Apple made much ado of the Lightning connector it launched side-by-side with the iPhone 5, but what we’ve known about it has been limited outside of the presence of an authentication chip. Double Helix Cables’ Peter Bradstock has delved deeper and tells AppleInsider that there’s some clever wiring that clinches the reversible design. While Lightning’s power supply is truly symmetrical among the contact pins, the data isn’t — which suggests a chip inside is redirecting data to keep the plug working as intended. The technique helps explain why Apple would need any elaborate circuitry in the first place. No matter the wizardry inside, Bradstock doesn’t see any cut-rate Lightning alternatives being useful in the near future: as it’s unlikely that anyone outside of Cupertino knows how the authentication works at this stage, clone cables may amount to little more than heaps of metal and plastic ~ Jon Fingaz
File photo of Comet Hale-Bopp which wowed observers in 1997. Image: Kazuhiro Seto.
A new comet has been discovered that is predicted to blaze incredibly brilliantly in the skies during late 2013. With a perihelion passage of less than two million kilometres from the Sun on 28 November 2013, current predictions are of an object that will dazzle the eye at up to magnitude —16. That’s far brighter than the full Moon. If predictions hold true then C/2012 S1 will certainly be one of the greatest comets in human history, far outshining the memorable Comet Hale-Bopp of 1997 and very likely to outdo the long-awaited Comet Pan-STARRS (C/2011 L4) which is set to stun in March 2013.
The new comet, named C/2012 S1 (ISON) was found by the International Scientific Optical Network (ISON) in Russia on 21 September when astronomers Vitali Nevski and Artyom Novichonok captured it on CCD images taken through a 0.4-metre reflector. Its near-parabolic orbit suggests that it has arrived fresh from the Oort Cloud, a vast zone of icy objects orbiting the Sun, pristine remnants of the formation of the Solar System.
C/2012 S1 currently resides in the northwestern corner of Cancer. At magnitude +18 it is too dim to be seen visually but it will be within the reach of experienced amateur astronomers with CCD equipment in the coming months as it brightens. It is expected to reach binocular visibility by late summer 2013 and a naked eye object in early November of that year. Northern hemisphere observers are highly favoured. Following its peak brightness in late November it will remain visible without optical aid until mid-January 2014.
Comet brightness predictions sometimes exceed their performance. Amateur astronomers of a certain age may remember the Comet Kohoutek hype of 1973 – not quite the ‘damp squib’ it has been portrayed, since it reached naked eye visibility! Even if C/2012 S1 takes on the same light curve as Kohoutek it is certain to be spectacular, quite possibly a once-in-a-civilisation’s-lifetime event. ~ Peter Grego
Using the lessons of the Apollo era and robotic missions to Mars, NASA scientists and engineers are studying the hazards involved in any extraterrestrial landings. They are seeking ways avoid the rocks and soil visible in the foreground of this image of Buzz Aldrin working at the lunar module during the Apollo 11 moonwalk in July 1969. Photo credit: NASA/Neil Armstrong When the Mars Science Laboratory’s Curiosity rover landed on Aug. 6, it was another step forward in the effort to eventually send humans to the Red Planet. Using the lessons of the Apollo era and robotic missions to Mars, NASA scientists and engineers are studying the challenges and hazards involved in any extraterrestrial landing.
The technology is known as “vertical takeoff-vertical landing.” According to a group working in NASA’s Engineering and Technology Directorate at the Kennedy Space Center in Florida, the best approach requires a landing pad already be in place.
“One of the greatest challenges to Apollo astronauts landing on the moon was dust, rocks and debris obscuring their vision during the final part of the descent,” said Rob Mueller, a senior technologist in Kennedy’s Surface Systems Office and Lunar Destination co-lead for NASA’s Human Spaceflight Architecture Team. “When the Apollo lunar modules reached the 30-meter point (about 100 feet), the dust was like a fog making it difficult to see their landing site. Similarly, photographs show there were some rocks and dust kicked up by the rocket engines on the sky-crane lowering the Curiosity lander onto the Martian surface.”
As the Mars Science Laboratory’s descent stage used rocket engines to hover, its sky crane lowered the Curiosity rover with a 25-foot tether to a soft landing on the surface.
Mueller and others are working on ways to develop landing pads that could be robotically constructed in advance of future human expeditions to destinations such as the moon or Mars. These specially constructed landing sites could greatly reduce the potential for blowing debris and improve safety for astronauts who make the trip to Mars or another destination.
“Our best estimates indicate that descent engines of the Apollo landers were ejecting up to one-and-a-half tons of rocks and soil,” said Dr. Phil Metzger, a research physicist in Kennedy’s Granular Mechanics and Regolith Operations Laboratory. “It will be even more challenging when we land humans on Mars. The rocket exhaust will dig a deep hole under the lander and fluidize the soil. We don’t know any way to make this safe without landing pads.”
Building a landing site in advance of human arrival is part of the plan.
“Robotic landers would go to a location on Mars and excavate a site, clearing rocks, leveling and grading an area and then stabilizing the regolith to withstand impact forces of the rocket plume,” Mueller said. “Another option is to excavate down to bedrock to give a firm foundation. Fabric or other geo-textile material could also be used to stabilize the soil and ensure there is a good landing site.”
Metzger explained that one of the ways to ensure an on-target landing would be to have robotic rovers place homing beacons around the site.
“Tracking and homing beacons would help a spacecraft reach the specific spot where the landing pad had been constructed,” he said.
Landing pad technology may be perfected on Earth well in advance of its use elsewhere in the solar system.
“Several commercial space companies are already discussing returning rocket stages to Kennedy or Cape Canaveral saving on the cost of sending payloads to low Earth orbit,” Mueller said. “Rather than the first stage simply falling into the ocean, the rocket would land vertically back here at the Cape to be reused.”
While landing pads will provide a smooth touchdown location, they will also require advanced technology design and decisions on how large the landing pad should be.
“One of the factors we have to consider is the atmosphere where a landing will take place,” Metzger said. “The Earth has a dense atmosphere that focuses the rocket exhaust onto the ground, but also reduces how far the ejected material is dispersed. Mars, on the other hand, has an atmospheric density that is 1 percent that of Earth. It still focuses the plume into a narrow jet that digs into the soil, but it provides less drag so the ejected soil will actually travel farther.
“Then compare that to the moon with no atmosphere,” he said. “The plume won’t be focused so it won’t dig a deep hole in the soil, but the ejected material will travel vast distances at high velocity. It is like a sandblaster on steroids. So the requirements for a landing pad are determined by the destination we’re landing on.”
Metzger envisions circular landing pads from about 50 to 100 meters (about 165 to 330 feet) in diameter.
“The specialized material taking the heat of the engine plume would be in the middle,” he said. “The area surrounding the center would be designed to hold up support equipment.”
Another issue is what substances to use in building the landing pads.
“Tests with prototype landers show that while pads are safer than touching down on natural surfaces, certain pad materials can produce debris of their own,” Metzger said. “A supersonic rocket exhaust becomes extremely hot when it impacts a surface. Asphalt or concrete are out of the question because the temperature causes those materials to break apart, throwing chunks of material in all directions.”
During investigations of prototype landers, various materials have been examined on the pads from which the vehicles have vertically taken off and landed.
“We’ve tested several types of materials and it seems that basalt regolith mixed with polymer binders hold up well,” Metzger said.
However, the one substance for landing pads that shows the most promise is the material used on spacecraft heat shields.
“Of all the substances we studied, ablative materials seem to work best,” Metzger said.
Ablative substances were used on the heat shields for spacecraft during Mercury, Gemini and Apollo. The heat of re-entry was dissipated by burning off successive layers.
“While ablative materials seem to work well, the layers will eventually all burn away,” Mueller said. “So next we may try reusable thermal protection material similar to that used on the space shuttle tiles or the Orion capsules.”
A human expedition to Mars is still many years away, but Mueller says now is the time to start planning for how to land on another planet.
“The technology we envision will take 10 to 15 years to develop,” he said. “We need to begin verifying that these concepts will work, and that’s why we are already involved in the research.”
For more information visit www.nasa.gov.
|A ring-shaped warp drive device could transport a football-shape starship (center) to effective speeds faster than light. The concept was first proposed by Mexican physicist Miguel Alcubierre.
CREDIT: Harold White
HOUSTON — A warp drive to achieve faster-than-light travel — a concept popularized in television’s Star Trek — may not be as unrealistic as once thought, scientists say.
A warp drive would manipulate space-time itself to move a starship, taking advantage of a loophole in the laws of physics that prevent anything from moving faster than light. A concept for a real-life warp drive was suggested in 1994 by Mexican physicist Miguel Alcubierre; however, subsequent calculations found that such a device would require prohibitive amounts of energy.
Now physicists say that adjustments can be made to the proposed warp drive that would enable it to run on significantly less energy, potentially bringing the idea back from the realm of science fiction into science.
“There is hope,” Harold “Sonny” White of NASA’s Johnson Space Center said here Friday (Sept. 14) at the 100 Year Starship Symposium, a meeting to discuss the challenges of interstellar spaceflight.
An Alcubierre warp drive would involve a football-shape spacecraft attached to a large ring encircling it. This ring, potentially made of exotic matter, would cause space-time to warp around the starship, creating a region of contracted space in front of it and expanded space behind. [Star Trek’s Warp Drive: Are We There Yet? | Video]
Meanwhile, the starship itself would stay inside a bubble of flat space-time that wasn’t being warped at all.
“Everything within space is restricted by the speed of light,” explained Richard Obousy, president of Icarus Interstellar, a non-profit group of scientists and engineers devoted to pursuing interstellar spaceflight. “But the really cool thing is space-time, the fabric of space, is not limited by the speed of light.”
With this concept, the spacecraft would be able to achieve an effective speed of about 10 times the speed of light, all without breaking the cosmic speed limit.
The only problem is, previous studies estimated the warp drive would require a minimum amount of energy about equal to the mass-energy of the planet Jupiter.
But recently White calculated what would happen if the shape of the ring encircling the spacecraft was adjusted into more of a rounded donut, as opposed to a flat ring. He found in that case, the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA launched in 1977.
Furthermore, if the intensity of the space warps can be oscillated over time, the energy required is reduced even more, White found.
“The findings I presented today change it from impractical to plausible and worth further investigation,” White told SPACE.com. “The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab.”
White and his colleagues have begun experimenting with a mini version of the warp drive in their laboratory.
They set up what they call the White-Juday Warp Field Interferometer at the Johnson Space Center, essentially creating a laser interferometer that instigates micro versions of space-time warps.
“We’re trying to see if we can generate a very tiny instance of this in a tabletop experiment, to try to perturb space-time by one part in 10 million,” White said.
He called the project a “humble experiment” compared to what would be needed for a real warp drive, but said it represents a promising first step.
And other scientists stressed that even outlandish-sounding ideas, such as the warp drive, need to be considered if humanity is serious about traveling to other stars.
“If we’re ever going to become a true spacefaring civilization, we’re going to have to think outside the box a little bit, we’re going to have to be a little bit audacious,” Obousy said.