NASA is celebrating the first successful landing on Mars by a U.S. spacecraft – Viking 1 — with a history discussion from 2 to 3:30 p.m. EDT Tuesday, July 19, and a Viking 40th anniversary symposium 8 a.m. to 5:10 p.m. Wednesday, July 20 at NASA’s Langley Research Center in Hampton, Virginia.

Portions of these events that highlight the initial steps on the Journey to Mars will air live on NASA Television and stream on the agency’s website.

Media interested in attending the talk and/or all or parts of the symposium should contact Sasha Ellis at sasha.c.ellis@nasa.gov or 757-272-9859 no later than noon July 19.

The July 19 history talk will include a panel of NASA historians and Roger Launius of the Smithsonian National Air and Space Museum, who will speak about the history of NASA’s Viking missions.

The symposium on July 20, called From NASA’s First Soft Landing to Humans on Mars, will include a lineup of about 20 speakers, including former Viking program scientists and engineers, The Martian author Andy Weir, NASA’s Associate Administrator for Space Technology Steve Jurczyk, and other key members contributing to past, present and future Mars missions.