Universe Today

Plenty of areas in the solar system are interesting for scientific purposes but hard to access by traditional rovers. Some of the most prominent are the caves and cliffs of Mars – where exposed strata could hold clues to whether life ever existed on the Red Planet. So far, none of the missions sent there has been able to explore those difficult-to-reach places. But a mission concept from a team at Stanford hopes to change that. 

A few years ago, there was a panic about lithium-ion batteries that exploded and could do things like take down a jetliner. On a recent trip, an airline asked passengers to turn in any devices with batteries that had been banned because of safety concerns. These are indicators of a widely understood downside of lithium-ion batteries, ubiquitous in cell phones, laptops, and other electronic hardware – they can easily catch fire very spectacularly. However, a team at the Aerospace Company is working on an idea to turn this potentially catastrophic event into an asset – by using it to deorbit defunct satellites.

Radioisotope thermoelectric generators (RTGs) are the power plants of the interplanetary spacecraft. Or at least they have been for going on 50 years now. But they have significant drawbacks, the primary one being that they’re heavy. Even modern-day RTG designs run into the hundreds of kilograms, making them useful for large-scale missions like Perseverance but prohibitively large for any small-scale mission that wants to get to the outer planets. Solar sails aren’t much better, with a combined solar sail and battery system, like the one on Juno, coming in at more than twice the weight of a similarly powered RTG. To solve this problem, a group of engineers from the Aerospace Corporation and the US Department of Energy’s Oak Ridge National Lab came up with a way to take the underlying idea of an RTG and shrink it dramatically to the point where it could not potentially be used for much smaller missions.