On December 3, 2018, the NASA Urprices, the spectral interpretation, the resource identification and the security regolite explorer (Osiris-Rex) successfully took the Bennu of Naherde-Salenoid (NEA) 101955. In the next two years, the Stein and Regolith samples from the surface of the asteroid collected. Until September 24, 2023, the rehearsal return capsule (SRC) entered the earth's atmosphere and was collected by NASA scientists. The analysis of these samples already provides insights into the conditions during the early solar system.
According to a recently carried out study, the well -known trajectory and the time of the return of the SRC offered a rare opportunity to record geophysical signals that were created by the capsule using a new method. Since it was traveling with hyper -sound speeds when it flew through the atmosphere, the return of the SRC led to a sound boom that affected the floor. Using the distributor (Distributed Acoustic Sensing) and fiber-optical cables with surface-strong surfaces), the team carried out the first reported recording of an SRC re-entry with distributed fiber-optical recording technology.
The team was made by Dr. Carly M. Donahue led and consisted of her colleagues from the Earth and Environmental Sciences department in the Los Alamos National Laboratory (Lanl) as well as the Department of Geosciences at Colorado State University and the fiber optic-based Silixa LLC. The paper, which describes its results “Detection of a spatial capsule in the earth's atmosphere with distributed acoustic cereal (das)”, recently appeared in the magazine Seismological Research Letters.
The sample return capsule from the Osiris Rex mission can be seen shortly after the appearance in the desert in Utah on September 24, 2023. Credit: NASA/Keegan Barber
Since the end of the Apollo era, scientists have examined rehearsal return capsules that have entered the atmosphere of the earth. These studies have helped scientists to return safe and effective methods for missions of samples and to provide an insight into the atmospheric entry of meteoroids and asteroids. So far, these studies have used infrastrate and seismic sensors to record the resulting geophysical signals. Dr. However, Donahue and her team saw an opportunity because the trajectory and the Timing of the SRC of Osiris-Rex Mission were known in advance.
Like Dr. Today Donahue said by e -mail to Universe, the re -entry was a chance for her to test the systems with fiber optic cables to record the geophysical effects generated by the Sonic Boom. “The system that question an optical fiber is still relatively rare,” she said. “If we know in advance, the exact trajectory gave us the narrow opportunity to set several the interrogators near the point of the highest heating and to conquer the sound boom if it influenced the soil.”
The team rapidly used two das-hearing and more than 12 km (7.45 mi) of fiber optic cables with surface systems. Your network comprised six compiled seismometer infrasound sensor couples, all of which were distributed at two locations near the city of Eureka in the desert of Nevada. Like Dr. Donahue described:
“As soon as the team rolled out the 4 coils of the optical fiber, each weighed over 100 kg, the installation and rels of the fiber needed less time than building the six co-located seismic and infrastination stations. About 5 km of the optical fiber were located at the local Eureka airport, together with many other teams that use sensors such as Infrasund, Seismic and GPS. The other 7 km fiber were located along a remote gravel road in Newark Valley. “
https://www.youtube.com/watch?v=hwrv7x69uci
With the help of this network, the team received a breathtaking profile of the sound boom when it hit the floor. The interrogators recorded an impulsive arrival with an extended coda that had similar features as the characteristics recorded by the seismometers and infrastensors. While traditional sensors only measure the sound booms at one point, Dr. Donahue that her team's data showed how the wave front of the boom had an impact on the irregular area of the landscape in Nevada.
In addition to the first time, these methods were used to record SRC recovery, but also the results of this test to predict a potential meteor and asteroid strike. Said Dr. Donahue:
“With an extremely dense series of sensors, this gives the opportunity to better characterize the trajectory and the size of a meteor. It is known that the topology (e.g. hill) of the soil has an impact on the wave front that was recorded on the surface of the earth. Through a dense line of sensors that extend over the changes in the increase in earth, these effects could be better taken into account in order to create a more precise characterization of the trajectory of a meteor. “
After completing its main task, NASA prepared the Osiris-Rex the spaceship for the next phase of its mission. In 2029, the spaceship-in Osiris-APEX (Apophis Explorer) will be renamed the near Earth-Salenoid 99942 Apophis and collects a different sample.
Further reading: GeoscienceWorld
Like this:
Load…
