Look, we’re all grown-ups here. We can talk about probing Uranus without lowering the tone and bringing shame on our families, right? Right...? Well, let’s try, together. Last week (November 15) the European Space Agency shared new research on the challenges of flying through the alien atmospheres of the ice giants Uranus and Neptune. Using simulations at the hypersonic plasma T6 Stalker Tunnel at Oxford University, this research could pave the way to properly explore the frosty planets for the first time.
What is the “hypersonic plasma T6 Stalker Tunnel” you ask? Essentially, it’s Europe’s fastest wind tunnel, capable of creating wind flows above 20 kilometres per second. This is needed to test the high speeds a probe must travel to pass through the planets’ atmospheres. A similar wind tunnel in Germany was also used in the tests, courtesy of the University of Stuttgart’s HEFDiG, which specialises in the conditions of a spacecraft entering a planet’s atmosphere.
“The challenge is that any probe would be subject to high pressures and temperatures, and therefore would require a high-performance thermal protection system to endure its atmospheric entry for a useful amount of time,” says ESA aerothermodynamics engineer Louis Walpot in a statement.
Besides the blistering speeds and pressure, there’s the problem of the unique gases that would bombard the spacecraft on entering Uranus (fgs). Both Uranus and Neptune have an abundance of hydrogen and helium in their atmospheres, like Jupiter and Saturn, which NASA’s space probes are alreadyexploring. However, they also have heavier elements, which take the form of oceans of “supercritical” fluid – not quite liquid, not quite gas – as well as methane, which is what makes them blue.
Simulation of passing into an ice giant’s atmosphereCourtesy of University of Stuttgart’s High Enthalpy Flow Diagnostics Group
Getting through these atmospheres, and surviving long enough to beam any meaningful findings back to Earth, will be no small feat, as shown in HEFDiG’s video of a simulated probe being pummelled by alien gases (shown above). Unfortunately, we’re not quite there yet. Currently, the necessary speed of entry for a Uranus probe is around 25 kilometres per second – so far, scientists have only reached a simulated speed of up to 19 kilometres per second.
“To begin designing such a system we need first to adapt current European testing facilities in order to reproduce the atmospheric compositions and velocities involved,” adds Walpot. In other words, if we want to reach Uranus, we first need to increase the force of our own wind, here on Earth.