3 engine re-ignited “to slow the booster as the landing gear deployed and the vehicle descended the last 100 feet at 4.4 mph to touch down on the pad.”

The New Shepard crew vehicle also landed safely, guided down to Earth by parachutes.

Blue Origin has been somewhat secretive about the progress of its spaceflight vehicles and rockets; the company typically doesn’t announce test flights until they are already completed. Blue Origin intends to use the New Shepard vehicle for suborbital space tourism and as a microgravity science laboratory. (Suborbital means the vehicle can fly only to a lower altitude than is necessary to start orbiting the Earth — it would have to travel higher, and faster, to reach altitudes achieved by orbiting satellites or the International Space Station, for example.)

The company is also working on an orbital vehicle, which has been nicknamed “Very Big Brother.”

“We are building Blue Origin to seed an enduring human presence in space, to help us move beyond this blue planet that is the origin of all we know,” Bezos wrote in the blog post. “We are pursuing this vision patiently, step by step. Our fantastic team in Kent [Washington], Van Horn [Texas] and Cape Canaveral [Florida] is working hard not just to build space vehicles, but to bring closer the day when millions of people can live and work in space.”

Blue Origin is not the only company pursuing a reusable rocket design. The private spaceflight company SpaceX, founded by another Internet billionaire, Elon Musk, has made two efforts to set down a rocket on a landing pad after flight. But both times, the rocket came in too hard and too fast, and crashed on the landing pad.

On Nov. 24, Musk tweeted, “Congrats to Jeff Bezos and the BO team for achieving VTOL [vertical takeoff and landing] on their booster.” But, in a second tweet, he said, “It is, however, important to clear up the difference between ‘space’ and ‘orbit,’ as described well by https://what-if.xkcd.com/58/.”

SpaceX is not building a suborbital vehicle like New Shepard. Musk’s company’s robotic Dragon cargo capsule has already flown supplies to the International Space Station, and SpaceX has been selected by NASA to build a crew vehicle that will take people to the orbiting laboratory.

Source

November 16, 2015

Hypersonic rocket engine could ‘revolutionize’ air travel

Filed under: Cool, Gadgets, Military, Space Ships, Uncategorized — bferrari @ 6:08 pm

skylon_sabre_cutaway_l

British aerospace giant BAE Systems is betting big on hypersonic travel — something its potential new partner says could be a reality within two decades.

BAE is planning to invest £20.6 million ($31.8 million) in a 20% stake of Reaction Engines, a UK-based engineering firm which has developed what it calls “breakthrough” aerospace engine technology, which could potentially be used for a new generation of reusable space vehicles and, as a commercial offshoot, could revolutionize air travel.

An announcement on BAE’s website states that the partnership will allow collaboration on Reaction Engines’ SABRE technology — “a new aerospace engine class that combines both jet and rocket technologies with the potential to revolutionize hypersonic flight and the economics of space access.”

Along with hypersonic air travel, Mark Thomas, Reaction Engines’ managing director, told CNN’s Richard Quest that a reusable space plane that takes off and lands like an aircraft is “one of the concepts that could be made possible by this engine.”

sabre_notes_1l1

Five times the speed of sound
SABRE, which stands for Synergetic Air-Breathing Rocket Engine, is an air-breathing engine, which uses ultra-lightweight heat exchangers to cool very hot air streams — such as those encountered at hypersonic speeds.

The technology will “enable aircraft to operate easily at speeds of up to five times the speed of sound or fly directly into Earth orbit,” Reaction Engines says in a press release on its website.

Through its ability to use atmospheric oxygen for propulsion, the engine’s design negates the need for heavy fuel reserves on board, drastically reducing the weight of a SABRE-powered vehicle.

BAE’s statement says that SABRE can also “transition” to a rocket mode, allowing spaceflight at speeds up to orbital velocity — or 25 times the speed of sound.

Thomas describes the design as an “absolutely revolutionary… visionary concept.”

He explains that SABRE is, at heart, a rocket engine but can breathe air when in the atmosphere “so you don’t need to carry so much liquid oxygen on board your vehicle, it massively reduces the weight, and you can put that into vehicle design capability or payload.”

The company’s advanced heat exchanger, which can reduce hypersonic air temperature by over a thousand degrees in a hundredth of a second, is fundamental to the engine’s design.

“If you’re doing hypersonic speed the air is around 1000˚C (1832˚F) which is more typical of the air coming out the back of the engine than goes in the front,” he explains. “So you have to be able to cool that down really quickly.”

Breaking boundaries

The company is focusing on developing the engine and Thomas says BAE will help translate its potential into a range of workable applications.

“I think we’re two decades away from a passenger carrying vehicle but a (reusable) space access vehicle within ten to 15 years.”

BAE’s proposed 20% investment is pending the approval of Reaction Engines’ shareholders.

October 19, 2015

Incredible Cross-section of the Saturn V Moon Rocket

Filed under: Cool, Earth, Moon, Space Ships — bferrari @ 9:12 pm
The Incredible Saturn V

The Incredible Saturn V

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