European-developed Ariane 4 was the world's dominant commercial space launch vehicle from its 1988 debut until its retirement in 2003.  The three-stage expendable flew in six configurations based on the number of solid or liquid strap-on boosters.  When flown in the Ariane 40 configuration without any boosters, the vehicle could put 2.17 tonnes into geosynchronous transfer orbit (GTO).  Two solid boosters (PAP) created an Ariane 42P.  Four solids made an Ariane 44P.  With two liquid boosters (PAL), the rocket become an Ariane 42L.  Two solids and two liquids made an Ariane 44LP.  The most powerful version, Ariane 44L, used four liquid boosters to put 4.79 tonnes into GTO.  

Ariane 4 was the last Ariane powered by Viking-series engines.  Originally developed by France during the 1970s for the never-flown Europa III, Viking engines burned nitrogen tetroxide and unsymmetrical dimethyl hydrazine (UDMH) to produce about 77,000 kgf thrust each in vacuum.  Four Viking 5 engines powered the first stage.  Each liquid booster used a single Viking 6.  The second stage was powered by a single Viking 4.  

The Ariane 4 third stage was powered by an advanced HM7B engine that burned liquid oxygen and liquid hydrogen (LOX/LH2) to produce 6,394 kgf thrust during a single 13 minute-long burn.  First developed for Ariane 1 during the late 1970s, HM7 was the first LH2 fueled upper stage engine developed and flown outside the United States.   

Using the Spelda dispenser system, Ariane 4 could orbit two satellites at a time.  This occurred less frequently during the later years as communication satellites grew heavier.

Ariane 4 was launched from Kourou's ELA-2 launch site.   At ELA-2, Ariane 4 launch vehicles were stacked atop a rail-mobile launch table inside a launcher integration building.  When the vehicle was ready, it was rolled out on about one kilometer of dual-rail track to the ELA-2 launch pad itself.  There, the vehicle was enclosed within a mobile service tower where payloads, already encapsulated within the payload fairing assembly, were added.  The mobile launch table technique allowed more than one launch campaign to proceed at the same time, supporting a nearly once-per-month flight rate during the late 1990s.

Vehicle Configurations

* GEO: Geosynchronous Earth Orbit
** Ariane V113, with special enhancements, boosted 4.95 tonnes to GTO

Vehicle Components

* Max Stage 1 Propellant Loading, Actual Loads Vary by Vehicle Type as Follows
     Ariane 40:  167 tonnes
     Ariane 42P:  217.2 tonnes
     Ariane 42L:  201 tonnes
     Ariane 44(LorP):  227.1 tonnes

Vehicle Components, Cont'd

References

Ariane 4 User's Manual, Arianespace, 1999
Airclaims Space Review, May 2003

Last Update:  April 11, 2009