This issue was inspired by a request from one of our Internet readers for more information about nuclear batteries. It seems that a short article in the April, 1995 issue of AEI was one of the few hits returned on a key word search for the phrase radioisotope thermal generator. He was interested in learning more about batteries that can supply continuous power for 10, 20 or even fifty years.
The more sources that we found, that the more intriguing the search became. Though the technology is several decades old, with a long history of technical success, there is little current activity either by commercial companies or government bodies.
In fact, most companies that we contacted that have previously been in the business of supplying radioisotope generators told us that the market is virtually dead. Some of them are trying to keep some hand in the business by modifying their thermocouple systems to work with other heat sources, while others have abandoned the technology altogether.
The major RTGs user in the United States has been NASA, but you would not know it by visiting NASA sponsored displays at public science museums. The displays often describe the incredibly sophisticated sensing systems that have been sent on exploratory voyages of the solar system, but they rarely mention that the spacecraft depend on a nuclear powered battery to enable the sensors to function and send their information back to earth.
It is almost as if NASA, ever cognizant of the need for taxpayer support of its programs, put this useful device “in the closet”, using it when necessary but maintaining an unofficial policy that technical details were best kept from public view.
Within the past few months, however, several new web sites sponsored by NASA have been posted that provide more details that previously available to the general public regarding the use of RTGs on the moon and in other missions.
Commercial companies that long ago decided that using RTGs was simply too hard are once again taking a new look to determine if there is some way to quantify just how hard it would be to go through the process of obtaining the needed material and regulatory permits. The incentive for this investigation is the realization that a few carefully placed RTGs might save millions of dollars in electrical cable, fuel supply systems, or chemical battery replacement missions to remote areas.
There is even a rumor that there will soon be a rather lucrative Request For Proposals (RFP) issued by NASA. It is possible that this rumor is based on the growing support for explorations of the surface of Mars.
We hope that this issue, in some small way, contributes to the new openness with which radioisotope generators are being discussed. There may be some new ideas here, possibly even some with commercial potential. Feel free to make contact with us if you have any questions or comments.