Using A Method Developed 50 Years Ago, NASA Aims Toward The Future.

By Wes Oleszewski

Waiting, fully assembled on its Mobile Launch Platform, the Ares I-X flight development vehicle carries forward a form of flight testing that was used in the early days of launch vehicle evolution.

Ares I-X Assembled

Consisting of a single, four segment Space Shuttle SRB plus a fifth segment simulator, a dummy upper stage, a spacecraft mock-up and a dummy Launch Abort System the Ares I-X is designed to validate computer modeling and gather data on suppositional issues such as bending moments, thrust oscillation and drift at liftoff. Testing of this kind has its roots in early projects such as the Titan I ICBM, Mercury Redstone and Saturn I.

Prior to the "All-Up" testing method that, was first implemented in the Minuteman ICBM, the standard for development of launch vehicles was the step-by-step method. In that method, every aspect of a vehicle's lower stages had to be well understood before adding the next stage. One of the best examples of the testing with dummy upper stages was the Titan I, Lot A, vehicles that began flying on February 6, 1959. The four Lot-A Titan I vehicles all had dummy upper stages that had little resemblance to the operational upper stages, yet valued data and handling procedures were gained by those flights.

Lot A Titan Photo Courtesy USAF

In the summer of 1961 that first Saturn I launch vehicle was stacked at Launch Complex 34 and launched in late October of that year. This "Block I" launcher carried two dummy upper stages filled with water to simulate fuel. The first four Saturn I vehicles differed greatly from the Block II launchers that, at the time, were intended for manned flight. The Block I vehicles had no fins, a different adapter skirt, no Instrument Unit and no Apollo spacecraft or escape tower. Additionally, the Block I vehicle's fuel and LOX tanks were approximately six feet shorter than the Block II.  Although the Block I Saturns bore little resemblance to the planned Block II and even less resemblance to the later Saturn IB, which actually did carry astronauts into space, the Block I launchers and their dummy upper stages provided valuable data and revealed equipment flaws that provided the Apollo moon program with a solid foundation on which to build.

Perhaps the most often overlooked launcher with a dummy payload is the MRBD, or the Mercury Redstone Booster Development flight. This flight was the result of 11 glitches that showed up in the final Mercury Redstone "Chimp" flight.  The MRBD was inserted into the schedule to prove out fixes that were made with the launch vehicle prior to committing a man to its use. The flight used a dummy Mercury capsule leftover from the Little Joe 1B flight and dummy escape tower, yet it cleared the way for Alan Shepard's Freedom 7 flight.

Saturn SA-1 Photo Courtesy NASA

Currently the Ares I-X vehicle waits to have its turn at making the first step in the step-by-step testing of the next generation of standard United States manned launch vehicles. Having stepped away from the desperation of the old "space race," and the accepted risk of all-up testing, NASA now has the benefit of time and the ability to use greater care in how the new generation of human spaceflight boosters are developed. Although the Ares I-X may not fully resemble the final launch vehicle in some ways, its benefits will be great. The launch date for the Ares I-X has been set for October 27, 2009, which is the 49th anniversary of the launching of the first Saturn I, SA-1. As the Ares I-X prepares to launch, the arm-chair critics claim that it will shake, drift and perhaps fold in half and explode and they often refer to it as "The world's largest model rocket." Thus it is interesting to note that these same sort of comments were made 49 years ago, when SA-1 was called "Cluster's last stand" implying that the cluster concept would shake, drift and explode. Instead- SA-1 led mankind to the moon.

FMI: www.nasa.gov