Welcome! Today we begin a dive into the incredible world of nuclear rockets (yes, you read that right, nuclear). This first article will focus on the genesis of Project ROVER and give you an overview of the whole ROVER-NERVA thingy.
A Kiwi reactor, used during the ROVER Project.
The ROVER Project was an American project, which existed from 1955 to 1973 at the Los Alamos Scientific Laboratory (LSLA), to develop a nuclear thermal rocket. The origins of the project lie, as it was common during that time in history, in a US Air Force project to develop an intercontinental ballistic missile (ICBM) upper stage. NASA picked up the project after the space race began, following the Soviet launch of the Sputnik satellite. Project ROVER was jointly managed by NASA and the Atomic Energy Commission (AEC) and was integrated into the NERVA (Nuclear Engine for Rocket Vehicle Application) project. Hence, ROVER was involved in the research about nuclear rocket engine designs while NERVA focused on the deployment of these reactors for use in space missions.
Prior to the start of the project, considerations were given to how NTR fuel elements could be tested in non-nuclear situations before, and two of the test stands that had been developed to test the thermal, chemical and erosion effects on these elements as individual components: the Compact Fuel Element Environment Simulator (CFEET) and the Nuclear Thermal Rocket Environment Effects Simulator (NTREES), were studied. These test stands provide cost-effective means of testing fuel elements before they are loaded into a nuclear reactor and can detect many chemical and structural problems without the nerve-racking situation that is testing a nuclear reactor.
However, as any engineer will tell you, computer modelling is not nearly able enough to test a complete system. Without extensive real-world testing, no system can be operated in a way that guarantees its safety in real situations. This is especially true for a system as complex as a nuclear reactor – even more for a rocket engine. NTRs have the wonderful idea of being both in one system.
Engine Maintenance and Disassembly Facility
During the Rover project, many nuclear propulsion tests were carried out. The test programs were spread over different sites across the United States. The test at the Nevada site began with the arrival of the rocket engines, fully built and pre-tested at Los Alamos, New Mexico, which arrived by rail with a contingent of additional scientists, engineers and technicians. After another safety check of the reactor, the engines were fitted with sensors and instrumentation, connected to the liquid hydrogen fuel tanks, and then subjected to a series of tests until full power was achieved, or the engine failed.
Over time, great strides were made not only in the design of the rocket engine, but also in metallurgy, fluid and reactors dynamics, materials engineering, manufacturing techniques, cryogenics and a plethora of other areas. These rocket engines were well beyond the limits of technology. Unfortunately, this also meant that there were many failures in the early days, with error-free testing being the exception rather than the norm. However, by the end of the Rover program in 1972, a nuclear thermal rocket engine had been successfully tested in flight configuration on several occasions. The rocket fuel elements advanced by leaps and bounds beyond the required specifications, and with the ability to iterate and test new versions of these elements in new multi-purpose and reusable test engines at little cost.
This concludes this introduction to the ROVER and NERVA project. If you are interested, in the next article we will elaborate on the steps taken before the ROVER reactors are fired.