In 1954, the space program unlocked its first high-speed cockpit, the conical or X-1 cockpit (appropriately from the X-1 aircraft, the first to break the speed of sound in level flight).
It was used, encased in a fairing, and with parachutes attached, to break records in crewed flight, and perform high atmosphere and suborbital crewed flight. It was launched on top of the Belemnite II rocket with an RD-102 engine. Pilots often experienced high g-forces upon returning through the atmosphere, so flight was not particularly comfortable. They reached at most around 200km above the Earth.
Sounding Rocket contracts were completed in this year by a similar launch vehicle, the Belemnite II, with varying amounts of payload, reaching around 400-480km above the Earth.
A bit of a dead-end design in terms of completing contracts for supersonic flight, the subsonic, low flight contracts having dried up, was the X-3, using the cockpit and engine from the real-life X-1, it was able to get above the sound barrier, but not much else.
