WASHINGTON — The European Space Agency said Aug. 12 that another test of the parachutes that will be used on the ExoMars 2020 lander mission failed last week, putting the schedule of the mission into jeopardy.

The Aug. 5 test, using a high-altitude balloon above the Esrange test site in northern Sweden, was intended to demonstrate the deployment of a 35-meter parachute, the larger of two main parachutes used to slow the descent of the spacecraft. That parachute, as well as a smaller one 15 meters across, suffered damage during a similar test in May.

However, ESA said in a statement that “damages to the canopy were observed prior to inflation” of the main parachute, similar to the tears in that earlier test. A test article mimicking the lander descended under only a small pilot chute used to extract the larger parachute.

“It is disappointing that the precautionary design adaptations introduced following the anomalies of the last test have not helped us to pass the second test successfully,” said Francois Spoto, team leader for the ExoMars mission at ESA, in the statement. He added that the mission team is still “working to understand and correct the flaw in order to launch next year.”

News of the failed test first appeared in Russian media Aug. 9. ESA did not respond to a request for comment that day about the reports, instead issuing the statement confirming the test failure Aug. 12.

ExoMars 2020 is a joint mission of ESA and the Russian state space corporation Roscosmos, which is providing the Proton rocket that will launch the mission, the surface platform and part of the science payload. ESA has overall mission responsibility, including the entry, descent and landing system, and the Rosalind Franklin rover.

In order to land on Mars as scheduled in March 2021, the mission must launch during a narrow window open only from July 25 to Aug. 13 of 2020. While ESA says it is still working to keep the mission on that schedule, there is some skepticism in the space community that it will be able to do so given the problems with the parachutes.

ESA said in its statement that it is planning to conduct another high-altitude test of the 15-meter parachute before the end of the year, with a test of the 35-meter parachute expected in early 2020. ESA will also convene a “workshop of Mars parachute specialists” in September to seek additional insights to help the mission.

The agency is considering developing additional parachute test models for use in ground-based simulations intended to “mimic the dynamic nature of parachute extraction,” it said in the statement, given that there are limited opportunities to perform high-altitude balloon tests of the system.

Other aspects of the ExoMars 2020 mission have encountered fewer problems. The Franklin rover will begin environmental testing at an Airbus facility in France in the near future, while the surface platform and descent module will begin a final series of tests around the same time at a separate Thales Alenia Space facility. The rover will be integrated with the lander in early 2020.

“Getting to Mars and in particular landing on Mars is very difficult,” Spoto said in the statement. “We are committed to flying a system that will safely deliver our payload to the surface of the Mars in order to conduct its unique science mission.”