Editing Discovery Program (section)

===Missions of opportunity===
These provide opportunities to participate in non-NASA missions by providing funding for a science instrument or hardware components of an instrument, or for an extended mission for a spacecraft that may differ from its original purpose.<ref>{{Cite web|title=Discovery Program|url=https://www.nasa.gov/planetarymissions/discovery.html|access-date=25 February 2021|website=[[NASA]]|date=June 18, 2019 }}</ref>

* '''[[Mars Express#Scientific instruments|ASPERA-3]]''', an instrument designed to study the interaction between the solar wind and the [[atmosphere of Mars]], is flying on board the [[European Space Agency]]'s [[Mars Express]] orbiter. Launched on 2 June 2003, it has been orbiting Mars since 30 December 2003.<ref>{{Cite web|title=Mars Express operations|url=https://www.esa.int/Enabling_Support/Operations/Mars_Express_operations|access-date=21 February 2021|website=[[European Space Agency|ESA]]}}</ref> The Principal Investigator is [[David Winningham]] of [[Southwest Research Institute]].<ref>{{Cite web|date=18 December 2003|title=ASPERA-3: Next Stop Mars|url=https://www.nasa.gov/audience/forstudents/postsecondary/features/F_ASPERA_3.html|access-date=21 February 2021|website=[[NASA]]}}</ref>
*A NASA contribution to the joint [[European Space Agency|ESA]] - [[CNES]] '''[[NetLander]]''' Mars meteorological mission was planned, consisting of meteorological, seismic, and geodetic instruments; however, the mission was terminated prior to its 2007 launch.<ref>{{Cite web|last=Heil|first=Martha|date=4 January 2001|title=NASA CONSIDERS DISCOVERY MISSION PROPOSALS|url=https://www2.jpl.nasa.gov/releases/2001/discovery.html|access-date=8 May 2021|website=[[Jet Propulsion Laboratory]]|publisher=[[NASA]]}}</ref><ref>{{Cite web|date=3 January 2006|title=Announcement of Opportunity Discovery Program 2006 and Missions of Opportunity|url=https://spacese.spacegrant.org/uploads/Design%20Module/Discovery_AO_2006.pdf|access-date=8 May 2021|website=Space Systems Engineering|publisher=[[National Space Grant College and Fellowship Program]]}}</ref>
* '''[[Moon Mineralogy Mapper]]''' (M3) is a NASA-designed instrument placed on board the [[Indian Space Research Organisation|ISRO]]'s [[Chandrayaan-1|Chandrayaan]] orbiter selected in February 2005.<ref>{{Cite web|url=https://www.nasa.gov/home/hqnews/2005/feb/HQ_05037_moon_mapper.html|title=NASA – NASA Selects Moon Mapper for Mission of Opportunity|website=www.nasa.gov|language=en|first1=Dolores |last1=Beasley|first2=Gretchen |last2=Cook-Anderson|access-date=2023-01-17}}</ref> Launched in 2008, it was designed to explore the Moon's mineral composition at high resolution. M3's detection of water on the Moon was announced in late September 2009, one month after the mission ended.<ref>{{Cite web|last1=Nemiroff|first1=Robert|last2=Bonnell|first2=Jerry|date=28 September 2009|title=Astronomy Picture of the Day 2009 - September 28|url=https://apod.nasa.gov/apod/ap090928.html|access-date=21 February 2021|website=[[NASA]]}}</ref> The Principal Investigator was [[Carle Pieters]] of [[Brown University]].<ref>{{Cite web|title=Carle M. Pieters|url=http://www.planetary.brown.edu/html_pages/pieters.htm|access-date=21 February 2021|website=Brown University Planetary Geosciences Group|archive-date=April 23, 2011|archive-url=https://web.archive.org/web/20110423105339/http://www.planetary.brown.edu/html_pages/pieters.htm|url-status=dead}}</ref>
* '''[[EPOXI|Extrasolar Planet Observation and Deep Impact Extended Investigation]]''' (EPOXI) was selected in July 2007.<ref>{{cite news |url=http://www.space.com/missionlaunches/061031_ap_deep_impact.html |title=Deep Impact Heads to New Comet |work=[[Space.com]] |date=October 31, 2006 |archive-url=https://web.archive.org/web/20061102042130/http://www.space.com/missionlaunches/061031_ap_deep_impact.html |archive-date=November 2, 2006 |url-status=dead  }}</ref><ref name=":0">{{Cite web|url=https://www.nasa.gov/home/hqnews/2007/jul/HQ_07147_Discovery_missions.html|title=NASA – NASA Gives Two Successful Spacecraft New Assignments|website=www.nasa.gov|language=en|first1=Grey |last1=Hautaluoma|first2=Tabatha |last2=Thompson|access-date=2023-01-17}}</ref> It was a series of two new missions for the existing ''[[Deep Impact (spacecraft)|Deep Impact]]'' probe following its success at Tempel 1:<ref>{{Cite web|title=Deep Impact - EPOXI|url=https://www.jpl.nasa.gov/missions/deep-impact-epoxi|access-date=21 February 2021|website=[[Jet Propulsion Laboratory]]}}</ref>
** The '''Extrasolar Planet Observations and Characterization''' (EPOCh) mission used the Deep Impact high-resolution camera in 2008<ref>{{Cite web|title=EPOXI Mission|url=https://pdssbn.astro.umd.edu/data_sb/missions/epoxi/index.shtml|access-date=21 February 2021|website=NASA PDS: Small Bodies Node}}</ref> to better characterize known giant [[extrasolar planets]] orbiting other stars and to search for additional planets in the same system, as well as to investigate possible moons and ring systems of said exoplanets. A secondary science goal was to better observe the earth in both infrared and visible light, in order to create better computer models of exoplanets.<ref>{{Cite web|title=EPOXI Mission Overview|url=https://epoxi.astro.umd.edu/1mission/#:~:text=The%20main%20objective%20of%20EPOXI's,planets%20of%20the%20targeted%20stars.|access-date=21 February 2021|website=[[EPOXI]]}}</ref> The Principal Investigator was [[L. Drake Deming]] of NASA's [[Goddard Space Flight Center]].<ref>{{Cite web|last1=Neal-Jones|first1=Nancy|last2=Zubritsky|first2=Liz|date=13 January 2010|title=NASA Goddard's Drake Deming Wins Astrophysics Award|url=https://www.nasa.gov/centers/goddard/news/topstory/2009/deming-award.html#:~:text=Tinsley.-,Dr.,Flight%20Center%2C%20Greenbelt%2C%20Md.|access-date=21 February 2021|website=[[NASA]]}}</ref> [[File:Comet Hartley 2.jpg|thumb|Nucleus of Comet Hartley 2 imaged by [[Deep Impact (spacecraft)|Deep Impact]]]]
** The '''Deep Impact eXtended Investigation of Comets''' (DIXI) mission used the Deep Impact spacecraft for a flyby mission to a second comet, [[103P/Hartley|Hartley 2]]. The goal was to take pictures of its nucleus to increase our understanding of the diversity of comets. The flyby of Hartley 2 was successful with closest approach occurring on November 4, 2010.<ref>{{Cite web|title=Deep Impact Extended Investigation (DIXI) and Extrasolar Planet Observation and Characterization (EPOCh)|url=https://astrobiology.nasa.gov/missions/epoxi/|access-date=21 February 2021|website=[[NASA]]}}</ref> [[Michael A'Hearn]] of the [[University of Maryland]] was the Principal Investigator.<ref>{{Cite web|date=1 November 2006|title=University of Maryland Proposal for Deep Impact Extended Mission Clears Major Hurdle|url=http://spaceref.com/news/viewpr.html?pid=21191|access-date=21 February 2021|website=SpaceRef}}</ref>
* '''[[Stardust (spacecraft)#New Exploration of Tempel 1 (NExT)|New Exploration of Tempel 1]]''' (NExT) was selected in July 2007 together with the EPOXI extension.<ref name=":0" /> It was a new mission for the ''[[Stardust (spacecraft)|Stardust]]'' spacecraft to fly by comet [[9P/Tempel|Tempel 1]] in 2011 and observe changes since the Deep Impact mission visited it in July 2005. Later in 2005, Tempel 1 made its closest approach to the [[Sun]], possibly changing the surface of the comet. The flyby was completed successfully on February 15, 2011. [[Joseph Veverka]] of [[Cornell University]] is the Principal Investigator.<ref>{{Cite news|last=Wall|first=Mike|date=10 February 2011|title=FAQ: Inside NASA's Valentine's Day Visit to Comet Tempel 1|work=[[Space.com]]|url=https://www.space.com/10813-nasa-stardust-comet-tempel1-flyby-faq.html|access-date=21 February 2021}}</ref><ref>{{Cite news|date=9 February 2011|title=Stardust NExT set to meet its second comet|work=[[ScienceDaily]]|url=https://www.sciencedaily.com/releases/2011/02/110209131953.htm|access-date=21 February 2021}}</ref>
* '''[[BepiColombo#Mercury Planetary Orbiter|Strofio]]''' is a [[Mass spectrometry|mass spectrometer]] that is a part of the SERENA instrument package on board the [[BepiColombo#Mercury Planetary Orbiter|Mercury Planetary Orbiter]] component of the [[European Space Agency|ESA's]] [[BepiColombo]] mission. Strofio will study the atoms and molecules that compose [[Mercury's atmosphere]] to reveal the composition of the planet's surface. [[Stefano Livi]] of Southwest Research Institute is the Principal Investigator.<ref>{{cite web|title=Discovery Program – Strofio|url=http://discovery.nasa.gov/strofio.cfml|url-status=dead|archive-url=https://web.archive.org/web/20110301014547/http://discovery.nasa.gov/strofio.cfml|archive-date=March 1, 2011|access-date=21 February 2021|website=[[NASA]]|publisher=}}</ref>
* '''[[Martian Moons Exploration#Scientific payload|MEGANE]]''' (Mars-moon Exploration with GAmma rays and NEutrons) is an instrument planned to fly aboard the [[Martian Moons Exploration]] (MMX), a [[Japanese Aerospace Exploration Agency]] (JAXA) probe to [[Phobos (moon)|Phobos]] and [[Deimos (moon)|Deimos]] launching in 2026. MEGANE includes a [[Gamma spectroscopy|gamma-ray spectrometer]] and a [[Neutron spectroscopy|neutron spectrometer]]. [[David J. Lawrence]] of [[Johns Hopkins University]] is the Principal Investigator.<ref>{{cite web|title=MEGANE Mars-moon Exploration with GAmma rays and Neutrons|url=https://megane.jhuapl.edu/|access-date=21 February 2021|website=MEGANE|publisher=JHU APL}}</ref><ref>{{Cite web|title=MEGANE:Team|url=https://megane.jhuapl.edu/Team/|access-date=21 February 2021|website=MEGANE|publisher=JHU APL}}</ref>
* '''[[EnVision#Instruments|VenSAR]]''' (Venus Synthetic Aperture Radar), is an instrument planned to fly aboard ESA's [[EnVision]] Venus orbiter. The principal investigator is [[Scott Hensley]], [[Jet Propulsion Laboratory]] NASA/California Institute of Technology.<ref>{{cite web|title=Then There Were 3: NASA to Collaborate on ESA’s New Venus Mission|url=https://www.jpl.nasa.gov/news/then-there-were-3-nasa-to-collaborate-on-esas-new-venus-mission/|publisher=Jet Propulsion Laboratory}}</ref>
* In addition, the '''[[Lunar Reconnaissance Orbiter]]''' was temporarily managed under the Discovery Program from the termination of the [[Lunar Precursor Robotic Program]]<ref>{{Cite web|title=LRO (Lunar Reconnaissance Orbiter) + LCROSS|url=https://directory.eoportal.org/web/eoportal/satellite-missions/l/lro|access-date=25 February 2021|website=eoPortal}}</ref> until the creation of the [[Lunar Discovery and Exploration Program]].<ref name=NASABudget19Estimates>{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/fy19_nasa_budget_estimates.pdf#page=369|title=NASA FY 2019 Budget Estimates}}</ref><ref name=ClarkePres>{{cite web|url=https://www.lpi.usra.edu/pac/presentations/0919/Day1/Clark.pdf|title=Lunar Discovery & Exploration Program Status|author=Clarke, Steve}}</ref>