- NASA’s OSIRIS-REx spacecraft to release a capsule with asteroid material collected from Bennu.
- The capsule will face intense temperatures and swift velocity during reentry.
- Weather conditions, including wind, rain, and desert terrain, pose challenges for retrieval.
- Scientists prepare for various weather scenarios and monitor conditions using weather balloons.
After an epic, billions-of-miles-long trip across our solar system, NASA’s OSIRIS-REx spacecraft will make a historic flyby of Earth in September.
During this celestial visit, it will unleash a mini-fridge-sized capsule, harboring a precious cargo—an assemblage of primordial space rock acquired from an asteroid nestled amidst the orbits of Earth and Mars.
This spacecraft, named OSIRIS-REx, an acronym for “Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer,” is an epochal endeavor, representing the maiden U.S. mission dedicated to the collection of an asteroid sample.
The celestial bounty, obtained from the asteroid Bennu in 2020, comprises approximately half a pound of granular debris and dust from the asteroid’s surface.
Scientists are eagerly anticipating that this pristine material will serve as a time capsule, unlocking glimpses into the distant past—specifically, the epoch when the Sun and planets commenced their formation some 4.5 billion years ago.
However, before this coveted sample can fulfill its destiny, it must endure a harrowing descent. Encased within its protective capsule, it will confront temperatures that rival the intensity of molten lava and attain the second swiftest velocity ever achieved by a man-made object upon entering Earth’s atmosphere.
When it embarks on this perilous journey, the capsule may contend with unpredictable atmospheric conditions, including wind, rain, and other meteorological vagaries as it approaches the Earth’s surface.
Irrespective of meteorological conditions, its ultimate destination is the Great Salt Lake Desert, an arid expanse celebrated for its blistering summertime temperatures and the vestiges of a prehistoric lakebed now adorned with a crust of salt deposits.
While the focus is often centered on the spacecraft’s technical intricacies and the capsule’s landing dynamics, a cadre of scientists and meteorologists will remain vigilantly attuned to the capricious weather, a factor that can significantly influence the capsule’s retrieval.
Eric Queen, a research engineer affiliated with NASA’s Langley Research Center in Hampton, Virginia, elucidates the capsule’s preparation for a gamut of plausible weather scenarios: “Before we launched seven years ago.
While the capsule boasts resilience against elements such as lightning and ice, Mark Johnson, leading the Entry, Descent, and Landing (EDL) analysis at Lockheed Martin, Colorado, underscores the paramount concern of wind dynamics.
This concern is rooted in the potential effect of wind speed and direction on the capsule’s touchdown point within the designated landing zone, measuring 36 miles by 8.5 miles (58 kilometers by 14 kilometers), situated in the Department of Defense’s Utah Test and Training Range, southwest of Salt Lake City.
The landing zone, referred to as a “safe, controlled area,” holds historical significance as it served as the landing site for the Stardust mission.
Additional contemplation was given to the conditions on the ground itself. Late summer in the desert coincides with the monsoon season, introducing the possibility of heavy rains saturating the silt-laden terrain. The emergence of mud resembling wet cement could complicate transportation, especially if off-road vehicles are required to assist helicopters in locating and ferrying the capsule.
To support the OSIRIS-REx mission, the team will launch weather balloons in the days leading up to the capsule’s return. These single-use balloons ascend to altitudes of approximately 60,000 feet, roughly double the cruising altitude of commercial jets.
As they ascend at a rate of 18 feet per second, they relay vital data on temperature, humidity, pressure, and wind before rupturing at high altitudes. These observations will be employed to estimate the capsule’s probable landing position within the designated range.
The capsule’s homestretch will commence when it separates from the OSIRIS-REx spacecraft and penetrates Earth’s atmosphere, approximately four hours later, along the West Coast.
Hurtling through space at hypersonic velocities, this roughly 100-pound capsule will rely on a protective entry system fortified by a heat shield constructed from lightweight ablative material, an invention originating from NASA’s Ames Research Center in California’s Silicon Valley. This ingenious shielding is engineered to withstand extreme temperatures.
Throughout its descent, radar and infrared tracking systems will diligently monitor the capsule’s progress.
As it streaks eastward on September 24th, traveling at speeds exceeding 1,150 mph, several aircraft, including a high-altitude WB-57 research plane from NASA’s Johnson Space Center in Houston, will shadow its trajectory, employing visual and thermal imaging systems.
The capsule will engage its drogue parachute at a velocity of around 1,150 mph, followed by the deployment of a round, main parachute closer to the ground to ensure a gentle touchdown.
The choice of a round parachute, rather than alternative designs, enhances stability and diminishes susceptibility to gusts of wind, thus reducing the likelihood of deviating from the intended landing site.
Upon safely alighting on Earth’s surface and undergoing retrieval by a specialized team, the precious sample will be transported to a specialized laboratory at NASA’s Johnson Space Center for preservation and extensive scientific analysis.
This historic landing will also serve as a valuable case study, informing future missions involving the safe delivery of celestial cargo.