OSIRIS-REx Taking Shape, Engineers Explain Innovative Asteroid Sample Return Mechanism

Artist concept of OSIRIS-REx. Image Credit: NASA/Goddard/University of Arizona
Artist concept of OSIRIS-REx in the environs of Asteroid Bennu, sometime after 2018. Image Credit: NASA/Goddard/University of Arizona

While avid space watchers may thrill to missions such as Stardust (which returned a sample from a comet), Dawn (which visited an asteroid and dwarf planet), and Rosetta (which placed a lander upon a comet’s surface), sometimes the significance of smaller solar system body missions is lost on the general public, as planetary missions seem more “glamorous.” Enter OSIRIS-REx (short for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer), which is on track for a September 2016 launch from Cape Canaveral Air Force Station’s (CCAFS) Space Launch Complex 41. This mission has been described as a “game changer” in small Solar System body exploration.

Why? This $800 million-plus mission is slated to send a spacecraft to the asteroid 101955 Bennu, eventually returning a sample to Earth in 2023. While it sounds “cool,” this NASA New Frontiers mission, selected by NASA in 2011, is more than just flashiness: It hopes to discover how the Solar System came to be and how life originated on our own planet, as asteroids are believed to be relics of the early Solar System. As the project’s website asks: “OSIRIS-REx seeks answers to the questions that are central to the human experience: Where did we come from? What is our destiny?” OSIRIS-REx exists to unveil the answers to these age-old questions.

The mission will start in Florida at CCAFS, launched aboard an Atlas V 441. After a two-year cruise, OSIRIS-REx is expected to arrive at 101955 Bennu in August 2018 to begin its scientific observations, which will include (but is not limited to) extensive mapping, checking for other satellites, and finding an optimal sample site. In 2023, the mission is expected to return a capsule back to Earth containing a sample of the carbonaceous asteroid (notably, carbon is the basis for life on our world).

OSIRIS-REx mission insignia with partners. Image Credit: OSIRIS-REx website
OSIRIS-REx mission insignia with partners. Image Credit: OSIRIS-REx website

Earlier this year, construction commenced on the spacecraft; a previous AmericaSpace report from March stated: “The System Integration Review—where the plan for integrating the scientific instrumentation, electrical and communication systems, and navigation systems are all looked over—was completed at Lockheed Martin’s Littleton, Colo., facility last month. Launch and test operations officially began March 27, marking a critical stage of the program know as ATLO, or assembly, test and launch operations. Over the next six months technicians with Lockheed will install the subsystems on the main spacecraft structure, comprising avionics, power, telecomm, thermal systems, and guidance, navigation, and control.” According to the article, the assembly is taking place after nearly four years of what was described as “intense design efforts.”

In July, NASA announced that the spacecraft had completed a critical Mission Operations Review (MOR), administered at the Goddard Space Flight Center in Greenbelt, Md., and is on track for a September 2016 launch.

While the spacecraft continues to take shape, a challenge posed to engineers designing OSIRIS-REx’s hardware included how to fabricate an appropriate sampling device. A “scoop” sampling device, used in previous planetary missions as far back as the Viking landers in the 1970s, may not prove to be most effective in a low-gravity environment such as an asteroid. Lockheed Martin’s Jim Harris answered the call to this issue, inventing TAGSAM (Touch and Go Sample Acquisition Mechanism).

Harris described the mechanism that makes this particular instrument work on such a mission: “Imagine a cup with air injected on one side, then holes on the other side and a filter outside of the holes. We used a compressor to blow air against the ground. As the air went out through the holes and through the filter, we collected particles.” He and his son tested TAGSAM prototypes at their home in Denver, Colo., on materials as diverse as popcorn, dirt, and rock. “It’s a very simple design, and we’ve done an extensive amount of testing. When you consider the full range of what the surface can be—from a rubble pile to a big rock with loose gravel on top, we’re ready,” he underscored confidently.

Video Credit: NASA Goddard on YouTube

The mission, which was synthesized by the University of Arizona with partners, has a better chance of returning rich samples utilizing this innovative method. Ed Beshore of the university enthused: “Rather than trying to land on the surface of Bennu and anchor ourselves in the asteroid’s microgravity environment—which is very difficult to do—we can just touch the surface using an elegant mechanism that has few moving parts and then quickly move away. This gives us a high degree of confidence that we are going to be able to pull this off.”

Technologies such as TAGSAM will undoubtedly aid NASA in its near-future human-helmed mission objectives, as the space agency has been developing an Asteroid Redirect Mission (ARM) for several years. NASA announced in March it will move forward with the Robotic Boulder Capture Option, bringing a near-Earth Asteroid (NEA) into the Moon’s orbit for eventual human exploration during the mid-2020s. OSIRIS-REx’s collection technologies and scientific findings will aid scientists and engineers immensely, making that “next giant leap for mankind” (or womankind) possible within the next decade.

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