WASHINGTON — A massive fire at a contractor’s shop in Los Angeles destroyed flight hardware for NASA’s Osiris-Rex asteroid sample-return probe this summer, but the mission remains on track for launch in 2016, according to a recent report from the agency’s inspector general.

The July fire at Highland Plating Co. destroyed a metal box that was supposed to house the optics and electronics for the Osiris-Rex Visible and Infrared Spectrometer (OVIRS) that NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is building for the $800 million mission, which is designed to return a sample of the carbonaceous asteroid Bennu to Earth in 2023.

The fire also destroyed a spare optics box, according to NASA spokeswoman Nancy Jones. Local media reported in July that the fire caused $1.8 million in damage and took 130 firefighters two hours to extinguish.

Highland Plating, a Goddard subcontractor, did not make the boxes; the company was applying protective coating to the hardware to reduce the amount of stray sunlight that will reach OVIRS’s detectors when the instrument is in space, Dante Lauretta, principal investigator for Osiris-Rex, told SpaceNews via email.

OVIRS will scan Bennu for traces of the organic materials and minerals that scientists are most interesting in bringing back to Earth.

Since the fire, a new optics box and a spare have been made, coated by Highland Plating, and shipped to Goddard for integration with OVIRS, Lauretta said.

The fire cost Osiris-Rex’s program manager some $400,000 in reserve funding, according to a Nov. 14 report from the NASA inspector general, “NASA’s Top Management and Performance Challenges.”

If for any reason Osiris-Rex misses its launch window, the mission will have to wait six years before it has another shot at Bennu.

Osiris-Rex was selected in 2010 as the fourth in NASA’s New Horizons series of competitively awarded, medium-sized planetary science missions. Development costs are capped at $800 million in 2010 dollars, but the total mission cost runs to about $1 billion after the cost of launch and an X-ray spectrometer provided by the Massachusetts Institute of Technology are included.

The spacecraft is slated to launch from Cape Canaveral, Florida, in September 2016 atop a United Launch Alliance Atlas 5 rocket.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.