The NASA OSIRIS-Rex spacecraft is on a first-of-its-kind mission to analyze and sample an asteroid called Bennu 200 million miles from Earth. Traveling onboard is a tiny, but highly sophisticated VIAVI optical filter array that is playing a critical role in the OSIRIS-Rex mission, enabling scientists to analyze the chemical composition of Bennu’s surface.
About the Mission
Thursday, September 8, 2016, NASA launched Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, OSIRIS-REx for short. This mission is the first of its kind to study and take samples from Bennu, a near-earth asteroid of special interest to planetary astronomers. The asteroid is a rare, “B-type”, asteroid dating back to the earliest days of our solar system and is carbon-rich, with the potential to contain chemical building blocks of early life on earth. Bennu is interesting in another way, too: there is a small probability that it will collide with the earth late in the 22nd century, with potentially dramatic consequences to life here. On Tuesday, October 20, 2020, the spacecraft descended to Bennu’s surface and performed a “Touch-and-Go” (TAG) maneuver and collected a sample of the asteroid before making the long trip back home.
OSIRIS-REx is expected to return home with its payload in late 2023.
The VIAVI Linear Variable Filter (LVF)
Deep inside the spacecraft are tiny, but highly sophisticated optical filters, critical to the success of the mission – VIAVI Linear Variable Filters (LVF). These filters are bandpass filters that have been intentionally wedged in one direction, providing a position-dependent dispersive optical element. LVF are ideally suited for use in compact instruments requiring high spectral resolution. The chemical survey of Bennu’s surface was done primarily by an instrument called OVIRS – OSIRIS-REx Visible and Infrared Spectrometer – that incorporates the VIAVI filter. The OVIRS images help mission scientists analyze the chemical composition of the surface and choose a sample site. Once the site was chosen, OSIRIS-REx arrived at the surface, scooped up a handful of rock and dust and the sample capsule for the return to Earth.