Spaceflight Now |
- Axiom signs deal with SpaceX for three more private crew missions
- Long March 2F rocket rolls out to launch pad for China’s next human spaceflight
- Relativity announces plans for fully reusable Terran R rocket
- Jupiter’s moon Ganymede seen up close for first time in 21 years
- NASA selects two robotic missions to Venus for launch in late 2020s
| Axiom signs deal with SpaceX for three more private crew missions Posted: 09 Jun 2021 04:53 PM PDT  SpaceX has signed a deal with Axiom Space, a Houston company that arranges private astronaut expeditions, for three more fully commercial Crew Dragon missions to the International Space Station beyond Axiom’s first Dragon flight in early 2022. Axiom announced the deal for the three new missions June 2, meaning the company has agreements with SpaceX for four Crew Dragon flights, each carrying up to four astronauts to the space station. In a statement, Axiom said the new deal with SpaceX was a sign that “the commercialization of low Earth orbit is in full swing.” “We are beyond excited to build upon our partnership with Axiom to help make human spaceflight more accessible for more people," said Gwynne Shotwell, SpaceX’s president and chief operating officer, in a statement. "A new era in human spaceflight is here." Axiom and SpaceX did not disclosed financial details of the deal. SpaceX now has 10 confirmed Crew Dragon missions scheduled for launch in the next few years, following liftoff of the company’s first three astronaut missions under a multibillion-dollar NASA contract. The first Crew Dragon flight with astronauts, a demonstration mission known as Demo-2, launched to the space station in May 2020 and returned to Earth last August. SpaceX’s first operational crew flight, Crew-1, launched last November and returned to Earth on May 2 with a four-person crew. And Crew-2, the second regular Crew Dragon mission, launched April 23 with NASA commander Shane Kimbrough, pilot Megan McArthur, and mission specialists Akihiko Hoshide and Thomas Pesquet, from the Japan Aerospace Exploration Agency and the European Space Agency, respectively. They are due to leave the space station and come home Oct. 31. SpaceX has four more Crew Dragon missions reserved by NASA, but that contract is likely to be extended. Along with Axiom’s four Crew Dragon flights, SpaceX has a deal with Space Adventures, a space tourism company, for a standalone Crew Dragon mission. The first fully commercial human spaceflight to low Earth orbit will be the Inspiration4 mission, which will carry four private citizens on a three-day trip to space without going to the International Space Station. The Inspiration4 mission, led by billionaire entrepreneur and civilian pilot Jared Isaacman, is a charity-focused project designed in part to raise money for St. Jude Children's Research Hospital. Isaacman, 38, will be joined on the mission by Sian Proctor, a private pilot and science educator with a master’s degree in geology, Hayley Arceneaux, a 29-year-old physician assistant at St. Jude, and Chris Sembroski, a data engineer from the Seattle area. Proctor and Sembroski got their seats through a competition and a lottery. Arceneaux, a survivor of childhood cancer, was named to the crew to represent “hope.”  Axiom’s first Crew Dragon mission is scheduled to launch no earlier than January 2022. That flight, designated Ax-1, will be commanded by veteran NASA astronaut Michael López-Alegría, who retired from the space agency in 2012 after nearly 258 days in orbit on four missions. Three wealthy businessmen will join López-Alegría for an eight-day stay on the space station. NASA announced in 2019 it would support up to two so-called “private astronaut missions” to the space station per year. NASA and Axiom confirmed last month that the Ax-1 mission next year will be the first private astronaut mission to visit the orbiting research complex. Crew Dragon seats sell for about $55 million, according to NASA, which also charges private spaceflight operators for commercial astronauts for space station training and use of space station equipment. Axiom’s second mission, Ax-2, could launch in late 2022, pending NASA approval. Retired NASA astronaut Peggy Whitson and John Shoffner, an experienced race car driver and pilot, will fly on the Ax-2 mission with up to two unnamed civilian crewmates. Officials have not announced crew members for the Ax-3 and Ax-4 missions, which will serve as precursors to the launch of an Axiom-owned module to link up with the International Space Station. Axiom eventually intends to build its own commercial space station, somewhat smaller but cheaper to operate than the ISS. Space tourists, government astronauts, and research experiments could fly to the commercial Axiom space station, which the company says it aims to deploy in low Earth orbit by 2028. "Axiom was founded on a vision of lasting commercial development of space," said Michael Suffredini, Axiom’s president and CEO. "We are on track to enable that future by managing the first-ever private missions to the ISS as a precursor to our development of the world's first commercial space station. “SpaceX has blazed the trail with reliable, commercial human launch capability and we are thrilled to partner with them on a truly historic moment,” Suffredini said in a press release. SpaceX has two operational Crew Dragon spaceships — named “Endeavour” and “Resilience” — that are each designed to fly in space at least five times. A third reusable Crew Dragon will debut on the next NASA crew mission set for launch in October. The Crew Dragon Endeavour capsule is currently docked at the space station, and Crew Dragon Resilience returned to Earth last month to be refurbished for the Inspiration4 mission scheduled for launch in September. All of SpaceX’s planned Crew Dragon flights will blast off from pad 39A at NASA’s Kennedy Space Center in Florida on top of Falcon 9 rockets. The capsule is designed to splash down under four parachutes off the coast of Florida. Follow Stephen Clark on Twitter: @StephenClark1.  |
| Long March 2F rocket rolls out to launch pad for China’s next human spaceflight Posted: 09 Jun 2021 08:25 AM PDT  The Long March 2F rocket and Shenzhou 12 spaceship set to ferry three Chinese astronauts to the country’s new space station later this month rolled out to a launch pad Wednesday at a remote military-operated spaceport in northwestern China. The launcher and crew capsule emerged from an assembly building at the Jiuquan space base in the Gobi Desert, riding a mobile platform along rail tracks to cover the one-mile (1.6-kilometer) distance to the launch pad. The 191-foot-tall (58-meter) rocket, the Shenzhou 12 spacecraft, and ground facilities are in good condition, according to the China Aerospace Science and Technology Corp., the state-owned prime contractor for China’s space program. Ground teams at Jiuquan will complete inspections and tests on the launch vehicle in the coming days. The Shenzhou 12 mission will be the first crew flight to China’s new space station. The first element of the complex, the Tianhe core module, launched April 28 aboard a heavy-lift Long March 5B rocket, China’s most powerful launch vehicle. An unpiloted cargo ship, named Tianzhou 2, launched May 29 and docked with the Tianhe core module eight hours later, delivering fuel, food and spacesuits for the Shenzhou 12 astronauts. The Shenzhou 12 mission will last about three months, the longest stay in space to date by Chinese astronauts. Shenzhou 12 will be China’s seventh crewed spaceflight since 2003. Chinese officials have not announced the launch date for the Shenzhou 12 mission, but rockets for China’s last three crewed spaceflights rolled to the pad at Jiuquan about a week before liftoff. That suggests the launch could occur around June 16 or June 17.  The identities of Shenzhou 12’s three crew members have not been announced. In remarks last month, China’s first astronaut — Yang Liwei — said all three crew members are men and come from the first two classes of Chinese astronauts. Future crews on China’s space station will include women, he said. While the Shenzhou 12 astronauts are quarantined before launch, ground crews at Jiuquan will load storable hydrazine and nitrogen tetroxide propellants into the Long March 2F rocket. The toxic propellant mixture will feed thee rocket’s engines, which will produce about 1.4 million pounds of thrust at liftoff. The Shenzhou 12 astronauts will dock with the Tianhe core module after taking off from Jiuquan, linking up with the outpost at an altitude of around 235 miles (380 kilometers). The Tianhe module will be joined next year by two research laboratories to complete assembly of the space station, named Tiangong. The Shenzhou 12 astronauts will unpack the Tianzhou 2 cargo ship after they arrive next month. Tianzhou 2 docked with the rear port on the Tianhe module, and Shenzhou 2 will link up with the lab's forward port.  Tiangong means heavenly palace in Chinese, while Shenzhou is translated as divine vessel. Tianhe means heavenly harmony, and Tianzhou means heavenly vessel. The Shenzhou 12 astronauts are scheduled to return to Earth in September for a parachute-assisted landing in China’s Inner Mongolia province. Around the same time, China will launch Tianzhou 3, the station’s next cargo resupply ship. China’s next crewed spaceflight, Shenzhou 13, is scheduled to launch in October, carrying three astronauts for a six-month mission in orbit, according to the China Manned Space Agency. Next year, China plans six more launches to support the space station program. Two Long March 5B rockets will boost the Wentian and Mengtian lab elements to dock with the Tianhe module, completing assembly of the three-segment, T-shaped space station. There are also two more cargo spacecraft and two more Shenzhou crew capsules scheduled to launch in 2022. While China’s space station is still under construction, the Tianhe core module already in orbit includes astronaut living quarters, medial equipment, a command and control element, and an airlock and exterior handrails for spacewalks. The Shenzhou 12 astronauts will perform spacewalks outside the Tianhe module during their three-month mission, Yang said..  The fully-assembled Chinese space station outpost will be around 66 metric tons, about one-sixth the mass of the International Space Station, and closer in size to Russia's retired Mir station than the International Space Station. With cargo and crew vehicles temporarily docked, the Chinese station's mass could reach nearly 100 metric tons, officials said. China launched two Tiangong prototype space labs in 2011 and 2016 to test out technologies for the permanently-occupied space station. The Tiangong 1 space lab hosted two Shenzhou crews in 2012 and 2013. China's most recent human spaceflight mission — Shenzhou 11 — docked with the Tiangong 2 module in 2016. In total, China has launched 11 astronauts into orbit on six crewed Shenzhou missions since 2003. Email the author. Follow Stephen Clark on Twitter: @StephenClark1.  |
| Relativity announces plans for fully reusable Terran R rocket Posted: 08 Jun 2021 04:13 PM PDT Relativity Space announced plans Tuesday for a fully reusable two-stage rocket named the Terran R, a 3D-printed vehicle designed to haul more than 20 metric tons of cargo to low Earth orbit from a launch pad at Cape Canaveral. The company, based in Long Beach, California, revealed plans for the new rocket at the same time it announced the closure of a $650 million Series E funding round led by Fidelity. Other investors in the funding round included venture capital and equity firms, billionaire Mark Cuban, and actor Jared Leto. The new funding round comes after Relativity announced a $500 million fundraising last November. The money will allow the company to move forward with development of the Terran R, Relativity said in a statement. Resembling a smaller version of SpaceX’s giant Starship rocket, the Terran R will stand 216 feet (66 meters) tall and measure 16 feet (5 meters) in diameter. It should be ready for launch in 2024, Relativity said. The next-generation Terran R rocket will eventually offer commercial and government customers a “point-to-point space freighter capable of missions between the Earth, moon and Mars,” Relativity said. The Terran R follows the development of Relativity’s Terran 1 rocket, an expendable launcher sized to place small satellites into orbit. Relativity says the Terran 1 rocket is scheduled for launch at the end of this year from Launch Complex 16 at Cape Canaveral Space Force Station. The Terran 1 will be capable of launching a payload of approximately 2,750 pounds (1,250 kilograms) into a low-altitude orbit. Like the Terran 1, the Terran R will be built using innovative 3D printers at Relativity’s factory. The company says it aims to produce an entire Terran 1 or Terran R rocket in 60 days. “Together with our first rocket Terran 1, our second product, Terran R, will continue to take advantage of Relativity’s disruptive approach to 3D printing — reduced part count, improved speed of innovation, flexibility, and reliability — to bring to market the next generation of launch vehicles,” said Tim Ellis, Relativity’s co-founder and CEO. “Relativity was founded with the mission to 3D print entire rockets and build humanity's industrial base on Mars,” said Ellis, who worked at Blue Origin, Jeff Bezos’s space company, before co-founding Relativity in 2015.  “We were inspired to make this vision a reality, and believe there needs to be dozens to hundreds of companies working to build humanity's multiplanetary future on Mars,” Ellis said in a statement. “Scalable, autonomous 3D printing is inevitably required to thrive on Mars, and Terran R is the second product step in a long-term journey Relativity is planning ahead." The Terran R’s first stage, second stage, engines, and payload fairing will be reusable. Relativity did not say whether it plans to recover the first stage using propulsive landings, like SpaceX’s Falcon 9 and Starship rockets, or from the ocean. The second stage and payload fairing, built as a single unit, will fly into orbit, release its payload and complete its mission, then re-enter the Earth’s atmosphere for landing. Flying in reusable mode, the Terran R rocket will be capable of delivering a payload of 20 metric tons, or 44,000 pounds, to low Earth orbit, according to Relativity. The payload capacity could increase if Relativity flew the Terran R as an expendable rocket. The Terran R first stage will be powered by seven reusable 3D-printed Aeon R engines capable of 302,000 pounds of thrust each, combining to generate 2.1 million pounds of thrust at full throttle. The Terran R second stage will have one Aeon Vac engine. Like the Terran 1, the Terran R will blast off from Launch Complex 16 at Cape Canaveral. “With satellite technology advancements, demand for bandwidth soaring and satellite constellations representing the largest part of the growing market, Terran R was developed to accommodate the growing demand for large constellation launch services, and the company's growing pipeline of commercial interest,” Relativity said, adding that it recently signed its first “anchor customer” launch contract for the Terran R rocket.  The Aeon R engine is an upgraded version of the Aeon 1 engine that will fly on the Terran 1 rocket. Seven Aeon 1 engines will power the 105-foot-tall (32-meter) Terran 1 launcher’s first stage, producing about 140,000 pounds of thrust, while a single vacuum-optimized Aeon 1 engine will power the second stage. The Aeon engine family consumes methane and liquid oxygen propellants. The company said Tuesday it has completed printing of more than 85% of the first Terran 1 orbital rocket, including its first and second stage. Relativity, now with more than 400 employees, says it has nine launch contracts for the Terran 1 rocket, including deals with NASA, the U.S. military, the smallsat rideshare broker TriSept, Iridium, and Telesat. Email the author. Follow Stephen Clark on Twitter: @StephenClark1.  |
| Jupiter’s moon Ganymede seen up close for first time in 21 years Posted: 08 Jun 2021 02:19 PM PDT  NASA’s Juno spacecraft flew by Ganymede, Jupiter’s largest moon, Monday on the first close-up visit to the icy world since 2000. The first images from the flyby show Ganymede’s cratered, icy surface in “remarkable detail,” NASA said. The moon is covered in patches of dark and bright terrain, with long, stripe-like grooves and ridges also visible. Scientists say the linear features could be linked to tectonic faults. The solar-powered Juno spacecraft’s JunoCam imager and navigation camera took pictures as the orbiter zipped by Ganymede at 1:35 p.m. EDT (1735 GMT) Monday at a distance of about 645 miles (1,038 kilometers). "This is the closest any spacecraft has come to this mammoth moon in a generation," said Scott Bolton, the Juno mission’s principal investigator from the Southwest Research Institute in San Antonio. "We are going to take our time before we draw any scientific conclusions, but until then we can simply marvel at this celestial wonder — the only moon in our solar system bigger than the planet Mercury." During the speedy flyby, Juno passed Ganymede at a speed of more than 40,000 mph, or 19 kilometers per second. In addition Juno’s scientific observations, the encounter used Ganymede’s gravity to shrink the period of spacecraft’s oval-shaped orbit around Jupiter from 53 days to 43 days, setting up for a flyby with Europa in September 2022, and flybys with the volcanic moon Io in 2023 and 2024. Juno is on an extended mission orbit around Jupiter, where it arrived July 4, 2016, to study the giant planet's atmosphere, magnetic field, and internal structure. The robotic mission launched Aug. 5, 2011, from Cape Canaveral aboard a United Launch Alliance Atlas 5 rocket. The JunoCam instrument’s visible light camera viewed almost an entire side of Ganymede during the flyby Monday. The first views returned to Earth show a black-and-white view of the icy moon, the largest in the solar system and the only moon with its own magnetic field. Future data downlinks allow imaging experts to create a color portrait of Ganymede, according to NASA. Juno’s Stellar Reference Unit, part of the spacecraft’s navigation system, captured a view of the night side of Ganymede. The light-sensitive camera resolved the moon’s surface illuminated by dim light scattered off Jupiter. NASA said the JunoCam view of Ganymede has a resolution of about 0.6 miles, or 1 kilometer. The high velocity Juno’s encounter with Ganymede meant there was enough time for JunoCam to take five images.  The navigation camera image resolution is between 0.37 to 0.56 miles (600 to 900 meters) per pixel. "The conditions in which we collected the dark side image of Ganymede were ideal for a low-light camera like our Stellar Reference Unit," said Heidi Becker, Juno's radiation monitoring lead at JPL. "So this is a different part of the surface than seen by JunoCam in direct sunlight. It will be fun to see what the two teams can piece together." Juno's ultraviolet spectrograph, Jovian infrared auroral mapper, and microwave radiometer were active during the Ganymede flyby to measure the composition, thickness, and temperature of the moon’s water-ice crust. Juno was also tuned to measure the radiation environment around Ganymede, collecting data to benefit future missions to study Jupiter and its moons. Bolton said Tuesday that the Juno spacecraft, built by Lockheed Martin, executed the flyby sequence as planned. Scientists believe Ganymede harbors an underground saltwater ocean. Evidence gathered during observations of Ganymede’s aurorae with the Hubble Space Telescope showed the light displays “rocking” back and forth, revealing insights about the moon’s magnetic field. Scientists can infer assumptions about Ganymede’s interior from the magnetic field measurements. A shell of water ice, likely with rock mixed in, covers Ganymede’s buried ocean, which scientists think contains more water than all the water on the surface of Earth.  The last mission to explore Jupiter’s moons was Galileo, a NASA spacecraft that orbited Jupiter from 1995 until 2003. Galileo’s last close flyby with Ganymede occurred May 20, 2000. NASA’s Voyager 1 and Voyager 2 probes also observed Ganymede and Jupiter’s other large moons during a pair of flybys in 1979. Juno’s science team will compare the fresh images of Ganymede with views captured by previous missions. Scientists will look for changes in Ganymede’s surface, such as fresh craters, which could help astronomers better understand the population of objects that impact moons in the outer solar system, according to NASA. Juno’s flyby of Ganymede offers a taste of what’s to come with the European Space Agency’s Jupiter Icy Moons Explorer, or JUICE, mission set for launch next year. The robotic JUICE spacecraft will arrive in orbit around Jupiter in 2029, perform flybys of several of Jupiter’s moons, then enter orbit at Ganymede in 2032. On Tuesday, Juno completed its 33rd close science pass of Jupiter, reaching the closest point in its elongated orbit around the giant planet. Jupiter's asymmetric gravity field is gradually perturbing Juno's trajectory and pulling the closest point of the spacecraft's orbit northward over time. The shift in Juno’s orbit will allow the spacecraft to get a better view of Jupiter’s North Pole, and also enables the flybys of Ganymede, Europa, and Io. Email the author. Follow Stephen Clark on Twitter: @StephenClark1.  |
| NASA selects two robotic missions to Venus for launch in late 2020s Posted: 07 Jun 2021 08:18 AM PDT  NASA has selected two robotic missions for launch to Venus around 2029, the U.S. space agency’s first spacecraft in more than 30 years dedicated to exploring the hellishly hot second planet from the sun. The two winning proposals — named DAVINCI+ and VERITAS — won a competition run by NASA to select the next projects for development under the agency’s Discovery program, a line of cost-capped planetary science missions. “Congratulations to the teams behind NASA's two planetary science missions: VERITAS — “truth” — and DAVINCI+,” said NASA Administrator Bill Nelson in the June 2 announcement. “These two sister missions both aim to understand how Venus became an inferno-like world capable of melting lead at the surface. They will offer the entire science community the chance to investigate a planet we haven't been to in more than 30 years.” NASA’s last mission devoted to observing Venus was Magellan, which launched on a space shuttle in 1989 and arrived in orbit around the planet in 1990. Megallan mapped Venus’s surface using radar waves, which can pierce the planet’s thick clouds, to reveal the planet’s mountains and topography. Since Magellan, several NASA spacecraft has sailed by Venus on the way to other planetary destinations, and Europe and Japan have sent orbiters to Venus. Nelson said further study of Venus, sometimes called Earth’s twin, will help scientists understand how Earth and Venus diverged in their evolution throughout the solar system’s 4.5-billion-year history. “In our solar system, of the rocky planets, there's Mercury, the closest to the sun. It has no atmosphere,” Nelson said. “Then there's Venus with an incredibly dense atmosphere, then there's Earth with a habitable atmosphere, and then there's Mars with an atmosphere that is just 1% of Earth's. We hope the missions will further our understanding of how Earth evolved, and why it's currently habitable when others in our solar system are not." Using a more sensitive radar instrument, VERITAS will update the topographic maps created by NASA’s Magellan spacecraft in the early 1990s, potentially revealing whether geologic processes such as volcanoes are currently active on the planet. DAVINCI+ will send a small probe, measuring roughly 3 feet (1 meter) across, into the thick atmosphere of Venus. The instrumented craft will plunge into Venus’s carbon dioxide-rich atmosphere, deploy a parachute, and descend through cloud layers made of sulfuric acid before eventually landing on the surface. "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. "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. “Our goals are profound,” Zurbuchen said in a statement. “It is not just understanding the evolution of planets and habitability in our own solar system, but extending beyond these boundaries to exoplanets, an exciting and emerging area of research for NASA." VERITAS stands for the Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy mission. The development of VERITAS will be led at NASA’s Jet Propulsion Laboratory in Pasadena, California. The DAVINCI+ mission, which stands for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging – Plus, will be managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. NASA said the missions will launch in the 2028-2030 timeframe. Each mission will get approximately $500 million for development, excluding launch costs and international contributions. In interviews with Spaceflight Now, the lead scientists for the VERITAS and DAVINCI+ missions said NASA has directed the teams to target launches in 2029, a schedule driven by budget availability. “We've waited a long time for a U.S. mission to go back through the atmosphere of Venus, and we're delighted to be that mission,” said Jim Garvin, chief scientist at Goddard and principal investigator for the DAVINCI+ mission. “So thanks to all fo the women and men that got us here. We can't wait to go." "We're just so thrilled to have this opportunity to go to Venus,” said Sue Smrekar, principal investigator for the VERITAS mission at JPL. “For me, it's a lifelong dream. For many, it's been a labor of love for a year, five years, 10 years. Many have been working on it for a long time." NASA selected the VERITAS and DAVINCI+ missions over two other finalists. One of the candidates, the Io Volcano Observer, would have sent a spacecraft to orbit Jupiter and pass near the moon Io, the most volcanically active body in the solar system. The Trident mission proposal would have dispatched a probe to fly by Triton, the largest moon of Neptune, which harbors geyser-like plumes erupting from its icy surface. But Venus, which NASA has bypassed in several recent mission selections, won support this time. Data from DAVINCI+ will help scientists understand how the atmosphere of Venus formed and evolved, and help determine whether the planet — about the same size as Earth — ever had an ocean. "The science is simple,” Garvin told Spaceflight Now. “Venus has a massive atmosphere. It’s layered, or stratified, and it records the history of billions of years of planetary evolution, which for Venus is still a mystery. It’s an enigmatic rocky planet with a big atmosphere. We think Venus likely harbored global oceans for billions of years. That's the best modeling that we can get from what little we know." While Earth and Venus may have been similar billions of years ago, Venus’s super-dense atmosphere is now 90 times thicker than Earth’s. The sweltering blanket of carbon dioxide turns up the temperature at the surface to 900 degrees Fahrenheit (480 degrees Celsius). "So what happened? What happened to the climate change? How does that couple through the crust and rocks? What does that do the clouds, which are thick and fascinating, and how does that work?” Garvin said.  "We're going to measure the history of water, other critical chemistries of carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, their cycles, from the top of the atmosphere to the surface,” Garvin said. “We're going re-measure the critical state of the lower atmosphere, temperature and pressure. It’s super critical, so it’s not a true gas, or an ideal gas. We'll measure that.” DAVINCI+ was designed and proposed before scientists announced last year evidence of phosphine gas in the clouds of Venus, an indicator of possible life. Phosphine, made by combining a phosphorus atom with three hydrogen atoms, is only generated on Earth from microbes and industrial activity. But some researchers have voiced doubts about the phosphine discovery. DAVINCI+ will be outfitted to make direct measurements of phosphine, if it is there. The descent probe will be a titanium sphere housing a mass spectrometer and a tunable laser spectrometer to measure the composition of the atmosphere from top to bottom. The craft will also have instruments to measure pressures, temperatures, winds, and accelerations during descent, and a near-infrared camera system peering out the bottom of the probe will take pictures of the surface of Venus. “Below the clouds, we'll use a very high resolution new kind of descent imaging system that will not only take pictures but it will make images from which we can infer composition and topography,” Garvin said. “So we're going to that all the way down from something like 90,000 feet (27.4 kilometers) to the surface, ever getting closer, and finally we'll be taking images with resolution like if you were flying a drone over your backyard." The probe will be suspended under a parachute as it falls through Venus’s atmosphere. The entire descent will take about an hour, targeting an area of Venus called Alpha Regio, a mountainous region first discovered in the 1960s using Earth-based radar observations. “We're going to go into those mountains,” Garvin said. “They've never been seen at human scales. We'll be seeing them, measuring them, and measuring the chemistry of the atmosphere above them. So all that will give us a storybook, an evolutionary history of Venus, and we'll apply that forward across the solar system, but also to exoplanets (planets around other stars) we'll be able to measure with the James Webb Space Telescope." The last U.S.-led mission to send a probe into the atmosphere of Venus was Pioneer Venus in 1978. The Soviet Union's Vega missions were the last to plunge deep into Venus's atmosphere in 1985. The descent probe itself will be built in-house at NASA’s Goddard Space Flight Center, while Lockheed Martin will supply the aeroshell, heat shield, and a carrier spacecraft to ferry the entry vehicle from Earth to Venus, according to Garvin. The carrier spacecraft will relay data from the DAVINCI+ descent probe back to Earth. The carrier will not enter orbit around Venus, but will fly by the planet on a trajectory to provide about an hour of solid communications with the entry vehicle. If the descent probe safely reaches the surface, the mission could return some bonus data. But scientists have not committed to that as part of the DAVINCI+ primary mission. “We get our own big radio communication system right there at Venus on a trajectory that gives us really favorable communications, a nice long arc that lasts up to an hour or so,” Garvin said. “In fact, if it survives surface impact, which we don't know … we could potentially communicate for another 10 or 15 minutes because we would have the comm link. We don't know if that will be possible, and it’s not part of our mission, but … we might have that opportunity. “The spacecraft is thermally conditioned to operate for about an hour-and-a-half,” Garvin said. “Once it’s down in that hot environment, (the conditions) will eventually get to the point that the electronics of our primary four instruments will not be functional.” The DAVINCI+ carrier spacecraft will have its own science instruments, including a suite of ultraviolet and near-infrared cameras to track cloud motion and measure thermal emissions from the surface. A technology demonstration package on DAVINCI+ will test the Compact Ultraviolet to Visible Spectrometer, or CUVIS, instrument to study an unknown ultraviolet absorber in Venus’s atmosphere that absorbs up to half the incoming solar energy, NASA said. According to Garvin, assuming DAVINCI+ launches in 2029, the mission will perform two flybys of Venus in 2030 before the returning to the planet in 2031 to release the descent probe.  The other Venus mission, VERITAS, will carry a synthetic aperture radar instrument on an orbiting spacecraft to survey the planet's surface over nearly the entire planet. “Our goal is to really understand the geologic evolution of Venus, why it’s different from the Earth, and try to understand why Venus never developed plate tectonics,” said Smrekar, the lead scientist on the VERITAS mission. “How has that affected the evolution of its climate? “We’re looking at the volcanic history trying to understand whether its craters were wiped out by catastrophic volcanism, or whether, or not there's steady, perhaps even Earth-like quantities of volcanism happening today,” Smrekar said in an interview. “So we have a lot of different science investigations to follow up on, but our overall goal is to understand the big picture evolution of Venus, and why it’s so different from its twin planet." The VERITAS spacecraft will carry two instruments to Venus. The primary payload is an X-band synthetic aperture radar to greatly improve the 3D topographic maps produced by the Magellan mission. “It will create global maps of the surface, a topography map, that has 100 times the resolution of Magellan,” Smrekar said. The radar on VERITAS will produce data with a vertical accuracy of about 16 feet, or 5 meters, and a horizontal resolution of about 100 feet, or 30 meters, on a global scale. About 25% of the surface of Venus will be mapped at about 50-foot, or 15-meter, resolution, according to Smrekar. “We also do repeat passage interferometry, which will be our first for any planet beyond the Earth,” she said. “We basically take radar images separated by about seven months, and then look for deformation between the images. “We could see volcanic deformations, such as a caldera inflating or deflating,” she said. “We could see faulting deformation. There are suggestions that the rifting features on Venus could be active, so we’ll be looking for deformation in those kinds of areas. And from (ESA’s) Venus Express, we got hints of recent volcanism as well, so we'll check out those areas.” A spectrometer on the VERITAS spacecraft will peer through clouds and measure the composition of Venus’s surface. The spectrometer will be tuned to detect iron, among other elements. “So we’ll be able to do things like assess the theory, the hypothesis, that Venus has continent-like features,” Smrekar said. “It has these big high plateaus that are highly deformed and are believed to be low in iron content. If that hypothesis is correct, they’re basically fingerprints of past water because on the Earth, when continents form, it's basically massive quantities of basalt melting in the presence of water. So they may be basically remnants from Venus's wetter past.” VERITAS will also look for thermal and chemical signatures of recent volcanic eruptions, and search for water that could be spewed out of Venus’s interior through volcanoes. If there’s evidence of that, it would indicate there must be significant amounts of water in the interior of Venus. The mission will also help refine estimates of the size of Venus’s core, Smrekar said. She said the VERITAS and DAVINCI+ missions, while developed by separate teams, are “very complementary.” “VERITAS provides the global mapping and context for any of the near-surface measurements that DAVINCI+ will make,” Smrekar said. “They will take imaging data as they descend below the cloud deck, so to have those images of areas that we have radar data for will be great ground truth for the radar. We can also provide to them targeting for the most exciting scientific targets.” The spacecraft bus for VERITAS will be manufactured by Lockheed Martin. The mission’s radar will be developed by JPL in partnership with ASI, the Italian space agency. Italy will also provide the mission’s high-gain antenna. DLR, the German space agency, is providing the infrared spectrometer for the VERITAS mission, and will assist in radar data processing. The French space agency, CNES, will provide components for the spacecraft’s Ka-band communications system, Smrekar said. VERITAS will also carry a deep space atomic clock built by JPL as a technology experiment. The atomic clock will help enable autonomous spacecraft maneuvers and enhance radio science observations to study the interior of Venus, NASA said. Smrekar said the VERITAS mission will take about four months to travel from Earth and enter orbit around Venus. DAVINCI+ and VERITAS join the successful “Discovery” line of NASA interplanetary missions. Previous Discovery-class missions included the Dawn spacecraft, which orbited two of the largest objects in the asteroid belt, the Messenger mission to Mercury, and the InSight lander currently listening for seismic activity on Mars. Two Discovery missions selected in 2017 — named Lucy and Psyche — are scheduled for launch in 2021 and 2022 to begin missions focused on asteroid exploration. "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. "It will be as if we have rediscovered the planet." Email the author. Follow Stephen Clark on Twitter: @StephenClark1.  |
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