The exploration of our solar system has picked up in recent years with missions going to several asteroids. The spacecraft Galileo was the first NASA mission to fly past an asteroid. Galileo flew by Gaspara in 1991 and Ida in 1993[1]. Three very exciting missions have made it to the news most recently. The Lucy spacecraft was launched on October 16, 2021 and is on its way to study the Troyan asteroids, which orbit along the same orbit as the planet Jupiter. The NASA sample collector Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) brought back to Earth a sample taken from the asteroid Bennu in September 2023. Then the NASA Psyche mission launched on October 13, 2023, and is on a 6 year trip to a very interesting metal-rich asteroid of the same name.
The spacecraft Lucy got its name after a fossilized skeleton of a human ancestor found in Ethiopia in 1974. Why the same name? Like the fossil skeleton of Lucy, the Lucy mission will expand our knowledge of the origins of the planets in our solar system. Lucy will do this with flybys to 10 Troyan belt asteroids to gather information and test planet formation and evolution models. These models suggest that the Jupyter Trojan asteroids are the remnants of the formation of the outer planets, which formed in different locations and then traveled to their current orbits. Once Lucy gets close, it will use its cameras and spectrometers to study their surface geology, color and composition, interior, and properties like mass and density. This is the information the planetary scientists need to test their theories [2]. Lucy is currently traveling at a speed of 10,000 mph and approaching the Dinkinesh asteroid in the Asteroid Belt. The closest it will get will be 265 miles from the surface on November 1, 2023. The scientific team plans to use this encounter to test Lucy's systems and procedures.
Credit: NASA/GSFC]
OSIRIS-REx had different goals. The mission brought to Earth a sample capsule with rocks and dust collected from the surface of an asteroid named Bennu in September 2023. Scientists were thrilled when the initial study of the asteroid sample revealed evidence of high carbon content and water. These findings are significant, as scientists speculate that asteroids like this one fell on Earth and provided our planet with the building blocks of life[3].
Credit: NASA/Erika Blumenfeld & Joseph Aebersold
Credits: NASA/Keegan Barber]
Scientists from NASA's Goddard Space Flight Center and the University of Arizona have now opened the canister that was inside the capsule and found they have plenty of material to analyze, share with scientists worldwide, and even leave some for future generations of scientists. For the first study, they will utilize various instruments, including a scanning electron microscope (SEM), to conduct a full chemical and morphological analysis. Using infrared measurements, they will determine whether the sample contains hydrated minerals and organic-rich particles. Finally, with the help of X-ray diffraction (XRD), they will identify the proportion of minerals in the sample[4].
Credit: NASA/Goddard/University of Arizona]
The journey of OSIRIS-REx to Bennu started on September 8, 2016. The spacecraft arrived on December 3, 2018, but the team spent one year identifying the best landing area to collect a sample. They had to choose a crater they believed had formed recently, so they could obtain a pristine specimen of the asteroid[5]. OSIRIS-REx briefly touched down on the asteroid and collected dust and pebbles with its robotic arm on October 20, 2020. Two days later, the science team confirmed that the sample capsule had collected enough material and commanded it to close and start its return flight to Earth on October 28, 2020. But this was not the end of the OSIRIS-REx spacecraft. After delivering the sample capsule, OSIRIS-REx was renamed OSIRIS-APEX (OSIRIS-Apophis Explorer) and departed for an extended mission to the asteroid Apophis, a near-Earth object estimated to be about 1,100 feet across. OSIRIS-APEX will reach Apophis in 2029[6]. This asteroid made a distant flyby of Earth around March 5, 2021.
Credit: NASA/Goddard/University of Arizona]
A similar mission called NASA Psyche launched on October 13, 2023, and is on its way to retrieve a sample of one of the most intriguing objects in the Main Asteroid Belt. Psyche is a metal-rich asteroid with a squashed oval shape, much like an irregular potato 173 miles long and 144 miles wide. Scientific observations indicate that the asteroid could be a mixture of metal and silicate, much like that found in glass and laEarths core, with metal composing 30% to 60% of its volume. Radio observations indicate significant variation in the metal content and color on its surface. NASA will confirm these observations when the Psyche spacecraft approaches the asteroid[7].
Credit: Credit: NASA/JPL-Caltech/ASU]
This asteroid Psyche orbits the Sun in the outer part of the Main Asteroid Belt, about 250 million miles from the Sun and between Mars and Jupiter. If correct about the metal content, it could shed some light on how the cores of planets like ours formed.
Motivated by these explorations, private companies are now looking for ways to mine asteroids and extract valuable minerals in space at a lower cost and with a smaller carbon footprint than the current terrestrial mining methods. One of these companies is Astroforge. Their second mission is expected to launch in the first half of 2024. Their first mission, Brokkr-1, launched in April 2023 and went to an Earth orbit. This mission was only a demonstration to test the technology developed for extracting metals from asteroids. This spacecraft holds a device that uses a laser to vaporize a small amount of asteroid-mimicking material to separate substances and isolate valuable metals. The Brokkr-2 surveyor spacecraft mission will fly by an M-type asteroid and study its metallic composition and surface[8][9]. We will be checking their progress in the coming year.
Credit:Astroforge
References:
[1] https://science.nasa.gov/solar-system/asteroids/exploration/
[2] https://science.nasa.gov/mission/lucy/
[3] https://science.nasa.gov/mission/osiris-rex/
[4] https://blogs.nasa.gov/osiris-rex/2023/09/29/initial-curation-of-nasas-osiris-rex-sample/
[5] https://www.nasa.gov/news-release/x-marks-the-spot-nasa-selects-site-for-asteroid-sample-collection/
[6] https://science.nasa.gov/mission/osiris-rex/in-depth/
[7] https://science.nasa.gov/mission/psyche/
[8[ https://www.astroforge.io/
[9] https://interestingengineering.com/innovation/space-mining-startup-asteroid-resources-can-save-planet