VERITAS

Selected in 2021 and still unbuilt, VERITAS depends on each year's budget. In early October 2026 its deputy project scientist, Dan Nunes of JPL, told the Venus Exploration Analysis Group that VERITAS was funded with a launch date of November 2032 and would reach Venus in mid-2033, Ars Technica reported. On 4 November 2026 JPL still listed the launch as 'TBD', NASA's overview and reference catalogue said no earlier than 2031, and the German Aerospace Center (DLR) said 2031 was planned. NASA's FY2026 spending plan allots it 24.0 million dollars; the President's FY2027 request does not mention it. A stopgap signed on 2 September holds NASA at its 2026 level until 11 December, and by 1 November no FY2027 spending bill had cleared Congress.

The name spells out Venus Emissivity, Radio science, InSAR, Topography, And Spectroscopy and is also the Latin for truth. The orbiter would map the whole planet with a radar much sharper than the one Magellan flew in the early 1990s, look for ground that is moving today, read rock types through infrared gaps in the clouds, and probe the interior through its own radio signal. NASA's questions include whether Venus's volcanism is steady or catastrophic, whether subduction is active, and whether the high plateaus called tesserae are like Earth's continents (which would point to a wetter past).

The proposal is older than its selection. NASA says the team, together for nearly a decade, proposed it three times, twice to Discovery and once to New Frontiers. A Discovery finalist in 2015, it lost to Lucy and Psyche in January 2017, returned as a finalist in 2020, and on 2 June 2021 was selected alongside DAVINCI, each with about 500 million dollars for development and launches expected in 2028 to 2030. NASA's FY2025 budget document puts the Discovery 2019 cost cap at 500 million dollars in FY2019 terms, excluding launch vehicle and operations, and a separate preliminary life-cycle cost range, estimated at selection, at 1.2 to 1.6 billion dollars. The 2021 announcement also assigned it JPL's Deep Space Atomic Clock-2 as a technology passenger, which NASA's current VERITAS pages do not mention.

Lockheed Martin is the contractor for the spacecraft, its integration and testing, and launch and mission operations, according to the FY2025 budget document, which lists the launch vehicle as TBD, to be chosen competitively. The design is based on NASA's MAVEN Mars orbiter, with two solar wings of about 28 square metres in all; one side of the outermost panel on each wing doubles as a drag flap. JPL manages the mission, operations and navigation.

Reaching the mapping orbit takes longer than the flight to Venus. NASA's overview describes about six months of cruise, capture into a 120-hour orbit and a burn down to 10 hours, then aerobraking: repeated shallow dips into the upper atmosphere, about 2,635 of them in a 2025 plan by engineers at NASA Langley and JPL, let drag on the solar arrays shrink the orbit. Figures for the final orbit differ. That 2025 plan ends aerobraking at 219 by 400 kilometres with a 1.6-hour period, matching the high point and period in NASA's overview. A 2021 study led from Sapienza University of Rome describes a final, nearly circular polar orbit of 180 by 255 kilometres; NASA's VISAR table gives an altitude of 180 to 250 kilometres and NSSDCA below 250 kilometres. Both NASA's overview and the 2021 study have aerobraking end in the final orbit, so the figures probably belong to different versions of the plan; no source says so.

Science would then run for four rotations of Venus: more than 2.5 Earth years and about 28 terabits of data, says NASA, against about three and a half Earth years and more than 19 terabits in DLR's account and three years in the FY2025 budget document. A typical day would bring 16 hours of VEM and VISAR observing, then an eight-hour Deep Space Network session with the high-gain antenna turned to Earth, when the gravity data are gathered.

VISAR, the Venus Interferometric Synthetic Aperture Radar, is JPL's instrument. It works at X-band with two antennas set 3.1 metres apart, so each pass records an image and, from the slight difference between the antennas' views, the height of the ground. Processing on board cuts the data to be sent home by two to three orders of magnitude, which NASA says is what makes global coverage possible. The targets are images at 30 metres resolution globally and 15 metres over part of the planet, and heights on a 250-metre grid. NASA's science page gives the 15-metre coverage as about 25 per cent of the surface and the height accuracy as 5 metres; NSSDCA gives about 20 per cent, and the FY2025 budget document 6 metres.

Change over time is the newer measurement. By flying over the same 200 by 200 kilometre patch twice, VISAR can compare the two radar images and pick out ground that has moved in between (repeat-pass interferometry). NASA plans 12 to 18 such sites and quotes an expected accuracy of 1.5 centimetres, allowing for changes in atmospheric sulfur dioxide between passes; NSSDCA quotes 2 millimetres of precision without saying what it includes. While VERITAS waited, the Italian space agency ASI reported in May 2024 that a new analysis of Magellan images, co-authored by VERITAS co-investigator Marco Mastrogiuseppe, found new lava flows at Sif Mons and Niobe Planitia. The wider story is in Volcanoes on Venus.

VEM, the Venus Emissivity Mapper, is Germany's instrument, led by the DLR Institute of Space Research in Berlin. A few narrow windows in the clouds near one micrometre let through heat glowing from rocks at more than 460 degrees Celsius, and VEM looks through them on the night side only, because reflected sunlight would swamp the signal by day. DLR describes a multispectral pushbroom imager with six bands in five atmospheric windows for the surface and eight more for calibration and near-surface water vapour. NASA and DLR credit the VIRTIS instrument on Venus Express with pioneering the technique.

Builder and sponsor quote VEM's performance differently. DLR states a goal of an instrument signal-to-noise ratio well above 1,000 and a relative emissivity error below one per cent, provided better topography is available, which VISAR is meant to supply. NASA lists a signal-to-noise ratio above 15 as enough to tell iron-rich (mafic) from silica-rich (felsic) rock, a 4 per cent relative uncertainty in emissivity and a resolution of about 100 kilometres. The two appear to measure different things: DLR's is the instrument's own signal-to-noise ratio, NASA's is tied to telling rock types apart at the surface.

Gravity science needs no instrument of its own. By tracking tiny frequency shifts in the spacecraft's X-band and Ka-band radio links, the team maps how the planet's pull varies and how Venus wobbles as it turns, which constrain the size and state of the core and the thickness of the crust. The FY2025 budget document names Goddard as provider, with ASI and the University of Rome as cost-share partner. A 2021 simulation led by Gael Cascioli at Sapienza found that VERITAS could pin down the moment of inertia factor, a measure of how mass is spread inside a planet, to 0.3 per cent (3-sigma); a recent ground-based measurement then carried a 7 per cent uncertainty. Stated resolutions vary: NASA gives 200 kilometres with 7 milligal accuracy, NSSDCA 160 kilometres and 3 milligals.

JPL's page, checked on 4 November 2026, credits ASI with the integrated deep space transponders, the high-gain antenna and the star trackers; DLR with VEM and algorithms for processing VISAR data; and the French space agency CNES with two Ka-band travelling-wave tube amplifiers and a telecom repair kit. ASI's own announcements of June 2021 and May 2024 list the transponder, the high-gain antenna and the radio-frequency part of VISAR, with no star trackers, and the FY2025 budget document agrees that ASI shares in VISAR. France has a second share that JPL's page leaves out: DLR says the VEM optics, including the spectral filter assembly, come from CNES and LESIA, the space instrumentation laboratory of the Paris Observatory.

The setback of 2022 had nothing to do with Venus. That year JPL's Psyche asteroid mission missed its launch window, and an independent review board found that a significant factor was an imbalance between the laboratory's workload and its available workforce. On 4 November 2022 NASA said it anticipated delaying VERITAS by at least three years so that experienced JPL staff could finish flagship missions further along, freeing money for Psyche and other planetary needs. JPL would stand down its VERITAS management and engineering teams while funding continued for the science team, and the launch, expected in December 2027, moved to no earlier than 2031.

Worse followed in March 2023, when the FY2024 budget request gave VERITAS 1.5 million dollars against about 124 million previously projected, a cut Gizmodo and Universe Today both called a soft cancellation; NASA's FY2025 document describes FY2024 as a directed stand-down. In August 2023 about twenty VERITAS scientists used the Holuhraun lava flow and the still-hot Litli-Hrútur eruption in Iceland as stand-ins for Venus (NASA's account counts 18 scientists and engineers over 15 days). DLR's F-SAR airborne radar made measurements similar to those planned from orbit, and a ground team used a VEM emulator with six Venus-like filters.

Reinstatement came in March 2024. At the Lunar and Planetary Science Conference, principal investigator Suzanne Smrekar announced that VERITAS was back in NASA's budget, and the FY2025 request gave it 36.1 million dollars. It also scheduled a Mission System Review, dated early FY2026 in one passage, December 2026 in another and no later than 2027 in the schedule table. In November 2024 Smrekar said the working target was June 2031 but that NASA might prefer November 2032, the date her team gave in October 2026. That slip, she warned, could see partner instruments delivered long before VERITAS reached preliminary design, bring it to Venus within weeks of EnVision in 2033, and cost scientists the chance to study sites that missions such as DAVINCI will target (reported by Jeff Foust in SpaceNews and summarised by Universe Magazine).

In May 2025 NASA's technical supplement to the FY2026 request stated that 'in order to achieve cost savings, the DAVINCI, VERITAS, and EnVision missions are eliminated'. Senate Report 119-44 of 17 July 2025 directed NASA to continue formulating both Discovery Venus missions and provided not less than 99 million dollars for DAVINCI and 36.1 million for VERITAS. The full-year act approved on 23 January 2026 (Public Law 119-74) binds NASA to minimum amounts in its explanatory statement's table, which lists DAVINCI at 99 million and has no VERITAS line; the statement gives Senate report language the same weight unless it says otherwise. In March 2026 Louise Prockter, NASA's planetary science director, said work on VERITAS was 'ramping up slowly' and that 'it's going to be a challenge getting all three Venus missions to continue'. The July 2026 spending plan then set VERITAS at 24.0 million dollars.

Fiscal year 2027 reopened the fight by silence. NASA's request of April 2026 never names VERITAS, DAVINCI or EnVision; Casey Dreier of the Planetary Society read it as eliminating NASA's entire Venus portfolio. The House Appropriations Committee's bill of 13 May 2026 leaves the Venus missions out of its report's mission-specific language, an omission the Planetary Society called a real challenge for advocates. Ars Technica reported in October that ending NASA's EnVision role and Mars Sample Return freed money for DAVINCI and VERITAS.

If it flies, VERITAS is meant to share the decade with DAVINCI, which would drop a probe through the atmosphere, and Europe's EnVision, which would carry a radar and a spectrometer, VenSpec-M, that DLR says is technically based on VEM. For now the public record shows preliminary design reviews for Italian components and for VEM's filters, detector radiation tests and a representative mock-up of VEM at DLR. No public source checked says whether the Mission System Review has happened.