Communications, Electronics and Satellites Chronology

 500BC, to 1970

Solar System Pythagoras 500 BC
Golden year [nineteen-year astronomical cycle] Meton 432 BC
Helio-centric [sun centered] universe AristArchus [then Copernicus] Respectively 350BC then 1543 AD
Speaking Trumpet Alexander the Great 335 BC
Oldest written description of data transmission system [alphabet characters represented by code of up to five torch positions on two walls] Polybius 300BC
Length of tropical year [accuracy 12 seconds] HippArchus 145BC
Julian Calendar [prepared for Julius Ceasar] Sosigenes 45BC
Decimal notation India 900
Magnetic compass [used 24 points, reckoned from south] China 12th century
Rockets in warfare China 1232
Decimal notation introduced to Britain - 1253
Difference between geographic and magnetic north pole Columbus 1492
Helio-centric [sun centered] universe Copernicus [after AristArchus] 1543
Mercator's map projection [Latinised form of name] Kremer 1560
Calendar reform [not adopted by England until 1752] Gregory 1582
Static electric forces described Gilbert 1600
Telescope Galileo 1608
First law - elliptical orbit Kepler 1609
Second law - constant angular momentum [i.e., equal swept areas in orbital plane in equal time periods] Kepler 1609
Third law - [orbital period] ∞  [semi-major axis] Kepler 1618
Calculating machine Pascal 1642
Law of universal gravitation Newton 1666
Semaphore with telescope Hooke 1684
First law - inertia [Galileo's law of inertia]. Second law - force, mass and acceleration. Third law - direct reaction Newton 1687
Possibility of artificial earth satellite Newton 1687
Insulated electrical lines von Guericke 1720
Marine chronometer Lloyd 1735
Gyroscope Setson 1744
Capacitor [known as Leyden phial or jar] Musschenbroek 1746
Electric conduction Grey 1720
Electricity propagated by wire [3km] Watson 1747
Gregorian calendar adopted by England - 1752
Static electric telegraph [24 lines to 24 pitch-ball electrometres] Lesage 1774
Single line static electric telegraph Lomond 1787
Pulse position modulation [timed sparks at end of line] Chappe 1790
Semaphore with mechanical arms Chappe 1794
Six shutter optical telegraph Murray 1795
Gravitational constant, G Cavendish 1797
Electrolysis Pearson 1797
Negative numbers India 1797
Primary electric cell [silver zinc] Volta 1800
Cloud formation classification Howard 1803
Arc light Davy 1808
Electro chemical telegraph [decomposed water - one line and electrode per character] Soemmering 1809
Mechanical computing "engine" Babbage 1812
Electro magnetism Oersted 1819
Light as "waves" Fresnel 1820
Magnetisation of soft iron Arago and Faraday 1820
Multi turn coil as electro magnet "multiplier" Schweigger 1820
Magnetised needle telegraph [one needle per character] Ampre 1820
Single magnetic needle telegraph [coded characters -up to four serial digits per character] Schiling 1825
Transformer [induction coil] Faraday 1831
Commercial electric telegraph Gauss and Weber 1833
Rectifier - asymmetric electric conduction Munk 1834
Refrigeration Perkins 1834
Five needle parallel coded telegraph Wheatstone and Cooke 1837
Telegraph using signal relay at distant end to key fresh power source Davy 1838
HF oscillations observed at a distance Henry 1840
Frequency effects of relative motion [light from stars] Doeppler 1843
Electromagnetic telegraph Morse and Vail 1844
Incandescent lamp [carbon in vacuum] Starr 1845
Telegraph printing roman characters instead of code House 1846
Automatic telegraph transmitter Bain and Wheatstone 1846
Gutta percha for submarine cables Faraday 1849
Submarine telegraph cable [Connecticut River] - 1849
Speaking tube Wishaw 1850
Submarine telegraph single wire cable Dover to Calais [operated only one day] Brett 1850
Submarine telegraph cable Dover to Calais [permanent - four, separated insulated wires] - 1851
Fundamental system of electrical and magnetic measurements Weber 1851
Duplex telegraphy Gintl 1853
Microphone Bourseul 1854
Transient response of a transmission line Kelvin 1855
Electric lighthouse illumination [South Foreland] - Arc with clockwork spacing control Foucault-Dubosq 1858
Telegraph polarised relay Siemens 1858
Submarine telegraph, Ireland to USA 2630 km [initial cable only lasted for 700 messages] Field 1858
Rubber insulation for cables Hooper 1859
Submarine telegraph, transatlantic permanent [25 words per minute Morse code] - 1866
Angstrom unit of length Angstroem 1868
Gyro stabiliser Watt - Boulton 1868
Navigational satellite proposal [a novel] Hale 1869
British telegraph installations taken over by Post Office - 1870
Multiplex telegraphy [f.d.m.] - morse code, mechanical resonance Bell 1870/1874
Telephone Bell 1872
500 b/s data transmission system Edison 1874
Vacuum carbon filament dockyard lamps Lodyguine 1874
First parallel connection of electric lamps [42 Arcs] Farmer 1875
Multiplex telegraphy [t.d.m.] five unit code Baudot 1875
Sidebands demonstrated in acoustics Mayer 1875
Electro magnetic microphone - moving iron Bell 1876
Carbon microphone Edison 1877
Dynamic microphone - moving coil Cuttris USA. Siemens Germany, then Wente 1877
Magneto telephone exchange with drop indicators [New Haven Connecticut] Jones 1878
Laser Bell and Tainer
then Townes and Schawlow
First telephone exchange switchboard in Britain - 1879
Piezo-electric effect Curie 1880
Condenser microphone Dolbear
then  Wente
Thermionic emission Edison 1883
Spark transmitter Hertz 1886
Frequency division multiplex speech using mechanical resonance Leblanc 1886
Parametric oscillation Rayleigh 1887
Wireless telegraph [morse code] Lodge 1887
Equalised line Heaviside 1887
Radar Hertz
then Watson-Watt]
Ratchet-and-pawl telephone selector Strowger 1889
Metallic valve filaments [platinum] Fleming 1890
Submarine four core telephone cable Dover to Calais - 1891
Standard primary cell - mercury-cadmium Weston 1892
Electrical resonance and f.d.m. telephone system Autin and Leblance 1892
Coherer detector Branley 1892
Revised five unit telegraph alphabet [now called ITA No 2. Murray 1895
Cathode ray tube Crookes 1895
X-rays [discovered from c.r.t. experiments] Roentgen 1895
Wireless telegraphy ship to ship Jackson 1895
Commercial common-battery telephone exchange - Worcester Massachusetts - 1896
Automatic telephone exchange Augusta New York - 1896
Quarter wave antenna MArconi 1896
Frequency tuning [called syntonic wireless] Lodge 1897
Rectifier as a.m. detector Pupin 1898
Coupling circuits Braun 1898
Radio controlled model boat Tesla 1898
Wireless telegraphy across English Channel MArconi 1899
Thermionic emission consisting of electrons Thomson 1899
Magnetic tape recording Poulsen 1899
Telephone line repeaters Lyons 1900
Radio telephony [2km with 10 kHz rotary spark gap] Fessenden 1900
Amplitude modulated radio Fessenden 1901
Wireless telegraphy Cornwall to Newfoundland [Receiver at St John-Marconi transmitter at Poldhu-Fleming] 1901
British telephone systems taken over by Post Office - 1901/2
Loaded transmission line [New York to Newark New Jersey] Pupin 1902
Upper atmosphere reflection of radio Heaviside 1902
Frequency modulation Ehret
then Armstrong
Multi stage rocket theory defined Tsiolkovsky 1903
Time division multiplex speech Miner 1903
Arc transmitter with frequency shift keying [f.s.k.] Poulsen 1903
Two electrode vacuum tube rectifier Fleming 1904
Directional antennae MArconi 1905
Quenched spark transmitter Wien 1906
C.W. Oscillations Poulsen 1906
320 km radio telephony Fessenden 1906
High frequency alternators Alexanderson 1907
Triode amplifier valve [called "audion"] de Forest 1907
Cathode ray oscillograph Ryan 1911
Crystal microphone [led to ASDIC] Langevin 1914-1918
Transatlantic radio telephony Arlington to Paris [transmitter with many paralleled triodes] [USA] 1915
Sidebands in electrical communications Carson 1915
Filters Campbell 1915
Modulo-2 addition circuits [used for message encryption] [Great Britain] 1915
Telephone New York - San Francisco [5200km over open wires] - 1915
Maser Einstein
then Gordon, Zerger and Thomas
'Relay' automatic exchange telephone co-ordinate selector Betulander 1917
Condenser microphone Wente 1917
FM infinite sidebands and 'Carson's Rule' Carson 1922
Ribbon microphone principle Schottky
then Olsen
FM practical development Armstrong
after Ehret
Radio facsimile cheque London to New York Ranger 1923
Commercial radio facsimile transatlantic - 1926
Tetrode [S625 valve] Round 1926
Liquid propellant rocket Goddard 1926
Mu-metal used for loading submarine cables [telegraph speed 2500 word per minute instead of 25] - 1926
Rugby [UK] HF transmitter - 1927
12 channel f.d.m. 400 word/min telegraph on single line pair [Western Electric] [USA] 1929
Superhet receiver Armstrong 1930
Improved dynamic [moving coil] microphone Wente 1931
Improved ribbon microphone Olsen 1931
Underground telephone cables in Britain - 1931
Radio telescope Jansky 1931
Microwave [20cm] telephone link Dover to Calais [56km] - 1931
Cosmic noise discovered Jansky 1932
FM 104km New York to Westhampton on 41 Mhz Armstrong 1933
FM feedback demodulator Chaffee 1933
Experimental crossbar telephone exchange Ericsson [Sweden] 1933
Klystron Varian 1934
Negative feedback amplifier [called inverse feedback Black 1934
Coaxial telephone cable London - Birmingham [4 core, 280 circuit, 0.5 to 2.1 MHz, repeaters every 8 miles] - 1937
Parabolic antenna Reber 1937
Pulse code modulation Reeves 1937
Radar Watson-Watt 1937
Gas discharge lamp - 1938
Crossbar telephone exchange Bell laboratories [USA] 1938
I am born in July  [future user of little sparks] Harry and Dorothy [my parents] 1938
FSK data link for picture transmission [AntArctic] Byrd 1939
Analogue vocoder Dudley 1939
Bell complex-number computer model 1 Stibitz 1940
Submerged repeater [Holyhead and Isle of Man] - 1943
Havard Mk1 electronic computer [used 3304 electromagnetic relays] Lake 1944
Multi stage combat rocket [Rheinbote] [Germany] 1944
Delta modulation Deloraine 1945
Synchronous global communication satellite system proposal Clarke 1945
Travelling wave tube Kompfner 1945
Atomic clock Libby 1946
Moon bounce communications [USA] 1946
Printed wiring component board Sargrove 1947
Transistor Shockley 1948
Experimental p.c.m. link of normal telephone quality Meacham and Peterson 1948
Companding suggested for p.c.m. links Reiling 1948
Bell tropospheric scatter communications ' beyond the horizon' [USA] 1952
Backward-wave-oscillator or cArcinotron [France] 1952
Cyclic binary code [e.g., for shaft encoders] Gray 1953
Maser Gordon Zerger and Townes 1954
Low altitude passive communication satellite proposal Pierce 1955
Transatlantic telephone cable TAT1 Oban, Scotland to Clarenville Newfoundland 51 repeaters 144 Mhz [ 2 separate single core cables - one go and one return- providing 35 duplex 4khz telephone circuits plus 1 telegraph channel] - 1956
Tunnel diode Esaki 1957
Low noise microwave amplifier [synthetic ruby maser cooled to 2 Kelvins] Bloembergen 1957
Artificial earth satellite SPUTNIK 1 [84kg, perigee 230km, apogee 950km] [USSR] 1957
Laser [known then as 'optical maser' Townes and Schawlow 1958
Store-and-forward communications satellite SCORE [3969kg, taped voice and teletype] [USA] 1958
VHF ship to shore public radio telephone in Britain - 1958
Transatlantic moon bounce communication, Joddrell Bank [with 33m diameter dish 200 Mhz at 1 kW] [UK] 1959
Inflated passive communications satellite ECHO 1 [68kg, perigee 1400km, apogee 1800km] [USA] 1960
Active, delayed-repeater communications satellite COURIER [227kg, perigee 970km, apogee 1240km, provided 16 duplex high speed teletype circuits] [USA] 1960
Navigation satellite TRANSIT 1B [USA] 1960
WOSTOCK manned satellite [4115kg, perigee 175km, apogee 302km] Gagarin [USSR] 1961
Spin-stabilised communication satellite TELESTAR for experimental television  [USA] 1962
Duplex 12-circuit NASA satellite communication telephone experiment RELAY [with redundant transponders] [USA] 1962
Synchronous communications satellite SYNCOM [USA] 1963
Commercial geostationary communications satellite EARLY BIRD [INTELSAT 1] [240 telephone channels, or 1 TV channel via 2 single-access transponders] [USA] 1965
INTELSAT II [240 telephone circuits or 1 TV channel via 1 multiple access transponder] [USA] 1969
Military geostationary communications satellite SKYNET [launch USA] [UK] 1969