“We shall not cease from exploration and the end of all our exploring will be to arrive where we
started and know the place for the first time.”~T.S. Eliot
Earth’s Formation and Early History:
The Earth, which coalesced from the primordial solar nebula approximately 4.5 billion years ago, underwent a dynamic transformation from an initial state characterized by intense heat and a molten surface. Gradual cooling allowed for the emergence of the first oceans, which played a pivotal role in the eventual evolution of complex life forms on our planet.
The OSIRIS-REx Mission:
NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) mission, initiated in September 2016, embarked on a scientific exploration of the asteroid Bennu with the primary objective of collecting a regolith sample. In October 2020, OSIRIS-REx executed a precision maneuver known as the “Touch-and-Go” (TAG) operation to secure a sample from Bennu’s surface.
Spacecraft and Subsystems:
The OSIRIS-REx spacecraft exhibits a cubic form, measuring 2.72 meters in height and 3.1 meters in width, equipped with solar panel wings for power generation, lithium-ion batteries for energy storage, and 200 N hydrazine thrusters for propulsion. Communication with Earth is facilitated through a 2-meter highgain directional dish antenna.
Sample Collection Mechanism:
The vital task of acquiring a sample from Bennu was accomplished through the Touch and Go Sample Acquisition Mechanism (TAGSAM). This mechanism employs an articulated arm and a sampler head, utilizing nitrogen gas to fluidize surface regolith and facilitate collection. Additionally, surface contact pads were used to gather material directly from the asteroid’s top layer.
Scientific Instruments:
The spacecraft’s scientific instrument suite includes the OSIRISREx Camera Suite (OCAMS) for high-resolution imaging, OSIRIS-REx Laser Altimetry (OLA) to measure the asteroid’s topography, OSIRIS-REx Visible and IR Spectrometer (OVIRS) for surface composition analysis, OSIRIS-REx Thermal Emission Spectrometer (OTES) to assess thermal properties, and a subsystem for tracking the spacecraft’s mass and gravitational interactions.
Mission Timeline:
OSIRIS-REx was launched on September 8, 2016, from Cape Canaveral Air Force Station. After an Earth flyby in 2017, it approached Bennu in 2018, executing a series of maneuvers to study and select a sample collection site. The TAG operation occurred on October 20, 2020, during which nitrogen gas was used to assist sample collection.
Sample Return and Analysis:
The sample, stored in a return capsule, re-entered Earth’s atmosphere on September 24, 2023, and landed in the Utah desert. The analysis of the returned sample will provide essential insights into the composition of Bennu and the early solar system’s chemical characteristics.
Future Perspectives of OSIRIS-REx Mission:
The mission’s immediate focus involves the extensive analysis of the collected sample, potentially resulting in numerous scientific publications. The data and findings from the mission will contribute to our understanding of asteroids, solar system formation, and potential asteroid resources. Future possibilities include an extended mission, technology development, contributions to planetary defense strategies, educational outreach, international collaborations, and long-term sample storage for continued research.
Astronomical and Astrobiological Perspectives: Astronomical perspectives encompass exoplanet exploration, the study of stellar evolution, the search for extraterrestrial
intelligence (SETI), cosmic chemistry, and the investigation of cosmic habitability zones. Astrobiological perspectives include the study of life in extreme environments, Mars exploration, ocean worlds, exoplanet biosignatures, panspermia hypotheses, and ethical and philosophical considerations.
Conclusion:
The OSIRIS-REx mission represents a significant milestone in space exploration, with the potential to reshape our understanding of the early solar system. Simultaneously, the
fields of astronomy and astrobiology converge to explore the vastness of the universe, identify potential habitable environments, and search for evidence of life beyond Earth.
These disciplines are highly dynamic, marked by technological advancements and a profound curiosity about our place in the cosmos.
References:
- https://science.nasa.gov/mission/osiris-rex/
- https://www.asteroidmission.org/
- PANSPERMIA ARTICLE: Anisha Patil, 2021, http://www.ijariit.com