by Sam Dinkin
|The X-15 is the road not taken by the US space program|
X-15 first and foremost was a research program. It had a great deal of resources to counter the perceived threat to US international prestige posed by the Russian Sputnik satellite. While these resources were a blessing, they also proved unsustainable as Apollo became the new vehicle for prestige and Vietnam War ate up more and more money.
The X-15 project was also more expensive than the private space programs getting underway today. At $300 million in 1961 dollars—$1.5 billion in today’s dollars—it had vigorous backing. Today’s programs at Scaled and Rocketplane have 1-2% as much funding reported or about $20-$30 million each in today’s dollars. XCOR has also reported that it can produce a winged suborbital aircraft, the Xerus, for cost levels in that ballpark. These programs are also meant to be profitable, with Paul Allen breaking even possibly by SpaceShipOne’s 3rd spaceflight, winning the Ansari X Prize and increasing viewership for the Vulcan Video documentary. If the documentary alone pays for the creation of an X-15 style rocket program only four decades later, that bodes well for future documentaries of recreations of more ambitious programs (See “Space as Entertainment”, The Space Review, May 17, 2004).
Granted, some of the cost difference between SpaceShipOne, Xerus, and XP versus the X-15 is because the current planes are not trying for speed records, only high altitude. Nevertheless, cost and commercial operation may be the primary differences between today’s programs and the X-15 program although composites, avionics, design, propulsion, navigation, telemetry, ferrying, and control have all changed in the last 40 years.
As today’s private space programs pick up where the X-15 program left off, it is interesting to look back at the X-15.