Interplanetary Robots: True Stories of Space Exploration

Rod Pyle, Prometheus Books, 2019, 376 pages, $18, ISBN 978-1-63388-502-8

Rod Pyle’s book Interplanetary Robots is a detailed account of all of the major and some minor robotic spacecraft missions that have explored our solar system. Each chapter describes the goals, technical and political challenges, and scientific accomplishments of a mission or set of missions. Pyle’s intimate personal connections and thorough research brings the reader into the control room of each mission, capturing the excitement.

The book starts at the Center of the Universe (also known as the Jet Propulsion Laboratory Headquarters) on the eve of the Curiosity Rover landing on Mars. Pyle is there along with other members of the press and brings readers along with his backstage pass to the event. He introduces the reader to the place and the people that created many of the robot explorers. It is not Pyle’s first time to the Center of the Universe, nor will it be his last. Similarly, the book comes back to this place and the people who work there several times.

After this brief introduction to the heart of it all, Pyle follows a rough chronological sequence starting with the early days of the space race. Although the peak of the race was humans landing on the Moon, much of the race was run using robotic craft. Pyle reminds readers that the space race at its heart was really a show of military might. Rockets that propel robots into space are descendants of Nazi military missiles. Initial plans were not to land humans on the Moon, but to use nuclear weapons on its surface. Adverse public reaction, ruining the pristine lunar environment, and the chance of an accidental misfire in Earth’s atmosphere changed that outcome. Pyle captures the stresses and tensions involved with many failures before success as well as the public acclaim following each success. On the robotic front, the Soviets were far ahead of the US. They were the first to crash (purposefully) into the Moon, take pictures of the far side (using stolen US film), land softly, and operate a rover. To date, the Soviets are the only ones to have successfully landed on Venus, although the US did better at Mars. With the background of the cold war, Pyle tells of espionage: the US covertly stealing Soviet Luna technology and Soviets shooting down a US spy balloon to steal film and take the first pictures of the far side of the Moon.

As the space race, and consequently funding, starts to wane, missions are dictated by money. Everything sent into space requires a cost-benefit analysis. For many of the early missions, cameras were large and expensive and therefore considered unnecessary. Yet, cameras are the singular instrument that captured people’s hearts. Pyle explains that the presence of a camera on a spacecraft was evidence that someone (usually at the Center of the Universe) had won a difficult fight with NASA to get it included. It was first realized in 1965 that a special once-every-175-years planetary alignment of the outer planets would happen in the late 1970s, allowing for flybys of each of the outer planets. A grand tour was proposed and quickly rejected because of its expense. However, NASA quickly learned the wisdom of proposing smaller projects and then adding on later. They used this technique to eventually approve and fund the grand tour and the ongoing interstellar mission of the two Voyager spacecraft. Similarly, other missions such as Cassini (at Saturn) and the Spirit and Opportunity rovers (on Mars) were extended years past their original mission plans using the same à la carte idea.

In addition to covering the missions that did happen, Pyle covers several missions that didn’t happen. Several of these got well past the initial planning stages. These asides help provide insight to what could be possible in the future. Furthermore, every few chapters Pyle connects the missions of the past to future missions with a “Flashforward.” These include:

• missions to look for frozen water on the lunar surface,
• using a fleet of miniaturized satellites, “cube sats”, to improve communication at Mars,
• private entities landing rovers on the Moon,
• generating O₂ on the surface of Mars,
• future robots utilizing steam-powered machinery rather than advanced technology for a landing on Venus and other extreme environments,
• nano-probes accelerated with lasers destined to go interstellar distances.

In addition to these flashforwards peppered throughout the book, the penultimate chapter provides an annotated list of projects to look for in the next few years. Although the space age started as an international competition, it is now progressing with the help of collaboration.

Hillary Stephens
Professor of Physics and Astronomy
Pierce College Fort Steilacoom
Email: hstephens@pierce.ctc.edu