Selection of Discovery Mission 13 and 14

Header of the Discovery program website, as of January 2016.[1]

The selection process for Mission 13 and 14 of the Discovery program began in February 2014, as NASA drafted an Announcement of Opportunity (AO) for the next Discovery mission. The winning mission proposals received $450 million in funding towards mission development and construction, along with bonus funding if missions were able to incorporate certain technologies. For Discovery Mission 13 and 14, NASA received 28 proposals, 16 of which notably centered around small Solar System bodies. Lucy, a multiple-flyby mission to the Jupiter trojans, and Psyche, a mission to the metallic asteroid 16 Psyche, were announced as the winners of the competition in January 2017, with launches in October 2021 and October 2023, respectively.

Both Lucy and Psyche were part of a finalist shortlist that was announced by NASA in September 2015, which also included DAVINCI, a Venus atmospheric probe, VERITAS, a Venus orbiter in the style of Magellan, and NEOCam, a space observatory focusing on the detection of potentially hazardous Near-Earth objects. It was the first time since the Discovery Mission 7 and 8 selection in 1999 that five finalists were chosen, as opposed to the traditional three. Each finalist received $3 million to develop their mission proposals, with the NEOCam concept winning additional year in funding from NASA at the end of the competition. It was also the first time since the selection of Discovery Mission 9 and 10 in 2001 that two missions were chosen to fly in a single round.

Background

Construction of the InSight spacecraft. Its launch would be delayed to 2018, leaving a 7-year gap in Discovery program launches.

The ability for the Discovery program to launch missions on a regular basis was hampered by cuts to NASA's budget over the course of the late 2000s and early 2010s, leading to only two Announcements of Opportunities for the Discovery program in the 21st century.[2][3] NASA's Small Bodies Assessment Group (SBAG), in their Visions and Voyages for Planetary Science in the Decade 2013-2022 survey published in March 2011, made a recommendation to NASA, calling to "maintain the original goals of the Discovery program" by creating a short time-frame cadence of two years between launches.[4][5] They also made a recommendation to select and fund two mission concepts during each 18-24 month period, rather than one, which would ultimately result in one Discovery mission launch each year.[4]

Prior to the call of opportunity that started the competition for the 13th Discovery mission, 11 missions had been launched in the program. The 12th mission, InSight, was delayed from its initial March 2016 launch date, following failed attempts to contain leaks in one of the spacecraft's main instruments, during numerous vacuum tests.[6][7] The launch was thus delayed to May 2018 - a year after the end of the competition and two years before the launch of the 13th Discovery mission, with a cost overrun of $155 million.[8][9] Concern for the cost overrun, the seven-year gap in Discovery program launches, and their effect on the program were raised,[10] though officials at NASA insisted that the issues faced with InSight would not affect the program and the Discovery Mission 13 competition.[11]

Process

NASA made the NEXT ion thruster technology available for proposals for the thirteenth Discovery Program mission.[12]

For the first time, the $450 million cost cap will not include post-launch operations expenses.[15] The final requirements were released on November 5, 2014; amongst other things they clarified the laser communication package was not a requirement but, if included, could grant a budgetary bonus.[16]

  • An additional $30 million available if it attempts to demonstrate laser communication (as opposed to radio communication) in space, by sending data with lasers beyond one lunar distance (distance from Earth to the Moon).[13][17][18] The system is called Deep Space Optical Communications (DSOC).[19] The device will be able to increase spacecraft communications performance and efficiency by 10 to 100 times over conventional means.[19][20]

Timeline

Announcement of Opportunity

Enceladus was the target of the largely publicized Enceladus Life Finder proposal.

Following the conclusion of the Discovery Mission 12 competition, the congressional deadline for the next Announcement of Opportunity (AO) was set for May 1, 2014. The United States Congress approved of a $75 million increase in the budget for the Discovery program from the Obama Administration's original FY14 request, as with other divisions and projects at NASA.[21] Officials from NASA's Science Mission Directorate, however, stated in January 2014 that this deadline would not be met, and that it would possibly be delayed by several months. James "Jim" Green, Director of NASA's Planetary Science Division, noted in a press conference that "they gave us the date of May 1st, and that's not realistic," stating that the deadline was not feasible in context of the declining budget allocated for the Discovery program over the past decade.[3][22] A month later, a draft AO for the 13th mission of the Discovery Program was released by the Goddard Space Flight Center, outlining a process in which three finalists will be chosen to receive $3 million to further develop their proposals, with the winner receiving $450 million in funding to construct their spacecraft and operate the mission, excluding launch costs – a $50 million decrease from the $500 million in funding originally anticipated by NASA.[21] The draft AO, which included potential financial incentives for technologies that would eventually make it into the final AO for Discovery Mission 13, such as the Heat Shield for Extreme Entry Environment Technology (HEEET) and the Deep Space Optical Communications (DSOC)[19] The device will be able to increase spacecraft communications performance and efficiency by 10 to 100 times over conventional means.[19][20] stated an anticipated release date for the final AO in September 2014 – four months after the original congressional deadline.[3][23] The official text of the draft was released in full on July 2, 2014,[24] with the final AO being released on November 5.[25][26]

28 proposals for the next Discovery mission were received by NASA before its deadline of February 26, 2015.[5][27] On the day of the deadline, Lockheed Martin Space Systems announced that they were supporting many of the proposals as contractors.[5] While NASA does not disclose which proposals they receive for Discovery program missions, many mission teams went public with their proposals, through various scientific and astronomical meetings and conferences throughout the year.[28] One particular entrant in the competition aimed at Enceladus, the astrobiology Enceladus Life Finder mission, received significant attention from news media over the course of the first round.[29][30][31][32] The Io Volcano Observer was also revealed as an entrant in the competition at the 64th Lunar and Planetary Science Conference in March 2015 - its third attempt after previously entering in the competitions for Discovery Mission 12 and New Frontiers Mission 3.[33] A number of proposals targeting minor planets were also unveiled by their respective teams through briefings held at the NASA Small Bodies Assessment Group's three-hour meeting on June 30, 2015.[27] During the meeting, three more contractors were revealed as supporting numerous entrants in the competition – Ball Aerospace, Boeing Defense, Space & Security, and Orbital ATK.[27] A notable event that occurred during the competition's first round was the September 2015 announcement of NASA's termination of involvement with the B612 Foundation's Sentinel Space Telescope, an infrared space observatory focused on discovering a number of new Near-Earth objects (NEOs).[34] The mostly similar NEOCam proposal, which was also a NEO-seeking infrared space observatory mission, sought to benefit from the termination of NASA's involvement with Sentinel by acting as a suitable replacement mission.[34]

Finals and selection

This time next year, when the [final proposals] come in and we do the analysis, there's a criteria [sic] on whether we'll be able to select one or two, and that criteria is, of course, a budgetary one. It's also how well they do. They have to demonstrate their ability to stay within the cost cap.

— James L. Green, Director of the Planetary Science Division, NASA[35]

In September 2015, out of the numerous proposals sent to NASA for consideration, five were officially chosen for selection to participate in the competition's final round.[36] The selections included DAVINCI and VERITAS, two spacecraft targeted at Venus; a planet NASA had not visited since 1994 with Magellan.[37] Also selected were Psyche and Lucy, two missions targeted at asteroids, and NEOcam, a space observatory focused on Near-Earth objects.[37] This is the first time since the selection of Discovery Mission 7 and 8, back in 1999, that five missions were selected to be finalists; typically only three are chosen to compete.[37][38] The reasoning behind this, according to NASA, was to open up the possibility of selecting two missions, instead of one, to fund and launch.[35] Site visits by NASA personnel of the proposed operations and manufacturing centers of each of the five proposed missions occurred in November and December 2016.[39] In particular, Karin Valentine of the Arizona State University recounted 30 representatives of NASA arriving at Space Systems Loral, the proposed manufacturing site for the Psyche mission, spending nine hours interviewing staff and members of the mission team during their site visit. Principal investigator Linda Elkins-Tanton stated that the Psyche team had spent up to six months preparing for the visit, though remarking that "was almost not enough time [...] presenting answers to these complex and technical questions about our mission really took the team of about 140 people many long and hard-worked days."[39]

Venus and asteroids were the two common themes among the finalists of the Discovery Mission 13 and 14 competition.

Throughout the year of the final, renewed focus and attention was drawn on Venus, following the selection of DAVINCI and VERITAS. Contemporary public and media interest in Venus had escalated after the successful second orbital insertion attempt of Akatsuki in December 2015,[40][41][42] and its subsequent early data returns from the planet through the year afterward.[43][44] Both VERITAS and DAVINCI were featured prominently in the media during this time, through recent discoveries concerning volcanism on the planet,[45] and a frigid cold layer in Venus atmosphere;[46] both subjects of interest to each respective mission. In addition, the missions were also treated features in journals and websites such as Nature,[40] and Universe Today.[47] Psyche was also publicized in the media in the final months leading up to the selection, after evidence for water on 16 Psyche, the target of the mission, was discovered in October 2016.[48][49][50]

The press conference convened to publicly reveal the winner of the competition on January 4, 2017 was announced the day earlier,[51][52] after two delays from original selection dates in September and December 2016.[11] The winners of the competition, Lucy and Psyche, were announced via a press release two hours before the conference.[53][54][55] An additional end result of the competition was also an additional year of funding for proposal development for NEOCam under a "Phase A" study.[56] Jim Green stated that the selection of the missions were a part of NASA's "larger strategy of investigating how the Solar System formed and evolved", describing asteroids and minor planets as the "additional pieces of the puzzle [that will] help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained, and what the future may hold."[57]

Mission proposals

The deadline for proposals was February 16, 2015 and may have included some of the following mission candidates:[15][58]

Saturn system
Jupiter system
  • Io Volcano Observer — a mission to explore Io's active volcanism and impact on the Jupiter system as a whole by measuring its global heat flow, its induced magnetic field, the temperature of its lava, and the composition of its atmosphere, volcanic plumes, and lavas.[62]
  • Advanced Jovian Asteroid eXplorer (AJAX) — a mission to a single Jupiter trojan[63]
Venus
Concept art of VERITAS orbiter at Venus
  • Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI)− Atmospheric probe to Venus that would study the chemical composition of its atmosphere during a 63-minute descent. Selected as one of five finalists in September 2015.
  • Radar at Venus (RAVEN) - High-resolution mapping of Venus[64]
  • Venus Atmosphere and Surface Explorer (VASE)— would measure the complete inventory of atmospheric noble gas and light stable isotopes and provide the first complete atmospheric structure profile from clouds to surface of temperature, pressure and wind.[65]
  • Venus Emissivity, Radio Science, InSAR Topography and Spectroscopy (VERITAS)— Orbiter that would produce global, high resolution topography and imaging of Venus' surface and global surface composition. Selected as one of five finalists in September 2015.
Mars system
Asteroid, comet, and lunar proposals
Lucy concept art
  • Binary Asteroid in-situ Explorer (BASiX)— a mission to visit a binary asteroid and set off small explosions to see how they affect the movement of both objects.[71]
  • Comet Radar Explorer (CORE)
  • Dark Asteroid Rendezvous (DARe)— a mission to visit up to nine asteroids using a spacecraft equipped with ion propulsion.[72]
  • Lucy — would perform the first reconnaissance of the Jupiter trojan asteroids. Some possible reported targets would be 3548 Eurybates, 21900 Orus, 11351 Leucus, the binary 617 Patroclus with its companion Menoetius, and main-belt asteroid 52246 Donaldjohanson.[73][74] Selected as one of five finalists in September 2015.
  • Moon Age and Regolith Explorer (MARE)[75][76]
  • NanoSWARM — CubeSat mission to study space weathering, lunar magnetism, lunar water and small-scale magnetospheres.
  • Near-Earth Object Camera (NEOCam)— is a space infrared telescope designed to survey the Solar System for potentially hazardous asteroids. Selected as one of five finalists in September 2015.
  • Proteus – mission to 238P/Read, a main-belt comet[77]
  • Psyche — orbiter to 16 Psyche, the most massive metallic asteroid in the asteroid belt, thought to be exposed iron core of a protoplanet.[78] Selected as one of five finalists in September 2015.
  • Kuiper Telescope — this would target multiple objects, including the giant planets, their satellites, and small bodies with a 1.2-meter diameter mirror space telescope placed at Earth L2 point.[79]

Finalists

Spacecraft art
 Name Institution Principal Investigator Target
Lucy Colorado Southwest Research Institute, Boulder Harold F. Levison Jupiter trojans

Lucy is reconnaissance mission to send a spacecraft on a tour of at least five of the Jupiter trojans in a multiple-flyby effort lasting from 2021 to a final flyby in 2032.[80] The spacecraft will perform observations of each trojan asteroid's geology, surface features, compositions, masses and densities, in order to enable study on the formation and evolution of the Solar System.[81] The mission will make use of the Deep Space Atomic Clock.[81]

Psyche Arizona Arizona State University Linda Elkins-Tanton 16 Psyche

Psyche, an asteroid belt mission, aims to send a spacecraft to the M-type asteroid 16 Psyche. The spacecraft will study the asteroid, believed to be the exposed core of an early Solar System protoplanet from orbit, with the goal of better understanding the processes of the early formation of the Solar System; studies not possible on existing planetary bodies, due to geologic activity.[82] The primary mission will last six months, focusing on studies of the asteroid's gravity, composition and topography.[83] In addition, the spacecraft will use a solar electric propulsion system, similar to Dawn.[82] However, Psyche will use a Hall-effect thruster unlike the Kaufman thruster used by Dawn [84]

N/A DAVINCI Maryland Goddard Space Flight Center Lori Glaze Venus

Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) is a mission to send an atmospheric probe through the Atmosphere of Venus, and study it during a 63-minute descent. A successor to the Pioneer Venus Multiprobe and Venera missions, studies will focus on finding evidence for the existence of active volcanoes on Venus, building on findings from both Pioneer Venus and Venus Express,[85] and focusing on sulfur dioxide signatures.[86]

NEOCam California Jet Propulsion Laboratory Amy Mainzer Near-Earth objects

Near-Earth Object Camera (NEOCam) is a space observatory mission, similar in design and concept to the Kepler space telescope, that will hunt for and identify potentially hazardous Near-Earth objects (NEOs). The team's scientists say that they will be able to discover at least ten times the amount of NEOs than all currently known, with the main objective being to characterize two thirds of the amount of asteroids over 140 metres (460 ft) in diameter estimated to exist in the main belt, over the course of its four-year primary mission.[87] One of the technologies aboard the spacecraft is an advanced infrared sensor that had been in development at the Jet Propulsion Laboratory for more than a decade.[88] The project's principal investigator, Amy Mainzer, was also the principal investigator of the NEOWISE mission of the Wide-field Infrared Survey Explorer (WISE), a similar mission that observed minor planets in near-earth orbits.[89] This will be the mission's second attempt at being funded by the Discovery program; it was originally submitted to NASA during the selection of Discovery Mission 11 in 2006, but was not chosen as a finalist.[90]

VERITAS California Jet Propulsion Laboratory Suzanne Smrekar Venus

Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) aims to place a spacecraft in orbit of Venus to study the planet's surface through high-resolution radar imagery, effectively succeeding Magellan.[91] The imagery would be obtained by using an X band radar configured as a single pass interferometric synthetic aperture radar (InSAR),[92] coupled with a multispectral near-infrared (NIR) emissivity mapping capability.[93] The main objective of the mission is to study the past geology of Venus, and whether or not it once would have supported life, along with other in-depth studies, such as the planet's tectonic and volcanic history, and searching for evidence of a possible resurfacing event in Venus' recent past.[94]

Submissions

For the competition to select the 13th Discovery mission, 28 proposals were submitted to NASA from various institutions; roughly the same number of proposals received during the competition for the 12th Discovery mission in 2011.[28] 16 of these proposals were notably focused on small Solar System bodies, including asteroids, comets, kuiper belt objects, and planetary moons.[27] 27 of the 28 proposals were disclosed to the public before finalists were chosen in September 2015:

References

  1. ^ "Discovery Program Official Website (January 2016)". National Aeronautics and Space Administration (NASA). January 15, 2016. Archived from the original on January 15, 2016. Retrieved January 15, 2016.
  2. ^ King, Ledyard (October 29, 2013). "Another year of sequestration would delay NASA missions". USA Today. Gannett Company. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  3. ^ a b c Kane, Van (February 9, 2014). "Discovery Next". The Planetary Society. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  4. ^ a b SBAG staff (April 21, 2011). "SBAG Assessment of Decadal Survey and Recommendations for Implementation" (PDF). NASA Small Bodies Assessment Group. Lunar and Planetary Institute. Archived (PDF) from the original on August 8, 2013. Retrieved April 20, 2016.
  5. ^ a b c Leone, Dan (February 23, 2015). "NASA Sorting Through Latest Discovery Proposals". SpaceNews. Pocket Ventures, LLC. Retrieved April 20, 2016.
  6. ^ Hand, Eric (December 22, 2015). "Updated: NASA delays Mars InSight mission". Science. American Association for the Advancement of Science. Archived from the original on January 1, 2017. Retrieved January 1, 2017.
  7. ^ Australian Associated Press (December 23, 2015). "NASA suspends launch of InSight mission to Mars". The Australian. News Corp Australia. Retrieved January 1, 2017.
  8. ^ Foust, Jeff (September 2, 2016). "InSight delay adds $150 million to mission's cost". SpaceNews. Pocket Ventures, LLC. Archived from the original on December 14, 2023. Retrieved January 1, 2017.
  9. ^ Pandey, Avaneesh (September 3, 2016). "InSight Mission: NASA Approves Spring 2018 Launch As Delay Adds $150 Million To Mission's Cost". International Business Times. IBT Media. Archived from the original on January 1, 2017. Retrieved January 1, 2017.
  10. ^ Powell, Devin (March 11, 2016). "NASA Mars woes could delay other planetary missions". Nature. 531 (7594). Nature Publishing Group: 289. Bibcode:2016Natur.531..289P. doi:10.1038/nature.2016.19549. PMID 26983520. S2CID 4406444.
  11. ^ a b Clark, Stephen (September 7, 2016). "NASA official says new mission selections on track despite InSight woes". Spaceflight Now. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  12. ^ Kane, Van (February 20, 2014). "Boundaries for the Next Discovery Mission Selection". Future Planets. Archived from the original on March 7, 2014.
  13. ^ a b c d "The DAVINCI spacecraft". Phys.org. Archived from the original on September 1, 2019. Retrieved January 11, 2016.
  14. ^ Clark, Stephen (March 3, 2015). "NASA eyes ion engines for Mars orbiter launching in 2022". Space Flight Now. Archived from the original on June 18, 2018. Retrieved March 4, 2015.
  15. ^ a b Clark, Stephen (April 6, 2015). "Diverse destinations considered for new interplanetary probe". Space Flight Now. Archived from the original on January 5, 2017. Retrieved April 7, 2015.
  16. ^ "NASA Drops Laser Comm Requirement From Discovery Solicitation". SpaceNews.com. November 5, 2014. Archived from the original on December 14, 2023. Retrieved January 11, 2016.
  17. ^ NASA Drops Laser Comm Requirement From Discovery Solicitation Archived December 14, 2023, at the Wayback Machine. Space News, Dan Leone. November 5, 2014
  18. ^ Clark, Stephen (February 24, 2014). "NASA receives proposals for new planetary science mission". Space Flight Now. Archived from the original on November 8, 2020. Retrieved February 25, 2015.
  19. ^ a b c d David, Leonard (October 18, 2017). "Deep Space Communications via Faraway Photons". NASA / Jet Propulsion Laboratory. Archived from the original on January 11, 2020. Retrieved November 4, 2017.
  20. ^ a b Greicius, Tony (September 14, 2017). "Psyche Overview". NASA. Archived from the original on November 10, 2021. Retrieved September 18, 2017.
  21. ^ a b Kane, Van (January 15, 2014). "NASA Budget: Will there be money for the mortgage payments?". Future Planetary Exploration. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  22. ^ Foust, Jeff (January 23, 2014). "NASA Will Miss Congressional Deadline for Next Discovery Solicitation". SpaceNews. Pocket Ventures, LLC. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  23. ^ NASA Science Mission Directorate (February 19, 2014). "NASA Discovery Program Draft Announcement of Opportunity". SpaceRef. SpaceRef Interactive Inc. Archived from the original on February 22, 2014. Retrieved January 5, 2017.
  24. ^ "DRAFT Announcement of Opportunity - Discovery 2014" (PDF). NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES). National Aeronautics and Space Administration (NASA). July 2, 2014. Archived (PDF) from the original on January 30, 2016. Retrieved January 5, 2017.
  25. ^ "NASA Releases Discovery Call for Proposals". Discovery Program Office. National Aeronautics and Space Administration (NASA). November 5, 2014. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  26. ^ Tygielski, Julie (November 5, 2014). "Release of Discovery 2014 Announcement of Opportunity". Lunar and Planetary Institute. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  27. ^ a b c d Leone, Dan (July 7, 2015). "Small Bodies Dominate NASA's Latest Discovery Competition". SpaceNews. Pocket Ventures, LLC. Archived from the original on January 4, 2017. Retrieved January 4, 2017.
  28. ^ a b Callahan, Jason (March 30, 2015). "Discovery lives". The Space Review. SpaceNews (Pocket Ventures, LLC). Archived from the original on January 4, 2017. Retrieved January 4, 2017.
  29. ^ Dorminey, Bruce (April 29, 2015). "NASA May Plumb For Signs Of Life In Enceladus' Plumes". Forbes. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  30. ^ Stone, Maddie (May 20, 2015). "The Plan to Hunt for Alien Life on the Most Promising Moon in the Solar System". Motherboard. Vice Media. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  31. ^ Wall, Mike (August 31, 2015). "NASA Mulling Life-Hunting Mission to Saturn Moon Enceladus". Space.com. Purch Group. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  32. ^ Solon, Olivia (December 15, 2015). "Two missions face off to seek life in icy seas of Enceladus". New Scientist. Reed Business Information. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  33. ^ Clark, Stephen (April 6, 2015). "Diverse destinations considered for new interplanetary probe". Spaceflight Now. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  34. ^ a b Watson, Traci (September 30, 2015). "NASA Drops Partnership with Private Asteroid Hunt". Scientific American. Springer Nature. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  35. ^ a b Clark, Stephen (October 5, 2015). "NASA might pick two Discovery missions, but at a price". Spaceflight Now. Archived from the original on August 8, 2020. Retrieved January 21, 2016.
  36. ^ Northon, Karen (October 1, 2015). "NASA Selects Investigations for Future Key Planetary Mission". National Aeronautics and Space Administration (NASA). Archived from the original on October 1, 2015. Retrieved January 14, 2016.
  37. ^ a b c Hand, Eric (September 30, 2015). "Venus and a bizarre metal asteroid are leading destinations for low-cost NASA missions". Science. American Association for the Advancement of Science. Archived from the original on December 14, 2023. Retrieved January 14, 2016.
  38. ^ Isbell, Douglas (November 12, 1998). "Five Discovery Mission proposals selected for feasibility studies". National Aeronautics and Space Administration (NASA). Archived from the original on November 26, 2020. Retrieved January 16, 2016.
  39. ^ a b Valentine, Karin (December 20, 2016). "Journey to a metal world". ASU Now. Arizona State University. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  40. ^ a b Nature staff (April 12, 2016). "Destination Venus". Nature. 532 (7598). Nature Publishing Group (Holtzbrinck Publishing Group): 148. Bibcode:2016Natur.532..148.. doi:10.1038/532148a. PMID 27075059. S2CID 4469300.
  41. ^ Watson, Traci (December 5, 2016). "Venus or bust: Wayward Japanese spacecraft hurtles toward destiny". USA Today. Gannett Company. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  42. ^ Cooper, Chris; Matsuda, Kiyotaka (November 29, 2016). "The U.S. and China Are Fighting Over Mars, but Japan May Win the Space Race". Bloomberg News. Bloomberg L.P. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  43. ^ Chang, Kenneth (October 17, 2016). "Venus: Inhospitable, and Perhaps Instructional". The New York Times. Archived from the original on November 8, 2020. Retrieved December 27, 2016.
  44. ^ Kramer, Miriam (June 12, 2016). "Photo of Venus reveals the mysterious clouds of the planet by night". Mashable. Mashable, Inc. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  45. ^ Europlanet Media Centre (October 18, 2016). "Recently active lava flows on the eastern flank of Idunn Mons on Venus". Phys.org. Omicron Technology. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  46. ^ Wenz, John (April 20, 2016). "A Frigid Surprise at Venus' Poles". Discover. Kalmbach Publishing. Archived from the original on July 30, 2018. Retrieved December 27, 2016.
  47. ^ Williams, Matt (December 23, 2015). "The Next Generation of Exploration: Back to Venus with VERITAS". Universe Today. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  48. ^ Astronomy Now staff (October 21, 2016). "Unexpected discoveries on a metal world". Astronomy Now. Pole Star Publications. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  49. ^ Atkinson, Nancy (November 2, 2016). "Pure metal asteroid has mysterious water deposits". Phys.org. Omicron Technology Limited. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  50. ^ Emspak, Jesse (October 27, 2016). "Giant Metallic Asteroid Psyche May Have Water". Space.com. Purch Group. Archived from the original on December 27, 2016. Retrieved December 27, 2016.
  51. ^ News.com.au staff (January 4, 2017). "NASA to make Discovery mission announcement". News.com.au. News Corp Australia. Archived from the original on January 4, 2017. Retrieved January 4, 2017.
  52. ^ Kramer, Miriam (January 3, 2017). "We're about to find out what part of the solar system NASA will explore next". Mashable. Archived from the original on January 4, 2017. Retrieved January 4, 2017.
  53. ^ Witze, Alexandra (January 4, 2017). "NASA sets sights on asteroid exploration". Nature. Nature Publishing Group. doi:10.1038/nature.2016.21234. S2CID 132998003. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  54. ^ Kaplan, Sarah (January 4, 2017). "NASA's newest missions will explore the solar system's asteroids". The Washington Post. Nash Holdings LLC. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  55. ^ Grush, Loren (January 4, 2017). "In the 2020s NASA will launch spacecraft to study Jupiter's asteroids, and another made of metal". The Verge. Vox Media. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  56. ^ Foust, Jeff (January 5, 2017). "NASA selects two asteroid missions for Discovery program". SpaceNews. Pocket Venutres, LLC. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  57. ^ "NASA Selects Two Missions to Explore the Early Solar System". National Aeronautics and Space Administration (NASA). January 5, 2017. Archived from the original on January 5, 2017. Retrieved January 5, 2017.
  58. ^ "NASA Sorting Through Latest Discovery Proposals". Spacenews.com. February 23, 2015. Archived from the original on December 14, 2023. Retrieved January 11, 2016.
  59. ^ Enceladus life finder: the search for life in a habitable moon Archived March 4, 2016, at the Wayback Machine. Geophysical Research Abstracts. Vol. 17, EGU2015-14923, 2015 EGU General Assembly 2015.
  60. ^ Kane, Van (April 3, 2014). "Discovery Missions for an Icy Moon with Active Plumes". The Planetary Society. Archived from the original on April 16, 2015. Retrieved April 9, 2015.
  61. ^ Tsou, Peter; Brownlee, Donald E.; McKay, Christopher P.; Anbar, Ariel D.; Yano, Hajime; Altwegg, Kathrin; Beegle, Luther W.; Dissly, Richard; Strange, Nathan J.; Kanik, Isik (2012). "LIFE: Life Investigation For Enceladus: A Sample Return Mission Concept in Search for Evidence of Life" (PDF). Astrobiology. 12 (8): 730–742. Bibcode:2012AsBio..12..730T. doi:10.1089/ast.2011.0813. PMID 22970863. Archived from the original (PDF) on March 4, 2016. Retrieved January 4, 2018.
  62. ^ Io Volcano Observer (IVO) Archived July 10, 2020, at the Wayback Machine. Geophysical Research Abstracts, Vol. 11, EGU2009-6448-1, 2009. EGU General Assembly 2009.
  63. ^ John F. Mustard; Scott L. Murchie; Andrew S. Rivkin; Douglas A. Eng; Elena Y. Adams; Patrick N. Peplowski; David J. Lawrence; Goestar Klingelhoefer (June 9–11, 2015). The Advanced Jovian Asteroid Explorer (PDF). 11th Low Cost Planetary Missions Conference. Archived (PDF) from the original on September 21, 2020. Retrieved August 23, 2017.
  64. ^ "RAVEN - High-resolution Mapping of Venus within a Discovery Mission Budget". Bibcode:2009AGUFM.P31D..04S. Archived from the original on January 27, 2019. Retrieved August 23, 2017.
  65. ^ Venus Atmosphere and Surface Explorer Archived May 10, 2017, at the Wayback Machine. American Astronomical Society, DPS meeting #46, #214.15 (2014)
  66. ^ a b c MERLIN: The Creative Choices Behind a Proposal to Explore the Martian Moons Archived April 7, 2020, at the Wayback Machine (Merlin and PADME info also)
  67. ^ Phobos And Deimos & Mars Environment (PADME) Archived February 13, 2021, at the Wayback Machine. 45th Lunar and Planetary Science Conference (2014).
  68. ^ McKay, Christopher P.; Stoker, Carol R.; Glass, Brian J.; Davé, Arwen I.; Davila, Alfonso F.; Heldmann, Jennifer L.; Marinova, Margarita M.; Fairen, Alberto G.; Quinn, Richard C.; Zacny, Kris A.; Paulsen, Gale; Smith, Peter H.; Parro, Victor; Andersen, Dale T.; Hecht, Michael H.; Lacelle, Denis; Pollard, Wayne H. (April 5, 2013). "The Icebreaker Life Mission to Mars: A Search for Biomolecular Evidence for Life". Astrobiology. 13 (4): 334–353. Bibcode:2013AsBio..13..334M. doi:10.1089/ast.2012.0878. PMID 23560417. S2CID 21073805.
  69. ^ Choi, Charles Q. (May 16, 2013). "Icebreaker Life Mission". Astrobiology Magazine. Archived from the original on August 15, 2013.
  70. ^ McKay, C. P.; Stoker, Carol R.; Glass, Brian J.; Davé, Arwen I.; Davila, Alfonso F.; Heldmann, Jennifer L.; Marinova, Margarita M.; Fairen, Alberto G.; Quinn, Richard C.; Zacny, Kris A.; Paulsen, Gale; Smith, Peter H.; Parro, Victor; Andersen, Dale T.; Hecht, Michael H.; Lacelle, Denis; Pollard, Wayne H. (2012), "The Icebreaker Life Mission to Mars: A Search for Biochemical Evidence for Life", Concepts and Approaches for Mars Exploration (PDF), Lunar and Planetary Institute, archived (PDF) from the original on December 3, 2013
  71. ^ Binary Asteroid in-situ Explorer Mission (BASiX): A Mission Concept to Explore a Binary Near Earth Asteroid System Archived March 4, 2016, at the Wayback Machine. 45th Lunar and Planetary Science Conference (2014)
  72. ^ Dark Asteroid Rendezvous (DARe) Archived March 4, 2016, at the Wayback Machine. 46th Lunar and Planetary Science Conference (2015)
  73. ^ jobs (March 16, 2015). "Five Solar System sights NASA should visit : Nature News & Comment". Nature. 519 (7543): 274–275. doi:10.1038/519274a. PMID 25788076. S2CID 4468466.
  74. ^ Dreier, Casey; Lakdawalla, Emily (September 30, 2015). "NASA announces five Discovery proposals selected for further study". The Planetary Society. Archived from the original on July 26, 2020. Retrieved October 1, 2015.
  75. ^ "Dating moon rocks accurately with new design mass spectrometer - News". SpectroscopyNOW.com. July 22, 2015. Archived from the original on March 16, 2019. Retrieved January 11, 2016.
  76. ^ Hurlbert, Eric; Morehead, Robert; Melcher, John C.; Atwell, Matt (2016). Integrated Pressure-Fed Liquid Oxygen / Methane Propulsion Systems – Morpheus Experience, MARE, and Future Applications (PDF). NASA CASI. NASA Johnson Space Center. Archived (PDF) from the original on October 27, 2020. Retrieved August 23, 2017.
  77. ^ "PROTEUS – A MISSION TO INVESTIGATE THE ORIGIN OF EARTH'S WATER: CREATING HABITABLE WORLDS" (PDF). Astrobiology Science Conference 2015. Archived (PDF) from the original on January 25, 2021. Retrieved January 11, 2016.
  78. ^ JOURNEY TO A METAL WORLD: CONCEPT FOR A DISCOVERY MISSION TO PSYCHE Archived February 27, 2014, at the Wayback Machine. (PDF) 45th Lunar and Planetary Science Conference (2014)
  79. ^ "Kuiper : A Discovery-Class Observatory for Outer Solar System Giant Planets, Satellites, & Small Bodies" (PDF). Lpi.usra.edu. Archived (PDF) from the original on September 18, 2020. Retrieved January 11, 2016.
  80. ^ Phys.org staff (October 2, 2015). "SwRI awarded $3 million NASA contract to develop mission to Jupiter's Trojan asteroids". Phys.org. Omicron Technology Limited. Archived from the original on October 10, 2020. Retrieved January 15, 2016.
  81. ^ a b Williams, Matt (October 13, 2015). "Surveying the "Fossils of Planet Formation": The Lucy Mission - Universe Today". Universe Today. Fraser Cain. Archived from the original on November 26, 2020. Retrieved January 15, 2016.
  82. ^ a b Kane, Van (February 19, 2014). "Mission to a Metallic World: A Discovery Proposal to Fly to the Asteroid Psyche". The Planetary Society. Archived from the original on October 4, 2015. Retrieved January 15, 2016.
  83. ^ Grossman, Lisa (December 20, 2013). "Astrophile: Heavy metal asteroid is a spacecraft magnet". New Scientist. Reed Business Information. Archived from the original on March 23, 2021. Retrieved January 15, 2016.
  84. ^ "Psyche: Journey to a metal world — Arizona State University". asu.pure.elsevier.com. Archived from the original on January 6, 2017.
  85. ^ Venus Express staff (June 18, 2015). "Hot lava flows discovered on Venus". European Space Agency. Archived from the original on June 19, 2015. Retrieved January 14, 2016.
  86. ^ Williams, Matt (October 5, 2015). "The Next Generation of Exploration: The DAVINCI Spacecraft". Universe Today. Fraiser Cain. Archived from the original on November 23, 2020. Retrieved January 14, 2016.
  87. ^ Williams, Matt (October 9, 2015). "The Next Generation of Exploration: The NEOCam Mission - Universe Today". Universe Today. Fraser Cain. Archived from the original on February 25, 2021. Retrieved January 15, 2016.
  88. ^ NASA staff (April 15, 2013). "NASA-Funded Asteroid Tracking Sensor Passes Key Test". National Aeronautics and Space Administration (NASA). Archived from the original on November 11, 2020. Retrieved January 15, 2016.
  89. ^ Amy Mainzer Is Hunting Asteroids With NEOWISE (podcast). The Planetary Society. December 30, 2013. Archived from the original on January 7, 2017. Retrieved January 16, 2016.
  90. ^ Watson, Traci (June 19, 2015). "Private asteroid hunt lacks cash to spy threats in orbit". Nature. 522 (7557). Nature Publishing Group (Holtzbrinck Publishing Group): 402–3. Bibcode:2015Natur.522..402W. doi:10.1038/522402a. PMID 26108830.
  91. ^ Williams, Matt (October 7, 2015). "The Next Generation of Exploration: Back to Venus with VERITAS - Universe Today". Universe Today. Fraser Cain. Archived from the original on December 27, 2016. Retrieved January 15, 2016.
  92. ^ Paller, M.; Figueroa, H.; Freeman, A.; et al. (2015). VISAR: A Next Generation Inteferometric Radar for Venus Exploration (PDF). Venus Lab and Technology Workshop (2015). Universities Space Research Association. Archived (PDF) from the original on September 28, 2020. Retrieved January 15, 2016.
  93. ^ Hensley, S.; Smrekar, S. E (2012). "VERITAS: A Mission Concept for the High Resolution Topographic Mapping and Imaging of Venus". American Geophysical Union, Fall Meeting. 2012. NASA: P33C–1950. Bibcode:2012AGUFM.P33C1950H.
  94. ^ Hensley, S.; Smrekar, S. E.; Pollard, B. (December 1, 2012). "VERITAS: A Mission Concept for the High Resolution Topographic Mapping and Imaging of Venus". AGU Fall Meeting Abstracts. 2012. Smithsonian Astrophysical Observatory: P33C–1950. Bibcode:2012AGUFM.P33C1950H.