On the morning of June 2, rumors began swirling that NASA was about to announce its latest choices for interplanetary missions, selecting the long-awaited winners of the agency’s competition for new spacecraft in its relatively low-priced Discovery exploration program. Four contending teams anxiously awaited the results: One wished to send a mission to Jupiter’s hypervolcanic moon Io. Another desired a visit to Triton, a cryovolcanic moon of Neptune. And the other two wanted to go to Venus, a destination the space agency had neglected for decades.
A press conference led by NASA administrator Bill Nelson got underway later that afternoon. After a lengthy preamble featuring updates of the agency’s efforts to combat climate change, plus its exploration plans for Mars and Earth’s moon—and an unexpected cameo by William Shatner—Nelson’s remarks turned to the Discovery program. As he spoke, a slickly-produced video began playing on nearby screens showing images of swirling, sickly yellow clouds and a desolate, volcano-scarred landscape. To the Venusian contingent of planetary scientists tuned in to the teleconference, the hellish view looked refreshingly familiar. Perhaps NASA was greenlighting one of the two Venus mission concepts. Then two acronyms flashed on-screen—“DAVINCI+ and VERITAS”—followed by cheers from the audience in the auditorium and online.
For the first time in three decades, NASA had chosen to go back to Venus—not once but twice. VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) will orbit the planet, studying its surface and interior with radar and gravitational measurements. DAVINCI+ (Deep Atmosphere Venus Investigation of Noble Gases, Chemistry, and Imaging Plus) will include an orbiter, as well as a probe designed to plunge through the atmosphere down to the planet’s mysterious, cloud-shrouded surface. If all goes according to plan, both missions should launch before this decade is out.
The last time NASA sent a dedicated mission to Venus was 1989, when its Magellan orbiter launched on a five-year mission to create a radar map of the planet. Ever since, Earth’s sister world—almost identical to our own planet in size, mass and bulk composition—had been relegated to the shadows of American space exploration. For the Venusian science community, which had labored, campaigned and struggled over the past quarter-century to raise the planet’s depressingly low profile, the decisive victory was pure catharsis.
In today's #StateOfNASA address, we announced two new @NASASolarSystem missions to study the planet Venus, which we haven't visited in over 30 years! DAVINCI+ will analyze Venus’ atmosphere, and VERITAS will map Venus’ surface. pic.twitter.com/yC5Etbpgb8— NASA (@NASA) June 2, 2021
“I jumped up and down more than I have in quite a few years,” says Martha Gilmore, a planetary geologist at Wesleyan University, who is part of both mission teams. “We are off to Venus!” gushes Jim Garvin, chief scientist of NASA’s Goddard Space Flight Center and the principal investigator of DAVINCI+.
“I don’t know what else we could have done better to make this the right mission for the moment,” says Sue Smrekar, a planetary geophysicist at NASA’s Jet Propulsion Laboratory and principal investigator of VERITAS. “I feel like we did that. And I feel like NASA noticed.”
Magellan was the very first mission Smrekar worked on, back when she was a postdoctoral researcher. She intends for VERITAS to be her last—and the crowning achievement of her life in science. “This is going to be the capstone of my career,” she says. “I can’t wait to see what we discover.”
There is no shortage of varied, favorite mysteries the researchers wish to solve about Venus, but each speaks to a single, shared conundrum: How did Earth and Venus, two planets made at the same time and out of the same stuff, have such divergent fates? Why is one a temperate biological oasis while the other is an infernal pandemonium?
“How do you build a habitable planet? That’s our main question, and we only have one answer right now: Earth,” Gilmore says. “Now we’ll have a chance for a second laboratory to understand that question.”
Armed with a sophisticated radar system, VERITAS is effectively Magellan’s successor, meant to produce extremely detailed topographic and geologic maps of planet while also peering deep into the world’s viscera with painstaking measurements of Venus’s gravitational field. DAVINCI+’s orbiter is less capable, but its probe will deliver invaluable in situ data on Venus’s atmosphere, sampling and studying the chemistry of the planet’s air throughout a one-way plunge to the spacecraft-annihilating surface. Both missions will also carry technology demonstrations to further NASA’s interplanetary capabilities: VERITAS will fly with a deep-space atomic clock for enhanced celestial navigation, and DAVINCI+ will host a novel high-resolution ultraviolet imager.
Just one mission to Venus would deliver myriad revelations. The fact that two are going to visit at practically the same time is especially exciting. At the conference, Nelson referred to them as “sister missions”—an apt description because the pair are studying two very different aspects of the world in order to address that same fundamental questions of planetary habitability. Like peanut butter and jelly, they are perfect complements to each other.
“The combined results of these missions will tell us about the planet from the clouds in its sky through the volcanoes on its surface all the way down to its very core,” said Tom Wagner, NASA’s Discovery Program scientist, in a statement following the announcement. “It will be as if we have rediscovered the planet.”
The fact that both missions were chosen shows that NASA is not content with giving the world a cursory glance, says Paul Byrne, a planetary scientist and vocal Venus advocate at North Carolina State University. Instead the space agency is pursuing a strategy designed to reveal exactly how the planet works, inside and out. And perhaps these dual missions are just the beginning of something even greater: the revolutionary data both could obtain might become the foundations of a future Venusian mission program, similar to NASA’s Mars Exploration Program, which has transformed our understanding of the Red Planet.
It is, of course, a disappointing day for the other two teams that had hoped for a coveted Discovery mission slot. The Io Volcano Observer team wanted to understand the immense gravitational forces responsible for maintaining the eponymous Jovian moon’s magmatic ocean—and, consequently, to comprehend how the same forces can keep potentially life-sustaining watery oceans warm for billions of years on other worlds, such as Jupiter’s moon Europa, which is Io’s neighbor. The team behind the Trident mission proposal wished to work out how a surreal and utterly alien form of icy volcanism could keep Neptune’s moon Triton—an ancient relic from the dawn of the solar system—looking so preternaturally youthful over eons of time.
Volcanism, too, is the most likely culprit behind Venus’s long-ago transformation from putative ocean world to hostile wasteland, a process both VERITAS and DAVINCI+ will study in their own way. No matter which mission of the four contenders had been picked, says Jacob Richardson, a planetary volcanologist at NASA’s Goddard Space Flight Center, volcanoes were always going to win. But in this case, choosing Venus so that we may understand how volcanoes can wreck entire planets seemed like a no-brainer.
For the vanquished, an inevitable melancholia is tinged with optimism. Proponents of an Io mission hope that they will clinch victory in the next Discovery competition—or perhaps even in the next tier up: a competition for the pricier and more technically capable missions in NASA’s New Frontiers program. Those wishing for a return to the oft-forgotten worlds of Uranus and Neptune, each of which last saw a spacecraft in the late 1980s, are eyeing a future “flagship” mission, one of the $1-billion-plus behemoths that constitute the pinnacle of NASA’s robotic space exploration fleet in terms of size, cost and capability.
This decade now belongs to the second planet from the sun, however. Like their DAVINCI+ colleagues, Smrekar and her VERITAS collaborators are thrilled, exhausted and incredulous all at once. The night before the announcement, she had snapped a photograph of Venus, pointlike and gleaming in the dark sky above. In the aftermath of NASA’s announcement—in the light of a new day—that diamantine speck suddenly looked quite different. It was no longer an unreachable isle but the destination for NASA’s next giant leap in interplanetary exploration.