On December 7, 1995, NASA’s Jupiter probe, of the Galileo mission, entered Jupiter’s atmosphere at 47.4 kilometers per second, about 29.5 miles a second or over 106.03 thousand miles an hour, making it the fastest man-made object of its time. As NASA expected, it immediately began to burn through the carbon phenolic heat shield. This is a process called ablation, meaning simply that the outside material was made so that it would be burned at a controlled rate, absorbing the brunt of the heat, and protect the ship itself. What NASA didn’t expect was that the heat would be over double the temperatures of the sun’s surface; the probe measured over 28,000 degrees Fahrenheit. Atoms were split and plasma was formed. The plasma decimated the probe’s heat shield, nearly destroying it.
The tests that NASA had preformed were flawed, because they lacked a heat source great enough to truly test the limits of the shield. For a long time they used lasers, high powered jets, and basically anything hot enough to disintegrate the heat shield, but as we’ve seen, this wasn’t quite enough. However, recently two people, Eva Kostadinova from Auburn University and Dimitri Orlov who works on a fusion reactor in San Diego, have come up with a solution. They’ve began shooting small carbon phenolic pellets into plasma filled fusion reactors, called tokamaks, to test the current heat shield and other potentially better materials.
Fusion reactors are certainly notmade for this purpose; nuclear fusion is an atomic reaction of, essentially, smashing atoms into each other to create a chain reaction of other atoms fusing to each other. Physicists say this bring virtually unlimited electricity, making it accessible anyone in the world.
Though it cost them over half a million dollars for merely one day of these tests, it could keep them from wasting the half a billion dollar planetary probe that they are working to protect. It may not seem like a big deal, but NASA is currently scheduling a similar trip to Venus, the DAVINCI+ mission, for the next few years and are determined not to make the same mistake again. After the semi-failed attempt in Jupiter, NASA realized how much more they could learn if they’d had a lighter, more efficient heat shield that didn’t take up over half of the weight of the entire probe, which could have been used for vital equipment.