A Failed Strut Caused the SpaceX Rocket Explosion

Stages of a SpaceX Falcon 9 rocket being assembled.

As reported by The Verge: The SpaceX explosion on June 28th was caused by a failed strut in the rocket's upper stage liquid oxygen tank, SpaceX chief executive officer Elon Musk said today. The strut was one of several hundred used to hold together the helium pressure vessels in the tank, which help to pressurize and maintain the buoyancy of the rocket. According to Musk, the strut was designed to handle 10,000 pounds of force, but failed at just 2,000 pounds of force.

"THIS IS THE BEST OF WHAT WE KNOW THUS FAR."

"This is the best of what we know thus far," said Musk during a press conference. "We emphasize this is an initial assessment, and further investigation may reveal more over time."

The strut was a steel rod that’s about two feet long and one inch thick. Struts like the one that failed have flown on several previous Falcon 9 flights before. Musk says SpaceX still doesn’t know why the steel rod snapped, but it’s possible that its material was faulty. Musk didn’t name the strut's supplier, but did say it may be that one strut of thousands wasn’t up to code.

When the strut snapped, the helium tanks released a lot of helium into the upper-stage liquid oxygen tank, Musk said. That put too much pressure on the tank and caused it to explode.

The Dragon capsule, filled with supplies for the International Space Station, survived the explosion and continued to communicate data to ground control for a while afterward. If the Dragon had been equipped with different software, the capsule what have been able to deploy its parachutes and save its contents. Future versions of the Dragon cargo capsule will have this capability, Musk said.

"It's the first time we've had a failure in seven years so, to some degree, the company as a whole got a little complacent," said Musk. "Especially with all the successes in a row, I think this is an important lesson and something we'll take with us into the future."

"THIS IS AN IMPORTANT LESSON AND SOMETHING WE'LL TAKE WITH US INTO THE FUTURE."

Nearly a month ago, SpaceX's Falcon 9 disintegrated during its ascent to the International Space Station. SpaceX has a contract with NASA to launch commercial resupply missions to the station; that rocket launch was the seventh of 12 planned missions. The Falcon 9 was carrying 4,000 pounds of supplies, including food and water for the station's crew and a new International Docking Adaptor. The IDA, meant to be mounted on the outside of the station, will allow future US crewed spacecrafts from commercial spaceflight companies to dock with the ISS. SpaceX and Boeing have contracts to ferry astronauts to the ISS beginning in 2017.

At the 2015 ISS Research and Development Conference, Musk described the failure as a "huge blow for SpaceX." Up until the June incident, SpaceX has had an impeccable launch record. This recent rocket loss was the first major failure out of 19 total Falcon 9 launches. As a result of the accident, SpaceX postponed its next scheduled launch of the Falcon 9, which was originally slated for August 9th. The mission, which doesn't have a definitive launch date yet, will carry the National Oceanic and Atmospheric Administration's Jason-3 Earth observation satellite to orbit.

Drones’ Agenda, 5GB of New Wireless Spectrum

As reported by EE Times: As the term UAV (unmanned aerial vehicle) suggests, drones are supposed to fly autonomously. And there’s the rub.

Unresolved questions for regulators and drone manufacturers are: a) how drones, while flying, can maintain a reliable communication link with the ground for “command and control,” and b) if so, what communication spectrum is available.

Panelists on the recent EE Times’ Radio Show on drone talk debated what lies ahead for commercial drones.

Michael Drobac

As currently proposed rules for commercial drones are written (proposed in Feb. by FAA), drones are banned from flying at night and operating beyond line-of-sight. More important, under proposed rules, “drones can’t fly over personnel unrelated to a [drone] project,” noted lobbyist Michael Drobac, executive director of the Small UAV Coalition, during the radio show. In essence, “you are for the most part prohibiting the use of drones for commercial purposes all together,” stressed Drobac.

The irony of the proposed drone regulation is that it permits “no robotization.”

“It’s as if we are putting some sort of manned overlay over what’s supposed to be an unmanned system,” Drobac summed up.

The chief concern that emerged during the drone debate is the communication link between drone and pilot. The key question is whether drones need a dedicated communication spectrum, or if Wi-Fi and cellular communication links suffice.

5GHz for dedicated drone communication
The drone industry will be getting two bands they can use for dedicated communication.

Jim Williams

The World Radio Conference, which takes place every four years, has already approved — in 2012 — “a spectrum around 5GHz” for command and control of UAVs, explained Jim Williams, ex-FAA chief. 

This is a vacant band originally set aside for “microwave landing systems.” It’s designed as an all-weather, precision landing system for aircraft. This spectrum has since been made obsolete by the wide availability of GPS, he said. Hence, it’s unused.

There is also “a small chunk of L-band around 1GHz” – originally set aside for aircraft to see ships at sea — now approved for dedicated drone communication, he added.

During the radio show, Williams acknowledged that a handful drones today are permitted to fly in the United States beyond line of sight and over people. But one of the requirements is that they have “reliable communication between a pilot and an aircraft.”

Those drones with permission to fly beyond line of sight, for example, depend on relatively unregulated public frequencies used by Wi-Fi and mobile phones. Williams noted, “But those [frequencies] are set up in such a way that is not tremendously reliable, since when a lot of people are using it, your range drops.” In some incidents, drones flew away when signals got jammed, he added.

Although drones are getting smarter and are dealing with [such potential problems], Williams insisted, “Reliable communication is a key for the [drone] industry.” For that, the world is moving toward allowing drones to use a dedicated spectrum – within 5GHz – for their communications.

Yannick Levy

Asked about the reliability of Wi-Fi and cellular networks as communication links, Yannick Levy, vice president, corporate business development at Parrot, said, “As a drone maker, I’d like to say that both Wi-Fi and cellular networks are good networks, developed by professionals. They have redundancy in place.” But he acknowledged that The French Civil Aviation Authority (Direction générale de l'aviation civile, DGAC) doesn’t allow commercial drones to use cellular networks, either. “They want a special network dedicated to drone flight.”

What about Delair-Tech, the French drone company known as the first civilian UAV in the world approved by an official government agency to fly beyond visual line-of-sight?  Delair-Tech’s drones use 3G for communication.

Levy said Delair-Tech is one of the French drone companies who exempted to fly beyond visual line of sight, with their drones having a cellular modem onboard. “Their intent is trying to demonstrate that it works.”

Who will manage the spectrum?
Although the FCC recently changed the U.S. table of allocation – issuing rules about what can and can’t be done to various portions of spectrum, drones can’t yet begin to transmit signals on those bands.

According to Williams, “channelization schemes” need to be worked out, which are essentially rules about how much power you can transmit, what center frequency you have to use and what out-of-band power you can tolerate, etc.

The Radio Technical Commission for Aeronautics (RTCA) is working to establish such rules. They’re due next summer. The regulatory process will start afrer that's done, said Williams.

The big question, however, is spectrum management. “Who’s going to… assign those channels to users,” the ex-FAA chief noted. “There really isn’t enough [spectrum] to pass out to all users and take all comers.”

An industry consortium or a government process must be put in place, and that’s when “a non-traditional approach” may be needed, observed Williams. “The traditional approach would take 10 years to get through this, and this is where the industry push is necessary so that they can start taking advantage of the spectrum.”

Compete with Wi-Fi?
As much as a dedicated drone communication spectrum makes sense, the 5GHz spectrum currently can’t be accessed by Wi-Fi chips.

According to Williams, new drone spectrum wouldn’t compete with Wi-Fi, because this is an “unused, clean band.” But Parrot’s Levy pointed noted that this isn’t exactly good news for drone makers like Parrot who thrive on standards components used in smartphones to keep the cost down. If the FAA assigns drones to the newly dedicated spectrum, drones can no longer use widely available, cheap Wi-Fi chips. Ergo, more expensive drones, he said.

During the online chat on the EE Times Radio Show, the ex-FAA drone chief reiterated why the existing cellular infrastructure is hardly ideal for drone communication.

He noted, “There are many problems with using existing cellular infrastructure for controlling drones. The antennas are pointed at the ground not the sky, the technology is not set up for high speeds, some of the spectrum used is prohibited from being transmitted from an airborne transmitter, and the lack of link reliability is also a problem.”

Chad Sweet

Qualcomm’s director of engineering Chad Sweet, countered: “Jim, it turns out, due to free space properties, even with the antennas pointed at the ground the problem is seeing too many towers and not too few.”

Obviously, the lack of cell signal availability worries drone users. Qualcomm’s Sweet said, “As the craft goes higher in rural areas, the coverage gets better.” However, he added, “Existing networks would likely only be a stop-gap. A dedicated network would be needed longer term.”

There are alternative communication methods, but they aren’t great. “A satellite transceiver is too heavy for small UAVs,” Sweet said. He opined that cellular networks might be designed for all sorts of coverage scenarios. “Australia is a great example. They have sites that go for up to 100 miles.”

Sweet concluded. “Cellular technology has been optimized for efficient multiple access over the last 30 years. It also has a nice property of being light weight. Regardless of spectrum chosen, leveraging cellular technology will help quickly deploy UAV to ground communications.”

Can Microwave-Powered Shuttles Make Space Travel Cheaper?

As reported by Engadget: How much does it take to launch a satellite? According to Rocket Lab's Peter Beck "You pretty much have to write a check for a billion dollars." Beck, along with Jeff Bezos andElon Musk are part of a new wave of inventors looking to make this cheaper by developing low cost or reusable rockets for launches. The folks at Escape Dynamics, however, have a very different idea about how to make trips to space economical for people who aren't multi-millionaires. The company claims that it's successfully tested the engine for a reusable spaceplane that, rather than being stuffed to the gills with expensive fuel, would glide into the stratosphere on a wave of microwave energy.

With traditional launch systems, the bulk of the weight and resources goes to filling a tube with explosives. Naturally, that's quite wasteful, so the proposed vehicle would ditch almost all of its on-board power systems. Instead, it would receive energy from a series of ground-based microwave emitters which pump power right into a collector based in the plane's heat shield. That energy would then be used to drive an electromagnetic motor that ignites a small quantity of on-board fuel (hydrogen or helium, for instance) that would be used to get into orbit.

The company claims that the engine running on helium was able to achieve a Specific Impulse (the equivalent of MP/H for a rocket) of 500 seconds. By comparison, Escape Dynamics says that your average chemical rocket tops out at 460, and if the test vehicle had been running hydrogen, that figure could rise to 600 Isp. That could prove to be a big breakthrough for the private spaceflight industry, assuming that these results can be replicated outside of the lab.

As Gizmodo notes, however, the idea is a little bit pie-in-the-sky, since the company would have to build a global network of microwave emitters to keep the craft aloft. Then there's the various environmental and energy considerations that such a system would have to deal with, not to mention the political aspect. Still, if ED can, somehow, create a dirt-cheap reusable spaceplane that'll do away with expensive rockets, we imagine plenty of people would get behind the idea.

A Quasiparticle that Acts Like a Massless Electron Could Change How We Build Electronics

As reported by Spectrum IEEE: After an 85-year hunt, scientists have detected an exotic particle, the “Weyl fermion,” which they suggest could lead to faster and more efficient electronics and to new types of quantum computing.

Electrons, protons, and neutrons belong to a class of particles known as fermions. Unlike the other major class of particles, the bosons, which include photons, fermions can collide with each other—no two fermions can share the same state at the same position at the same time.

Whereas electrons and all the other known fermions have mass, in 1929, mathematician and physicist Hermann Weyl theorized that massless fermions that carry electric charge could exist, so-called Weyl fermions. “Weyl fermions are basic building blocks; you can combine two Weyl fermions to make an electron,” says condensed matter physicist Zahid Hasan at Princeton University.

The fact that Weyl fermions have no mass suggests they could shuffle electric charge along inside electronics far more quickly than electrons can. Another potentially useful quality of Weyl fermions is that they cannot move backward—instead of bouncing away from obstacles, they zip through or around roadblocks. In contrast, electrons can scatter backward when they collide with obstructions, hindering the efficiency of their flow and generating heat.

“Weyl fermions could be used to solve the traffic jams that you get with electrons in electronics—they can move in a much more efficient, ordered way than electrons,” Hasan says. “They could lead to a new type of electronics we call ‘Weyltronics.’”

Electricity in these crystals can move at least twice as fast as it does in graphene and 1,000 times faster than in conventional semiconductors

For decades, physicists thought that subatomic particles called neutrinos were Weyl fermions. However, in 1998, scientists discovered neutrinos do have mass. (Their antimatter equivalent, the antineutrino could be a key technology in ensuring Iran’s compliance in this week’s nuclear deal.)

Now, after 85 years, scientists have finally detected Weyl fermions within large crystals of tantalum monoarsenide. They detailed their findings this week online in the journal Science.

Particles such as the famous Higgs boson are often detected in the aftermath of high-energy particle collisions, but in a study published in June the researchers theorized that Weyl fermions could exist in certain crystals known as “Weyl semimetals,” which can essentially split electrons inside into pairs of Weyl fermions that move in opposite directions, Hasan says.

The researchers noted these Weyl fermions are not freestanding particles. Instead, they are quasiparticles that can only exist within those crystals. In other words, they are electronic activity that behaves as if they were particles in free space. By shining beams of ultraviolet light and X-rays at these crystals, the researchers detected the telltale effects of Weyl fermions on those beams.

“These results are very exciting for me personally, since I've been involved significantly in the theoretical discovery of Weyl semimetals a few years ago,” says physicist Anton Burkov at the University of Waterloo, who did not take part in this research. “It’s very exciting to finally see them discovered experimentally in real materials.”

The way that Weyl fermions are constrained from moving backwards is similar to how electrons behave in exotic materials called topological insulators. Such constraints can help current flow highly efficiently; Hasan says that electricity in these crystals can (theoretically) move at least twice as fast as it does in graphene and 1,000 times faster than in conventional semiconductors, “and the crystals can be improved to do even better.” The upshot could be faster electronics that consume less energy. “Power consumption and associated heating is what currently limits a further increase in processor speed in our computers,” Burkov says.

In addition, Weyl fermions could also lead to new kinds of quantum computers that are more resistant to disruption. Quantum computers rely on states known as superpositions, in which a bit can essentially represent both one and zero at the same time. Superpositions offer the chance to solve previously intractable problems, but they are notoriously prone to collapsing  if they interact with the environment. The fact that Weyl fermions are less prone to interacting with their surroundings could lead to new ways of encoding quantum information, Hasan says.

The researchers are now investigating other materials in which Weyl fermions could exist. “We’ve found a niobium-based material, and a silicon-based crystal,” Hasan says.

Google Blames Careless Humans after First Driverless Car Injury

As reported by The Telegraph: Google has said the first injury involving a driverless car was down to a careless driver slamming into the back of one of its vehicles.

On Thursday, Google revealed that three of its employees, who had been riding in one of its driverless Lexus cars, were taken to hospital with minor whiplash after a car rear-ended it at traffic lights in Mountain View, California, earlier this month.

It was the 14th accident in six years and almost 2 million miles of testing. Chris Urmson, who leads the company's driverless car project, said not a single accident had been caused by Google's cars.

"Our self-driving cars are being hit surprisingly often by other drivers who are distracted and not paying attention to the road. That’s a big motivator for us," he wrote in a blog post. "The most recent collision... is a perfect example.

Urmson released a video showing how the crash appeared to the car, which uses a number of sensors to interpret the environment around it.

Self-driving cars have raised fears that the technology would make mistakes, resulting in injuries or road deaths. However, Urmson said the statistics were starting to show that Google's cars were significantly safer than human drivers.

In the most recent collision, the car had failed to break at traffic lights, and had hit the back of the Google vehicle at 17 miles per hour.

"Other drivers have hit us 14 times since the start of our project in 2009 (including 11 rear-enders), and not once has the self-driving car been the cause of the collision," Urmson wrote.

"so what did you do before self-driving cars?" "we just drove 'em ourselves!" "wow, no one died that way?" "oh no, millions of people died"

— gregory erskine (@cat_beltane) April 15, 2015

"Instead, the clear theme is human error and inattention. We’ll take all this as a signal that we’re starting to compare favorably with human drivers.

"Our self-driving cars can pay attention to hundreds of objects at once, 360 degrees in all directions, and they never get tired, irritable or distracted."

The car in question was a Lexus SUV. Last year, Google said a more compact, bubble-shaped vehicle would hit the roads for testing this year.

GPS Network Marks its 20th Anniversary

As reported by the Denver Post: It's hard to imagine life without GPS technology.

We rely on it daily to navigate cities, schedule flights, receive severe weather warnings and check in on Facebook.

A mere two decades ago, it was not even a thing.

This week marks the 20th anniversary of the Global Positioning System being declared fully operational by the U.S. Air Force.

Since that time — July 17, 1995, to be exact — GPS technology has become commonplace in both military and civilian life.

What few realize is that the worldwide GPS network is a military operation — provided for free — operated right here in Colorado by the 2nd Space Operations Squadron at Schriever Air Force Base in Colorado Springs.

"Since 1995, GPS has been the gold standard for global space-based navigation, providing highly reliable and accurate navigation and timing signals to users around the world," said Air Force Space Command chief Gen. John E. Hyten in a statement.

Space-related projects like GPS contribute about 163,000 jobs to Colorado, making the state first for the amount of private aerospace workers per capita, according to data from the Metro Denver Economic Development Corp.

There are 4 billion GPS-enabled devices worldwide — a number that's expected to double in the next five years — and the global GPS market is estimated to reach more than $26 billion in value by 2016, per the EDC.

This can only help Colorado because geospatial technologies, remote sensing and satellite-based services make up the bulk of the state's space economy to the tune of $6.3 billion in annual revenue, according to the EDC.

On Wednesday, Centennial-based United Launch Alliance added another satellite to the $3.6 billion GPS network with the launch of GPS IIF-10 from Cape Canaveral, Fla.

In fact, every operational GPS mission has been launched by ULA or vehicles from the two companies that make up ULA: Littleton-based Lockheed Martin Space Systems' Atlas rocket or Boeing's Delta rocket.

Gov. John Hickenlooper will declare Friday as "GPS Day" to recognize the myriad contributions of Colorado companies, among them ground control systems from Aurora-based Raytheon and Colorado Springs-based Braxton Technologies, and next-gen GPS technologies, such as the forthcoming GPS-III satellites from Lockheed Martin Space Systems.

If Tesla Designed a Motorcycle: The Tesla Model M Concept

As reported by HiConsumption: Tesla’s four-wheeled offerings have been a huge hit among automotive enthusiasts, so we can only imagine just how nuts fans will go if/when the brand ever reveals a 2-wheeled electric vehicle. Independent designer Jans Slapins shows us what he thinks Elon Musk and company could cook up with this Tesla Model M motorcycle concept.

The London-based designer has done a stellar job with the concept bike, keeping the design aesthetics in line with what we’ve become accustomed to from the California EV producer. The bike is powered by a 204 PS (150kW) electric motor that allows the rider to choose from four different computer controlled modes including Race, Cruise, Standard and Eco. The electric motor is powered by lithium-ion batteries that are installed low on the bike’s frame. The motorcycle features no transmission, offers up a trunk storage space where the fuel tank would normally be (perfect for holding a full face helmet), lightweight carbon fiber wheels, and a mono shock out back along with upside down forks up front for suspension. [Via]