The Skydiving and Aviation Related Photo Thread! (OT)

Cleared for Mach 2 after departure, this supersonic jet of the future would yaw 90 degrees and put a new set of wings into the wind. The brainchild of Ge-Chen Zha of the University of Miami, the “supersonic, bi-directional flying wing” recently landed a $100,000 NASA grant to continue development of a concept that could cut the New York to Tokyo travel time to four hours—and perhaps significantly faster than that, Zha said.

Zha, who is collaborating with peers from Florida State University on the concept design, said “there’s no limit” to the potential speed the star-shaped airframe could allow, with single-stage to orbit and hypersonic speeds (above Mach 5) well within the realm of possibility. That speed would be delivered with low drag, low fuel consumption, and no sonic boom—the noise of which has stalled previous attempts to create supersonic travel routes over populated areas.

While the concept design is sized as a business jet, Zha said there should be little difficulty scaling it up to airline size.

Zha, who has followed recent difficulties that the U.S. Air Force has had launching a missile to Mach 5, said propulsion and aerodynamic challenges must be overcome, and many of those challenges still are not well-understood. It may take decades to solve some of the problems faced by all hypersonic designs.

Still, Zha said, the bi-directional design “does provide a very promising configuration.” By combining the virtues of two very different wings, the concept sidesteps—literally—one of the major challenges posed by high-speed flight: Wings that provide the lift required for low-speed maneuvering, including takeoff and landing, produce too much drag to be efficient at supersonic speeds. An ideal high-speed wing, on the other hand, would be downright dangerous in the traffic pattern.

Computer models predict the bi-directional aircraft would perform well both at low speeds—taking off and landing from airports—and at high speed. Making the 90-degree rotation that exchanges wings would be a complicated maneuver, controlled by a computer to span the transition over several seconds and make the change barely perceptible to passengers and crew in flight. As engines rotate and control forces transfer to different sets of control surfaces, passengers would feel an acceleration of just 0.2-Gs as the aircraft rotated on its axis, Zha said, noting the concept has been extensively modeled in digital form. Long, thick wings designed for low-speed flight would rotate to the longitudinal axis, and shorter, thinner wings better suited for efficient high-speed flight would provide lift at supersonic speeds—and beyond.

The funding from NASA’s Innovative Advanced Concepts grant program is just enough to begin wind tunnel testing, Zha said. Design refinement and mission analysis will also be paid for with the one-year grant; Zha hopes to secure a Phase II grant from the same NASA program that would bring another $500,000, but that is still a small amount relative to what will be required to build a prototype. Zha said private investment could accelerate the process, and make a certified aircraft available in as little as a decade.

“If we have all the money we need, probably 10 years could be doable,” Zha said.

A more realistic estimate, however, puts this new design in the air in about 20 years, Zha said, noting that the research team is eager to work with private investors interested in speeding things up.

Pilot and author Richard Bach (Jonathan Livingston Seagull) remained in serious condition after his aircraft crashed while he was attempting to land in Washington state, according to media reports. The amphibious aircraft came to rest inverted in a field Aug. 31 after clipping a power line on approach to landing at a grass strip, his son James Bach told The Associated Press.

SCIENTISTS DISCOVER ANCIENT RIVERBED ON MARS

The latest rover mission to Mars, Curiosity, has stumbled upon something quite remarkable. There have been previous findings supporting the theory that liquid water did exist on the red planet at one point in time. But this is the first time that anything quite like this has been found. Curiosity has found what appear to be riverbeds on Mars that are remarkably similar to the ones found on Earth. There is evidence of water erosion as well as river-looking stones cemented into a gravel conglomerate rock. The shape and placement of some of these stones indicates long-distance travel, showing that these rivers were not just there, that they indeed flowed quite freely and were fairly long channels.

Previous research on channels on Mars had hypothesised about the flows that created them. This is the first time researchers have been able to see water-transported gravel on Mars. Rather than speculate about the size of streambed material, scientists can now directly observe it. The riverbed was found between the north rim of Gale Crater and the base of Mount Sharp, an area which was imaged from Mars orbit and therefore allows for further interpretation of the gravel-conglomerate. The imagery from orbit shows that the ancient streambed is part of an alluvial fan. A sedimentary feature made up of, among other things, many channels that have washed material down from the rim. The shape of stones within deposits like this allows geologists to interpret the forming environment. As the stones found are rounded, this indicates long-distance travel from above the rim where a channel named Peace Vallis feeds into the alluvial fan. Read about how alluvial fans form here: http://on.fb.me/QOKhP8. The longer a stone is transported, the more rounded it becomes from abrasion. If the stones were angular shaped, the deposit would be called a breccia and the source would be interpreted to be much closer. There is a range of grain size within the conglomerate, from a grain of sand to a golf ball. Though most of the stones are rounded, some are angular. The size of the stones within the conglomerate shows that they could not have been transported by wind, but must have been transported by water flow.

By looking at the size of the objects that the river was carrying, it is estimated that the water was flowing at just under 1 meter per second, and that this particular ancient river discovered was anywhere between ankle and waist-deep. These discoveries came after investigating two outcrops, given the names "Hottah" and "Link". The Curiosity science team may also decide to examine the chemical compositions of the cement that holds the conglomerate rock together, as well as the stones themselves.

Curiosity’s main destination is the slope of Mount Sharp. Clay and sulphate minerals were detected from orbit; these minerals can be good preservers of carbon-based organic chemicals, which are potential ingredients for life.

The images show the Link outcrop of rocks on Mars (left) compared with similar rocks seen on Earth (right). The image from Mars shows that the gravel fragments within the conglomerate are rounded and up to a few centimetres wide, and highlights a piece of gravel that is about 1 centimetre across. The image from Earth is of a typical sedimentary conglomerate formed of gravel fragments in a stream.