Nose cone

A nose cone is the pointed front section of a rocket, guided missile, or aircraft, shaped to control how air flows around it and reduce drag. Similar designs are used on submarines, torpedoes, and fast land vehicles like rocket cars and velomobiles.

Rockets

On a suborbital rocket, the nose cone contains chambers for instruments, animals, plants, or equipment, and its outer surface must withstand intense heat from aerodynamic friction. Much early research into hypersonic flight focused on creating nose cones for spacecraft and ICBM reentry vehicles. In a satellite launch vehicle, the nose cone can either become the satellite itself after separating from the final rocket stage, or it can serve as a payload fairing that shields the satellite until it leaves the atmosphere, then splits in two and falls away.

Aircraft

On airliners, the nose cone is also a radome that protects the weather radar from aerodynamic forces. To minimize drag, the nose cone is usually a solid of revolution—a shape offering the least resistance to motion. The article on nose cone design lists possible shapes and formulas.

Supersonic

For high-speed applications like supersonic flight or atmospheric reentry, extreme temperatures require nose cones made of refractory materials. Options include pyrolytic carbon, reinforced carbon-carbon composite, or HRSI ceramics.

Another approach is an ablative heat shield, which burns away during operation, carrying heat with it. Ablative materials include carbon phenolic, a polydimethylsiloxane composite with silica filler and carbon fibers, or even oak wood, as used in some Chinese FSW reentry vehicles. Generally, the demands of reentry conflict with those of other high-speed flight: reentry often uses a blunt, high-drag shape that reduces heat transfer by creating a detached shock wave, though very-high-temperature materials can allow sharper designs.

Design

Designing a nose cone for a vehicle moving through a compressible fluid (like air) involves finding the optimal geometric shape for minimal resistance. This typically means defining a solid of revolution that offers the least drag in a fluid made of elastic particles.

See also: Aircraft fairing, Droop nose (aeronautics), Inlet cone, Payload fairing, Nose bullet.