European Space Agency and Roscosmos's 2020 ExoMars launch is in jeopardy after a failed parachute test.
The test was focused on the largest of the four parachutes, a predecessor of which had suffered a tear the last time around. Things went awry once more and an issue "similar to the previous test" was observed.
Radial tears appeared after the parachutes were released and ahead of peak inflation loads.
#ExoMars 2020 parachute testing update: troubleshooting continues following unsuccessful drop test last week. Recovered hardware & data currently under evaluation; team is focused on resolving the problem in order to launch next year. Full story: https://t.co/7ExyaQi352 pic.twitter.com/kfgk5XGgj9— @ESA_ExoMars (@ESA_ExoMars) August 12, 2019
Back in June, ExoMars team leader Francois Spoto promised improvements to the parachute bags as well as the packing process, but in the following test, on 5 August, it happened again, and the test module descended only on the drag of the pilot parachute.
The 35m parachute – the largest ever sent on a Mars mission – worked fine when dropped from an altitude of 1.2km from a helicopter last year.
Being dropped from a balloon at 29km has not gone quite so well. While the deployment sequence went to plan, a parachute failure in 2021 will result in yet more European and Russian hardware scattered over the Martian surface.
Spoto described the second failure as "disappointing" but bravely insisted: "We remain focused and are working to understand and correct the flaw in order to launch next year."
An ESA representative told The Register that backup tests had always been planned for November 2019 and February 2020. The first main parachute will likely be tested in the former and the second main parachute in the latter.
ESA also intends to convene a panel of experts in Mars parachutes to ponder a way forward, in addition to its usual NASA/ESA meetups, as well as devise ground tests to mimic the high-altitude experience.
It's all getting a bit tight. The performance of the rocket involved means that the mission can only launch once every two years, and the next window is 25 July-13 August 2020, which will place the Russian lander and Rosalind Franklin rover on the red planet in March 2021.
ESA told us: "Prior confirmation of a launch possibility in 2022, a number of programmatic questions need to be addressed with all involved stakeholders."
A previous ESA lander, the Schiaparelli probe, slammed into the surface of the planet in 2016 after deployment of the parachutes caused it to spin. The excessive rotation saturated sensors, leading to premature parachute ejection and, er, splat.
One of the four main root causes identified was "Insufficient conservative modelling of the parachute dynamics which led to expect much lower dynamics than observed in flight."
Add to ESA's litany of landing mishaps those of its mission partner, Russia, and a certain nervousness is understandable.
At the moment, the agency is continuing to work on the basis that the boffins will be able to sort things out. However, mindful of the agency's history with the Martian surface, a spokesperson told us: "For the time being we assume that those corrective measures can be implemented in a timely manner, first priority remains mission success." ®