Scientific Human Exploration of Venus as a Prelude to Mars

While NASA often talks about Mars being the next place for humans to explore after the Moon, a crewed flyby of Venus is an often overlooked—and arguably more logical—intermediate destination. Even for crewed Mars missions, the two-year, opposition class requires a Venus flyby gravity assist; and, if the Venus flyby were enroute to Mars, it would offer the chance for an abortive Earth return if needed. A human flyby of Venus allows 1) practicing the delayed, deep space communications of a Mars mission; and 2) experience with solar and galactic cosmic radiation in only a 1-1.5 year mission compared to a 2-3 year Mars mission and with much lower delta-V requirements. The confidence gained from such an experience would bolster the safety of a later human Mars mission. As the crew flies by Venus, they could teleoperate deployed or pre-deployed robotic landers, rovers, and aircraft at Venus to quickly collect in situ scientific observations of the surface, subsurface, and atmosphere allowing humans-in-the-loop responsiveness to time-limited near-surface investigations. Certain heliocentric trajectories around Venus could possibly even allow crew to stay within ~1 light minute (~18 million km) of Venus for months without needing the propellant to enter orbit. Augmented reality control of such systems by the astronauts—potentially using the planetary Avatar control interface being developed at Johns Hopkins APL—could enable rapid surface and atmospheric exploration. With Mars in NASA's sights for the human spaceflight program, and with formidable difficulties still ahead for safe and successful long-duration human spaceflight, it is now time to consider adding the scientific human exploration of Venus on the path to Mars.