Main-belt comets are a rare sub-class of comets that have mostly circular orbits entirely confined to the main asteroid belt between the orbits of Mars and Jupiter, but show comet-like behavior – ejecting material that creates a fuzzy appearance and often tails – that astronomers believe is produced by sublimation – or the transition of ice directly to gas – of icy material. Planetary Science Institute Senior Scientist Henry Hsieh is a co-author on the paper. Hsieh (Planetary Science Institute), Alyssa Pagan (STScI)Īfter 15 years of attempts, researchers using the James Webb Space Telescope (JWST) have for the first time successfully detected water outgassing from a main-belt comet.Ī recently published Nature paper “ Direct detection of water from a main-belt comet with JWST” led by Michael Kelley of the University of Maryland reports the first direct spectroscopic detection of water outgassing from a main-belt comet named Comet Read. The SRC releases 4 hours prior to atmospheric entry interface and, using the Stardust capsule heritage design, employs a traditional drogue and main parachute descent system for a soft touchdown.Composite near-infrared image of Comet Read created from data captured by JWST’s Near-Infrared Camera (NIRCam) on September 8, 2022, showing the comet’s appearance at the time of a successful water outgassing detection by JWST. The final two trajectory correction maneuvers bring the spacecraft on target toward the Utah Test and Training Range (UTTR), with sufficient time for contingency resolution. ![]() ![]() The spacecraft is targeted away from the Earth until 7 days before entry. As OSIRIS-REx approaches Earth, the reentry plans are reviewed starting about a year before arrival, and preparations begin. During the cruise, tracking and trajectory correction maneuvers (TCMs) are performed as necessary to precisely target the entry corridor. No additional large deterministic maneuvers are required to return the SRC to Earth. Following sample collection, OSIRIS-REx drifts away from Bennu until the Asteroid Departure Maneuver is commanded on March 4, 2021, sending OSIRIS-REx on a ballistic return cruise to Earth. Highlights of the mission are included below.The OSIRIS-REx spacecraft provides the essential functions for an asteroid characterization and sample return mission: attitude control propulsion power thermal control telecommunications command and data handling structural support to ensure successful rendezvous with Bennu characterization of Bennus properties delivery of the sampler to the surface, and return of the spacecraft to the vicinity of the Earth sample collection, performed by the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), to acquire a regolith sample from the surface Earth re-entry and SRC recovery. Study of Bennu addresses multiple NASA objectives to understand the origin of the Solar System and the origin of life and will provide a greater understanding of both the hazards and resources in near-Earth space, serving as a precursor to future human missions to asteroids.This paper focuses on the technical aspects of the Sample Return Capsule (SRC) design and concept of operations, including trajectory design and reentry retrieval. Bennu is both the most accessible carbonaceous asteroid and one of the most potentially Earth-hazardous asteroids known. ![]() ![]() The return to Earth of pristine samples with known geologic context will enable precise analyses that cannot be duplicated by spacecraft-based instruments, revolutionizing our understanding of the early Solar System. Targeting the near-Earth asteroid Bennu, the mission launches in September 2016 with an Earth reentry date of September 24, 2023.OSIRIS-REx will thoroughly characterize asteroid Bennu providing knowledge of the nature of near-Earth asteroids that is fundamental to understanding planet formation and the origin of life. The overall mission design and current implementation are presented as an overview to establish a context for the technical description of the reentry and landing segment of the mission.The prime objective of the OSIRIS-REx mission is to sample a primitive, carbonaceous asteroid and to return that sample to Earth in pristine condition for detailed laboratory analysis. OSIRIS-REx, Returning the Asteroid Sample This paper addresses the technical aspects of the sample return system for the upcoming Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission.
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