Review: Dream Missionsby Jeff Foust
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| In Ehricke’s 1966 vision of the future, by 2001 there would be “manned vehicles of relatively luxurious and sophisticated design” traveling throughout the solar system, from Mercury out to Saturn. |
In the book, van Pelt rounds up some of those concepts proposed over the years and why they didn’t become reality. Chapters on launch vehicles include both extreme heavy-lift vehicles like the Nova as well as the various reusable vehicles proposed but never flown, including the X-33 and X-34. Giant ringed space stations and O’Neillian space colonies get coverage, as do space solar power concepts and human expeditions to Mars. Visions of grandiose robotic spaceflight are also included, from ambitious large space observatories to Mars sample return concepts to the recent concept of tiny laser-propelled spacecraft being studied by the Breakthrough Starshot project.
While the failures of individual projects are included in each chapter, van Pelt tries to offer an overarching perspective in the book’s concluding chapter. He concludes that many of the failed concepts covered in the book required a “perfect storm” of circumstances to be achievable, something that in retrospect clearly happened for Apollo but which has not been duplicated. (One argument van Pelt doesn’t make, but could be taken from that assessment, is that the fast pace of achievements in the early Space Age enabled by Apollo’s perfect storm skewed perceptions of what was feasible in spaceflight without realizing those conditions were short-lived.) He also notes that spaceflight advocates often gloss over the challenges of their grandiose proposals, and the funding required to enable them.
In the book’s conclusion, van Pelt returns to that Ehricke talk form 1966 and finds that some of his predictions weren’t too far off the mark. Ehricke thought that, by 2001, robotic spacecraft would have traveled “throughout the solar system and slightly beyond,” something that is arguably true today. He also predicted that “applications and utilizations of aerospace technology will become commonplace,” which can also be considered accurate looking at either spinoff technologies or the growing dependence on satellite systems for navigation, communications, and other applications.
Dream Missions offers a reminder, among its recounting of failed dreams, that some do still come true, if perhaps in different forms than once envisioned. Reusable rockets got a bad rap after the various programs either failed to get off the ground or, in the vase of the shuttle, failed to meet its ambitious predictions of flight rates and costs. But, in the last few years, SpaceX has made the recovery of its Falcon 9 first stages almost commonplace, and a substantial fraction of its launches now use “flight-proven” boosters. We’re still far from the promised land of $10 per pound to low Earth orbit, but sometimes dreams do become reality—just not the way we imagined them.