USSR · OKB-1firstrobotic
October 4, 1957
Sputnik 1 — first artificial satellite
Experience this missionOn 4 October 1957, at 22:28 Moscow time, a Soviet R-7 rocket lifted off from Baikonur Cosmodrome carrying a polished aluminium sphere 58 centimetres across and weighing 83.6 kilograms. Named Sputnik — Russian for 'travelling companion' — it was the first artificial object placed in Earth orbit, completing one revolution of the planet every 96.2 minutes.
For 21 days, Sputnik's two radio transmitters broadcast a distinctive 'beep-beep-beep' signal on 20.005 and 40.002 MHz. Amateur radio operators around the world could hear it. Its orbit, ranging from 228 to 947 kilometres altitude, was easily tracked with binoculars at dawn and dusk.
The launch sent shockwaves through Washington. American scientists and military planners realised that a rocket powerful enough to orbit an 84-kilogram satellite was powerful enough to deliver a nuclear warhead to any city on Earth. Congress doubled NASA's budget the following year and passed the National Defense Education Act.
Sputnik burned up on re-entry on 4 January 1958 after 1,440 orbits and roughly 70 million kilometres travelled. It had spent three months in orbit — long enough to start the Space Race.
“The Soviet satellite is now circling the globe. It calls upon free nations to combine their resources and their courage to turn this threat into an opportunity.”
Mission Data
Launch date
4 Oct 1957
Mass
83.6 kg
Orbit
228 × 947 km
Orbital period
96.2 min
Transmitting
21 days
Re-entry
4 Jan 1958
Key Facts
Its polished aluminium shell was deliberately made reflective so it could be tracked with binoculars at dawn and dusk
The R-7 rocket used to launch Sputnik was powerful enough to deliver a nuclear warhead to any US city — the Pentagon's real concern
Amateur radio operators worldwide could hear its 'beep-beep-beep' signal on 20.005 MHz with basic equipment
Congress doubled NASA's budget and passed the National Defense Education Act within a year of the launch
Sputnik completed 1,440 orbits over 92 days before burning up on re-entry on 4 January 1958
Why It Mattered
Sputnik triggered the Space Race and reshaped American science and defence policy overnight. DARPA was founded, NASA was created, and the National Defense Education Act poured billions into US science and engineering — all within 12 months of that first beep.
Photo Gallery
Part of
Soviet Sputnik Program
NASA / NSSDC
Official source