Rod Pyle's Secrets of Apollo: the missions that might have been
In our six-part series, author and spaceflight expert Rod Pyle looks at at some of the daunting challenges of the lunar landing effort, and the incredible engineering feats that allowed the Apollo programme to succeed.
The lunar missions of Apollo are well chronicled, but there were extensive plans made for follow-on missions, of which only 1973 ‘s Skylab and 1975’s Apollo-Soyuz survived.
Starting in the mid-1960s, the Apollo Applications Program, which was overseen by Apollo 12 and Skylab astronaut Alan Bean for a time, dreamed up various ways to continue using Apollo hardware after the lunar landing program.
These included Apollo-derived space stations, lunar outposts, Lunar Module-based 'moon trucks' and even a possible Mars flyby.
But of these mission plans, perhaps the most inspired—or outlandish, depending on your point of view—was one that outlined a crewed flyby of the planet Venus.
NASA had flirted with the notion of sending a spacecraft on a free-return trajectory to Mars, Venus, or possibly both for a number of years.
A number of studies were contracted out and while complex and expensive, there were no technical hurdles that could not have been overcome with enough engineering and money.
The Saturn V had the power to launch the spacecraft toward Venus, the Apollo capsule would soon be battle-tested via the lunar flights, and the upper stage of the Saturn rocket- the S IV-B stage - could have been converted into a habitat for the Venus-bound explorers.
Protecting them from the ghastly amounts of solar and cosmic radiation was another matter, and a major solar event such as a coronal mass ejection, could have done serious harm to the astronauts, even with extra shielding installed in the Apollo capsule.
Nonetheless, the plan was seriously considered for a time.
The round trip to Venus and back would have taken just over a year, with the crew living in quarters about the size of a small apartment.
While their loop past Venus would only last a few hours, they would drop various probes into the planet’s atmosphere and conduct astronomy en route from a large telescope mounted on the S IV-B stage.
In the end, the Apollo Applications Program’s budget was cut along with the rest of the post-Apollo 17 lunar flights, dooming the more exotic mission plans.
But had it been attempted, Apollo’s journey to Venus would have been an amazing - if dangerous - journey.
This article originally appeared in the August 2019 issue of BBC Sky at Night Magazine.
Rod Pyle is the author of 15 space books and Editor-in-Chief of Ad Astramagazine for the National Space Society.