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.
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.
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.
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.
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.
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.”
Enlarge/ “High Bay Bob” is an unofficial mascot of the High Bay clean rooms at JPL.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
