Dedicated to uncovering and understanding mysteries of the solar system, NASA’s Discovery program has spent nearly three decades exploring outer space with 20 missions. With an emphasis on innovative planetary missions, the program is now heading toward Earth’s closest neighbor: Venus.
Source: Smithsonian Magazine
NASA selected two new missions to study the second planet from the sun. These two missions will set out to understand how Earth’s sister planet may have been the first habitable planet in the solar system and how it has become the volcanic and mountainous planet it is today. Both are expected to launch by 2028 to 2030.
From a total of four finalists announced last year, the winning missions are DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry and Imaging) and VERITAS (Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy). The Discovery competition involved an extensive, peer-review process that emphasized a mission’s potential scientific value and its overall achievability. NASA will be awarding about $500 million to each mission to aid the respective teams as they work to finalize plans for designs and development.
“We’re revving up our planetary science program with intense exploration of a world that NASA hasn’t visited in over 30 years,” said Thomas Zurbuchen, NASA’s associate administrator for science, in the NASA press release.
NASA last visited Venus in 1990 with the Magellan spacecraft. The Magellan probe collected data from Venus while orbiting the planet for four years, resulting in the first map of the planet’s surface. It collected data from Venus’ gravitational field while in orbit before eventually plunging toward the planet to study its atmosphere. While NASA lost contact with the spacecraft before reachingVenus’ surface, its tenure in space produced valuable data and images of Venusian terrain.
While NASA is overdue for a visit to Venus, other spacecrafts from Europe and Japan have orbited the planet since Magellan. The United States has primarily focused on Mars-related missions in the past few decades. From rovers like Opportunity to landers like InSight, Mars has held the scientific spotlight for some time. Now, NASA plans to better understand Venus’ toxic and incredibly hot atmosphere.
“It is astounding how little we know about Venus, but 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 the NASA press release. “It will be as if we have rediscovered the planet.”
While Venus holds similarities to Earth in structure, it’s both smaller and hotter, with a thick atmosphere of carbon dioxide. The air is so dense, the gas looks like fluid near the surface. The temperatures rise to as high as 880 degrees Fahrenheit because of the runaway greenhouse effect occurring on Venus.
Venus may be pressurized and toxic now, but before greenhouse gases likely vaporized its oceans, the planet may have once hosted life, reports Steve Gorman for Reuters. Scientists suspect we have a lot to learn from our sister planet’s past.
“Using cutting-edge technologies that NASA has developed and refined over many years of missions and technology programs, we’re ushering in a new decade of Venus to understand how an Earth-like planet can become a hothouse,” said Zurbuchen.
DAVINCI+ will measure the atmosphere composition on Venus to interpret how the planet formed and evolved. Similar to the Magellan spacecraft, DAVINCI+ will plunge through Venus’ atmosphere after flying by the planet twice to capture a time-lapse of the planet’s clouds. The spacecraft will then release its spherical probe that will plummet into Venus’ atmosphere for one hour, to measure noble gases and other elements, temperature and pressure. This information is intended to help scientists understand the planet’s runaway greenhouse effect and its inability to cool down, compared to Earth’s atmosphere, reports BBC News. According to Garvin, the spacecraft is expected to overheat in less than a half hour even if it survives the landing.
The mission will also attempt to determine if Venus ever had an ocean. DAVINCI+ will be sent to obtain the first high-resolution images of Venus’ “tesserae,” the planet’s distinct geological features, to further investigative the possibility of plate tectonics on the planet and allow scientists to compare Venus and Earth’s surfaces.
VERITAS will explore why Venus developed differently than Earth through collecting data about its geologic history. As VERITAS orbits the planet, the spacecraft will make 3-D topographic models of Venus’s surface elevations in search of active plate tectonics and volcanism. The mission will also map the surface’s infrared emissions to explore Venus’ unknown rock type in an effort to determine if active volcanoes are secreting water vapor. The German Aerospace Center, the Italian Space Agency and France’s Centre National d’Etudes Spatiales will contribute materials to this project, according to NASA.
Both missions will be accompanied by technology demonstrations. DAVINCI+ will have the Compact Ultraviolet to Visible Imaging Spectrometer (CUVIS). CUVIS will be able to take high resolution measurements of ultraviolet light to further investigate Venus’ atmosphere and how it absorbs almost half of the incoming solar energy. VERITAS will be joined by the Deep Space Atomic Clock-2. The precise clock will enhance radio observations and enable spacecrafts to independently maneuver themselves.
Source: Smithsonian Magazine