Ye-1 No. 1 (Luna)

This was the Soviet Union's first attempt to send a probe into interplanetary space and only the second spacecraft in history to be directed beyond Earth orbit.

• The spacecraft was only slightly bigger than basketball-sized Sputnik.

• The upper stage carried 2.2 pounds (1 kilogram) of sodium to create an artificial comet that could be photographed from Earth.

• Shortly after launch, the rocket’s strap-on boosters began to vibrate and the rocket disintegrated at T+93 seconds, destroying its payload.

Nation	Soviet Union (1)
Objective(s)	Lunar Impact
Spacecraft	Ye-1 (No. 1)
Spacecraft Mass	About 794 pounds (360 kilograms) (including the power sources installed on the upper stage)
Mission Design and Management	Experimental Design Bureau-1 (OKB-1)
Launch Vehicle	8K72 (no. B1-3)
Launch Date and Time	Sept. 23, 1958 / 07:03:23 UT
Launch Site	Baikonur Cosmodrome / Site 1/5 (NIIP-5)
Scientific Instruments	Ye-1: 1. Flux-Gate Magnetometer 2. Sodium-Iodide Scintillation Counter 3. Two Gas Discharge Geiger Counters 4. Two Micrometeorite Counters 5. Cherenkov Detector 6. Four Ion Traps Blok Ye (upper stage): 1. Sodium Vapor Experiment 2. Scintillation Counter

Firsts

• This was the Soviet Union's first attempt to reach the Moon and to impact on its surface.

Key Dates

Launch: Sept. 23, 1958

End of Mission: Sept. 23, 1958

In Depth: Ye-1 No. 1 (Luna)

The Soviet government approved a modest plan for initial exploration of the Moon in March 1958. Engineers conceived of four initial probes, the Ye-1 (for lunar impact), Ye-2 (to photograph the far side of the Moon), Ye-3 (to photograph the far side of the Moon with advanced imaging equipment), and Ye-4 (lunar impact with a nuclear explosion).

The Ye-1 was a simple probe, a pressurized spherical object made from aluminum-magnesium alloy slightly bigger than the first Sputnik. The goals were to detect the magnetic field of the Moon, study the intensity and variation of cosmic rays, record photons in cosmic rays, detect lunar radiation, study the distribution of heavy nuclei in primary cosmic radiation, study the gas component of interplanetary matter, study corpuscular solar radiation, and to record the incidence of meteoric particles.

The Blok Ye upper stage (with the 8D714 engine) carried additional instruments, including radio transmitters and two pounds (one kilogram) of sodium to create an artificial comet on the outbound trajectory that could be photographed from Earth.

Shortly after launch, at T+87 seconds, the launch vehicle’s strap-on boosters began to develop longitudinal resonant vibrations. The rocket eventually disintegrated at T+93 seconds, destroying its payload.

The problem was traced to violent pressure oscillations in the combustion chamber of one of the strap-on booster engines. This generated a resonant frequency vibration throughout the frame causing it to shake violently. A fix was proposed by reducing the thrust at T+85 seconds when the rocket reached maximum dynamic pressure.

Key Source

Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.