The News That Matters about the Nuclear Industry Fukushima Chernobyl Mayak Three Mile Island Atomic Testing Radiation Isotope

Problems of nuclear power in space

Houston, are we going to have a problem with space nuclear power? Bulletin of the Atomic Scientists, By Beau Rideout | July 19, 2021  ” ………….. space nuclear power isn’t just about propulsion. The dynamic commercial space and national security sectors can also benefit from nuclear capabilities and have an important role to play in developing dual-use technologies that have both military and civilian applications, though with some caveats to ensure human safety.

While the National Academies report published in February advocates for the use of nuclear power in propulsion, nuclear power for non-propulsion applications is becoming increasingly attractive as the commercial space sector seeks to expand its activities. It would be prudent to discuss and establish policy on the use of space nuclear power now, so that policy and safety concerns can be fully addressed during the development proposed by NASA and the National Academies. The United States, and the world, has important decisions to make about whether, when, and how to use nuclear power in space.

Nuclear propulsion in space. The fiscal year 2021 spending approved by Congress provides $110 million for space nuclear propulsion development. This reflects growing NASA interest in more ambitious deep-space missions and a burgeoning commercial interest in exploiting extraterrestrial resources on the Moon, Mars, and the asteroid belt, for which nuclear power would be a key enabling technology……………….

With both a high-power output and high mass efficiency, nuclear propulsion would strike a mighty blow against the tyranny of the rocket equation, which dictates that spacecraft need exponentially more fuel to travel farther. Space nuclear propulsion would enable entirely novel types of space missions, such as capturing small asteroids or, as NASA plans, sending humans to Mars.

Non-propulsion activities in space. In addition to providing advanced propulsion capabilities, nuclear power would enable other space activities and allow the commercial space industry to reduce its reliance on solar panels. For example, space-based radar systems can image the ground day or night, regardless of cloud cover, but require large amounts of electrical power. Communication systems relay data across the world but are constrained by the size of their solar panels. With nuclear power, they could send more data down to Earth, or serve more customers by operating from higher orbits.

The space industry is offering new in-space services and aiming for new destinations beyond geostationary orbit but within the moon’s orbit. Lockheed Martin has announced that future GPS satellites will be designed to receive hardware upgrades of processors and sensors while in orbit. A DARPA program is investigating future in-space manufacturing of large, lightweight structures using raw materials harvested from the Moon. And the NASA Commercial Lunar Payload Services program is scheduled to begin sending commercial lunar landers to the Moon in the fourth quarter of this year. This uptick of activity requiring frequent trips beyond low Earth orbit indicates that requirements for propulsion and power generation will continue to expand, making nuclear power an increasingly attractive solution. In anticipation of this demand, conversations about the proper, safe use of nuclear power in space must begin now.

…………  The United States should lead the way in identifying the types of applications that should be encouraged, those where caution may be indicated, and perhaps some applications that should be discouraged because the risks outweigh potential benefits.

…………. Interagency review should also identify measures to protect human safety. For example, the National Academies report has recommended that nuclear applications in space minimize the amount of radioactive material required, undergo sufficient testing to ensure reliable operations prior to any orbital flight, restrict reactor use until a spacecraft has achieved a safe orbit, and design all space-going reactors to automatically go into a “safe state,” in which the reactor is highly unlikely to achieve criticality and sustain a fission chain reaction, if a launch failure occurs. Nuclear power applications in low Earth orbits should be required to include back-up safety mechanisms such as redundant communications or a secondary propulsion system, as objects in these orbits are most at risk of uncontrolled reentry events like the Soviet Kosmos 954 reactor accident

In that 1978 accident, the Kosmos 954 satellite broke apart over Canada, spreading radioactive debris over the Northwest Territories and requiring a multimillion-dollar cleanup operation. Kosmos 954 was not the first fission reactor in space. The United States flew an experimental satellite called SNAPSHOT in 1965 to test a small nuclear reactor powering an early form of electric propulsion. SNAPSHOT failed 43 days after launch, but the reactor safely shut down and was left in a high orbit. The Soviet Union launched 33 RORSAT radar satellites powered by reactors between 1967 and 1988. Unlike SNAPSHOT, these RORSAT satellites orbited at low altitude and would fall back to Earth unless boosted up to a higher disposal orbit from which they would not return for several centuries. However, this boosting maneuver was not always successful and on two occasions resulted in the reactor cores crashing back to Earth. ……………….

July 20, 2021 Posted by | space travel, USA | Leave a comment