It promises to be an extraordinary journey to an ordinary star. On Saturday, if all goes to plan, an unmanned spacecraft will set sail for the Sun, coming closer than any before it. The Parker Solar Probe will take about seven years to reach its destination, using fly-bys of Venus for gravitational kicks.
The engineering would make Icarus weep: the car-sized Nasa probe has been built to survive a cautious encounter with the Sun’s corona, the superheated outer atmosphere that stretches millions of miles into space and is visible as a shimmering halo during a total solar eclipse. The body armour is a carbon-composite heat shield more than 11cm thick; it will be sustained by a solar-powered (what else?) cooling system.
The craft will fly within 4m miles of the Sun’s surface — beating Helios 2, which came within 27m miles in 1976 — and endure temperatures up to 1,400C. Nasa bills the mission, rather poetically, as humankind’s attempt to “touch the Sun”.
