By Lee Goldberg

What’s at Stake:

NASA investigated multiple launch systems to put a man into Space and ultimately decided to put the Mercury capsule atop derivatives of ballistic missiles. 40 years later, economics and technology evolution allowed the engineers and scientists working on SpaceShipOne, to make a different decision.

The first two crewed Mercury flights were carried on their suborbital trajectories by human-rated derivatives of the Redstone ballistic missile. These rockets were highly-evolved versions of the V2 ballistic weapons originally developed by Wernher von Braun that Germany used to bombard Britain during WWII.

Among the direct similarities between the two rockets was the use of a 75 percent alcohol/25 percent water fuel mixture and liquid oxygen (LOX) as its oxidizer, and a steering mechanism which used a set of carbon vanes placed just below the rocket exhaust. Although the Redstone’s Rocketdyne A-7 motor, and the turbopumps, that fed it were significant improvements on those used by the original V2, their basic concepts and functions were remarkably similar.

To achieve the velocities needed for orbital flights, subsequent missions were flown aboard an Atlas-D rocket, originally created to serve as an intercontinental ballistic delivery vehicle for nuclear weapons. Powered by a pair of Rocketdyne XLR-85 engines burning kerosene and liquid oxygen that produced up to 360,000 pounds of thrust, and an LR-101 sustainer engine, the Atlas used super-thin fuel tanks and other lightweight construction techniques to maximize its payload capacity.

Read More »Mercury and SpaceShipOne: Very Different Launch Systems

By Lee Goldberg

What’s at Stake:

In the beginning, US efforts in Space were largely driven by militaristic goals and the belief in US exceptionalism. Later, while those motivations still existed, the pioneer spirit and entrepreneurialism pushed further development.

In late 1958, the U.S. government’s fear of falling behind the Russians drove NASA to impose an ambitious schedule on the Mercury program that included the production of the capsules that would be used for the first crewed flight on May 5, 1961, and five subsequent missions, as well as several engineering prototypes.

Designed and integrated by McDonnell Aircraft, the vehicles’ compact structure provided just enough room to shoehorn in an astronaut and their space suit, along with the minimum complement of life support, communication, propulsion, and guidance systems needed to support brief forays into space.

Mercury’s aluminum and titanium structure was sheathed in panels made of Rene 41, a heat-resistant nickel-based alloy. The capsule was equipped with small hydrogen peroxide-powered thrusters that could orient the craft while in orbit and three solid-fuel retrorockets which could be fired to slow the craft down enough to fall towards Earth. The cone-shaped vehicle would reenter the atmosphere leading with its blunt circular base, protected by an ablative heat shield that used the same principles and technologies originally developed to enable ballistic nuclear warheads to survive the fiery conditions they would encounter on the way to their targets. Mercury’s nose contained three parachutes which would deploy after entering the lower atmosphere, further slowing the craft to make a relatively soft water landing where it would be plucked from the ocean by helicopters and delivered to a nearby ship.

Read More »Mercury and SpaceShipOne: The Spacecraft

By Lee Goldberg, Contributing Editor

What’s at Stake:

Technological evolution is about building on the foundations and lessons of the past. The heritage of the US Space Program is a testament to that evolution. There is great value in comparing and contrasting two groundbreaking “firsts.” Read the 3-part mission to learn more.

More than six decades ago, Alan Shepard became the first American in space aboard a Mercury capsule which was propelled into its suborbital flight by a rocket derived from the V2, a WWII-era ballistic weapon. Roughly forty years later, Mike Melvill piloted SpaceShipOne, a privately funded, air-launched, rocket-propelled vehicle to the edge of space, becoming the world’s first licensed commercial astronaut.

Although they served very different objectives and were separated by decades of technological advances, each project laid the foundations for the more advanced missions that followed. Surprisingly, Mercury and SpaceShipOne also shared several important elements that contributed to their missions’ success. In this first of a three-part series, we’ll look at both spacecraft to see how they were different and, especially, how they were similar.

Two Very Different Spacecraft – or were they?

At first glance, the Mercury capsule and SpaceShipOne appeared to have had little in common. 

Read More »Mercury and SpaceShipOne: 40-years of Technical Evolution