The Discovery Program is a series of Solar System exploration missions funded by the U.S. National Aeronautics and Space Administration (NASA) through its Planetary Missions Program Office. The cost of each mission is capped at a lower level than missions from NASA's New Frontiers or Flagship Programs. As a result, Discovery missions tend to be more focused on a specific scientific goal rather than serving a general purpose. The Discovery Program was founded in 1990 to implement the policy of the then-NASA administrator Daniel S. Goldin of "faster, better, cheaper" planetary science missions. Existing NASA programs had specified mission targets and objectives in advance, then sought bidders to construct and operate them. In contrast, Discovery missions are solicited through a call for proposals on any science topic and assessed through peer review. Selected missions are led by a scientist called the principal investigator (PI) and may include contributions from industry, universities or government laboratories. The Discovery Program also includes Missions of Opportunity, which fund U.S. participation in spacecraft operated by other space agencies, for example by contributing a single scientific instrument. It can also be used to re-purpose an existing NASA spacecraft for a new mission. As of June 2021, the most recently selected Discovery missions were VERITAS and DAVINCI, the fifteenth and sixteenth missions in the program.

History

In 1989, NASA's Solar System Exploration Division began to define a new strategy for Solar System exploration up to the year 2000. This included a Small Mission Program Group that investigated missions that would be low cost and allow focused scientific questions to be addressed in shorter time than existing programs. The result was a request for rapid studies of potential missions and NASA committed funding in 1990. The new program was called "Discovery". The panel assessed several concepts that could be implemented as low-cost programs, selecting NEAR Shoemaker which became the first launch in the Discovery Program on February 17, 1996. The second mission, Mars Pathfinder, launched on December 4, 1996, carried the Sojourner rover to Mars.

Missions

Standalone missions

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.

Mission timeline

Proposals and concepts

However often the funding comes in, there is a selection process with perhaps two dozen concepts. These sometimes get further matured and re-proposed in another selection or program. An example of this is Suess-Urey Mission, which was passed over in favor of the successful Stardust mission, but was eventually flown as Genesis, while a more extensive mission similar to INSIDE was flown as Juno in the New Frontiers program. Some of these concepts went on to become actual missions, or similar concepts were eventually realized in another mission class. This list is a mix of previous and current proposals. Additional examples of Discovery-class mission proposals include:

Mars focused

Lunar focused

Venus focused

Selection process

Discovery 1 and 2

The first two Discovery missions were Near Earth Asteroid Rendezvous (NEAR) (later called Shoemaker NEAR) and Mars Pathfinder. These initial missions did not follow the same selection process that started once the program was under-way. Mars Pathfinder was salvaged from the idea for a technology and EDL demonstrator from the Mars Environmental Survey program. One of the goals of Pathfinder was to support the Mars Surveyor program. Later missions would be selected by a more sequential process involving Announcements of Opportunity. In the case of NEAR, a working group for the program recommended that the first mission should be to a near-Earth asteroid. A series of proposals limited to missions to a near-Earth asteroid missions were reviewed in 1991. What would be the NEAR spacecraft mission was formally selected in December 1993, after which began a 2-year development period prior to launch. NEAR was launched on February 15, 1996, and arrived to orbit asteroid Eros on February 14, 2000. Mars Pathfinder launched on December 4, 1996, and landed on Mars on July 4, 1997, bringing along with it the first NASA Mars rover, Sojourner.

Discovery 3 and 4

In August 1994, NASA made an Announcement of Opportunity for the next proposed Discovery missions. There were 28 proposals submitted to NASA in October 1994: In February 1995, Lunar Prospector, a lunar orbiter mission, was selected for launch. Three other missions were left to undergo a further selection later in 1995 for the fourth Discovery mission: Stardust, Suess-Urey, and Venus Multiprobe. Stardust, a comet sample-return mission, was selected in November 1995 over the two other finalists.

Discovery 5 and 6

In October 1997, NASA selected Genesis and CONTOUR as the next Discovery missions, out of 34 proposals that were submitted in December 1996. The five finalists were:

Discovery 7 and 8

In July 1999, NASA selected MESSENGER and Deep Impact as the next Discovery Program missions. MESSENGER was the first Mercury orbiter and mission to that planet since Mariner 10. Both missions targeted a launch in late 2004 and the cost was constrained at about US$300 million each. In 1998 five finalists had been selected to receive US$375,000 to further mature their design concept. The five proposals were selected out of about 30 with the goal of achieving the best science. Those missions were: Aladdin and MESSENGER were also finalists in the 1997 selection.

Discovery 9 and 10

26 proposals were submitted to the 2000 Discovery solicitation, with budget initially targeted at US$300 million. Three candidates were shortlisted in January 2001 for a phase-A design study: Dawn, Kepler space telescope, and INSIDE Jupiter. INSIDE Jupiter was similar to a later New Frontiers mission called Juno; Dawn was a mission to asteroids Vesta and Ceres, and Kepler was a space telescope mission aimed to discover extrasolar planets. The three finalists received US$450,000 to further mature the mission concept. In December 2001, Kepler and Dawn were selected for flight. At this time, only 80 exoplanets had been detected, and the main mission of Kepler to look for more exoplanets, especially Earth-sized. Both Kepler and Dawn were initially projected for launch in 2006.

Discovery 11

The original Announcement of Opportunity for a Discovery mission released on April 16, 2004. The only candidate for selection for a concept Phase A study was JASSI, which was a Jupiter flyby mission based on the New Frontiers Mission Juno that was already under consideration for final selection (eventually Juno was selected as the 2nd New Frontiers mission in 2005 and launched in 2011). No other discovery mission proposed in response to the Announcement of Opportunity was considered for concept study and therefore no Discovery mission was selected for this opportunity (although a mission of opportunity was selected (Moon Mineralogy Mapper) as part of the AO in 2004 ). The next Announcement of Opportunity for a Discovery mission was released on January 3, 2006. There were three finalists for this Discovery selection including GRAIL (the eventual winner), OSIRIS, and VESPER. OSIRIS was very similar to the later OSIRIS-REx mission, an asteroid sample-return mission to 101955 Bennu, and Vesper, a Venus orbiter mission. A previous proposal of Vesper had also been a finalist in the 1998 round of selection. The three finalists were announced in October 2006 and awarded US$1.2 million to further develop their proposals for the final round. In November 2007 NASA selected the GRAIL mission as the next Discovery mission, with a goal of mapping lunar gravity and a 2011 launch. There were 23 other proposals that were also under consideration. The mission had a budget of US$375 million (then-year dollars) which included construction and launch.

Discovery 12

The Announcement of Opportunity for a Discovery mission released on June 7, 2010. For this cycle, 28 proposals were received; 3 were for the Moon, 4 for Mars, 7 for Venus, 1 for Jupiter, 1 to a Jupiter Trojan, 2 to Saturn, 7 to asteroids, and 3 to comets. Out of the 28 proposals, three finalists received US$3 million in May 2011 to develop a detailed concept study: In August 2012, InSight was selected for development and launch. The mission launched on May 5, 2018, and successfully landed on Mars on November 26.

Discovery 13 and 14

In February 2014, NASA released a Discovery Program 'Draft Announcement of Opportunity' for launch readiness date of December 31, 2021. The final AO was released on November 5, 2014, and on September 30, 2015, NASA selected five mission concepts as finalists, each received $3 million for one-year of further study and concept refinement. On January 4, 2017, Lucy and Psyche were selected for the 13th and 14th Discovery missions, respectively and launched on 16 October 2021 and 13 October 2023, respectively. Lucy will fly by five Jupiter trojans, asteroids which share Jupiter's orbit around the Sun, orbiting either ahead of or behind the planet. Psyche will explore the origin of planetary cores by orbiting and studying the metallic asteroid 16 Psyche.

Discovery 15 and 16

On December 22, 2018, NASA released a draft of its Discovery 2019 Announcement of Opportunity, which outlined its intent to select up to two missions with launch readiness dates of July 1, 2025 – December 31, 2026, and/or July 1, 2028 – December 31, 2029, as Discovery 15 and 16, respectively. The final Announcement of Opportunity was released on April 1, 2019, and proposal submissions were accepted between then and July 1, 2019. Finalists, announced on February 13, 2020, were: On June 2, 2021, NASA administrator Bill Nelson announced in his "State of NASA" address that the two Venus missions, VERITAS and DAVINCI, had been selected for development. The two missions will launch between 2031 and 2032. Other proposal submissions for Discovery 15 and 16 missions included:

Gallery

Artists' impressions

Mission insignias

This section includes an image of the Discovery missions' patches or logos, as well as the launch year.

Launches

This section includes an image of the Discovery missions' rockets, as well as the launch year.