||This article's lead section may not adequately summarize key points of its contents. (July 2009)|
The Aussat A-Class satellites were funded by the Government for Aussat Pty Ltd. When Optus was granted a telecommunications carrier licence in 1991, it was bundled with the purchase of Aussat Pty Limited as part of the carrier licence deal.
Optus B1 was moved to Junk orbit in May 2008.
Satellite Control Processor
On 21 May 2005 services were temporarily lost when the Primary Satellite Control Processor failed. The satellite was switched to use the Backup SCP in order to restore services. Thereafter the satellite continued to operate from the Backup SCP.
March 2006 Positioning Failure
|Wikinews has related news: Optus B1 outage leaves all New Zealand Sky TV digital subscribers without service|
At 06:52 GMT on 30 March 2006, a routine repositioning manoeuvre failed, resulting in loss of pointing control of the satellite. Although communication with the satellite was not lost, transmission services provided by the satellite failed due to its incorrect positioning. Services were progressively restored between 18:00 and 20:00 GMT.
Local time at the time of the start of the outage ranged from 14:52 AWST to 18:52 NZST, a peak time for listeners and viewers of the radio and television broadcast and subscription services provided directly or indirectly by the satellite.
The launchcraft containing Optus B2 exploded on launch and was subsequently destroyed, for reasons that the designer Hughes and the Chinese (Launch Location) authorities were unable to determine.
However, according to one source, shortcomings in the launch vehicle guidance system meant that it failed to compensate for wind-shear effects within the first minute after launch.
Optus B3 was launched as a replacement for the failed Optus B2.
Partially funded by the Australian Government (Defence Department) - Optus C1's use is shared between Defence and Telecommunications, in particular the supply of Television services to Australia. Mitsubishi Electric was the prime contractor responsible for manufacturing all the Optus C1 communications systems.
The D1 and D2 satellites replace and expand the services provided by the B1 and B3 satellites respectively, which had both been operating beyond their design lifetimes. The D3 satellite is co-located with C1 to expand capacity.
Customers on D1 include the Australian Broadcasting Corporation (ABC), Special Broadcasting Service (SBS), the Seven Network, the Nine Network, Sky Television New Zealand and New Zealand's Kordia (formerly known as BCL). D1 also supports VSAT users.
During in-orbit testing of the satellite, it was discovered that the New Zealand spot beam had been configured with horizontal polarisation instead of the expected vertical polarisation - as had been used on its predecessor Optus B1.
As many existing receivers did not have the ability to receive horizontally aligned signals, Sky Television was unable to transfer services from Optus B1 to this beam as expected. Sky was instead assigned capacity on the more general Australia/NZ beam. Due to restrictions on broadcast rights (in terms of both broadcast licensing and copyright), the unencrypted Freeview service could not make a similar allocation switch and was set up as a horizontally-aligned service on the New Zealand spot beam. 
On 2007-07-31, Sky successfully performed an over the air software upgrade to all of its customer set-top boxes, enabling them to receive the horizontally-aligned signals from the New Zealand spot beam. Accordingly, Sky was able to return to their original capacity allocation.
Optus D2 replaced Optus B3, which had been in operation for 13 years at the time of D2's launch.
D2 also carries a large number of Free To Air channels, many in languages other than English
The third in the D series of Optus satellites was successfully launched into a geostationary transfer orbit on 21 August 2009 at 22:09 GMT by Arianespace using an Ariane 5 ECA launch vehicle from Europe's Spaceport in Kourou, French Guiana. The satellite will be co-located with Optus C1 at 156° east. Optus sold 25% of the transponder capacity (6 out of 24) to Foxtel to provide High Definition programming as well as "new channels, expanded digital services and enhanced picture and sound quality".
"Optus 10", was awarded to Space Systems/Loral, and announced on 21 March 2011 in a press release by Optus CEO Paul O'Sullivan. The satellite will provide "high quality broadcast services to households, and twoway voice and data communication services to areas in and around Australia and NZ", and "satellite services to Australia and NZ Government departments, premium companies and broadcasters including FOXTEL, ABC, SBS, Seven Network, Nine Network, Network Ten, Globecast Australia and Sky TV New Zealand.".
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