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Aerospace Blog

The Aerospace Blog is the place for conversation and discussion about aeronautics, astronautics, fixed-wing aircraft, future space travel, satellites, NASA, and much more.

Comet Flyby

Posted October 28, 2014 12:00 AM by Chelsey H

On October 19th, a once-in-a-lifetime opportunity presented itself to scientists. Comet Siding Spring, also known as comet C/2013 A1, was discovered last year at the Siding Spring observatory in Australia. It was expected to pass within about 87,000 miles of Mars at a relative velocity of 126,000 mph. The comet gave scientists a chance to study a "pristine remnant" of the 4.6 billion year old Solar System.

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The comet was predicted to pass very close to the Mars surface, about one third the Earth-moon distance! The closest a comet has ever approached Earth in modern records is 16 times greater than the distance of the comet passing Mars. Although it was not bright enough at Earth's distance to be seen by the naked eye, observers in the Southern Hemisphere were able to watch the comet's trajectory pass Mars and on toward perihelion.

Due to the high volume of spacecraft near Mars, there was no shortage of opportunities to see the high-speed flyby. The Hubble Space Telescope, more than a half-dozen other spacecraft, and ground-based telescopes were focused on the show. NASA's MAVEN orbiter arrived on Mars in September and was ready to look for changes in the Martian atmosphere due to interactions with the comet's dust tail. Most of the spacecrafts, though, were not designed for looking at comets and had to be adapted; for example they were not designed for real time data transmission, so it will take the science teams hours to days to receive and process the data before any pictures are unveiled.

Another reason this comet is so exciting is because it originated in the Oort

Cloud, a spherical realm of icy debris left over from the creation of the Sun and planets 4.6 billion years ago. This cloud is located beyond Pluto (side note- anyone else still upset that Pluto isn't a planet anymore?) which means it takes a million plus years to make the trip into the inner Solar System.

Scientists are very excited to review the data and have many questions concerning the comet's size and shape, and how it interacts with the Martian surface.

While we wait for the full report - here is a sneak peek at some of the pictures.

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Partnership to Launch 'New American Rocket Engine'

Posted October 23, 2014 12:00 AM by IHS GlobalSpec eNewsletter

Blue Origin LLC, the aerospace company owned by Amazon.com founder Jeff Bezos, and United Launch Alliance have agreed to work towards a common goal: developing the "next great U.S.-made rocket engine." The liquid oxygen, liquified natural gas BE-4 rocket engine will deliver 550,000 lbs of thrust at sea level, giving it the capacity to pursue national security, as well as civil, human, and commercial missions. Full-scale testing is scheduled for 2016; watch for the first flight in 2019.


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7 comments; last comment on 10/27/2014
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HUSH Loves Airships, Part 3

Posted September 24, 2014 8:32 AM by HUSH

Twice now I've taken to my CR4 soapbox to proclaim, "This is the airship of the future!" The first was back in November 2012; the second was this past March.

Almost certainly, my desire to see new life breathed into an obsolete mode of transportation is heavily nostalgic and novelty. They fascinated me as a kid on the rare occasion I glimpsed one. As an adult, they serve primarily as billboards, but they are also a faint reminder that I once recognized them as something more than that. Blimps and airships were once the truest form of airliner; they melded luxurious accommodation with efficient service and travel. Today, 'airliner' refers to company who charges you per cracker served mid-flight.

So I won't argue that airships are coming back or that they have a bright future. Rather, let's examine how one peculiar type of theoretical airship could push aerospace material science to new heights.

Enter the vacuum airship. This type of aircraft is considered the first concept of a flying machine that, if built, could actually fly. It was devised by the Italian monk Francesco Lana-Terzi in 1686, who was a professor of physics and math. He was inspired by the atmospheric pressure work of Otto von Guericke, developer of the vacuum pump, and utilizing his scientific knowledge he envisioned an airship whose balloons were completely empty.

Lana theorized that he could construct a boat-like vehicle tethered to four evacuated spheres, with a sail and rudder for sailing. The craft would float until the density of the atmosphere counter-balanced the weight of the ship, and it could be landed by letting small amounts of air into the spheres.

There were several reasons Lana never built his airship. He believed God wouldn't let such a device succeed, on account it could grant an insurmountable advantage to armies. He also pledged himself to a life of poverty as a monk, so he could never amount the resources required.

Oh yeah, he also had no clue what to make it out of, and this represents the same problem with vacuum airships today. The vacuum tanks would need to withstand enormous atmospheric pressure once evacuated. While modern materials can overcome this structural load, it can't be done without weighing down the vessel to a non-buoyant density.

Of course, researchers and scientists have had 300 years to solve this problem, right? Yes, but virtually no attention has been paid to this reliable concept. Once Portuguese priest Bartolomeu de Gusmao nearly burned down the royal palace while demonstrating a successful hot air balloon, vacuum-based atmospheric buoyancy lost all interest.

As sustainable engineering and resource management become integral routines, not just chores, many ideas once considered impractical are revisited if they can be efficient. Obviously, blimps need large amounts of helium or hydrogen to remain buoyant, but helium is in low supply and expensive while hydrogen goes boom. But a vacuumed structure would create static lift which can be drawn upon to fly almost anything. And this is 2014, the age of supermaterials--graphene, aerographite, buckminsterfullerene--something has to be able to support this extreme pressure, right? And even if such an invention isn't used for a vacuum airship, it could be practical for thousands of other applications. Entire floating cities could be a reality and flying cars would require minimal energy resources.

So far, the closest we've gotten is a three-layer shell with a low-density core of aluminum honeycomb or ceramic foam that is between two ceramic sheets of boron carbide or silicon carbide. The initial research suggests that thousands of 10 cm or smaller balloons could be constructed and harnessed to deliver lift to a vehicle or platform. While not useful quite yet, there are developments being made. Perhaps the most interesting case is for carbon nanotubes that have buckminsterfullerene caps. If they could be manufactured in a vacuum and produced on a large enough scale, they could provide captured static lift.

Even though vacuum airships were obsolete before they were even realized, they continue to forge presence in the aerospace industry. Just because it wasn't built, doesn't mean potential real engineering solutions are valueless.


6 comments; last comment on 10/05/2014
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Guided Robots to Speed Fuselage Build

Posted September 15, 2014 9:06 PM by IHS GlobalSpec eNewsletter

Boeing intends to improve workplace safety by automating the production of its 777 fuselage. Rather than relying on the manual installation of some 60,000 fasteners, the company wants guided robots to fasten fuselage panels together. The program, under development since 2012, uses a robotic system designed for Boeing by KUKA Systems. It joins other automated manufacturing systems now involved with 777 production, including the wing painting operation shown here.


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1 comments; last comment on 09/17/2014
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The Evolution of Aerspace Design Verification

Posted September 03, 2014 12:00 AM by IHS GlobalSpec eNewsletter

As aerospace systems become more complex, so do the validation and verification processes needed to ensure product integrity. Today's simulation tools plus hardware-in-the-loop (HIL) systems are required to verify code and replicate standard communication bus interfaces, such as ARINC 429 or 1394B. This ability to perform tests without real components keeps costs down. It also helps quality assurance engineers anticipate all potential problems. This report from SAE International explains why there are "no shortcuts for verifying, validating aerospace system designs."


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The Aircraft Manufacturing Revolution Continues

Posted August 26, 2014 12:00 AM by IHS GlobalSpec eNewsletter

The tools necessary for aircraft manufacture have changed rapidly over the past decade. Who could have predicted that the most critical pieces of equipment in the factory - enormous autoclaves for curing very large components - would evolve from their smaller counterparts in medicine and other applications. But, as this article points out, autoclave size, high cost, and power consumption has encouraged the search for alternatives. Microwave curing, for example, can reduce energy consumption 90% and accommodate curing in sections, impossible with an autoclave. The next step? Additive manufacturing (aka 3D printing), at least for small, intricate parts.


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1 comments; last comment on 10/05/2014
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