Editing Delta III (section)

== History ==
Due to the continual size and mass growth of commercial satellites in the late 1980s, McDonnell Douglas realized the need for a higher-performance rocket than even their new [[Delta II]]. New satellite bus offerings from [[Hughes Aircraft Company|Hughes]] required a launch vehicle with a 4-meter diameter payload fairing as well as the ability to send 3.5 tons of payload to a [[geostationary transfer orbit]] – neither of which Delta II offered.<ref name=slr>{{cite web |last1=Kyle |first1=Ed |title=Thunder Lost – The Delta 3 Story |url=https://www.spacelaunchreport.com/thorh13.html|archive-url=https://web.archive.org/web/20220321061514/https://www.spacelaunchreport.com/thorh13.html |url-status=dead |archive-date=March 21, 2022 |website=spacelaunchreport.com}}</ref>

Multiple options for evolving the Delta II to support larger payloads were considered in the late 1980s and early 1990s, namely using higher-performing liquid hydrogen/liquid oxygen upper stages. Eventually, the Delta III was announced in 1995, boasting an evolved Delta II first stage and a second stage based on that of the Japanese [[H-II]] rocket. This led to Delta III being similar in size to Delta II, meaning that the existing Delta II infrastructure at [[Space Launch Complex 17|SLC-17B]] could be used after some modifications. Soon after the announcement, Hughes placed an order for 13 Delta III launches.<ref name=slr />

Delta III would only fly three times. The first two launches, both carrying live satellites, ended in failure. The third and final launch, carrying a dummy payload, was only partially successful after the RL-10B second-stage engine shut down prematurely. After commercial interest declined, the Delta III program was officially ended in 2003. Boeing then transitioned their focus to the new [[Delta IV]] rocket, which was much more capable than Delta III.<ref name=slr />

Multiple Delta III rockets were already built and would have been unused, but they were cannibalized for parts for both Delta II and Delta IV.<ref name=slr />