Editing Discovery Program (section)

=== Discovery 7 and 8 ===
[[File:Deep Impact HRI.jpeg|thumb|''Deep Impact'' impacted a comet nucleus]]
In July 1999, NASA selected ''[[MESSENGER]]'' and [[Deep Impact (spacecraft)|''Deep Impact'']] as the next Discovery Program missions.<ref name="nssdc.gsfc.nasa.gov"/> ''MESSENGER'' was the first [[Mercury (planet)|Mercury]] orbiter and mission to that planet since [[Mariner 10]].<ref name="nssdc.gsfc.nasa.gov">{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/news/discovery_pr_19990707.html |title=NASA Selects Missions to Mercury and a Comet's Interior as Next Discovery Flights |website=Nssdc.gsfc.nasa.gov |access-date=January 11, 2016}}</ref> Both missions targeted a launch in late 2004 and the cost was constrained at about US$300 million each.<ref name="nssdc.gsfc.nasa.gov"/>

In 1998 five finalists had been selected to receive US$375,000 to further mature their design concept.<ref name="autogenerated1998">{{cite web |url=http://www.nasa.gov/home/hqnews/1998/98-203.txt |format=TXT |title=Five Discovery Mission Proposals Selected For Feasibility Studies |website=Nasa.gov |access-date=January 11, 2016 |archive-date=November 26, 2020 |archive-url=https://web.archive.org/web/20201126075335/https://www.nasa.gov/home/hqnews/1998/98-203.txt |url-status=dead }}</ref> The five proposals were selected out of about 30 with the goal of achieving the best science.<ref name="autogenerated1998"/> Those missions were:<ref name="autogenerated1998"/>
* ''Aladdin''
* ''[[Deep Impact (spacecraft)|Deep Impact]]''
* [[MErcury Surface, Space ENvironment, GEochemistry and Ranging|''MESSENGER'']]
* ''INSIDE Jupiter''
* ''Vesper''

''Aladdin'' and ''MESSENGER'' were also finalists in the 1997 selection.<ref name="autogenerated1998"/>