On This Day in Space Exploration

  February 12 12 February 1947 Painting of the Sikhote-Alin meteorite fall by by Pyotr Medvedev, a Soviet artist who witnessed the fall On February 12, 1947, at around 10:30 local time, a large iron meteoroid exploded and fell over the Sikhote-Alin mountains in Primorsky Krai, Russia, creating one of the largest meteorite falls observed in recorded history. The meteoroid is estimated to have a pre-atmospheric mass of around 200–500 tons and a post-atmospheric mass of around 100 tons. As it traveled at ~12–15 km/s, the meteorite left a trail of smoke in its wake approximately 32 kilometers long that remained in the sky for hours after impact. Fragmentation probably occurred in two stages, with breakups at altitudes of ~22–28 km and at ~16 km and lower.     The meteorite shattered in a powerful airburst explosion, causing a rain of debris. The bright flash and the loud sound of the fall were observed for 300 kilometres around the point of impact not far from ...

  February 11 11 February 1970 Artist's impression of the Ohsumi satellite. Credit: JAXA Ohsumi, Japan's first satellite, was launched on February 11, 1970 at 04:25 UTC on a Lambda 4S-5 rocket from the Kagoshima Space Center by Institute of Space and Aeronautical Science, University of Tokyo. This made Japan the fourth country, after the USSR, the United States, and France, to launch a satellite into orbit using its own rocket. Ohsumi satellite during prelaunch preparations. Credit: JAXA    The Ohsumi satellite was a small observatory, with a mass of 24 kg, carrying five experiments designed to make ionospheric observations of temperature and density, measurements of solar emission, and measurements of energetic particles. A 500-km circular orbit was intended, but an elliptical orbit was achieved, with a perigee 350 km and an apogee 5,140 km. The satellite was a regular 26-sided polygonal prism with a circumscribed radius of 75 cm. The batteries were powered by 5184 solar...

  February 10 10 February 1974 Mars 4 and Mars 5 spacecraft. Credit: NPO Lavochkin On February 10, 1974, Mars 4 spacecraft failed to enter orbit around Mars and instead flew past the planet, with the closest approach being 1844 km. During its flyby the probe returned 12 photographs and two panoramas of the surface from its cameras.    Mars 4 was intended to be a Mars orbiter mission. Less than four months prior to launch, ground testing detected a major problem with the 2T312 transistors, which used aluminum instead of gold-plated contacts, dramatically increasing degradation. The spacecraft was launched by a Proton-K with Block D launch vehicle on July 21, 1973. A mid-course correction burn was made on July 30, 1973, but soon two of three channels of the onboard computer failed due to the faulty transistors. As a result, the second mid-course correction by its main engine could not be implemented.    With no possibility for Mars orbit insertion, ...