Actually, already Lunar 1 was intended as an impactor and was launched as part of the Luna program in 1959. But, due to an incorrectly timed upper stage burn during its launch, it missed the Moon. However, while traveling through the outer Van Allen radiation belt, the spacecraft's scintillator made observations indicating that a small number of high energy particles exist in the outer belt. The measurements obtained during this mission provided new data on the Earth's radiation belt and outer space. The Moon was found to have no detectable magnetic field. The first ever direct observations and measurements of the solar wind, a strong flow of ionized plasma emanating from the Sun and streaming through interplanetary space, were performed. The spacecraft also marked the first instance of radio communication at the half-million-kilometer distance.
Luna 2, also known as Lunik 2, was similar in design to Luna 1, a spherical spacecraft with protruding antennas and instrument parts. The instrumentation was also similar, including scintillation counters, geiger counters, a magnetometer, Cherenkov detectors, and micrometeorite detectors. The spacecraft also carried Soviet pennants. Two of them, located in the spacecraft, were sphere-shaped, with the surface covered by identical pentagonal elements. In the center of this sphere was an explosive for the purpose of slowing the huge impact velocity. This was designed as a very simple way to provide the last necessary delta-v for those elements on the retro side of the sphere to not get vaporized. The spacecraft's launch was originally scheduled for September 9, but after the Blok I core stage failed to reach full thrust at ignition it was shut down. After all, the flight was delayed by three days because the booster had to be removed from the pad and replaced by a different vehicle. The spacecraft took a direct path to the Moon with a journey time of around 36 hours. Luna 2 hit the Moon about 800 kilometers from the centre of the visible disk 1959 September 13 at around 9pm.
At yovisto, you may be interested in an American News Report on Luna 2.
References and Further Reading: