Vanguard 1

Launch data: Designation 00005 / 1958 Beta 2 / 58002B Launch date 17 Mar 1958 - 12:15:41 UT Launch site CC, LC18A Launch vehicle Vanguard TV-4 #3 Payload code 6.5in sat #2 Mission Scientific: high atmosphere study Earth orbit on 17 Mar 1958 - 12:00 (.50) Perigee / Apogee 650 x 3968 km Eccentricity  0.191 Inclination 34,25° Period 134,18 min Earth orbit on Jan 2012: Perigee / Apogee  656 x 3849 km Eccentricity  0.156 Inclination  34.3° Period  132.8 min

Spacecraft data: Prime contractor   Operator  NASA Mass at launch  1.47 kg Dry Mass   kg Basic shape  Sphere Dimension  0.16 dia Design lifetime  300 years

Description:

• Vanguard 1 was a small earth-orbiting satellite designed to test the launch capabilities of a three-stage launch vehicle and the effects of the environment on a satellite and its systems in Earth orbit. It also was used to obtain geodetic measurements through orbit analysis.
• The spacecraft was a 1.47-kg aluminum sphere 15.2 cm in diameter. It contained a 10-mW, 108-MHz mercury-battery powered transmitter and a 5-mW, 108.03-MHz transmitter powered by six solar cells mounted on the body of the satellite. Six short aerials protruded from the sphere. The transmitters were used primarily for engineering and tracking data, but were also used to determine the total electron content between the satellite and ground stations. Vanguard also carried two thermistors which measured the interior temperature over 16 days in order to track the effectiveness of the thermal protection.

Mission details:

• Vanguard 1 was placed into a 654 x 3969 km 134.2 minute orbit inclined at 34.25 degrees by the three stage Vanguard launch vehicle. Original estimates had the orbit lasting for 2000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to only about 240 years. The battery powered transmitter stopped operating in June 1958 when the batteries ran down. The solar powered transmitter operated until May 1964 (when the last signals were received in Quito, Ecuador) after which the spacecraft was optically tracked from Earth.

Satellite tracking:

Astrophilately covers:

Launch cancel Port Canaveral