Category: Science & Technology

Radio Search for Artificial Emissions from ‘Oumuamua

It’s the first time a visitor from another star system has been seen nearby. But what is it? An asteroid, a comet … or an alien artifact?

Scientists at the SETI Institute have attempted to address this question by using the Allen Telescope Array (ATA) to observe ‘Oumuamua when it was about 170 million miles away, or slightly less than the diameter of Earth’s orbit.

The intention was to measure artificial radio transmissions which, if found, would be strong evidence that this object is not simply a rock tossed into space by a random gravitational slingshot interaction that occurred in its home star system.

“We were looking for a signal that would prove that this object incorporates some technology – that it was of artificial origin,” says Gerry Harp, lead author of a paper to be published in the February 2019 issue of Acta Astronautica.

“We didn’t find any such emissions, despite a quite sensitive search. While our observations don’t conclusively rule out a non-natural origin for ‘Oumuamua, they constitute important data in accessing its likely makeup.”

Following its discovery in October 2017, ‘Oumuamua was the subject of popular speculation about a possible non-natural origin largely because it brought to mind the interstellar spaceship in Arthur C. Clarke’s novel Rendezvous with Rama. Its highly elongated shape and the fact that no coma was observed strengthened this hypothesis for some, as these are uncharacteristic of asteroids and comets.

A recent paper published in Astrophysical Journal Letters by researchers at Harvard has also suggested the possibility that ‘Oumuamua is a deliberate construction. The Harvard researchers argue that the slight, unexpected acceleration observed for this object could be caused by pressure from sunlight as ‘Oumuamua swung around the Sun.

Their hypothesis is that the object might be a light sail, either deliberately or accidentally sent our way. A deliberate origin is considered somewhat more likely because our solar system is a very small target for any object that is not being aimed.

Such arguments strengthen the importance of observations such as those conducted on the ATA that can constrain the true nature of ‘Oumuamua.

Observations were made between November 23 and December 5, 2017, using the wide-band correlator of the ATA at frequencies between 1 and 10 GHz and with a frequency resolution of 100 kHz. No signals were found at a level that would be produced by an omnidirectional transmitter on-board the object of power 30 to 300 milliwatts.

In portions of the radio spectrum that are routinely cluttered by artificial satellite telemetry, the threshold for detection was as high as 10 watts. In all cases, these limits to the powers that could be detected are quite modest – comparable to that of cell phones or citizen band radios.

While no signals were found coming from ‘Oumuamua, the types of observations reported by SETI Institute scientists may have utility in constraining the nature of any interstellar objects detected in the future, or even the small, well-known objects in our own solar system.

It has been long-hypothesized that some of the latter could be interstellar probes, and radio observations offer a way to address this imaginative, but by no means impossible, idea.

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Electronic Skin Bridges The Gap Between You and Iron Man

Human skin contains sensitive nerve cells that detect pressure, temperature and other sensations that allow tactile interactions with the environment. To help robots and prosthetic devices attain these abilities, scientists are trying to develop electronic skins.

Now researchers report a new method in ACS Applied Materials and Interfaces that creates an ultrathin, stretchable electronic skin, which could be used for a variety of human-machine interactions. See a video of the e-skin here.

Electronic skin could be used for many applications, including prosthetic devices, wearable health monitors, robotics and virtual reality. A major challenge is transferring ultrathin electrical circuits onto complex 3D surfaces and then having the electronics be bendable and stretchable enough to allow movement.

Some scientists have developed flexible “electronic tattoos” for this purpose, but their production is typically slow, expensive and requires clean-room fabrication methods such as photolithography. Mahmoud Tavakoli, Carmel Majidi and colleagues wanted to develop a fast, simple and inexpensive method for producing thin-film circuits with integrated microelectronics.

In the new approach, the researchers patterned a circuit template onto a sheet of transfer tattoo paper with an ordinary desktop laser printer. They then coated the template with silver paste, which adhered only to the printed toner ink. On top of the silver paste, the team deposited a gallium-indium liquid metal alloy

Lockheed Martin To Develop New Missle Defense Laser System

The Missile Defense Agency, a part of the Department of Defense, awarded Lockheed Martin a nine month, $25.5 million contract extension to continue development of its Low Power Laser Demonstrator (LPLD) missile interceptor concept. This program, awarded Aug. 31, builds on a 2017 contract to develop an initial LPLD concept.

Lockheed Martin’s LPLD concept consists of a fiber laser system on a high-performing, high-altitude airborne platform. LPLD is designed to engage missiles during their boost phase – the short window after launch – which is the ideal time to destroy the threat, before it can deploy multiple warheads and decoys.

Over the course of this contract, Lockheed Martin will mature its LPLD concept to a tailored critical design review phase, which will bring the design to a level that can support full-scale fabrication.

“We have made great progress on our LPLD design, and in this stage we are particularly focused on maturing our technology for beam control – the ability to keep the laser beam stable and focused at operationally relevant ranges,” said Sarah Reeves, vice president for Missile Defense Programs at Lockheed Martin Space.

“LPLD is one of many breakthrough capabilities the Missile Defense Agency is pursuing to stay ahead of rapidly-evolving threats, and we’re committed to bringing together Lockheed Martin’s full expertise in directed energy for this important program.”

Lockheed Martin expands on advanced technology through its laser device, beam control capabilities, and platform integration – ranging from internal research and development investments in systems like ATHENA to programs such as LANCE for the Air Force Research Laboratory.

Continued LPLD development will take place at Lockheed Martin’s Sunnyvale, California campus through July 2019.

As a proven world leader in systems integration and development of air and missile defense systems and technologies, Lockheed Martin has already delivered the U.S.  several high-quality missile defense solutions that protect citizens, critical assets and deployed forces from current and future threats.

The company’s experience spans directed energy systems development, missile design and production, hit-to-kill capabilities, infrared seekers, command and control/battle management, and communications, precision pointing and tracking optics, radar and signal processing, as well as threat-representative targets for missile defense tests.

New Techniques Yields Tiny Results To Produce Great Resolution In Astronomy

This “super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft Monday, Oct. 29, 2018, from a distance of about 205 miles (330 km).

The spacecraft was moving as it captured the images with the PolyCam camera, and Bennu rotated 1.2 degrees during the nearly one minute that elapsed between the first and the last snapshot.

The team used a super-resolution algorithm to combine the eight images and produce a higher resolution view of the asteroid. Bennu occupies about 100 pixels and is oriented with its north pole at the top of the image.

OSIRIS-REx executes third asteroid approach maneuver
NASA’s OSIRIS-REx spacecraft has executed its third Asteroid Approach Maneuver (AAM-3). The trajectory correction maneuver (TCM) thrusters fired in a series of two braking maneuvers designed to slow the spacecraft’s speed relative to Bennu from approximately 11.7 mph (5.2 m/sec) to .24 mph (.11 m/sec).

Due to constraints that science instruments not be pointed too closely to the Sun, this maneuver was designed as two separate burns of approximately 5.8 mph (2.6 m/sec) each, to accomplish a net change in velocity of around 11.5 mph (5.13 m/sec). The mission team will continue to examine telemetry and tracking data over the next week to verify the new trajectory.

The maneuver targeted the spacecraft to fly through a corridor designed for the collection of high-resolution images that will be used to build a shape model of Bennu.

The OSIRIS-REx spacecraft is in the midst of a six-week series of final approach maneuvers. AAM-1 and AAM-2, which executed on Oct. 1 and Oct. 15 respectively, slowed the spacecraft by a total of approximately 1,088 mph (486 m/sec).

The last of the burns, AAM-4, is scheduled for Nov. 12 and will adjust the spacecraft’s trajectory to arrive at a position 12 miles (20 km) from Bennu on Dec. 3.

Russia Implies Americans Sabotaged International Space Station

Russian investigators looking into the origin of a hole that caused an oxygen leak on the International Space Station have said it was caused deliberately, the space agency chief said.

A first commission had delivered its report, Dmitry Rogozin, the head of the Russian space agency Roskosmos, said in televised remarks late Monday.

“It concluded that a manufacturing defect had been ruled out which is important to establish the truth.”

Rogozin said the commission’s main line of inquiry was that the hole had been drilled deliberately, a position that has been voiced in the past.

“Where it was made will be established by a second commission, which is at work now,” he said.

The small hole in the wall of a Russian-made Soyuz space capsule docked onto the ISS was located in August and quickly sealed up.

Officials have suggested a number of possible reasons for the appearance of the hole.

A top government official has denied a Russian media report that the investigation looked at the possibility that US astronauts had drilled the hole in order to get a sick colleague sent back to Earth.

The current ISS commander, US astronaut Drew Feustel, called the suggestion that the crew was somehow involved “embarrassing”.

Rogozin — who previously oversaw the Russian space industry as deputy prime minister — was appointed head of Roskosmos last May, in a move analysts said would spell trouble for the embattled sector.

The official, who was placed under US sanctions over the Ukraine crisis in 2014, admitted it had become difficult to work with NASA.

“Problems with NASA have certainly appeared but not through the fault of NASA,” he said, blaming unnamed American officials for telling the US space agency what to do.

He also claimed that SpaceX founder Elon Musk sought to squeeze Russia out of the space launch services market and complained about the US military drone X-37.

“Americans have this thing, the X-37,” Rogozin said. “We don’t understand its purposes. Rather, we do understand, but we have not received an official explanation.

“Essentially, this thing can be used as a weapons carrier.”

What this has to do with the investigation into a hole in the ISS is unknown, and the question remains: Could anyone take a drill to the ISS, a small contained environment with less internal area than many houses, with external cameras, and go unnoticed?

NASA representatives assure us that space walks are all carefully monitored in real time to assure astronaut safety.

The Sentinel believes that if the hole was drilled deliberately, the mostly likely explanation is that it must have been done before the capsule left  Earth. That means Russia.