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Ars takes a clean room tour of JPL’s asteroid-orbiting Psyche spacecraft – Ars Technica

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Enlarge / Artist’s illustration of NASA’s Psyche spacecraft, set to launch in August 2022. The Psyche mission will explore a metal-rich asteroid of the same name that lies in the main asteroid belt between Mars and Jupiter.
NASA/JPL-Caltech/ASU

Ars Technica had the opportunity to tour NASA’s Jet Propulsion Laboratory in California this week, suiting up for a clean room sneak peek at the Psyche spacecraft now nearing completion. This ambitious mission, named after the eponymous asteroid it will explore, is due to launch in August on a Falcon Heavy rocket. Scientists are hopeful that learning more about this unusual asteroid will advance our understanding of planet formation and the earliest days of our solar system.

Discovered in March 1852 by the Italian astronomer Annibale de Gasparis, 16 Psyche is an M-type asteroid (meaning it has high metallic content) orbiting the Sun in the main asteroid belt, with an unusual potato-like shape. The longstanding preferred hypothesis is that Psyche is the exposed metallic core of a protoplanet (planetesimal) from the earliest days of our solar system, with the crust and mantle stripped away by a collision (or multiple collisions) with other objects. In recent years, scientists concluded that the mass and density estimates aren’t consistent with an entirely metallic remnant core. Rather, it’s more likely a complex mix of metals and silicates.

Alternatively, the asteroid might once have been a parent body for a particular class of stony-iron meteorites, one that broke up and re-accreted into a mix of metal and silicate. Or perhaps it’s an object like 1 Ceres, a dwarf planet in the asteroid belt between the orbits of Mars and Jupiter—except 16 Psyche may have experienced a period of iron volcanism while cooling, leaving highly enriched metals in those volcanic centers.

Multiple views of 16 Psyche imaged by the Very Large Telescope.
Enlarge / Multiple views of 16 Psyche imaged by the Very Large Telescope.

Scientists have long suspected that metallic cores lurk deep within terrestrial planets like Earth. But those cores are buried too far beneath rocky mantles and crusts for researchers to find out. As the only metallic core-like body discovered, Psyche provides the perfect opportunity to shed light on how the rocky planets in our solar system (Earth, Mercury, Venus, and Mars) may have formed. NASA approved the Psyche mission in 2017, intending to send a spacecraft to orbit the asteroid and collect crucial data about its characteristics.

“Our understanding of what Psyche might be has not changed all that much over the last few years,” Linda Elkins-Tanton of Arizona State University, principal investigator of the Psyche mission, told Ars. “It has to have a large metal content, but we’ve never really known how much. It could be the part of a metal core of a tiny planet from early in the solar system, or it could be something that never melted and formed a core but has metal mixed into it, like pebbles with the rock. We won’t really know until we get there.”

Several instruments will be aboard the Psyche spacecraft to collect that precious scientific data. There is a multi-spectral imager capable of producing sufficiently high-resolution images for scientists to tell the difference between the asteroid’s metallic and silicate (mineral) constituents. The job of mapping the asteroid’s composition and identifying all the elements falls to a gamma ray and neutron spectrometer. There is also a magnetometer that will measure and map any remnants of a magnetic field. Finally, a microwave radio telecommunications system will also be able to measure the asteroid’s gravity field, gleaning clues about its interior structure.

A miniature model of the Psyche spacecraft.
Enlarge / A miniature model of the Psyche spacecraft.
Jennifer Ouellette

The chassis, constructed by a satellite company called Maxar Technologies, was delivered last April. It’s roughly the size of a passenger van and was built largely from commercial, off-the-shelf technology. “Once in space, the spacecraft will use an innovative means of propulsion, known as Hall thrusters, to reach the asteroid,” Ars Senior Space Editor Eric Berger wrote last year. “This will be the first time a spacecraft has ventured into deep space using Hall thrusters, and absent this technology, the Psyche mission probably wouldn’t be happening—certainly not at its cost of just less than $1 billion.” Here’s a bit more from Berger about this innovative approach:

Engines powered by chemical propulsion are great for getting rockets off the surface of the Earth when you need a brawny burst of energy to break out of the planet’s gravitational well. But chemical rocket engines are not the most fuel-efficient machines in the world, as they guzzle propellant. And once a spacecraft is in space, there are more fuel-efficient means of moving around. NASA has been experimenting with  [solar electric propulsion] technology for a while. The space agency first tested electric propulsion technology in its Deep Space 1 mission, which launched in 1998, and later in the Dawn mission in 2007 that visited Vesta and Ceres in the asteroid belt.

These spacecraft used ion thrusters. Hall thrusters, by contrast, use a simpler design, with a magnetic field to confine the flow of propellant. These thrusters were invented in the Soviet Union and later adapted for commercial purposes by Maxar and other companies. Many of the largest communications satellites in geostationary orbit today, such as those delivering DirecTV, use Hall thrusters for station-keeping.

Using Hall thruster-based technology enabled the mission’s scientists and engineers to design a smaller and more affordable spacecraft. Each of the Hall thrusters on Psyche will generate three times as much thrust as the ion thrusters on the Dawn spacecraft and can process twice as much power. This will allow the spacecraft to reach the Psyche asteroid, located in the main belt, in January 2026, after a 3.5-year journey.

The Psyche team tested the twin solar arrays in March, attaching the arrays to the spacecraft body and unfolding them lengthwise, before stowing the panels until the August launch. The five-panel, cross-shaped solar arrays are the largest installed at JPL, measuring 800 square feet (75 square meters). They are specially designed to work in low-light conditions, far away from the Sun.

One of two solar arrays on NASA’s Psyche spacecraft was successfully deployed in JPL’s storied High Bay 2 clean room in March. The twin arrays will power the spacecraft and its science instruments during the mission.
Enlarge / One of two solar arrays on NASA’s Psyche spacecraft was successfully deployed in JPL’s storied High Bay 2 clean room in March. The twin arrays will power the spacecraft and its science instruments during the mission.
NASA/JPL-Caltech

After launching from NASA’s Kennedy Space Center in August, the Psyche spacecraft will plug along on its Hall thrusters until it reaches Mars in May 2023. Then it will slingshot around the red planet for a gravitational assist for the final leg of the journey to its namesake asteroid.

“The most important thing is to get the engine and thrusters going right away,” JPL’s Henry Stone, Psyche project manager, told Ars. “This is not a chemical propulsion, this is an electrical propulsion mission. That means we are powering the vehicle, propulsing all the way to Psyche, in addition to doing a gravitational assist around Mars. We need to launch the vehicle, get it into a safe state quickly, and be prepared to get the engines up and running so that we can get to the final destination.”

Once everything is up and running, testing will begin on a laser communications experiment called Deep Space Optical Communications (DSOC), which will operate for about a year. The objective of this optical system is to improve the performance of spacecraft communications substantially over conventional radio frequency (rf) systems, similar to how fiber optic cables replaced old-school telephone wires.

Your intrepid Ars correspondent in full clean room gear.
Enlarge / Your intrepid Ars correspondent in full clean room gear.
Jennifer Ouellette

“There’s a huge bandwidth crunch,” JPL’s Abhijit “Abi” Biswas, DSOC project technologist, told Ars. “We’re running out of bandwidth because of demand from near-Earth satellites. Moving to optical opens up a nice slice of spectrum. You get much higher data rates than rf— roughly a factor of 10 for large distances—all for the same mass and power, once we work out all the kinks. We have targeted data rates at targeted distances so if we can hit those data rates, then definitely it’s worked.”

DSOC boasts a flight laser transceiver, a ground laser transmitter, and a ground laser receiver. The experiment on board the Psyche spacecraft is a proof of principle. Substantial infrastructure on the ground would need to be developed for similar optical systems to be deployed in future missions. “There has to be some investment in that because, for deep space, you need large aperture ground collectors which don’t exist today,” Biswas said.

For the Psyche technology demonstration, Biswas’ team is relying on the near-infrared laser transmitter at JPL’s Table Mountain facility, with the Hale Telescope at California’s Palomar Observatory serving as a receiver. But that won’t be operationally feasible for broad deployment on future deep space missions, such as a manned mission to Mars. According to Biswas, JPL is currently experimenting with putting mirrors on the Goldstone antennas in hopes of using the same infrastructure to operate in both the optical and rf regimes.

Underneath all that clean room gear is Linda Elkins-Tanton of Arizona State University (right), Psyche principal investigator, chatting with a reporter in front of the actual spacecraft.
Enlarge / Underneath all that clean room gear is Linda Elkins-Tanton of Arizona State University (right), Psyche principal investigator, chatting with a reporter in front of the actual spacecraft.
NASA/JPL-Caltech

The spacecraft will reach the asteroid in January 2026 and spend the next 21 months in orbit mapping the body and measuring its properties. There will be three orbital stages, as the spacecraft gradually dips into successively lower orbits until it is orbiting just 53 miles (85 kilometers) above the surface.

Because the asteroid Psyche has such an odd shape, the mission scientists expect it most likely has a very irregular gravitational field. “We had to design the spacecraft in such a way to be able to account for that from a navigation and control standpoint,” said Stone. “That’s in part why we start out at a very high altitude, so we can safely orbit far away, and make measurements of the gravitational field. Then we can build that model and refine it in real time, so that we then know how to drop down successively these closer and closer orbits.”

And then we wait for all that data to be analyzed so Psyche can reveal its secrets. “My secret hope is that Psyche is not part of a metal core, that it’s something quite unusual,” Elkins-Tanton said. “I would love for it to be ‘reduced’: Some material that had all its oxygen stripped off it so that the metal is made up of the iron that’s left behind. Some previously undetected building block of planets, something we haven’t seen in the meteorite collection. That would be the biggest thrill to me.”

"High Bay Bob" is an unofficial mascot of the High Bay clean rooms at JPL.
Enlarge / “High Bay Bob” is an unofficial mascot of the High Bay clean rooms at JPL.
Jennifer Ouellette

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See Astronaut's Sublime Shot of Total Lunar Eclipse Snapped From the ISS – CNET

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Earthlings on Earth weren’t the only ones who got to witness the lovely blushing of the “flower blood moon” total lunar eclipse on Sunday night and Monday morning. Residents of the International Space Station had a great view of the spectacular celestial event.

European Space Agency astronaut Samantha Cristoforetti shared a beautiful series of photos of the eclipse as seen from orbit. “A partially eclipsed moon playing hide-and-seek with our solar panel,” Cristoforetti tweeted on Monday.

The photos show the eclipse in progress, with the moon peeking under the station’s solar panels. One stunning view also shows Earth below, clouds visible against an expanse of blue. The images highlight the subtle shading of the moon as our planet threw its shadow across it.

Cristoforetti shared another look with just the eclipsed moon peeking over the curve of Earth.

Cristoforetti is an accomplished space photographer, having snapped plenty of gorgeous images during her last stay on the ISS in 2014 and 2015. Her most recent stint started in late April as part of NASA’s Crew-4 mission launched by SpaceX. 

I watched the eclipse last night from New Mexico. As the shadow moved across the moon, the ISS flew over, a bright bead of light crossing against the starry sky. So as I was seeing the ISS, Cristoforetti was likely tracking the eclipse, too. It doesn’t matter whether you’re on the ground or up in orbit, an eclipse is worth witnessing.

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NASA's InSight still hunting marsquakes as power levels diminish – Phys.org

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InSight captured this image of one of its dust-covered solar panels on April 24, 2022, the 1,211th Martian day, or sol, of the mission. Credit: NASA/JPL-Caltech

Dusty solar panels and darker skies are expected to bring the Mars lander mission to a close around the end of this year.

NASA’s InSight Mars lander is gradually losing power and is anticipated to end science operations later this summer. By December, InSight’s team expects the lander to have become inoperative, concluding a mission that has thus far detected more than 1,300 marsquakes—most recently, a magnitude 5 that occurred on May 4—and located quake-prone regions of the Red Planet.

The information gathered from those quakes has allowed scientists to measure the depth and composition of Mars’ crust, mantle, and core. Additionally, InSight (short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) has recorded invaluable weather data and studied remnants of Mars’ ancient magnetic field.

“InSight has transformed our understanding of the interiors of rocky planets and set the stage for future missions,” said Lori Glaze, director of NASA’s Planetary Science Division. “We can apply what we’ve learned about Mars’ inner structure to Earth, the Moon, Venus, and even rocky planets in other solar systems.”

InSight landed on Mars Nov. 26, 2018. Equipped with a pair of solar panels that each measures about 7 feet (2.2 meters) wide, it was designed to accomplish the mission’s primary science goals in its first Mars year (nearly two Earth years). Having achieved them, the spacecraft is now into an extended mission, and its solar panels have been producing less power as they continue to accumulate dust.

Because of the reduced power, the team will soon put the lander’s robotic arm in its resting position (called the “retirement pose”) for the last time later this month. Originally intended to deploy the seismometer and the lander’s heat probe, the arm has played an unexpected role in the mission: Along with using it to help bury the heat probe after sticky Martian soil presented the probe with challenges, the team used the arm in an innovative way to remove dust from the solar panels. As a result, the seismometer was able to operate more often than it would have otherwise, leading to new discoveries.

[embedded content]

NASA’s InSight Mars lander team speak about the mission’s science and the innovative ways they took on engineering challenges. During its time on Mars, InSight has achieved all its primary science goals and continues to hunt for quakes. Its mission is expected to conclude around the end of 2022. Credit: NASA/JPL-Caltech

When InSight landed, the produced around 5,000 watt-hours each Martian day, or sol—enough to power an electric oven for an hour and 40 minutes. Now, they’re producing roughly 500 watt-hours per sol—enough to power the same electric oven for just 10 minutes.

Additionally, seasonal changes are beginning in Elysium Planitia, InSight’s location on Mars. Over the next few months, there will be more dust in the air, reducing sunlight—and the lander’s energy. While past efforts removed some dust, the mission would need a more powerful dust-cleaning event, such as a “dust devil” (a passing whirlwind), to reverse the current trend.

“We’ve been hoping for a cleaning like we saw happen several times to the Spirit and Opportunity rovers,” said Bruce Banerdt, InSight’s principal investigator at NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission. “That’s still possible, but energy is low enough that our focus is making the most of the science we can still collect.”

If just 25% of InSight’s panels were swept clean by the wind, the lander would gain about 1,000 watt-hours per sol—enough to continue collecting science. However, at the current rate power is declining, InSight’s non-seismic instruments will rarely be turned on after the end of May.

Energy is being prioritized for the lander’s seismometer, which will operate at select times of day, such as at night, when winds are low and marsquakes are easier for the seismometer to “hear.” The seismometer itself is expected to be off by the end of summer, concluding the science phase of the .

At that point, the lander will still have enough power to operate, taking the occasional picture and communicating with Earth. But the team expects that around December, will be low enough that one day InSight will simply stop responding.


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NASA’s InSight still hunting marsquakes as power levels diminish (2022, May 17)
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Peek-a-Boo Moon: Astronaut on Space Station Captures Spectacular Photos of the Lunar Eclipse – SciTechDaily

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ESA astronaut Samantha Cristoforetti captured pictures of the May 2022 lunar eclipse from the International Space Station.

On the evening of May 15, 2022, Earth passed between the Sun and the Moon blocking sunlight and casting a shadow on the lunar surface. ESA astronaut Samantha Cristoforetti witnessed this lunar eclipse from the International Space Station and captured it in a series of photographs.

During a lunar eclipse, Earth’s atmosphere scatters sunlight. The blue light from the Sun scatters away, and longer-wavelength red, orange, and yellow light pass through, turning our Moon red.

Lunar Eclipse From International Space Station 1

An image of a lunar eclipse as seen from the International Space Station. Credit: ESA-S.Cristoforetti

In these images, the Moon appears to play hide and seek with one of the International Space Station’s solar panels:

Lunar Eclipse From International Space Station 4

A partially eclipsed Moon playing hide and seek with the solar panel of the International Space Station. Credit: ESA-S.Cristoforetti

Lunar Eclipse From International Space Station 3

A partially eclipsed Moon playing hide and seek with the solar panel of the International Space Station. Credit: ESA-S.Cristoforetti

Lunar Eclipse From International Space Station 2

A partially eclipsed Moon playing hide and seek with the solar panel of the International Space Station. Credit: ESA-S.Cristoforetti

Samantha is living and working aboard the Space Station for her second mission, ‘Minerva’. Learn more about Samantha and the Minerva mission.

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