Connect with us

Science

Russian test blamed for space junk threatening space station – Brandon Sun

Published

 on







In this image from video provided by NASA, the International Space Station is seen as astronauts in the SpaceX Dragon capsule undock on Monday, Nov. 8, 2021, (NASA via AP)

CAPE CANAVERAL, Fla. (AP) — A Russian weapons test created more than 1,500 pieces of space junk that is now threatening the seven astronauts aboard the International Space Station, U.S. officials said Monday.

The State Department confirmed that the debris was from an old Russian satellite destroyed by the missile strike.

“It was dangerous. It was reckless. It was irresponsible,” said State Department spokesman Ned Price.

Earlier Monday, the four Americans, one German and two Russians on board were forced to briefly seek shelter in their docked capsules because of the debris.

At least 1,500 pieces of the destroyed satellite were sizable enough to show up on radar and with telescopes, Price said. But countless other fragments were too small to track, yet still posed a danger to the space station as well as orbiting satellites.

Even a fleck of paint can do major damage when orbiting at 17,500 mph (28,000 kph). Something big, upon impact, could be catastrophic.

“We are going to continue to make very clear that we won’t tolerate this kind of activity,” Price said.


FILE - In this April 24, 2021 file photo made available by NASA, the SpaceX Crew Dragon capsule approaches the International Space Station for docking. Space junk is threatening the seven astronauts aboard the International Space Station and forcing them to seek shelter in their docked capsules. The U.S. Space Command says it's tracking a field of orbiting debris, the apparent result of some satellite break-up event. The astronauts retreated into their docked capsules on Monday, Nov. 15, 2021 after being informed of the threat. (NASA via AP, File)

FILE – In this April 24, 2021 file photo made available by NASA, the SpaceX Crew Dragon capsule approaches the International Space Station for docking. Space junk is threatening the seven astronauts aboard the International Space Station and forcing them to seek shelter in their docked capsules. The U.S. Space Command says it’s tracking a field of orbiting debris, the apparent result of some satellite break-up event. The astronauts retreated into their docked capsules on Monday, Nov. 15, 2021 after being informed of the threat. (NASA via AP, File)

He said the U.S. has “repeatedly raised with Russian counterparts our concerns for a potential satellite test”.

NASA Mission Control said the heightened threat from the debris might continue for another couple days and continue to interrupt the astronauts’ science research and other work. Four of the seven crew members arrived at the orbiting outpost Thursday night.

NASA astronaut Mark Vande Hei, who’s midway through a yearlong mission, called it “a crazy but well-coordinated day” as he bid Mission Control good night.

“It was certainly a great way to bond as a crew, starting off with our very first work day in space,” he said.

The U.S. Space Command said it was tracking the field of orbiting debris. NASA had made no comment by late afternoon, and there was no word late Monday from Russia about the missile strike.

A similar weapons test by China in 2007 also resulted in countless debris. One of those pieces threatened to come dangerously close to the space station last week. While it later was dismissed as a risk, NASA had the station move anyway.

Anti-satellite missile tests by the U.S. in 2008 and India in 2019 were conducted at much lower altitudes, well below the space station.

Until Monday, the Space Command already was tracking some 20,000 pieces of space junk, including old and broken satellites from around the world.

Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics said it will take days if not weeks and months to catalogue the latest wreckage and confirm their orbits. The fragments will begin to spread out over time, due to atmospheric drag and other forces, he said in an email.

The space station is at especially high risk because the test occurred near its orbit, McDowell said. But all objects in low-Earth orbit — including China’s three-person space station and even the Hubble Space Telescope — will be at “somewhat enhanced risk” over the next few years, he noted.

John Kirby, the Pentagon press secretary, said the most immediate concern was the space debris. Beyond that, the United States is monitoring “the kinds of capabilities that Russia seems to want to develop which could pose a threat not just to our national security interest but to the security interests of other space-faring nations.”

Earlier in the day, the Russian Space Agency said via Twitter that the astronauts were ordered into their docked capsules, in case they had to make a quick getaway. The agency said the crew was back doing routine operations, and the space station’s commander, Russian Anton Shkaplerov, tweeted: “Friends, everything is regular with us!”

But the cloud of debris posed a threat on each passing orbit — or every 1 1/2 hours — and all robotic activity on the U.S. side was put on hold. German astronaut Matthias Maurer also had to find a safer place to sleep than the European lab.

__

AP reporters Matthew Lee and Robert Burns in Washington contributed.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Adblock test (Why?)



Source link

Continue Reading

Science

BEYOND LOCAL: NASA launches spacecraft to test asteroid defense concept – BayToday

Published

 on


LOS ANGELES (AP) — NASA launched a spacecraft Tuesday night on a mission to smash into an asteroid and test whether it would be possible to knock a speeding space rock off course if one were to threaten Earth.

The DART spacecraft, short for Double Asteroid Redirection Test, lifted off from Vandenberg Space Force Base atop a SpaceX Falcon 9 rocket in a $330 million project with echoes of the Bruce Willis movie “Armageddon.”

If all goes well, the boxy, 1,200-pound (540-kilogram) craft will slam head-on into Dimorphos, an asteroid 525 feet (160 meters) across, at 15,000 mph (24,139 kph) next September.

“This isn’t going to destroy the asteroid. It’s just going to give it a small nudge,” said mission official Nancy Chabot of Johns Hopkins Applied Physics Laboratory, which is managing the project.

Dimorphos orbits a much larger asteroid called Didymos. The pair are no danger to Earth but offer scientists a better way to measure the effectiveness of a collision than a single asteroid flying through space.

Dimorphos completes one orbit of Didymos every 11 hours, 55 minutes. DART’s goal is a crash that will slow Dimorphos down and cause it to fall closer toward the bigger asteroid, shaving 10 minutes off its orbit.

The change in the orbital period will be measured by telescopes on Earth. The minimum change for the mission to be considered a success is 73 seconds.

The DART technique could prove useful for altering the course of an asteroid years or decades before it bears down on Earth with the potential for catastrophe.

A small nudge “would add up to a big change in its future position, and then the asteroid and the Earth wouldn’t be on a collision course,” Chabot said.

Scientists constantly search for asteroids and plot their courses to determine whether they could hit the planet.

“Although there isn’t a currently known asteroid that’s on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there,” said Lindley Johnson, planetary defense officer at NASA. “The key to planetary defense is finding them well before they are an impact threat.”

DART will take 10 months to reach the asteroid pair. The collision will occur about 6.8 million miles (11 million kilometers) from Earth.

Ten days beforehand, DART will release a tiny observation spacecraft supplied by the Italian space agency that will follow it.

DART will stream video until it is destroyed on impact. Three minutes later, the trailing craft will make images of the impact site and material that is ejected.

John Antczak, The Associated Press

Adblock test (Why?)



Source link

Continue Reading

Science

Doing Photon Upconversion A Solid: Crystals That Convert Light To More Useful Wavelengths – Eurasia Review

Published

 on


Solid-solution organic crystals have been brought into the quest for superior photon upconversion materials, which transform presently wasted long-wavelength light into more useful shorter wavelength light. Scientists from Tokyo Institute of Technology revisited a materials approach previously deemed lackluster—using a molecule originally developed for organic LEDs—achieving outstanding performance and efficiency. Their findings pave the way for many novel photonic technologies, such as better solar cells and photocatalysts for hydrogen and hydrocarbon productions.

Light is a powerful source of energy that can, if leveraged correctly, be used to drive stubborn chemical reactions, generate electricity, and run optoelectronic devices. However, in most applications, not all the wavelengths of light can be used. This is because the energy that each photon carries is inversely proportional to its wavelength, and chemical and physical processes are triggered by light only when the energy provided by individual photons exceeds a certain threshold.

This means that devices like solar cells cannot benefit from all the color contained in sunlight, as it comprises a mixture of photons with both high and low energies. Scientists worldwide are actively exploring materials to realize photon upconversion (PUC), by which photons with lower energies (longer wavelengths) are captured and re-emitted as photons with higher energies (shorter wavelengths). One promising way to realize this is through triplet-triplet annihilation (TTA). This process requires the combination of a sensitizer material and an annihilator material. The sensitizer absorbs low energy photons (long-wavelength light) and transfers its excited energy to the annihilator, which emits higher energy photons (light of shorter wavelength) as a result of TTA (Figure 1).

Finding good solid materials for PUC has proven challenging for a long time. Although liquid samples can achieve relatively high PUC efficiency, working with liquids, especially those comprising organic solvents, is inherently risky and cumbersome in many applications. However, previous trials to create PUC solids generally suffered from poor crystal quality and small crystal domains, which lead to short travelling distances of triplet excited states and thus, low PUC efficiency. Additionally, in most previous solid PUC samples, stability under continuous photoirradiation was not tested and experimental data were often acquired in inert gas atmospheres. Hence, the low efficiency and insufficient materials stability had been of concern for a long time.

Now, in a recent study led by Associate Professor Yoichi Murakami from Tokyo Tech, Japan, a team of researchers found the answer to this challenge. Published in Materials Horizon, their paper (open access) describes how they focused on van der Waals crystals, a classical materials class that has not been considered for the quest of high-efficiency PUC solids. After discovering that 9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (ANNP), a hydrocarbon molecule originally developed for blue organic LEDs, was an excellent annihilator for embodying their concept, they tried mixing it with platinum octaethylporphyrin (PtOEP), a staple sensitizer that absorbs green light.

The team found that aggregation of the sensitizer molecules could be completely avoided by utilizing the crystalline phase of a van der Waals solid solution with a sufficiently low proportion of PtOEP to ANNP (around 1:50000). They proceeded to thoroughly characterize the obtained crystals and found some insight into why using the ANNP annihilator prevented the aggregation of the sensitizer when other existing annihilators had failed to do so in previous studies. Moreover, the solid crystals the team produced were highly stable and exhibited outstanding performance, as Dr. Murakami remarks: “The results of our experiments using simulated sunlight indicate that solar concentration optics such as lenses are no longer needed to efficiently upconvert terrestrial sunlight.”

Overall, this study brings van der Waals crystals back into the game of PUC as an effective way of creating outstanding solid materials using versatile hydrocarbon annihilators. “The proof-of-concept we presented in our paper is a major technical leap forward in the quest for high-performance PUC solids, which will open up diverse photonics technologies in the future,” concludes Dr. Murakami. Let us hope further research in this topic allows us to efficiently transform light into its most useful forms.

Adblock test (Why?)



Source link

Continue Reading

Science

New Russian module docks with International Space Station – CGTN

Published

 on


A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Soyuz rocket carrying the Progress cargo spacecraft and the Prichal node module lifts off from a launch pad at the Baikonur Cosmodrome, Kazakhstan, November 24, 2021. /CFP

A Russian cargo craft carrying a new docking module successfully hooked up with the International Space Station Friday after a two-day space journey.

The new spherical module, named Prichal (Pier), docked with the orbiting outpost at 6:19 p.m. Moscow time (1519 GMT). It has six docking ports and will allow potential future expansion of the Russian segment of the station.

The module has moored to the docking port of the new Russian Nauka (Science) laboratory module.

On Wednesday, a Soyuz rocket took off from the Russian launch facility in Baikonur, Kazakhstan, carrying the Progress cargo ship with Prichal attached to it. After entering space, the cargo ship with the module went into orbit.

Progress is also delivering 700 kilograms of various cargoes to the space station and is expected to undock from the station on December 22.

The first Soyuz spacecraft is expected to dock at the new module on March 18, 2022, with a crew of three cosmonauts: Oleg Artemyev, Denis Matveev and Sergei Korsakov.

Earlier this week, the Russian crew on the station started training for the module’s arrival, simulating the use of manual controls in case the automatic docking system failed.

The space outpost is currently operated by NASA astronauts Raja Chari, Thomas Marshburn, Kayla Barron, and Mark Vande Hei; Russian cosmonauts Anton Shkaplerov and Pyotr Dubrov; and Matthias Maurer of the European Space Agency.

Source(s): AP

Adblock test (Why?)



Source link

Continue Reading

Trending