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Tag: NASA

  • NASA’s New PACE Observatory Searches for Clues to Humanity’s Future

    NASA’s New PACE Observatory Searches for Clues to Humanity’s Future

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    Way up in the sky and sprinkled across the seas, two of the littlest yet most influential things in the world have stubbornly guarded their secrets: aerosols and phytoplankton. Today, NASA launched its Plankton, Aerosol, Cloud, Ocean Ecosystem mission, or PACE, to unravel their mysteries. The mission’s findings could be a key to understanding how drastically the world is changing as it warms.

    Aerosols are little bits of dust, wildfire smoke, and fossil fuel pollution floating around the atmosphere, which both absorb and reflect the sun’s energy and help build clouds—wildly complex dynamics that climate models still struggle to account for. And phytoplankton are the microscopic, plant-like marine organisms that form the foundation of the food web. They also sequester carbon, keeping Earth’s climate from warming even further. “Phytoplankton are basically moving carbon around, and we need to understand how that changes with time,” says Jeremy Werdell of NASA’s Goddard Space Flight Center.

    PACE is a satellite observatory that’ll provide scientists with unprecedented views of these ultra-important denizens of the skies and seas, to help them try to predict how our world will evolve. “The warming atmosphere and warming oceans have a cost, and that cost from a biological point of view is that the base of the food chain will unequivocally change,” says Werdell, who is the project scientist of PACE.

    Microscopic photo of green phytoplankton on a black background

    Plankton come in all shapes, sizes, and shades of green, filling all kinds of different roles in the ecosystem.

    Photograph: Alamy

    Though phytoplankton are minuscule, they bloom in such numbers that they smear great green streaks across the oceans. That’s been easy enough to monitor by satellite, sure, but up until now what’s been observed has been more or less a uniform streak of green. But PACE is equipped with an extremely sensitive instrument that can see in high resolution across the electromagnetic spectrum, from ultraviolet to the near infrared. (The visible spectrum, which we can see, is in between the two.) The effect is that PACE can see all kinds of different greens.

    Think about what you see staring into a forest. “All the leaves on the various trees are green, but they’re very subtly different greens, which means they’re different plants,” says Werdell. “Really what we’re searching for are these very, very subtle changes in color.”

    That’ll allow scientists to determine not just where phytoplankton are blooming and why, but what kind of community that creates. There are thousands upon thousands of phytoplankton species—some that act as food for tiny animals known as zooplankton, others that are highly toxic, some that sequester carbon better than others. What modern satellites can see from space is like drawing with a box of eight crayons, but the species will look different to PACE’s eye. “What we’re getting with PACE is a box of 128,” says Werdell.

    Video: Andy Sayer/NASA

    Better understanding these phytoplanktonic communities is critical because of how rapidly the oceans are transforming. They’ve absorbed something like 90 percent of the excess heat humanity has added to the atmosphere, and over the past year or so in particular, sea surface temperatures have soared to record highs and stayed there. The high temperatures themselves might adversely affect the growth of some phytoplankton species, but might actually benefit others that thrive as the mercury climbs.

    More subtly, warm water acts like a kind of cap at the ocean surface, with cooler waters swirling below. “It’s kind of like drinking a half and half at your favorite Irish pub: Guinness floating on top of Harp,” says Werdell. “That creates a barrier in this huge stretch of real estate in the upper ocean, where nutrients in the cold water underneath this layer of warm water can’t penetrate.”

    Phytoplankton need those nutrients to grow, so if the cap of warm water persists in a given area, that’ll further shake up the community of photosynthesizing species. If there’s less of the species that zooplankton need for food, their numbers may decline too. And then the larger predators like fish that eat the zooplankton will be impacted, on up the food chain. That could eventually affect the food species that humans rely on for protein.

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  • NASA Engineers Are Racing to Fix Voyager 1

    NASA Engineers Are Racing to Fix Voyager 1

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    Voyager 1 is still alive out there, barreling into the cosmos more than 15 billion miles away. However, a computer problem has kept the mission’s loyal support team in Southern California from knowing much more about the status of one of NASA’s longest-lived spacecraft.

    The computer glitch cropped up on November 14, and it affected Voyager 1’s ability to send back telemetry data, such as measurements from the craft’s science instruments or basic engineering information about how the probe was doing. As a result, the team has no insight into key parameters regarding the craft’s propulsion, power, or control systems.

    “It would be the biggest miracle if we get it back. We certainly haven’t given up,” said Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory, in an interview with Ars. “There are other things we can try. But this is, by far, the most serious since I’ve been project manager.”

    Dodd became the project manager for NASA’s Voyager mission in 2010, overseeing a small cadre of engineers responsible for humanity’s exploration into interstellar space. Voyager 1 is the most distant spacecraft ever, speeding away from the sun at 38,000 mph (17 kilometers per second).

    Voyager 2, which launched 16 days before Voyager 1 in 1977, isn’t quite as far away. It took a more leisurely route through the solar system, flying past Jupiter, Saturn, Uranus, and Neptune, while Voyager 1 picked up speed during an encounter with Saturn to overtake its sister spacecraft.

    For the past couple of decades, NASA has devoted Voyager’s instruments to studying cosmic rays, the magnetic field, and the plasma environment in interstellar space. They’re not taking pictures anymore. Both probes have traveled beyond the heliopause, where the flow of particles emanating from the sun runs into the interstellar medium.

    There are no other operational spacecraft currently exploring interstellar space. NASA’s New Horizons probe, which flew past Pluto in 2015, is on track to reach interstellar space in the 2040s.

    State-of-the-Art 50 Years Ago

    The latest problem with Voyager 1 lies in the probe’s Flight Data Subsystem (FDS), one of three computers on the spacecraft working alongside a command-and-control central computer and another device overseeing attitude control and pointing.

    The FDS is responsible for collecting science and engineering data from the spacecraft’s network of sensors and then combining the information into a single data package in binary code—a series of 1s and 0s. A separate component called the Telemetry Modulation Unit actually sends the data package back to Earth through Voyager’s 12-foot (3.7-meter) dish antenna.

    In November, the data packages transmitted by Voyager 1 manifested a repeating pattern of 1s and 0s as if it were stuck, according to NASA. Dodd said engineers at JPL have spent the better part of three months trying to diagnose the cause of the problem. She said the engineering team is “99.9 percent sure” the problem originated in the FDS, which appears to be having trouble “frame syncing” data.

    So far, the ground team believes the most likely explanation for the problem is a bit of corrupted memory in the FDS. However, because of the computer hangup, engineers lack detailed data from Voyager 1 that might lead them to the root of the issue. “It’s likely somewhere in the FDS memory,” Dodd said. “A bit got flipped or corrupted. But without the telemetry, we can’t see where that FDS memory corruption is.”

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  • NASA sends cat video 31 million kilometres through space

    NASA sends cat video 31 million kilometres through space

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    NASA has broken its own record by transmitting ultra-high-definition video over a distance of 31 million kilometres from deep space. The footage wasn’t of distant celestial bodies or spacecraft, but of a cat called Taters chasing the light from a laser pointer.

    Abhijit Biswas at NASA’s Jet Propulsion Laboratory (JPL) tells New Scientist that Taters was chosen for the first transmission over that distance because one of the first television test broadcasts also featured a cat – the cartoon feline Felix. The inclusion of a laser pointer was a visual nod to the use of lasers in the transmission, he says.

    “Apparently this cat is very fond of chasing laser pointers, so somehow that all came together in this video,” says Biswas.

    The 15 seconds of footage was transmitted from NASA’s Deep Space Optical Communications (DSOC) experiment, which is hitching a ride on the Psyche spacecraft that launched in October to intercept an asteroid of the same name.

    Taters the cat chasing a laser light

    A video of Taters the cat chasing a laser light has been beamed back from space

    NASA

    The video of Taters – a JPL employee’s pet – was shot and uploaded to the craft before launch. The film also shows Psyche’s orbital path, the telescope dome of the Palomar Observatory in California and technical information about the laser and its data transmission rate.

    The DSOC experiment will send high-bandwidth test data to Earth during a two-year run, and is part of NASA’s long-term plan to use lasers rather than radios to transmit information from space. This will enable wider bandwidths and therefore faster data transfer rates that can carry complex scientific information and high-definition images and videos for future missions.

    “DSOC is really a proof of concept which hopefully will make believers out of everybody that this can be done,” says Biswas. The technique had already been used to send data between the moon and Earth, but that is a mere 384,400 kilometres. He says longer distances than the Taters test should be possible in future.

    One issue is ensuring the laser light is precisely directed so it hits the receiving station. “It’s a very narrow beam; at the distance that Psyche is right now, it [is] only a few hundred kilometres [wide by the time it reaches Earth],” says Biswas. “So if you mispoint it ever so slightly, you’ll be in the Pacific Ocean or somewhere else. You’ll completely miss. So that was something there was a lot of anxiety over.”

    The video was transmitted at near-infrared wavelength by a laser transceiver and took 101 seconds to travel from the craft to Earth.

    The 267-megabits-per-second message was received by equipment at the Hale Telescope at Palomar, before being transmitted over the internet to JPL in southern California, where the video was played in real time. That data rate makes DSOC faster than most domestic broadband connections.

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