May 25, 2017May 25, 2017 by Matt Williams

New Way to Make Plasma Propulsion Lighter and More Efficient

Image of the Neptune thruster (right) with plasma expanding into a space simulation chamber. Credit: Dmytro Rafalskyi

Plasma propulsion is a subject of keen interest to astronomers and space agencies. As a highly-advanced technology that offers considerable fuel-efficiency over conventional chemical rockets, it is currently being used in everything from spacecraft and satellites to exploratory missions. And looking to the future, flowing plasma is also being investigated for more advanced propulsion concepts, as well as magnetic-confined fusion.

However, a common problem with plasma propulsion is the fact that it relies on what is known as a “neutralizer”. This instrument, which allows spacecraft to remain charge-neutral, is an additional drain on power. Luckily, a team of researchers from the University of York and École Polytechnique are investigating a plasma thruster design that would do away with a neutralizer altogether.

A study detailing their research findings – titled “Transient propagation dynamics of flowing plasmas accelerated by radio-frequency electric fields” – was released earlier this month in Physics of Plasmas – a journal published by the American Institute of Physics. Led by Dr. James Dendrick, a physicist from the York Plasma Institute at the University of York, they present a concept for a self-regulating plasma thruster.

*A 6 kW Hall thruster in operation at NASA;s Jet Propulsion Laboratory. Credit: NASA/JPL*

Basically, plasma propulsion systems rely on electric power to ionize propellant gas and transform it into plasma (i.e. negatively charged electrons and positively-charged ions). These ions and electrons are then accelerated by engine nozzles to generate thrust and propel a spacecraft. Examples include the Gridded-ion and Hall-effect thruster, both of which are established propulsion technologies.

The Gridden-ion thruster was first tested in the 1960s and 70s as part of the Space Electric Rocket Test (SERT) program. Since then, it has been used by NASA’s Dawn mission, which is currently exploring Ceres in the Main Asteroid Belt. And in the future, the ESA and JAXA plan to use Gridded-iron thrusters to propel their BepiColombo mission to Mercury.

Similarly, Hall-effect thrusters have been investigated since the 1960s by both NASA and the Soviet space programs. They were first used as part of the ESA’s Small Missions for Advanced Research in Technology-1 (SMART-1) mission. This mission, which launched in 2003 and crashed into the lunar surface three years later, was the first ESA mission to go to the Moon.

As noted, spacecraft that use these thrusters all require a neutralizer to ensure that they remain “charge-neutral”. This is necessary since conventional plasma thrusters generate more positively-charged particles than they do negatively-charged ones. As such, neutralizers inject electrons (which carry a negative charge) in order to maintain the balance between positive and negative ions.

An artist's illustration of NASA's Dawn spacecraft approaching Ceres. Image: NASA/JPL-Caltech. — *An artist’s illustration of NASA’s Dawn spacecraft with its ion propulsion system approaching Ceres. Credit: NASA/JPL-Caltech.*

As you might suspect, these electrons are generated by the spacecraft’s electrical power systems, which means that the neutralizer is an additional drain on power. The addition of this component also means that the propulsion system itself will have to be larger and heavier. To address this, the York/École Polytechnique team proposed a design for a plasma thruster that can remain charge neutral on its own.

Known as the Neptune engine, this concept was first demonstrated in 2014 by Dmytro Rafalskyi and Ane Aanesland, two researchers from the École Polytechnique’s Laboratory of Plasma Physics (LPP) and co-authors on the recent paper. As they demonstrated, the concept builds upon the technology used to create gridded-ion thrusters, but manages to generate exhaust that contains comparable amounts of positively and negatively charged ions.

As they explain in the course of their study:

“Its design is based on the principle of plasma acceleration, whereby the coincident extraction of ions and electrons is achieved by applying an oscillating electrical field to the gridded acceleration optics. In traditional gridded-ion thrusters, ions are accelerated using a designated voltage source to apply a direct-current (dc) electric field between the extraction grids. In this work, a dc self-bias voltage is formed when radio-frequency (rf) power is coupled to the extraction grids due to the difference in the area of the powered and grounded surfaces in contact with the plasma.”

*The hall-effect thruster used by the SMART-1 mission, which relied on xenon as its reaction mass. Copyright: ESA*

In short, the thruster creates exhaust that is effectively charge-neutral through the application of radio waves. This has the same effect of adding an electrical field to the thrust, and effectively removes the need for a neutralizer. As their study found, the Neptune thruster is also capable of generating thrust that is comparable to a conventional ion thruster.

To advance the technology even further, they teamed up with James Dedrick and Andrew Gibson from the York Plasma Institute to study how the thruster would work under different conditions. With Dedrick and Gibson on board, they began to study how the plasma beam might interact with space and whether this would affect its balanced charge.

What they found was that the engine’s exhaust beam played a large role in keeping the beam neutral, where the propagation of electrons after they are introduced at the extraction grids acts to compensate for space-charge in the plasma beam. As they state in their study:

“[P]hase-resolved optical emission spectroscopy has been applied in combination with electrical measurements (ion and electron energy distribution functions, ion and electron currents, and beam potential) to study the transient propagation of energetic electrons in a flowing plasma generated by an rf self-bias driven plasma thruster. The results suggest that the propagation of electrons during the interval of sheath collapse at the extraction grids acts to compensate space-charge in the plasma beam.”

Naturally, they also emphasize that further testing will be needed before a Neptune thruster can ever be used. But the results are encouraging, since they offer up the possibility of ion thrusters that are lighter and smaller, which would allow for spacecraft that are even more compact and energy-efficient. For space agencies looking to explore the Solar System (and beyond) on a budget, such technology is nothing if not desirable!

Further Reading: Physics of Plasmas, AIP

May 11, 2017May 11, 2017 by Evan Gough

Rise of the Super Telescopes: Why We Build Them

This illustration shows what the Giant Magellan Telescope will look like when it comes online. The fifth of its seven mirror segments is being cast now. Each of the segments is a 20 ton piece of glass. Image: Giant Magellan — This illustration shows what the Giant Magellan Telescope will look like when it comes online. Each of its mirror segments is a 20 ton piece of glass. Image: Giant Magellan Telescope – GMTO Corporation

One night 400 years ago, Galileo pointed his 2 inch telescope at Jupiter and spotted 3 of its moons. On subsequent nights, he spotted another, and saw one of the moons disappear behind Jupiter. With those simple observations, he propelled human understanding onto a path it still travels.

Galileo’s observations set off a revolution in astronomy. Prior to his observations of Jupiter’s moons, the prevailing belief was that the entire Universe rotated around the Earth, which lay at the center of everything. That’s a delightfully childish viewpoint, in retrospect, but it was dogma at the time.

Until Galileo’s telescope, this Earth-centric viewpoint, called Aristotelian cosmology, made sense. To all appearances, we were at the center of the action. Which just goes to show you how wrong we can be.

But once it became clear that Jupiter had other bodies orbiting it, our cherished position at the center of the Universe was doomed.

Galileo Galilei set off a revolution in astronomy when he used his telescope to observe moons orbiting Jupiter. By Justus Sustermans - http://www.nmm.ac.uk/mag/pages/mnuExplore/PaintingDetail.cfm?ID=BHC2700, Public Domain, https://commons.wikimedia.org/w/index.php?curid=230543 — Galileo Galilei set off a revolution in astronomy when he used his telescope to observe moons orbiting Jupiter. By Justus Sustermans – http://www.nmm.ac.uk/mag/pages/mnuExplore/PaintingDetail.cfm?ID=BHC2700, Public Domain, https://commons.wikimedia.org/w/index.php?curid=230543

Galileo’s observations were an enormous challenge to our understanding of ourselves at the time, and to the authorities at the time. He was forced to recant what he had seen, and he was put under house arrest. But he never really backed down from the observations he made with his 2 inch telescope. How could he?

Now, of course, there isn’t so much hostility towards people with telescopes. As time went on, larger and more powerful telescopes were built, and we’ve gotten used to our understanding going through tumultuous changes. We expect it, even anticipate it.

In our current times, Super Telescopes rule the day, and their sizes are measured in meters, not inches. And when new observations challenge our understanding of things, we cluster around out of curiosity, and try to work our way through it. We don’t condemn the results and order scientists to keep quiet.

The first of the Super Telescopes, as far as most of us are concerned, is the Hubble Space Telescope. From its perch in Low Earth Orbit (LEO), the Hubble has changed our understanding of the Universe on numerous fronts. With its cameras, and the steady stream of mesmerizing images those cameras deliver, a whole generation of people have been exposed to the beauty and mystery of the cosmos.

The Hubble Space Telescope could be considered the first of the Super Telescopes. In this image it is being released from the cargo bay of the Space Shuttle Discovery in 1990. Image: By NASA/IMAX - http://mix.msfc.nasa.gov/abstracts.php?p=1711, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6061254 — The Hubble Space Telescope could be considered the first of the Super Telescopes. In this image it is being released from the cargo bay of the Space Shuttle Discovery in 1990. Image: By NASA/IMAX – http://mix.msfc.nasa.gov/abstracts.php?p=1711, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6061254

Hubble has gazed at everything, from our close companion the Moon, all the way to galaxies billions of light years away. It’s spotted a comet breaking apart and crashing into Jupiter, dust storms on Mars, and regions of energetic star-birth in other galaxies. But Hubble’s time may be coming to an end soon, and other Super Telescopes are on the way.

Nowadays, Super Telescopes are expensive megaprojects, often involving several nations. They’re built to pursue specific lines of inquiry, such as:

What is the nature of Dark Matter and Dark Energy? How are they distributed in the Universe and what role do they play?
Are there other planets like Earth, and solar systems like ours? Are there other habitable worlds?
Are we alone or is there other life somewhere?
How do planets, solar systems, and galaxies form and evolve?

Some of the Super Telescopes will be on Earth, some will be in space. Some have enormous mirrors made up of individual, computer-controlled segments. The Thirty Meter Telescope has almost 500 of these segments, while the European Extremely Large Telescope has almost 800 of them. Following a different design, the Giant Magellan Telescope has only seven segments, but each one is over 8 meters in diameter, and each one weighs in at a whopping 20 tons of glass each.

This artistic bird's-eye view shows the dome of the ESO European Extremely Large Telescope (E-ELT) in all its glory, on top of the Chilean Cerro Armazones. The telescope is currently under construction and its first light is targeted for 2024. — This artistic bird’s-eye view shows the dome of the ESO European Extremely Large Telescope (E-ELT) in all its glory, on top of the Chilean Cerro Armazones. The telescope is currently under construction and its first light is targeted for 2024.

Some of the Super Telescopes see in UV or Infrared, while others can see in visible light. Some see in several spectrums. The most futuristic of them all, the Large Ultra-Violet, Optical, and Infrared Surveyor (LUVOIR), will be a massive space telescope situated a million-and-a-half kilometers away, with a 16 meter segmented mirror that dwarfs that of the Hubble, at a mere 2.4 meters.

Some of the Super Telescopes will discern the finest distant details, while another, the Large Synoptic Survey Telescope, will complete a ten-year survey of the entire available sky, repeatedly imaging the same area of sky over and over. The result will be a living, dynamic map of the sky showing change over time. That living map will be available to anyone with a computer and an internet connection.

A group photo of the team behind the Large Synoptic Survey Telescope. The group gathered to celebrate the casting of the 'scope's 27.5 ft diameter mirror. The LSST will create a living, detailed, dynamic map of the sky and make it available to anyone. Image: LSST Corporation — A group photo of the team behind the Large Synoptic Survey Telescope. The group gathered to celebrate the casting of the ‘scope’s 27.5 ft diameter mirror. The LSST will create a living, detailed, dynamic map of the sky and make it available to anyone. Image: LSST Corporation

We’re in for exciting times when it comes to our understanding of the cosmos. We’ll be able to watch planets forming around young stars, glimpse the earliest ages of the Universe, and peer into the atmospheres of distant exoplanets looking for signs of life. We may even finally crack the code of Dark Matter and Dark Energy, and understand their role in the Universe.

Along the way there will be surprises, of course. There always are, and it’s the unanticipated discoveries and observations that fuel our sense of intellectual adventure.

The Super Telescopes are technological masterpieces. They couldn’t be built without the level of technology we have now, and in fact, the development of Super Telescopes help drives our technology forward.

But they all have their roots in Galileo and his simple act of observing with a 2-inch telescope. That, and the curiosity about nature that inspired him.

The Rise of the Super Telescopes Series:

March 24, 2017April 4, 2017 by Evan Gough

German ‘Largest Artificial Sun’ To Generate Climate Friendly Fuel

Technicians at the DLR's Institute for Solar Research inspecting lamps in the Synlight. Image: DLR/Markus Hauschild.

Hydrogen is the most abundant element in the Universe. But here on Earth, it’s rather rare. That’s unfortunate, because in our warming world, its status as an emissions-free fuel makes it a coveted chemical. If German researchers are successful, their Synlight project will help make renewable hydrogen fuel a reality.

Dubbed the “artificial Sun”, the Synlight uses concentrated light to power Thermochemical Water Splitting (TWS.) Every school child knows you can produce hydrogen by electrolysis—running an electric current through water. But that takes an enormous amount of electricity. TWS might be a better way of getting hydrogen out of water, but it takes an enormous amount of energy too, and that’s what the German research is about.

When combusted with pure oxygen—inside a fuel cell for example—hydrogen’s only waste product is water. No greenhouse gases or particulates are produced. But if we want to use it to power our cars, buses, trucks, and even airplanes, we need enormous amounts of it. And we need to produce it cost-effectively.

“Renewable energies will be the mainstay of global power supply in the future.” – Karsten Lemmer DLR Executive Board Member

The idea is to use the heat generated by Concentrated Solar Power (CSP) to extract hydrogen from water, thereby eliminating the need for electricity. CSP systems use mirrors or lenses to concentrate a large area of sunlight into a small area. The heat from that action can be used to power TWS. The Synlight project in Germany is demonstrating the viability of TWS by mimicking the effect of concentrated sunlight. In doing so, researchers there are building what’s being called the world’s largest artificial Sun.

Each of Synlight’s 149 zenon short-arc lamps can be controlled individually. Image: DLR/Synlight/Markus Hauschild

German researchers at the German Aerospace Center (DLR) at Julich near Cologne built the Synlight, a system of 149, high power lamps of the type used in film projections. When all these lamps are turned on, Synlight produces light that is about 10,000 times more intense than natural sunlight on Earth. When all the lamps are aimed at a single spot, Synlight generates temperatures up to 3000 Celsius. The challenge now is to develop materials and processes that can operate in such an extreme temperature.

The 15m tall Synlight experiment is housed in this building in Julich. The building contains 3 separate radiation chambers for different experiments. Image: DLR CC By 3.0

The Synlight system itself uses an enormous amount of electrical power to operate. But that’s often the case with experimental facilities. The Synlight project will mimic the effect of intense, continuous solar energy, something that is not readily available in Germany. By building a test facility powered by electricity, researchers will be able to reliably perform experiments without being delayed or affected by cloudy weather.

“Fuels, propellants and combustibles acquired using solar power offer immense potential for long-term storage and the production of chemical raw materials, and the reduction of carbon dioxide emissions. Synlight will enhance our research in this field.” – Karsten Lemmer, DLR Executive Board Member

As Johannes Remmel, the North Rhine-Westphalia Minister for Climate Protection, said, “”We need to expand existing technology in practical ways in order to achieve renewable energy targets, but the energy transition will falter without investments in innovative research, in state-of-the-art technologies and in global lighthouse projects like Synlight.”

The DLR is involved in the PS10 solar power tower in Spain. The PS10 is the world’s fist commercial concentrating solar power tower. Image: By afloresm – SOLUCAR PS10, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=2821733

This is not the German Aerospace Center’s first foray in concentrated solar power. They’re involved in a number of projects to advance concentrated solar power and thermal water splitting. The DLR is a partner in the Hydrosol II pilot in Spain. It’s a reactor for solar thermochemical hydrogen production that has been in operation since 2008. They’re also involved in the first commercially operated solar tower plant, an 11 megawatt system in Spain called the PS10 solar power tower.

December 10, 2016December 15, 2016 by Matt Williams

Showcasing the Benefits of NASA Technology Here on Earth

Every year, NASA showcases how the technology it develops for exploring space and studying other worlds has applications here on planet Earth. It’s what known as Spinoff, an annual publication that NASA’s Technology Transfer Program has been putting out since 1976. Since that time, they have showcased over 2000 examples where NASA technology was used for the sake of creating products that had wide-ranging benefits.

For Spinoff 2017, NASA selected 50 different companies that are using NASA technology – which included innovations developed by NASA, those made with the help of NASA funding, or those produced under contract with the agency. With examples ranging from GPS and satellite imaging, to light detection and ranging (Lidar) and biomedical devices, the list of commercial applications for this year is quite impressive!

For over 50 years, the NASA Technology Transfer Program has share NASA resources with private industries, a process which is colloquially referred to as “spin-offs”. In finding the widest possible applications for NASA technology and leveraging partnerships and licensing agreements with industry, they ensure that the large investments made in space exploration find additional uses that benefit humanity here on Earth.

*Spinoff is an annual publication exploring the many applications NASA technology has. Credit: NASA*

In the past, spin-offs have included memory foam, freeze-dried food, emergency thermal blankets, Dustbusters, cochlear implants, and numerous other application that have benefited the computer, medical, transportation, manufacturing and safety industries – thought not Velcro or Tang (contrary to popular conception). As Dan Lockney, the executive of NASA’s Technology Transfer program, told Universe Today via email:

“Spinoff is NASA’s annual publication featuring technologies that have left NASA’s launchpads and laboratories and moved into the public sector. We’ve published Spinoff each year since 1976, featuring about 50 of the best examples of commercialized NASA technologies each year. These range from consumer goods to public safety and medical equipment to advances in round and aire transportation.

“These commercialized technologies are often a direct outcome of the work that NASA’s Technology Transfer Program conducts. Our Tech Transfer Program works to get the technolgoes developed for NASA missions out to industry so that they can have second lives as new products and services.”

This year’s spinoffs were certainly numerous, but some are particularly worthy of mention. For instance, there is the metal oxide semiconductor (CMOS) image sensor that was developed by NASA’s Jet Propulsion Laboratory. Since its creation, it has become one of NASA’s most ubiquitous technologies, leading to the development of DSLR cameras, camera phones, and digital cameras that are available on every handheld device on the market.

And then there’s the GPS technology NASA began developing back in the 1990s, which included software capable of correcting for GPS signal errors and enabling incredible accuracy. John Deere recently acquired this technology and used it to develop a popular class of self-driving farm tractors. Today, as much as 70% of North American farmland is cultivated by self-driving tractors that rely on this technology.

Aerial photograph of a forest in Connecticut (left), and bare-earth lidar image beneath the overgrown vegetation (right) showing the remnants of stone walls, building foundations, abandoned roads and what was once cleared farm land. Credits: NASA/Katharine Johnson

And then there is the spinoff involving NASA-developed laser imaging and ranging technology (Lidar). This technology allowed the Pheonix Lander to detect snow falling from the skies of Mars, and will be used to OSIRIS-REx mission to land on an asteroid in the coming decade. And recently, this same technology was used by a team of archaeologists to map prehistoric sites in North America where hunter-gatherers hunted bison en masse.

In addition, “Robotics Spinoffs” get a special mention in this year’s report, with homage being paid to missions like Curiosity and Juno (which have explored the surfaces and atmospheres of other planets) and space-based observatories like Spitzer, Chandra and Hubble – which have looked deep into the cosmic field. The technologies used by these missions has also had an impact in virtually every sector of the world’s economy.

The publication also includes a section called “Spinoffs of Tomorrow“, which highlights 20 technologies that are especially well-suited for commercial adaptation. These include thin-film piezoelectric and composite materials that could be used in wind turbines to generate more electricity and improve electrode durability, as well as in personal devices to generate power from mere movement.

There’s also the new Armstrong wing design that lower drags, which could make airplanes and wind turbines more efficient. The Glenn Research Center is also cited for their development of a suite of materials and methods that optimize the performance of nanomaterials by making them tougher, more resistant, and easier to process. This could be used to build super-resilient fabrics and consumer products.

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL — NASA’s Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

Then there’s an underwater vehicle developed by JPL that uses thermally-generated changes in buoyancy to generate electricity and recharge its batteries. This technology, which enables submarines to remain underwater for years at a time, could lead to the creation of nearly self-sufficient undersea drones – something that has applications in everything from sea exploration to pipeline monitoring.

The section also makes mention of an easy-to-use device that separates DNA, RNA, and proteins outside a traditional lab environment. Originally intended for use aboard the ISS, this device could be a boon for developing nations where medical infrastructure may be limited. And there’s also a system that autonomously detects faulty wiring and reroutes around it.

As always, the development of cutting-edge technologies can have applications that go far beyond the purpose for which they were originally intended. Whether it is robotic landers or probes, miniaturized cameras, improved electronics, or advanced materials, commercial industries here on Earth have always benefited from the research, development and exploration efforts of the space industry.

And as our efforts to send astronauts to Mars, return to the Moon, and explore the outer Solar System andbeyond continue, who knows what commercial applications will emerge as a result? And in the meantime, be sure to enjoy this video which explains how NASA technology is licensed through the TTP:

Further Reading: NASA

December 6, 2016December 7, 2016 by Ken Kremer

Advanced USAF Tactical Satcom Set for Stunning Dec. 7 Nighttime Blastoff- Watch Live

ULA Delta IV rocket poised for blastoff with the WGS-7 mission for the U.S. Air Force from Cape Canaveral Air Force Station, Fl, on July 23, 2015. Credit: Ken Kremer/kenkremer.com

CAPE CANAVERAL AIR FORCE STATION, FL – Less than 24 hours from now the evening skies along the Florida Space Coast will light up with a spectacular burst of fire and fury as a Delta rocket roars to space with a super advanced tactical satcom for the U.S. Air Force that will provide a huge increase in communications bandwidth for American forces around the globe.

Blastoff of the Wideband Global SATCOM (WGS-8) mission for the U.S. Air Force is slated for 6:53 p.m. EST on Wednesday, Dec. 7, 2016 from Space Launch Complex-37 at Cape Canaveral Air Force Station, Florida.

WGS-8 will be delivered to a supersynchronous transfer orbit atop a United Launch Alliance Delta IV Medium+ rocket. The launch window runs for 49 minutes from 6:53-7:42 p.m. EST.

You can watch the Delta launch live on a ULA webcast. The live launch broadcast will begin at 6:33 p.m. EST here:

http://www.ulalaunch.com/webcast.aspx

The weather forecast for Wednesday Dec. 6, calls for an 80 percent chance of acceptable weather conditions at launch time.

In case of a scrub for any reason the chances for a favorable launch drop slightly to 60% GO.

WGS-8 is the first in a newly upgraded series of a trio of WGS satellites built by Boeing.

The major upgrade is inclusion of the Wideband Digital Channelizer, awarded to Boeing in June 2012.

The Wideband Digital Channelizer will provide a 90 percent improvement in satellite bandwidth for US forces.

It is also the only military satellite communications system that can support simultaneous X and Ka band communications.

WGS-8 can instantaneously filter and downlink up to 8.088 GHz of bandwidth compared to 4.410 GHz for the earlier Block I and II satellite series.

The prior Wideband Global SATCOM-7 (WGS-7) communications satellite was launched on July 23, 2015 from Space Launch Complex-37.

A United Launch Alliance (ULA) Delta IV rocket carrying the WGS-7 mission for the U.S. Air Force launches from Cape Canaveral Air Force Station, Fl, on July 23, 2015. Credit: Ken Kremer/kenkremer.com

The Wideband Global SATCOM system provides “anytime, anywhere communication” for allied military forces “through broadcast, multicast and point to point connections,” according to ULA.

The $426 million WGS 8 satellite is part of a significant upgraded constellation of high capacity communications satellites providing enhanced communications capabilities to American and allied troops in the field for the coming two decades.

“WGS provides essential communications services, allowing Combatant Commanders to exert command and control of their tactical forces, from peace time to military operations.”

WGS-8 is the eighth in a series of high capacity communication satellites that will broaden tactical communications for U.S. and allied forces at both a significantly higher capacity and lower cost.

“WGS satellites are important elements of a high-capacity satellite communications system providing enhanced communications capabilities to America’s troops in the field for the next decade and beyond,” according to a ULA factsheet.

“WGS enables more robust and flexible execution of Command and Control, Communications Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), as well as battle management and combat support information functions. The WGS constellation augments the existing service available through the UHF Follow-on satellite by providing enhanced information broadcast capabilities.”

The 217 foot tall Delta IV Medium+ rocket will launch in the 5,4 configuration with a 5 meter diameter payload fairing and 4 solid rocket boosters to augment the first stage.

The is the sixth flight in the Medium+ (5,4) configuration; all of which were for prior WGS missions.

WGS-8 logo

WGS-8 also counts as the first of three launches from the Cape this December. A Pegasus XL rocket will launch on Dec. 12 carrying NASA’s CGYNSS hurricane monitoring satellites. And an Atlas V will launch on Dec. 12 with the EchoStar 23 comsat.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

November 11, 2016 by Evan Gough

Princeton Team Directly Observes Planets Around Nearby Stars

The Subaru Telescope atop Mauna Kea. CHARIS works in conjunction with Subaru. Image: Dr. Hideaki Fujiwara - Subaru Telescope, NAOJ.

The revelation that there are thousands of planets out there, orbiting other stars, is mostly due to the success of the Kepler mission. But now that we know these exoplanets are there, we want to know all about them. We want to know their mass, their temperature, how old they are, and pretty much everything else about them.

Now, a new instrument called the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) has captured the light from one of those exoplanets. This has the researchers excited about what they can see.

“We couldn’t have been more pleased by the results.” – N. Jeremy Kasdin

CHARIS allows astronomers to isolate light reflecting from planets. That’s difficult to do, since they are so much dimmer than the stars they orbit. CHARIS is able to isolate the reflective light from planets larger than Jupiter. Then astronomers can analyze that light to learn about the planet’s age, atmospheric composition, and its size.

“By analyzing the spectrum of a planet, we can really understand a lot about the planet. You can see specific features that can allow you to understand the mass, the temperature, the age of the planet.” – team member Tyler Groff

This image from the CHARIS instrument shows planets located around a star in the planetary system HR8799. Image: N. Jeremy Kasdin and team.

CHARIS was designed and built by a team led by N. Jeremy Kasdin, a professor of mechanical and aerospace engineering at Princeton University. It took them five years to build CHARIS.

The spectrograph sits inside a 500 lb case that measures 30x30x12. Inside that case, it’s kept at -223.15 Celsius (50 Kelvin, -369 F.) The CHARIS instrument has nine mirrors, five filters, two prism assemblies and a microlens array. The microlens array is a special optical device with an array of tiny lenses etched into its surface.

During a CHARIS field test, researchers captured images of celestial objects, including vapor clouds moving across a section of the planet Neptune. (Images courtesy of N. Jeremy Kasdin and the research team)

CHARIS works in conjunction with the Subaru Telescope in Hawaii. It’s part of a long-time collaboration between Princeton, the University of Tokyo and the National Astronomical Observatory of Japan, which operates the Subaru Telescope at Mauna Kea, Hawaii. And these first results are generating a lot of interest.

According to Tyler Groff, a team member from Princeton who now works for NASA, the preliminary result from CHARIS have generated a lot of interest from the astronomy community. The CHARIS team is now reviewing research proposals.

“There is a lot of excitement,” Groff said. “Charis is going to open for science in February to everyone.”

CHARIS is designed to capture the light from distant exoplanets, so its field of view is tiny. It’s only 2 arc-seconds, which is a tiny patch of sky. For reference, the full Moon is about 1,800 arc-seconds. But it can take images across a wide band of light wavelengths. The fact that it captures such a wide band of light is what allows such detailed analysis of anything it’s pointed at.

“We tested CHARIS on Neptune, but the entire planet doesn’t even fit on our detector.” -Tyler Groff

CHARIS is located behind a coronagraph. The coronagraph channels light from the Subaru Telescope and divides the light coming directly from a star from the light that is reflecting off planets orbiting that star. The team says it’s like picking out the light reflecting from a speck of tinsel floating in front of a spotlight that’s hundreds of miles away.

November 10, 2016November 21, 2016 by Matt Williams

Was Physics Really Violated By EM Drive In “Leaked” NASA Paper?

A model of the EmDrive, by NASA/Eagleworks. Credit: NASA Spaceflight Forum/emdrive.com

Ever since NASA announced that they had created a prototype of the controversial Radio Frequency Resonant Cavity Thruster (aka. the EM Drive), any and all reported results have been the subject of controversy. And with most of the announcements taking the form of “leaks” and rumors, all reported developments have been naturally treated with skepticism.

And yet, the reports keep coming. The latest alleged results come from the Eagleworks Laboratories at the Johnson Space Center, where a “leaked” report revealed that the controversial drive is capable of generating thrust in a vacuum. Much like the critical peer-review process, whether or not the engine can pass muster in space has been a lingering issue for some time.

Given the advantages of the EM Drive, it is understandable that people want to see it work. Theoretically, these include the ability to generate enough thrust to fly to the Moon in just four hours, to Mars in 70 days, and to Pluto in 18 months, and the ability to do it all without the need for propellant. Unfortunately, the drive system is based on principles that violate the Conservation of Momentum law.

Aerial Photography of Johnson Space Center site and facilities. Credit: NASA/James Blair — *Aerial photograph of NASA’s Johnson Space Center, where the Eagleworks Laboratory is located. Credit: NASA/James Blair*

This law states that within a system, the amount of momentum remains constant and is neither created nor destroyed, but only changes through the action of forces. Since the EM Drive involves electromagnetic microwave cavities converting electrical energy directly into thrust, it has no reaction mass. It is therefore “impossible”, as far as conventional physics go.

The report, titled “Measurement of Impulsive Thrust from a Closed Radio Frequency Cavity in Vacuum“, was apparently leaked in early November. It’s lead author is predictably Harold White, the Advanced Propulsion Team Lead for the NASA Engineering Directorate and the Principal Investigator for NASA’s Eagleworks lab.

As he and his colleagues (allegedly) report in the paper, they completed an impulsive thrust test on a “tapered RF test article”. This consisted of a forward and reverse thrust phase, a low thrust pendulum, and three thrust tests at power levels of 40, 60 and 80 watts. As they stated in the report:

“It is shown here that a dielectrically loaded tapered RF test article excited in the TM212 mode at 1,937 MHz is capable of consistently generating force at a thrust level of 1.2 ± 0.1 mN/kW with the force directed to the narrow end under vacuum conditions.”

Ionic propulsion is currently the slowest, but fmost fuel-efficient, form of space travel. Credit: NASA/JPL — *Ionic propulsion is currently the slowest, but most fuel-efficient, form of space travel. Credit: NASA/JPL*

To be clear, this level of thrust to power – 1.2. millinewtons per kilowatt – is quite insignificant. In fact, the paper goes on to place these results in context, comparing them to ion thrusters and laser sail proposals:

“The current state of the art thrust to power for a Hall thruster is on the order of 60 mN/kW. This is an order of magnitude higher than the test article evaluated during the course of this vacuum campaign… The 1.2 mN/kW performance parameter is two orders of magnitude higher than other forms of ‘zero propellant’ propulsion such as light sails, laser propulsion and photon rockets having thrust to power levels in the 3.33-6.67 [micronewton]/kW (or 0.0033 – 0.0067 mN/kW) range.”

Currently, ion engines are considered the most fuel-efficient form of propulsion. However, they are notoriously slow compared to conventional, solid-propellant thrusters. To offer some perspective, NASA’s Dawn mission relied on a xenon-ion engine that had a thrust to power generation of 90 millinewtons per kilowatt. Using this technology, it took the probe almost four years to travel from Earth to the asteroid Vesta.

The concept of direct-energy (aka. laser sails), by contrast, requires very little thrust since it involves wafer-sized craft – tiny probes which weight about a gram and carry all their instruments they need in the form of chips. This concept is currently being explored for the sake of making the journey to neighboring planets and star systems within our own lifetimes.

Two good examples are the NASA-funded DEEP-IN interstellar concept that is being developed at UCSB, which attempts to use lasers to power a craft up to 0.25 the speed of light. Meanwhile, Project Starshot (part of Breakthrough Initiatives) is developing a craft which they claim will reach speeds of 20% the speed of light, and thus be able to make the trip to Alpha Centauri in 20 years.

Compared to these proposals, the EM Drive can still boast the fact that it does not require any propellant or an external power source. But based on these test results, the amount of power that would be needed to generate a significant amount of thrust would make it impractical. However, one should keep in mind that this low power test was designed to see if any thrust detected could be attributed to anomalies (none of which were detected).

The report also acknowledges that further testing will be necessary to rule out other possible causes, such as center of gravity (CG) shifts and thermal expansion. And if outside causes can again be ruled out, future tests will no doubt attempt to maximize performance to see just how much thrust the EM Drive is capable of generating.

But of course, this is all assuming that the “leaked” paper is genuine. Until NASA can confirm that these results are indeed real, the EM Drive will be stuck in controversy limbo. And while we’re waiting, check out this descriptive video by astronomer Scott Manley from the Armagh Observatory:

Further Reading: Science Alert

October 28, 2016October 26, 2019 by Bob King

The Search Is On For Alien Signals Around Tabby’s Star

There’s a remote chance that inexplicable light variations in a star in the Northern Cross may be caused by the works of an alien civilization.

1,480 light years from Earth twinkles one of the greatest mysteries of recent times. There in the constellation Cygnus the Swan, you’ll find a dim, ordinary-looking point of light with an innocent sounding name — Tabby’s Star. Named for Louisiana State University astronomer Tabetha Boyajian, who was the lead author on a paper about its behavior, this star has so confounded astronomers with its unpredictable ups and downs in its brightness, they’ve gone to war on the object, drilling down on it with everything from the Hubble to the monster 393.7-inch (10-meter) Keck Telescope in Hawaii. Continue reading “The Search Is On For Alien Signals Around Tabby’s Star”

October 21, 2016October 22, 2016 by Matt Williams

MIT Claims they are Programming Humanoid Robots to help Explore Mars. But we all Know It’s Cylons!

NASA's R5 "Valkyrie" robot may become a regular part of future crewed missions to Mars and beyond. Credit: NASA/B. Stafford/J. Blair/R. Geeseman

For over a decade, robots have been exploring Mars in advance of the crewed missions that are being planned for the coming decades. And when it comes time for astronauts to set foot on the Red Planet, they will be looking for robots to help them with some of the legwork. After all, exploring Mars is tough, laborious, and dangerous work, so some robotic assistance will probably be necessary.

For this reason, back in November of 2015, NASA gave the Massachusetts Institute of Technology one of their R5 “Valkyrie” humanoid robots. Since that time, MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) has been developing special algorithms that will allow these robots to help out during future missions to Mars and beyond.

These efforts are being led Professor Russ Tedrake, an electrical engineer and computer programmer who helped program the Atlas robot to take part in the 2015 DARPA Robotics Challenge. Together with members of an advanced independent research group – known as the Super Undergraduate Research Opportunities Program (SuperUROP) – he is getting this R5 robot ready for NASA’s Space Robotics Challenge.

The DARPA Robotics Challenge (DRC) sought to inspire the creation of robots that could perform human tasks, in that case, for the sake of disaster relief. Credit: DARPA — *The DARPA Robotics Challenge (DRC) sought to inspire the creation of robots that could perform human tasks; in that case, for the sake of disaster relief. Credit: DARPA*

As part of NASA’s Centennial Challenges Program, and with a prize purse of $1 million, this competition aims to push the boundaries of what robots are capable of in the realm of space exploration. In addition to MIT, Northeastern University and the University of Edinburgh have been tasked with programming an R5 to complete tasks normally handled by astronauts.

Ultimately, the robots will be tested in a simulated environment and judged based on their ability to complete three tasks. These include aligning a communications array, repairing a broken solar array, and identifying and repairing a habitat leak. There will also be a qualifying round where teams will be tasked with demonstrating autonomous tracking abilities (which will have to be completed in order to move towards the main round).

Naturally, this presents quite a few challenges. NASA designed the R5 robot to be capable of performing human tasks and move like a human being as much as possible, which necessitated a body with 28 torque-controlled joints. However, getting those joints to work together to perform mission-related work and operate independently is a bit of a challenge.

In short, the robot is not like other robotic missions – such as the Opportunity or Curiosity rovers. Instead of having a human being pushing levers to get them to move about and collect samples, the R5 will be tasked with things like opening airlock hatches, attaching and removing power cables, repairing equipment, and retrieving samples all on its own. And of course, if it takes a spill and falls down, it will have to be able to get up on its own.

NASA's Space Robotics Challenge seeks to foster the development of robots that can help human astronauts during future missions, like to Mars. Credit: NASA — *NASA’s Space Robotics Challenge seeks to foster the development of robots that can help human astronauts during future missions, like to Mars. Credit: NASA/STMD*

With the help of the special algorithms being generated by Tedrake and his colleagues – as well as other teams competing in this challenge – robots could play an important role in future missions. This could involve robots selecting landing sites for astronaut crews, setting up habitats in advance of crews arriving, and even conducting preliminary research on celestial bodies.

In addition, robots could take the place of crews on long-distance missions (such as Europa). Instead of sending a crew that would require months of food and supplies, a robot crew could be dispatched to the Jovian moon to collect ice samples, explore the surface, and interface with drones being sent to explore the interior ocean. And if the mission failed, there would be no grieving families (just grieving robotics teams).

And now to address the elephant in the room. The idea of sending robot explorers on space missions to help astronauts (or even replace them) is sure to make some people out there nervous. But for those who fear that this might bring one step closer to a robot revolution, rest assured that the machines are nowhere near where they’d need to be to go all “Judgement Day” on us just yet.

Long before they can launch nuclear weapons, pick up laser guns and stalk us through a post-apocalyptic landscape, or start upgrading themselves to look (and feel) human, robots will first need to master the simple tasks of walking upright and holding a screwdriver.

Still, if any of the robots end up having creepy red visor eyes (or saying things like “by your command”), we might want to consider including the Three Laws of Robotics in their programming. It’s never too soon to make sure they can’t turn on humanity!

Registration for the Space Robotics Challenge opened in August, 2016. The qualifying round, which began in mid-October, will run until mid-December. Finalists of that round will be announced in January, with the final virtual competition taking place in June 2017. The winning team will be awarded $500,000 over a two year period from NASA’s Space Technology Mission Directive.

Further Reading: MIT, NASA

October 19, 2016 by Matt Williams

Forget Mars, Now You Can Kickstart an Antimatter Propulsion System to Another Star!

Artist's concept of Antimatter propulsion system. Credit: NASA/MFSC

When it comes to the future of space exploration, one of the biggest questions is, “how and when will we travel to the nearest star?” And while space agencies have been pondering this question and coming up with proposals for decades, none of them have advanced beyond the theory stage. For the most part, their efforts has been focused on possible missions to Mars and the outer Solar System.

But there are some people, like Dr. Gerald Jackson, who are working towards making an interstellar mission possible in the near future. He and his research team, which have been funded by NASA in the past, are looking to create an antimatter engine that will be capable of reaching (or exceeding) 5% the speed of light. Towards this end, they have launched a Kickstarter campaign to fund their efforts.

As advanced propulsion concepts go, antimatter has quite a lot going for it. As propulsion goes, it has the highest specific energy of any known method, 100 times more than fission/fusion reactions, and 10 billion times more than chemical propellants. It is also the most fuel-efficient, requiring mere milligrams of antimatter to produce the same amount of energy as tons of chemical fuel.

Typically, this theoretical concept relies on the collision between hydrogen and antihydrogen (which have the same mass but opposite charge) to generate thrust. This process unleashes energy and a shower of particles (pions and muons), which can be channeled by a magnetic nozzle to generate thrust.

And while laboratories like CERN have been producing antimatter, and research is being conducted on large-scale storage, no propulsion systems exist that could turn antimatter into thrust. Dr. Jackson, a graduate of Cornell University, is hoping to change that. Before entering the private sector, Jackson worked as an accelerator physicist at the Fermi National Accelerator Laboratory for 14 years.

In 2002, he co-founded a limited-liability company (HBar Technologies) for the sake of developing commercial markets for antimatter. In 2002, NASA’s Institute for Advanced Concepts (NIAC) awarded Dr. Jackson and his company $75,000 to develop a mission concept that could traverse 250 AUs of space within 10 years time, and with a fuel supply of 10 kg.

These specifications essentially called for the creation of an antimatter rocket that could travel as far as the heliopause within a decade’s time. The result was a propulsion concept that relied on a beam that would fire focused antiprotons onto a sail to generate propulsion. This sail would measure 5 meters in diameter and be composed of a carbon backing on one side and uranium foil on the other (measuring 15 and 296 microns thick, respectively).

The solar system and its nearby galactic neighborhood are illustrated here on a logarithmic scale extending (from < 1 to) 1 million Astornomical Units (AU). Credit: NASA/JPL — *Illustration of the solar system and its nearby galactic neighborhood on a logarithmic scale extending (from < 1 to) 1 million AU. Credit: NASA/JPL*

When a pulse of antiprotons is annihilated against a small section of the uranium side, the resulting fission causes momentum. As Dr. Jackson explained to Universe Today via email:

“Note that antiprotons have a negative electrical charge, similar to an electron. When the antiprotons enter the sail, they displace an electron orbiting an uranium nucleus. Because antiprotons and electrons do not share any quantum numbers, the antiproton immediately cascades down into the atomic ground state, causing a high probability of interaction between the antiproton and either a proton or neutron within the nucleus.

“On average, a fission event results in the creation of two daughter nuclei of roughly equal mass. These daughters travel in opposite directions with a kinetic energy of 1 MeV per proton or neutron. Because the daughters are charged, the one travelling further into the sail is absorbed and transfers is forward momentum. The other daughter flies into space with an exhaust velocity of 4.6% of lightspeed. This selective transfer of momentum is thrust.”

Unfortunately, due to the budget environment of the time, the NIAC was forced to cancel its funding after a second round had been granted. Because of this, Dr. Jackson and his colleagues are now seeking public support so that they may finish their work on the experimental sail and prepare it for exposure to an antiproton beam.

Diagram showing Hbar's concept for a antimatter-driven propulsion system. Credit: antimatterdrive.org — *Diagram showing Hbar’s concept for a antimatter-driven propulsion system. Credit: antimatterdrive.org*

Much like Project Starshot (whom they acknowledge on their campaign page), Jackson and his team are looking to produce an interstellar mission proposal that does not involve shortcuts (i.e. warp drive, wormholes, star gates, etc.). Starshot, as you may recall, calls for a wafer craft and a laser-driven lightsail that would be capable of reaching speeds of up to 20% the speed of light, thus making the journey to Alpha Centauri in 20 years.

In the same vein, a antiproton-driven sail that could reach speeds of 5% the speed of light or more would be capable of making it to Alpha Centauri (or Proxima Centauri) in about 90 years time. All the while, the science behind it would remain within the realm of established physics, being consistent with Newton’s Laws of Motion and Einstein’s Theory of Special Relativity.

“The revolutionary aspect of the antimatter-driven sail is that the antimatter is not the fuel, but rather the spark plug that initiates fission reactions,” said Jackson. “Because the fission reactions can produce thrust without heavy shielding or other structures, the mass of the propulsion system can be comparable to the mass of the instrument package.”

Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity's first interstellar voyage. Credit: breakthroughinitiatives.org — *Project Starshot, an initiative sponsored by the Breakthrough Foundation, is another concept for making humanity’s first interstellar voyage. Credit: breakthroughinitiatives.org*

To see their project through, Jackson and his colleagues are hoping to raise $200,000. Should they prove successful, they hope to mount follow-up campaigns to finance a series of validation experiments, storage demonstrations, and mission details. In the end, their goal is nothing less than making antimatter propulsion a reality, which they hope will one day lead interstellar mission.

“We expect that these campaigns will provide the data needed to convince people to fund full scale antimatter production and an actual mission to a nearby solar system,” Jackson added. “The goal of those early interstellar missions is to provide information about these other solar systems, such as whether they are habitable or inhabited. If the latter, we will want to study or interact with those life forms in follow-on missions. If habitable and not inhabited, we need sufficient information to assure the success of a manned migratory mission.”

As of the penning of this article, Jackson and his colleagues have raised $672 of their $200,000 goal. However, the campaign launched only a few days ago and will remain open for another 25 days. For those interesting in following their progress, or have an interest in donating to their cause, check out the links below.

Further Reading: Kickstarter, Antima:tterDrive