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The European Space Agency has confirmed that a parachute for the ExoMars rover mission scheduled for launch in July failed in a test on Sweden earlier this month, the second test project accident in September. parachute since May.
The failure during a high-altitude parachute test on August 5 was a setback for the ExoMars team, as engineers prepared for a 19-day launch window to count of July 25, 2020. This was the second parachute failure encountered by ExoMars engineers in pre-launch testing, following a similar accident on May 28th.
Four parachutes, two pilot falls and supersonic and subsonic main falls, will slow down the ExoMars lander after it enters the Martian atmosphere. The lander will drop the parachutes and launch braking rockets to slowly settle on the surface of Mars.
Engineers made changes to the critical parachute system after the May 28 accident, but follow-up tests were also problematic, ESA said in a statement released on Monday. The ESA and industrial teams conducted both tests from the Esrange Space Center, operated by the Swedish Space Corp. in northern Sweden.
"A preliminary badessment shows that the initial steps were done correctly, but that the veil suffered damage before inflation, similar to those of the previous test," said the ESA about the test of 5 August. "As a result, the test module descended under the drag of the driver chute alone."
In the May 28 test, the engineers tested the four parachutes of the ExoMars landing system after dropping a test vehicle from a stratospheric balloon at an altitude of about 29 km (95,000 feet).
During a normal landing sequence, a pilot chute is expected to exit and unwind a 15-meter (49-foot) supersonic main parachute, a larger version of the disc-gap parachute successfully piloted by the European Huygens spacecraft. Titan, the moon of Saturn. Once the vehicle slows below the speed of sound, a second pilot chute will extract a 35-meter (114-foot) subsonic main parachute, which will be the largest ever flown on Mars and use another model of ring 'intended to produce more drag.
In a statement released on Monday, ESA said the "global sequence" was completed at the May 28th test and that all deployment mechanisms were working as expected. The two main parachute louvers were torn, but the slides generated "a good level of aerodynamic drag expected," said ESA.
After modifying the parachutes and their bags, ground crews conducted a second high altitude test on August 5, focusing only on the largest subsonic main parachute, ESA said. This test also produced an unsatisfactory result.
"It is disappointing that the precautionary design adaptations introduced as a result of the last test failures did not help us pbad the second test, but as always, we remain focused and working to understand and correct the flaw in order to launch next year, "said Francois Spoto, head of the ExoMars team of ESA.
ESA said the engineers had recovered all the equipment from the August 5 test for the inspections. Teams also badyze video and telemetry from the test to determine what's wrong.
Two more high altitude parachute tests, one for each main parachute, are planned for later this year and early in 2020. These tests should perform well – and stay close to their current schedules – if the ExoMars LG needs to stay on the way of launch. in July or August 2020, officials said.
High altitude parachute testing is expensive and requires advance planning. ESA said the ExoMars team is studying the possibility of building additional parachute test models and ground simulations to "replicate the dynamic nature of parachute extraction".
ESA is also interested in NASA's expertise in designing parachutes on Mars.
The largest of the two main parachutes of the ExoMars mission worked as expected during a low-level fall test in Sweden last year.
The 35-meter parachute for the ExoMars mission is manufactured by the Italian company Arescosmo. British engineering firm Vorticity Ltd. leads the test campaign in Sweden under the supervision of the French division of Thales Alenia Space, which has overall responsibility for the ExoMars parachute system.
"Getting to Mars and in particular landing on Mars is very difficult," Spoto said in a statement. "We are committed to using a system that safely delivers our payload to the surface of the planet Mars in order to carry out its unique scientific mission."
If the Lander and the ExoMars rover miss the launch window the next year, the next opportunity to leave the Earth in direct flight for Mars will be in late 2022. Mars's planetary launch windows Open around every 26 months, when Earth and Mars are in the right positions in the solar system to make possible a direct trip.
The ambitious ExoMars program is a partnership between ESA and Roscosmos, the Russian space agency. The ExoMars program consists of two parts.
Launched in March 2016, the Orbiter ExoMars Orbit Trace Gas monitors the Martian atmosphere with a suite of scientific instruments to search for methane and a camera to map the changes on the surface of the planet. The Trace Gas Orbiter was launched aboard a Russian Proton rocket in tandem with a landing craft called Schiaparelli, which crashed on the red planet in final descent.
Like its precursor orbiter, the second ExoMars mission will be launched on a Russian proton amplifier from the Baikonur Cosmodrome in Kazakhstan. A European-made support module will guide the ExoMars lander from Earth to Mars, where a Russian-made descent stage will bring the European ExoMars rover to the surface.
The Russian descent phase will remain operational as a fixed landing platform – named Kazachok, in Russian for "Little Cossack" – to carry out its own scientific measurements, while the European rover will travel for several kilometers and will drill to a depth of 2 meters (6.6 feet). collect basic samples for badysis in the mobile robot's onboard laboratory.
Scientists have never studied such deep materials beneath the Martian surface, where biomarkers and organic molecules could survive from life forms that could have inhabited the planet when it was warmer and wetter there was billions of years.
Italy is the largest financial contributor to the ExoMars program, with the Italian division of Thales taking care of all European industrial works. Britain is the second largest donor of ExoMars, and the Airbus Defense and Space plant in Stevenage, North London, is responsible for the construction of the vehicle itself.
The ExoMars rover owes its name to Rosalind Franklin, British chemist and X-ray crystallographer, whose work has contributed to the discovery of the double-helical form of the DNA molecule. The vehicle Rosalind Franklin, currently being finalized at Stevenage, is the first European rover.
Rover Rosalind Franklin and Kazachok Lander were already scheduled for launch in 2018, but officials postponed the mission to 2020 as both vehicles experienced development delays.
Jorge Vago, scientific leader of ESA's ExoMars project, said on July 26 that the Airbus crews at Stevenage have badociated the main structure of the Rosalind Franklin rover to the Analytical Laboratory Drawer, an instrument box containing equipment to provide rock and soil samples to three scientific instruments. housed inside the container.
Connecting the mobile structure to the instrument case was an important step in mobile badembly, Vago said. The rover drill has also been installed and the robot suspension system and six wheels will be added later.
"At the moment, on the rover, the only thing missing is the locomotion system," Vago said in a presentation on July 26 to the exploration program badysis group. from NASA, March. "Everything else has already been set up."
The rover is smaller than NASA's Curiosity rover currently exploring Mars and a little larger than the Spirit and Opportunity rovers that landed on the red planet in 2004.
In March, the Kazachok landing platform arrived from its NPO Lavochkin plant in Russia at the Thales Alenia Space facility in Turin, Italy. Other components of descent module, such as aerodynamic shield and solar panels of the LG, arrived in Italy from Russia in June.
The ExoMars cruise phase, which will drive the lander and the rover on Mars, arrived at the Thales Alenia Space site in Turin in April from its OHB System manufacturer in Germany.
Once completed, the Rosalind Franklin rover will be shipped from the UK to an Airbus plant in Toulouse (France) for environmental testing, according to ESA.
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Follow Stephen Clark on Twitter: @ StephenClark1.
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