1957–1958 Foundational Epoch: Sputnik-1 (1957-001B) & the 1.47 kg Vanguard-1 (1958-002B) Establish VHF Telemetry, Silicon Solar Cells & Thermospheric Drag Physics
The Space Age began with small spheres: Sputnik-1 (4 Oct 1957, 20/40 MHz beacons) and the 1.47 kg, 15.2 cm Vanguard-1 (17 Mar 1958), the first solar-powered satellite.
Every physical equation in the nadir lab. engineering suite—circular orbital velocity, atmospheric drag decay, Doppler shift, and photovoltaic power balance—traces directly to the first six months of the Space Age (October 1957 – March 1958).
On 4 October 1957, Sputnik-1 (PS-1, 83.6 kg, 58 cm pressurized aluminum-magnesium-titanium sphere) entered a 215×939 km orbit, radiating 1 W on 20.005 MHz and 40.002 MHz via four swept-back whip antennas. Variations in its pulse duration encoded internal pressure and temperature, while its 92-day orbital decay provided the first empirical measurements of upper-thermospheric mass density.
Five months later, on 17 March 1958, the US Naval Research Laboratory launched Vanguard-1 (1958-002B): a 1.47 kg, 15.2 cm aluminum sphere into a high-apogee elliptical Earth orbit (654×3,969 km, 34.25°). Equipped with six body-mounted Bell Labs silicon solar cells driving a 5 mW, 108.03 MHz transmitter for over six years, Vanguard-1 proved photovoltaic power in space, revealed Earth’s pear-shaped J3 gravitational harmonic, and remains the oldest human-made object in orbit.
CELESTRAK SATCAT & TELEMETRY RECORD
Verified Spacecraft Key Facts & Orbital Dossier
| Spacecraft | Class | Operator / Country | Launch & Vehicle | NORAD / COSPAR | Orbit & RF Downlink | Catalog Status |
|---|---|---|---|---|---|---|
$50SAT | 1.5P | Morehead State Univ. US | Dnepr · UniSat-5 (MRFOD) | NORAD 39436 2013-066W | UHF | Decayed |
XI-IV | 1U | University of Tokyo (ISSL) JP | Rockot / Breeze-KM | NORAD 27848 2003-031J | LEO, Sun-synchronous 436.8475 MHz, 437.49 MHz (UHF) | Active |
Catalogued Mission Summaries & Flight Notes
- $50SAT (1.5P, 2013):
- Amateur-radio demonstrator built by Morehead State University and three radio amateurs from parts costing less than US$250, emblematic of the class’s low-cost philosophy.
- XI-IV (1U, 2003):
- Member of the first CubeSat launch group and one of the earliest proofs that a 1U can live for decades in orbit. Operational in SatNOGS DB; CW beacon observations reported up to October 2026.