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Raumfahrt - ESA´s ExoMars Mission Rover 2021 -Update-3

3.07.2019

European Mars lander suffers parachute damage in test

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The 35-meter main parachute for the ExoMars 2020 lander in an earlier test. In a high-altitude test in May, two large parachutes suffered tears after deployment. Credit: ESA

TITUSVILLE, Fla. — Development of a European-Russian Mars lander hit a setback when the spacecraft’s parachutes malfunctioned in a recent test, but project officials said they still have time to correct the problem before its launch in a year.

In a June 28 statement, the European Space Agency said that two parachutes suffered “unexpected damage” during a high-altitude test a month earlier in Sweden of the system that will slow down the ExoMars 2020 lander.

The lander makes use of two main parachutes, each deployed with the assistance of a smaller pilot parachute. The first parachute, 15 meters in diameter, is deployed when the descending spacecraft is traveling at supersonic speeds in the thin Martian atmosphere. It is released and the second parachute, 35 meters across, is deployed once the spacecraft slows to subsonic speeds.

A May 28 test of the parachute system used a high-altitude balloon above the Swedish Space Corporation’s Esrange test site in northern Sweden. The test was intended to demonstrate the end-to-end performance of the entire system, including both the pilot and main chutes as well as the mortars used to extract the pilot chutes.

ESA said that the first main parachute suffered several radial tears in its fabric, all occurring before reaching its maximum load. The second main parachute also suffered a single tear, also before peak loading.

The other parts of the parachute system worked as expected, and ESA said “a good level of the expected aerodynamic drag was nevertheless achieved” despite the damage sustained by the parachutes. However, the agency acknowledged that the problem needs to be understood and corrected prior to the mission’s launch in one year.

“We will implement design improvements to the parachute bags to ensure smoother extraction of the parachute, as well as reinforcements to the parachute itself to limit tear propagation in case some would still occur,” said Francois Spoto, ExoMars team leader, in a statement. “The complex process of folding and packing the parachutes and hundreds of lines will also be examined.”

Two additional tests of the parachute system are planned for later this year, but the agency didn’t state when those tests would take place and what the planned corrective actions would do to the schedule. “We are working harder than ever to keep on track for our launch window next year,” Spoto said.

ExoMars 2020 features a Russian-built landing platform, called Kazachok, that will bring to surface the European rover Rosalind Franklin. Kazachok arrived in Italy in March for payload integration activities with a separate European-built cruise stage, while technicians are installing instruments on the rover in the U.K. The integrated spacecraft will be shipped to Kazakhstan for launch on a Proton rocket in July 2020.

The spacecraft will land on Mars in March 2021, likely in a region of the planet called Oxia Planum. If that landing is successful, the solar-powered rover will then explore the surface, equipped with scientific instruments and a drill capable of sampling material up to two meters below the surface to look for evidence of life.

ExoMars 2020 is ESA’s second attempt to land a spacecraft on Mars. In October 2016, ESA’s Schiaparelli spacecraft attempted a landing on Mars to test entry, descent and landing technologies, but crashed into the surface. An investigation concluded that a software problem caused the lander to prematurely shut down its landing thrusters while still several kilometers above the surface.

A British-built lander, Beagle 2, was flown on ESA’s Mars Express mission, but was not heard from after landing in December 2003. Images of the landing site taken by NASA’s Mars Reconnaissance Orbiter more than a decade later suggest the spacecraft landed intact, but was unable to deploy all its solar panels or its communications antenna.

ESA currently has no Mars landers planned after Mars 2020. The agency is considering participating in a NASA-led Mars sample return effort that will start with NASA’s Mars 2020 rover, which will cache samples for later return to Earth. ESA, in one concept, would provide a “fetch rover” on a later NASA lander that would collect the Mars 2020 samples and load them into a Mars ascent vehicle to place them into orbit. An ESA orbiter would then collect that sample canister and return it to Earth.

NASA and ESA signed July 2 a “statement of intent” regarding the science benefits of a joint Mars sample return mission, although the agencies released few additional details about that statement. ESA plans to seek approval from its member states to pursue a role on a Mars sample return mission at its “Space19+” ministerial meeting in November.

Quelle: SN

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Update: 13.08.2019

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PARACHUTE TROUBLES FOR EXOMARS 2020, WITH LAUNCH LESS THAN A YEAR AWAY

The ExoMars 2020 project suffered another parachute test failure last week.  The European-Russian mission to land a rover on Mars is scheduled for launch next summer, so time is running short for the international team to solve whatever is causing the parachutes to rip apart during high altitude drop tests.  Despite all the buzz about sending humans to Mars, just trying to land robotic probes continues to demonstrate the challenges involved.

 

The European Space Agency (ESA) and the Russian state space corporation Roscosmos are partners in the ExoMars (Exobiology on Mars) project.  The first portion of the project launched in 2016:  the ExoMars Trace Gas Orbiter (TGO) and the Schiaparelli experimental lander.  TGO successfully reached orbit and continues to send back data and serve as a communications relay between Earth and two NASA spacecraft on the surface (Curiosity and InSight).

Schiaparelli, however, crashed on landing. The problem was not parachutes in that case, but bad data from an inertial measurement unit.  Its purpose was to gain experience in preparation for the ExoMars 2020 lander/rover combination. Roscosmos and Russia’s Space Research Institute (IKI) are responsible for the lander, named Kazachok.  ESA is responsible for the rover, named Rosalind Franklin after the renowned British chemist who contributed to unraveling the double helix structure of DNA.  The rover is being built by Airbus Defence and Space in Stevenage, UK.

ESA also is responsible for the carrier and descent modules that will deliver the lander and rover to Mars.

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Illustration of ESA’s ExoMars 2020 robotic rover, Rosalind Franklin. Credit: ESA

The United States is the only country to land on Mars repeatedly — eight of nine attempts since 1976 have been successful.  Every time, NASA stresses how difficult it is, however, especially the entry-descent-and-landing (EDL) sequence where the spacecraft enters the Martian atmosphere and must slow down enough to land safely.  There are several methods for the landing itself, but parachutes are critical during descent.  NASA coined the phrase “seven minutes of terror” to describe the EDL process for the Curiosity rover that arrived at Mars in 2012.  NASA’s Mars 2020 mission will use the same profile.

The ExoMars 2020 EDL process is different from Curiosity’s, but still challenging.  The descent module will have two sets of parachutes, each comprised of a drogue chute and a main chute.  The main parachute has a diameter of 35 meters, the largest for any Mars mission according to ESA.

The main parachute deployed properly last year during a test where it was dropped from a helicopter at an altitude of 1.2 kilometers.  But on May 28, all four parachutes were dropped from a stratospheric balloon at an altitude of 29 kilometers. Both main parachute canopies suffered damage.

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Illustration of ExoMars 2020 parachute deployment sequence. Credit: ESA

Design changes were implemented and a second test of the main parachute was conducted on August 5, but similar damage was observed.  Francois Spoto, ESA’s ExoMars Team Leader, said it was “disappointing,” but the team remains focused on finding and fixing “the flaw in order to launch next year.”

The launch window is July 25 – August 13, 2020, with Mars arrival in March 2021.  Earth and Mars are aligned properly only every 26 months to permit direct launches from one to the other and some windows are better than others.  Russia will launch the spacecraft on a Proton rocket.

NASA is providing an astrobiology instrument for the rover — Mars Organic Molecule Analyzer (MOMA).  Originally NASA intended to be a major partner in ExoMars, but had to withdraw when the Obama Administration proposed deep cuts to NASA’s planetary exploration program.  Russia stepped in to replace the United States as ESA’s primary partner.  NASA later decided to build Mars 2020 using some of Curiosity’s backup hardware and new scientific instruments.

Russia has launched a number of missions to Mars since the 1960s, mostly orbiters, but it sent landers at least four times.  Mars 2 and 3 were orbiter/lander combinations, Mars 5 and 6 were flyby/landers.  Only one, Mars 3, survived the trip to the surface. It transmitted data for just 20 seconds before falling silent.

ESA’s Mars Express orbiter, launched in 2003, took along a very small (2-meter diameter) British-built lander, Beagle 2.  It separated from Mars Express, but contact was lost after its scheduled landing.  Its fate remained unknown until 2015 when it was discovered in images from a high resolution camera on NASA’s Mars Reconnaissance Orbiter.  It landed intact, but was unable to communicate because solar panels did not deploy properly.

NASA’s Mars 2020 and ExoMars 2020 will have company.  The United Arab Emirates (UAE) and China also are planning missions.  The UAE’s Hope is an orbiter.  China plans to launch an orbiter/rover, but it requires China’s new Long March 5 rocket, which has not yet returned to flight after a 2017 failure.

Quelle: SpacePolicyOnline.com

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Update: 14.08.2019

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Europe and Russia Have ExoMars Parachute Problems. It Could Threaten the 2020 Mars Launch

 

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