The planetary scene 60+ years ago, and how it suddenly changed with Mariner 4

On July 15, 1965, human understanding of another planet in the solar system took a remarkable turn. That was the day Mariner 4, the first successful mission to Mars, encountered and took close up photos of that planet. By today’s smart phone standards those images are laughingly crude; then they were amazing.

Roger Bourke had recently joined JPL after receiving his PhD in Aeronautics & Astronautics from a prominent Bay Area university; hint, it’s not Cal. Two days before Mariner 4 had been launched after many tense days following the mission failure of Mariner 3. The ensuing 10 months were breath holders as the spacecraft ventured further away from the sun than any robotic being had ever before done. Would things work? Would the camera turn on? A few months earlier Ranger 6 had gotten to the moon successfully but in the final few minutes the camera failed and no images were transmitted. Was the spacecraft on the right trajectory? Mariner 2, which was the only other mission to reach another planet, would have passed on the wrong side of Venus had not an updated value of the AU been recently adopted. Roger, although new to the Lab, was acutely aware of the tension. But it did work and the images that came down, at a stunning rate of 8 1/3 bits/sec, revealed a surface that few if any expected.

Roger will tell this story from the perspective of young engineer who was actually there.

EAS is truly fortunate to have such a distinguished speaker. Dr. Bourke played an important role as a mission planner for a number of missions in the early days of the Jet Propulsion Laboratory. Among many other major accomplishments, Dr. Bourke was one of the originators of the idea of taking advantage of a fortuitous alignment of the planets to do a “Grand Tour of the Solar System,” a mission which ultimately became the Voyager missions.

The speaker will present remotely