Asteroid exploration is a pertinent challenge due to the varying complexity of their dynamical environments, shape and communication delays due to distance. Thus, autonomous navigation methods are continually being developed and improved in current research to enable their safe exploration. These methods often involve using horizon-based Optical Navigation (OpNav) to determine the spacecraft's location, which is reliant on the visibility of the horizon. It is critical to ensure the reliability of this measurement such that the spacecraft may maintain an accurate state estimate throughout its mission. This paper presents an algorithm that generates control maneuvers for spacecraft to follow trajectories that allow continuously usable optical measurements to maintain system observability for safe navigation. This algorithm improves upon existing asteroid navigation capabilities by allowing the safe and robust autonomous targeting of various trajectories and orbits at a wide range of distances within optical measurement range. It is adaptable to different asteroid scenarios. Overall, the approach develops an all-encompassing system that simulates the asteroid dynamics, synthetic image generation, edge detection, horizon-based OpNav, filtering and observability-enhancing control.

It's been several months, but NASA has finally prized the lid off the capsule that returned the Bennu asteroid to Earth. NASA engineers removed two metal fasteners from the TAGSAM robotic arm that were keeping the lid stuck and trapping the precious cargo inside. Now the business of analyzing the entirety of the 250g sample for clues about the history of the solar system can begin. It was back in October 2020 that the robotic arm aboard the OSIRIS-REx spacecraft nabbed a handful of the Bennu asteroid. Space fans rejoiced in September last year when the craft finally returned to Earth, marking the end of the 1.16 billion mission, one of NASA's most ambitious ever.

A NASA space capsule carrying the largest soil sample ever collected from the surface of an asteroid has landed in the Utah desert seven years after the mission's launch. Flight Control announced on Sunday. The gumdrop-shaped capsule, released from the robotic spacecraft OSIRIS-REx as the mothership passed within 108,000km (67,000 miles) of Earth hours earlier, touched down within a designated landing zone west of Salt Lake City on the United States military's vast Utah Test and Training Range. The samples will be flown on Monday to a new lab at NASA's Johnson Space Center in Houston. The building already houses nearly 400kg (842lb) of moon rocks gathered by the Apollo astronauts more than a half-century ago.

A space capsule carrying a sample of rocky material removed from the surface of an asteroid three years ago is expected to make a parachute landing in the Utah desert on Sunday. If successful, the OSIRIS-REx mission, a joint effort between NASA and scientists at the University of Arizona, would mark the third asteroid sample, and by far the largest, ever returned to Earth for analysis. OSIRIS-REx collected its samples from Bennu, a carbon-rich asteroid, before embarking on a 1.9-billion-km (1.2-billion-mile) journey back to Earth in May 2021. The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) is an unmanned spacecraft from NASA that was sent to collect samples from Bennu. The spacecraft was equipped with cameras to capture images that were essential to collecting samples from the asteroid during the mission.

Its cargo is so precious it could help answer some of humanity's biggest existential questions. That's why there is so much excitement about the return of the OSIRIS-REx spacecraft, which will drop a capsule full of 4.5 billion-year-old space dust back to Earth on Sunday. The 8.8oz (250g) sample, audaciously grabbed from the mountain-sized asteroid Bennu in October 2020, could shed light on how life emerged on Earth and whether we are alone in the universe. OSIRIS-REx began its two-year, four-month journey home in May 2021, having been powered down to conserve energy during the trip. In the early hours of Sunday, however, the probe will be woken from this low-power mode ahead of its all-important delivery.

Planet Earth is about to receive a special delivery -- the biggest sample yet from an asteroid. A United States space agency (NASA) spacecraft will fly by Earth on Sunday and drop off what is expected to be at least a cupful of rubble it grabbed from the asteroid Bennu, closing out a seven-year quest. The sample capsule will parachute into the Utah desert as its mothership, the OSIRIS-REx spacecraft, zooms off for an encounter with another asteroid. Scientists anticipate getting about 250g (0.5lb) of pebbles and dust, much more than the teaspoon or so brought back by Japan from two other asteroids. No other country has fetched pieces of asteroids, preserved time capsules from the dawn of our solar system that can help explain how Earth -- and life -- came to be.

NASA has spent seven years trying to prevent Bennu -- an asteroid taller than the Empire State Building and named after ancient Egypt's fiery bird-god -- from crashing cataclysmically into Earth. While Bennu's chances of impact are just 1-in-2,700, more than five times a person's chance of being struck by lightning, NASA's team nevertheless has categorized it as one of the two'most hazardous known asteroids.' In a worst-case scenario, the roughly 510-meter wide, carbon-based behemoth would smash into Earth with 1,200 megatons of energy: 24 times the power of the largest nuclear bomb ever detonated (the Soviet Union's'Tsar Bomba'). If it happens, Bennu's impact would unleash its 1.2 gigaton impact 159 years from this Sunday, on September 24, 2182. While Bennu is nowhere near the size of the dino-killing, six-mile across space rock that hit the Yucatan 66 million years ago, astronomers believe that the asteroid'could cause continental devastation if it became an Earth impactor.'

It has been recently recognized that the surface of sub-km asteroids in contact with the space environment is not fine-grained regolith but consists of centimeter to meter-scale rocks. Here we aim to understand how the rocky morphology of minor bodies react to the well known space erosion agents on the Moon. We deploy a neural network and map a total of ~130,000 fragmented boulders scattered across the lunar surface and visually identify a dozen different desintegration morphologies corresponding to different failure modes. We find that several fragmented boulder morphologies are equivalent to morphologies observed on asteroid Bennu, suggesting that these morphologies on the Moon and on asteroids are likely not diagnostic of their formation mechanism. Our findings suggest that the boulder fragmentation process is characterized by an internal weakening period with limited morphological signs of damage at rock scale until a sudden highly efficient impact shattering event occurs. In addition, we identify new morphologies such as breccia boulders with an advection-like erosion style. We publicly release the produced fractured boulder catalog along with this paper.

This image shows a view of asteroid Bennu's rocky surface in a region near the equator. Scientists thought Bennu's surface was like a sandy beach, abundant in fine sand and pebbles, which would have been perfect for collecting samples. Past telescope observations from Earth had suggested the presence of large swaths of fine-grained material smaller than a few centimeters called fine regolith. But when NASA's OSIRIS-REx mission arrived at Bennu in late 2018, the mission saw a surface covered in boulders. The mysterious lack of fine regolith became even more surprising when mission scientists observed evidence of processes potentially capable of grinding boulders into fine regolith.

We present a novel approach based on artificial neural networks, so-called geodesyNets, and present compelling evidence of their ability to serve as accurate geodetic models of highly irregular bodies using minimal prior information on the body. The approach does not rely on the body shape information but, if available, can harness it. GeodesyNets learn a three-dimensional, differentiable, function representing the body density, which we call neural density field. The body shape, as well as other geodetic properties, can easily be recovered. We investigate six different shapes including the bodies 101955 Bennu, 67P Churyumov-Gerasimenko, 433 Eros and 25143 Itokawa for which shape models developed during close proximity surveys are available. Both heterogeneous and homogeneous mass distributions are considered. The gravitational acceleration computed from the trained geodesyNets models, as well as the inferred body shape, show great accuracy in all cases with a relative error on the predicted acceleration smaller than 1\% even close to the asteroid surface. When the body shape information is available, geodesyNets can seamlessly exploit it and be trained to represent a high-fidelity neural density field able to give insights into the internal structure of the body. This work introduces a new unexplored approach to geodesy, adding a powerful tool to consolidated ones based on spherical harmonics, mascon models and polyhedral gravity.