Test cell that helped put man on moon completed 60 years ago

  • Published
  • By Bradley Hicks
  • AEDC/PA
ARNOLD AIR FORCE BASE, Tenn. --  The Satellite Rocket Test Cell still stands above much of the surrounding landscape at Arnold Air Force Base, serving as a reminder of the work performed across the installation to not only ensure national defense but to meet a goal as lofty as the cell’s stature – landing Americans on the moon.

The test cell, more commonly known as J-3, played its part in both of these objectives, the latter of which was met just a little more than 51 years ago.

It was 60 years ago that construction on J-3 was completed and the Air Force turned the test cell over to ARO Inc., then the operating contractor at Arnold, to oversee its operation.

J-3, which was part of what was then known as the Arnold Engineering Development Center Rocket Test Facility, was designed to test rocket engines in their natural vertical position to provide information to enhance the accuracy and reliability of U.S. satellite and space probe boosters and ballistic missiles.

As a propulsion system test facility, J-3 was capable of accommodating solid- or liquid-propellant units with thrust ratings up to 200,000 pounds at simulated altitudes of more than 100,000 feet. The first vertically-oriented rocket motor test cell at Arnold, J-3 measures around 17 feet in diameter internally and 40 feet in height. It is situated high within a tall covered structure and houses the test article directly above the attached exhaust ducting.

The test cell took only two years to complete, being first proposed in 1958 and handed over to ARO in August 1960. It cost $1.2 million to construct, an amount that may seem relatively nominal by today’s standards but a price tag then-editors of the High Mach highlighted in an editorial published in January 1961. In their piece, however, the editors pointed out that there was a good chance J-3 would likely pay for itself.

“On the face of it, $1,200,000 is a lot of money,” the editorial reads. “In perspective, however, the vastness of the sum dwindles considerably. To illustrate, let’s assume the cell produces data that lead to only a single successful landing of, say, a satellite such as Midas or Samos. That one success will pay for the cell several times over, for a launch of one of these systems costs on the order of $8-10 million and failure usually means total loss.

“It’s not difficult, therefore, to see that the Satellite Rocket Cell is an important addition to the Center, as well as a valuable asset to the country.”

Not long after the ARO took the reins of J-3, the first operational test began in the new cell. To aid in the development of the engine, a full-scale second stage engine for the multistage Titan I intercontinental ballistic missiles was fired in J-3 in late December 1960. This engine, the LR91, also served as second stage engine of the Titan II. The Titan II began life as an ICBM but was later adapted as a space launch vehicle used to transport payloads into orbit. These included satellites and manned space capsules launched as part of NASA’s Project Gemini program, which ran from 1961 to 1966 and, over its last two years, saw more than a dozen astronauts across 10 crews fly low Earth orbit missions.

Additional testing on variants of the LR91 would be conducted within J-3 through 1962. Testing conducted on the Titan II second stage engine in J-3 in March 1962 generated the highest total impulse ever recorded in an altitude simulation cell.

By the end of 1962, construction would begin on AEDC Rocket Developmental Test Cell J-4, another vertical rocket motor test cell at Arnold designed to supplement and exceed J-3 in thrust capacity. J-4 came into service in 1964, but J-3 would continue to be utilized throughout the following years.

One such significant instance was the usage of J-3 in support of the NASA Project Apollo program. The aim of this spaceflight program, established in 1961, was to land a man on the moon and return to earth by 1970.

NASA designed a test program for AEDC to support the Apollo program. The goal of this test program was to obtain data on aerodynamic heating, stability during reentry, reentry ablation, interaction between separating components during escape operations and aerodynamic loading throughout the flight regime, as well as to help address issues that arose during systems development.

J-3 was used to test the variant of the AJ10 rocket engine employed in the Apollo service module propulsion system. The series of tests using the full-scale service module primary propulsion system to flight-qualify the engine for its lunar mission began at Arnold in mid-1963 and continued through 1968.

The Apollo service module was attached to the command module, where astronauts were housed. The service module was responsible for carrying consumables such as fuel, water and oxygen and the main propulsion system for the combined modules.

The service module engine provided the thrust needed for the combined modules to exit earth orbit for the trip to the moon and to leave lunar orbit for the astronauts’ return to earth.

During testing in J-3, the Apollo service module motor was fired repeatedly in near-space conditions, helping NASA qualify the system as man-rated for the flight to the moon. Test data obtained from testing in J-3 also aided in the development of more reliable engine nozzles.

Following eight preceding missions, the goal of the Project Apollo program was accomplished on July 20, 1969, when Neil Armstrong, one of the three astronauts on the Apollo 11 flight, exited the lunar module known as “Eagle” and became the first man to set foot on the surface of the moon.

Throughout the 1960s, approximately 55,000 hours of testing were conducted in more than two dozen of the then-40 AEDC test facilities in support of the Apollo program. This included more than 3,300 hours of wind tunnel tests and more than 1,700 rocket firings conducted and performed from 1960 to 1968.

The NASA Apollo program ran through 1972. Five of the six Apollo missions that followed the Apollo 11 flight resulted in moon landings.

Among propulsion system tests conducted in J-3 over the years were tests involving systems for both the Minuteman and Peacekeeper ICBMs.

Arnold Engineering Development Center was re-designated Arnold Engineering Development Complex in July 2012. The J-3 test cell is no longer active. The J-6 Large Rocket Motor Test Facility, which went into service in 1994, is currently the only active rocket testing facility at AEDC.