Landers, balloons and rovers on the drawing board

Every spacecraft that has reached the surface of Venus stopped working within about two hours, a limit NASA Glenn engineers still quote in 2025. Almost every idea on this page is a way around that number: survive longer on the ground, move across it, or stay in the clouds where the air is mild and let the wind do the travelling. The ideas come from NASA centres and the universities NASA funds, the European Space Agency, a French engineering society and one aerospace company, and they run from 1998 to 2026. None has flown. What they have produced is paper, weeks of furnace time in a chamber that recreates Venus, and one silver balloon that flew twice over Nevada. Proposals that lost a NASA or ESA competition have their own page, the Venus missions that lost the competition. This page holds the rest: agency design studies, technology projects and the long-shot concepts NASA pays for through its Innovative Advanced Concepts programme (NIAC).

Bringing rock back from Venus runs into the same two walls in every study that has tried it. Venus has a gravity well close to Earth's, and a rocket fired from the ground would start at about 92 times Earth's surface pressure and about 465 °C. The Jet Propulsion Laboratory study titled Venus Surface Sample Return: A Weighty High-Pressure Challenge, written by Ted Sweetser, Jim Cutts and colleagues with JPL's Team X (revisions to 24 February 1999), answered with a single launch in the Delta IV class. An inflatable drag device would capture the spacecraft into orbit, a lander would spend about 90 minutes on the ground, and an ultrasonic corer would take an intact rock of about one cubic centimetre plus a sample of the lower atmosphere. A balloon inflated from helium tanks on the lander would then lift a three-stage solid-fuel Venus ascent vehicle to about 66 km, the height that minimised the combined size of balloon and rocket. From there the rocket would put the sample into orbit, the orbiter would chase it down, and solar electric propulsion would bring it home in about two and a half years in total. The team thought advanced technology could shrink the job to one launch where earlier studies had needed two.

One of those earlier studies was European. ESA's Venus Sample Return Assessment Study Report, SCI(98)3, by G.E.N. Scoon and J.-P. Lebreton, is dated June 1998 at Noordwijk. It is known here only from the reference lists of the JPL paper and a 2019 white paper; the report itself was not found. That white paper, Venus sample return mission revisited, was written by Dominique Valentian, Christophe Koppel, Philippe Mairet and Loup Mairet of the EOS commission of the Association Aéronautique et Astronautique de France for ESA's Voyage 2050 consultation. It reread the JPL design, as published by David Rodgers and colleagues in 2000, and listed its weak points: solid motors that might buckle under about 9 MPa of outside pressure, propellant warming during a four-hour balloon climb, and a balloon that must swell almost a thousandfold between the surface and its float height. Its own answer used several landers built as vertical take-off drones that would fly their samples up to a rocket hanging under a balloon at about 55 km, needing two or three Ariane 64 launches. The authors wrote that it "may be ranked" in ESA's large (L) mission class. In 2024 Geoffrey Landis of NASA Glenn presented a NIAC variant in which a high-temperature solar aircraft carries the sample above the clouds to a balloon platform that makes carbon monoxide and oxygen propellant from the atmosphere, removing the need to ship about three tonnes of propellant to Venus. Two years earlier Sara Seager's NIAC team at MIT had studied returning cloud particles and gas instead of rock. The Russian sample return idea appears on the Venera-D page, China's atmosphere sample return on China and Venus, and the MIT group's flight plans on Venus Life Finder.

ESA's Venus Entry Probe, completed in 2005, belonged to a series called Technology Reference Studies: model missions outside the science programme, drawn up to show which technologies Europe would need. It paired two small orbiters. The Venus Polar Orbiter (905 kg fuelled) would watch the atmosphere; the Venus Elliptical Orbiter (558 kg) would carry a ground-penetrating radar, deliver a 91 kg entry probe and relay its data. Inside the probe was a balloon meant to settle at 55 km, circle the planet at least twice (about 14 Earth days) and drop fifteen small ballast probes to measure pressure, temperature, light and wind in the lower atmosphere. The whole stack came to 1,508 kg on a Soyuz-Fregat 2-1b from Kourou, with a reference launch in November 2013 that was never more than a planning date.

NASA's Venus Flagship Mission study began when NASA commissioned a Science and Technology Definition Team in January 2008, and the team's final report was out by May 2009. The team, with members from the United States, Russia, France, Germany, the Netherlands and Japan, worked to NASA guidelines of a launch between 2020 and 2025 and a cost cap of 3 to 4 billion dollars. Its Design Reference Mission had an orbiter, two balloons in the clouds and two landers built to last five hours on different terrain. It needed two Atlas V 551 rockets. The carrier, with two entry vehicles each holding a balloon and a lander, would launch in late April 2021 and arrive in July 2022; the orbiter would launch six months later on a faster path and get there three months earlier. The landers were aimed at the tessera of Alpha Regio (27° S, 3° E) and at lava flow fields at 47.4° S, 6.5° E. The balloons would circle Venus up to seven times, and the orbiter would then aerobrake to a 230 km circular orbit for two years of radar mapping. The preliminary cost came to 2.7 to 3.8 billion dollars in 2009 money.

For the planetary decadal survey covering 2013 to 2022, the National Research Council's Inner Planets Panel had NASA's Goddard Space Flight Center, working with Ames and (for two of them) JPL, run three quicker studies. The Venus Mobile Explorer (report dated 18 December 2009, science champion Lori Glaze) would land in the highlands, analyse the ground, then fill a metal bellows with helium and float about 3 km above the surface for roughly 220 minutes, imaging an 8 to 16 km traverse before dropping the bellows and falling to a second site. Its whole science mission lasted six hours, five of them near the surface. The Venus Intrepid Tessera Lander, VITaL (March 2010, co-champions Martha Gilmore and Lori Glaze), was a low ring-shaped lander designed to stay upright on steep, blocky tessera, with Ovda Regio as the study site, two hours of surface work and a Raman and laser-induced breakdown spectrometer to read rock chemistry and mineralogy. The Venus Climate Mission (June 2010, science champion David Grinspoon) would put a balloon at 55.5 km for a 21-day campaign drifting toward the south pole, releasing a mini-probe and two drop sondes. All three came out at or above the top of the New Frontiers range: 1.1 to 1.7 billion dollars for VME and 740 million to 1.1 billion for VITaL in 2015 dollars without the rocket, and 1,145 to 1,577 million for VCM with it.

The survey, published in 2011 as Vision and Voyages, recommended none of them for a start. Its programme carried three flagships: MAX-C at Mars, the Jupiter Europa Orbiter and the Uranus Orbiter and Probe. Only if budgets turned out better than assumed did it list additions, in order: more Discovery money, another New Frontiers mission, and then either the Enceladus Orbiter or the Venus Climate Mission. A Venus In Situ Explorer stayed on the list of New Frontiers candidates. The next survey, Origins, Worlds, and Life (released in April 2022), chose the Uranus Orbiter and Probe and an Enceladus Orbilander as its new flagships and again kept the Venus In Situ Explorer as a New Frontiers theme. In early 2023 NASA dropped that theme from its draft call for the fifth New Frontiers mission, for programmatic balance after DAVINCI, VERITAS and EnVision; a 2025 National Academies review agreed but ranked it high for later calls. NASA's 2027 budget request schedules the call for fiscal year 2027.

Surface mobility has produced three NIAC rovers. Zephyr, a landsailer drawn up by Geoffrey Landis and Glenn's COMPASS design team for a NIAC Phase I study and published as a NASA technical memorandum in December 2019, was a wheeled craft of about 250 kg with an 8 m tall rigid sail of 12 square metres that also carried its solar cells. It would carry 25 kg of instruments, return 2 gigabits over a 30-day mission and cover more than 30 km, sailing in 2025 on the plains near the Venera 10 site, where Soviet landers had measured winds of 80 to 120 cm/s. At JPL, Jonathan Sauder proposed the Automaton Rover for Extreme Environments, AREE, in 2015, inspired by mechanical computers: wind turbines inside the body for power, tank-style treads, and radar targets that an orbiter could ping to read data out like Morse code. "With a fully mechanical rover, you might be able to survive as long as a year," he told JPL in August 2017. The Phase I result was more sober. A purely mechanical rover was feasible but impractical, an all-electronic one impossible with current technology, and a hybrid with a small core of heat-proof electronics "extremely compelling"; NIAC funded a Phase II in 2017. The third, CANVAS, picked in July 2026 for a nine-month study led by David Bugby at JPL, is a radioisotope-powered ball that would roll, with no exposed mechanisms, by blowing compressed Venus air out of opposite sides and, its study page says, could outlast several Earth years.

NIAC's smaller Venus studies explored power more than mobility. ALIVE (2012), from Glenn's COMPASS team and Penn State's Applied Research Laboratory, would burn lithium in the carbon dioxide air to drive a Stirling engine that powered and cooled a lander for five days. Ratnakumar Bugga's VIP-INSPR at JPL (a NIAC Phase I, then a Phase II selected in 2017) would top up hydrogen and oxygen brought from Earth by splitting sulfuric acid and water from the clouds, feeding a fuel cell and a balloon that cycles between about 65 and 15 km. Erik Brandon's 2019 study would charge a balloon's batteries in the sunlit upper air, bring the balloon down, and beam the energy by radio or microwave to a lander's batteries, since cloud blocks lasers. Jeffrey Balcerski's LEAVES (2018) would scatter a hundred or more sensors of 120 g each that descend for about nine hours. BREEZE, from Javid Bayandor at the University at Buffalo (2019), was an inflatable ray-shaped flier that flaps its fins, dipping to about 50 km for data and climbing above 60 km to recharge. A NIAC Phase I study by L. Lemke and colleagues, filed in January 2024, sketched an aircraft that would fly between about 5 and 30 km with 25 kg of instruments, drawing power from heat carried between the hot lower air and cooler heights.

One aircraft concept came from industry. Northrop Grumman and the inflatable-structures firm L'Garde designed the Venus Atmospheric Maneuverable Platform, VAMP, an inflatable flying wing that would enter the atmosphere with no aeroshell and then fly semi-buoyant on solar power in the upper and middle cloud layers for up to a year, carrying about 100 pounds of instruments. In May 2015 SpaceNews, which described a years-long cruise, reported the company gearing up to enter it in NASA's next New Frontiers competition. No record was found of NASA selecting or funding it; Northrop Grumman still hosts a page describing it.

In March 2017 NASA's Planetary Science Deep Space SmallSat Studies, PSDS3, announced ten concept studies worth 3.6 million dollars in total, for craft under 180 kg. Two were for Venus. Cupid's Arrow, led by Christophe Sotin at JPL, was a 30 kg probe that would skim into the upper atmosphere, take in a gas sample, climb back out and measure noble gases and their isotopes; it began as a technology demonstration riding with the VERITAS proposal in NASA's 2014 Discovery round. CUVE, led by Valeria Cottini of the University of Maryland with Goddard, was a 12-unit CubeSat that would spend about six months in polar orbit reading the planet in ultraviolet and visible light (190 to 570 nm) to identify the unknown ultraviolet absorber in the clouds. A Glenn abstract of November 2017 counts nineteen studies against the release's ten; the Venus work also covered VAMOS, a JPL orbiter that would look for venusquakes as ripples in the airglow high above them, and SAEVe. Early the same year NASA's science chief put a question to the leaders of the Venus Exploration Analysis Group: "What can you do for $200M?" The answer, the Venus Bridge report of 20 April 2018, paired an orbiter with an in-situ element. Glenn's V-BOSS, a small orbiter carrying a lander meant to last a full Venus solar day of 117 days, was priced at 201 million dollars before launch and operations.

Behind V-BOSS and SAEVe sat real hardware. LLISSE, the Long-Lived In-Situ Solar System Explorer, is NASA Glenn's attempt at a lander built from electronics and sensors that work at the surface temperature. Its 2017 fact sheet describes a cube of about 20 cm and 10 kg, running on a high-temperature battery for about 60 Earth days and reporting wind, temperature, pressure, sunlight and gas chemistry to an orbiter at intervals, using silicon carbide circuits that tolerate the surface heat. In November 2018 the MIPT magazine Za nauku described the plan for Russian readers: a long-lived NASA station working at least 60 days, and one to four more, some lasting 120. Two months later the Russian-American science team for Venera-D wrote LLISSE into its baseline, attached to the Russian lander. SAEVe, the smallsat study of 2017 to 2018 built on LLISSE, costed two such stations placed 300 to 800 km apart for 120 days, with seismometers. By August 2021 LLISSE electronics had run through a 60-day test in the Glenn Extreme Environment Rig at Venus temperature and pressure, and a NASA Glenn review of August 2025 shows four chemical sensors (sulfur dioxide, carbon monoxide, carbonyl sulfide and hydrogen fluoride) working through a 60-day test in the same chamber, its sulfur dioxide record running from late August to late October 2017. A May 2025 summary offered a 15 to 50 kg lander to ride along on someone else's Venus orbiter, and reported an independent assessment that it could reach TRL 6 (a prototype demonstrated in a relevant environment) within four years given the budget profile presented to NASA. No carrier for it, and no LLISSE report newer than August 2025, appears in any source consulted up to November 2026.

The 2020 Venus Flagship Mission study, led by Martha Gilmore of Wesleyan University with Patricia Beauchamp of JPL and delivered on 8 August 2020 for the 2023 to 2032 decadal survey, folded several of these threads into one design. A single expendable Falcon Heavy would launch in June 2031 with five platforms: an orbiter, a lander bound for the tessera of western Ovda Regio, a variable-altitude aerobot, and two small satellites that study atmospheric loss and help track the aerobot. The lander would carry a LLISSE, released on the surface to work for 60 days while the main lander lasted six to eight hours. The aerobot would cycle between 52 and 62 km for a nominal 60 days, circling Venus about every five days. The estimated cost was 3.7 billion dollars in 2025 money.

JPL's aerobot has flown, on Earth. JPL and Near Space Corporation built a two-part balloon: an inner helium reservoir and an outer envelope, with helium pumped between them to change buoyancy and so altitude, and a Teflon skin to resist sulfuric acid. A one-third scale prototype, about 4 m across, flew twice over the Black Rock Desert in Nevada in July 2022, climbing more than 1 km to air whose temperature and density resemble the Venus cloud layer around 55 km. The full-size version would be 12 m across and carry about 100 kg for 100 days or more. The idea continues on paper: at the March 2026 Lunar and Planetary Science Conference, an MIT-led team that included JPL engineers modelled a 12.5 m super-pressure aerobot that would replace leaking helium with carbon monoxide and oxygen split from the carbon dioxide air, giving a nominal design life of ten years against four months for a helium-only reference balloon.

Nothing on this page has a ride yet. NASA's budget request of April 2026 for fiscal year 2027 would cancel DAVINCI and VERITAS and the American part of EnVision, and would also remove the Venus Technology line, the small account that proves out hardware for future Venus missions, according to The Planetary Society, which identified most of the request's proposed terminations from line items missing from it and said NASA had not answered requests to confirm them. Congress had not settled that budget by early November 2026; a stopgap law holds 2026 spending levels until 11 December. The concepts remain a library to borrow from: the 2020 flagship design reused the variable-altitude balloon and LLISSE, and LLISSE's electronics resurfaced in the 2025 ride-along offer.