ESA Racing Against Time to Fix ExoMars Parachutes

The European Space Agency (ESA) has been working on ExoMars, a lander/rover combination. Originally, this was going to be a collaboration with NASA, but NASA had to pull out about a decade ago when their budget for the NASA rover was not approved. Because of that, ESA went into a teaming arrangement with the Russians: the Russians are providing various stages and the rockets for the landers.

There were three parts of the mission: an orbiter (trace gas orbiter), a lander (Schiaparelli) and a rover (Rosalind Franklin). The orbiter and lander were launched on schedule in 2016, but one minute before landing, Schiaparelli failed and impacted the martian surface. The orbiter continues to orbit Mars and do useful scientific observations. The Franklin rover was delayed due to various problems with deliveries. The plan was to have the rover launch in 2020. However, the rover mission has run into problems and ESA is scrambling to fix them.

The current problem appears to be the parachute. During tests, the parachute meant to slow the rover before landing has torn. Multiple times. If ESA doesn't get the problem fixed very soon, the mission itself will need to be postponed again. In a scramble, ESA has reached out to NASA to to get help. The "tiger team" is attempting to clean up the problem, but they literally have about 4 months to do so. If they do, there are many potential issues still.

While the parachute may be fixable, there are still more potential problems. The Russian rocket stage that delivered the Trace Gas Orbiter and Schiaparelli into a mars transfer orbit exploded after the payloads were separated. Neither were damaged, but the concerns should be obvious. Likewise, the Schiaparelli lander failed because of the retro rockets...also Russian provided.

While I wish the Euros much luck with their mission, they have some serious challenges ahead, inclusive of and especially the parachutes, but hardly exclusively. The question becomes will the Euros actually join the armada for Mars in 2020 or will they be delayed? Again.

science.sciencemag.org...

spacenews.com...

a reply to: anzha
It's nice to see some posters like you still post a lot more than just a link with a snippet from the source. That's a very nice opening post with your thoughts and a description of the problem.

It's good the ESA can admit that NASA knows more about parachutes and that they aren't too proud to seek NASA's help solving the problem. I have watched some videos of NASA doing some of their Mars parachute testing, and they had some problems too at one point which they managed to solve, it seemed a bit tricky.

Mars missions are tough even without known problems, only roughly half the missions succeed and that's the success rate of the first two parts of ExoMars with the orbiter succeeding and the lander failing.

not to mention the shadow that as been photo'd hanging over Mars missions, huh!!

was Mariner 1, 2, and 3 got smacked outt the air !

originally posted by: Arbitrageur
a reply to: anzha
It's nice to see some posters like you still post a lot more than just a link with a snippet from the source. That's a very nice opening post with your thoughts and a description of the problem.

It's good the ESA can admit that NASA knows more about parachutes and that they aren't too proud to seek NASA's help solving the problem. I have watched some videos of NASA doing some of their Mars parachute testing, and they had some problems too at one point which they managed to solve, it seemed a bit tricky.

Mars missions are tough even without known problems, only roughly half the missions succeed and that's the success rate of the first two parts of ExoMars with the orbiter succeeding and the lander failing.

NASA is in a good position to help ESA on this problem because NASA had a similar problem and solved it on the Curiosity Rover mission back in 2011. That mission had the heaviest atmospheric entry vehicle that NASA had ever tried to fly to Mars. During hardware development, JPL tested the full scale parachute in the large wind tunnel (80 x 120 ft test section) at NASA Ames. They shredded it, during the first test. I'm not sure what they did to fix the problem, but whatever it was, it worked. One difference is that ESA is planning to use a rectangular, steerable parachute (at least they were the last time I looked) while NASA has always used round parachutes.

a reply to: anzha

A four part series by NASA. The vids are about 5 minutes each. Worth the watch IMO. Or scubb through this first one and check out the chute opened in a computer simulation and IRL.



The Martians: Testing Curiosity's Parachute - Part 1

Fortunately, the heat shield -- through friction with the atmosphere -- absorbs 98% of all that energy.

So we start off at 17,000 miles per hour, and we can slow down to about 1,000 miles per hour.



That's the point when we have to open up the parachute.

But the problem is, on Mars the atmosphere is so thin that even at a thousand miles per hour, we're not generating that much force.

So we need a really, really, really big parachute.
One of the most difficult things to do is to test the strength of the parachute.

The only way to do that is to actually inflate it. Either you drop it from a helicopter, or you put it in a wind tunnel.

We tried dropping it from a helicopter, but we were so big, and it was just not a very elegant test.

So we abandoned that, and we decided to go into the wind tunnel.

Well, we had to go to the world's largest wind tunnel in order to accommodate this big of a parachute.

The test section in this wind tunnel is 120 feet wide and 80 feet high -- it's

absolutely enormous.

So it sounds pretty straightforward, it sounds pretty easy, but parachute testing is never without its surprises.

a reply to: GBP/JPY

Mars learning curves a itch.

You looked at the first missions now look at the last several.

They know the answers now...

a reply to: LookingAtMars

They used to joke about the Galactic Ghoul hanging out around Mars because a lot of missions disappeared. Soviet AND American.

a reply to: anzha

Yea. I know the story.

Just saying it was a learning curve. Things would fail and it took time to find out why. Something as hard as Mars of course you are going to fail a lot at first.

Now NASA (and only NASA IMO) knows what it needs to know to land safely on Mars.

Look how far they have come. At my count the last 6 missions sent to land on Mars that NASA was involved in were a success.

The last 14 missions sent to Mars that NASA was involved in were a success.

So people can say oooo the chances are 50/50 on Mars missions. Technically that is true.

NASA Mars missions today are almost a sure thing. No where near 50/50.

a reply to: LookingAtMars
Yes, you have a point. The Russians are dragging the global average success rate down for missions to Mars, and the US is doing much better as this graphic shows:

www.forbes.com...


Maybe if the US had converted to the metric system like most of the rest of the civilized world, two of those United States failures could have been avoided which were related to conversion errors from not using the metric system exclusively, or something like that, but even counting those, the US still has a much better track record than the global average.

a reply to: Arbitrageur

As you pointed out a lot of the problems were right here on Earth. One fail was caused by a sensor/switch being mounted upside down, I think it was the Polar Lander that crashed because of this.

ESA claims progress.

www.parabolicarc.com...

The mission has been delayed for 2 years. They won't make this deadline. This is, iirc, the second delay for the mission.

www.parabolicarc.com...

www.nature.com...

a reply to: anzha

Looks like Perseverance will be the only one finding bio signatures then.

Sad to hear.

a reply to: LookingAtMars

Yup.

First they had another delay on the parachute test:

spacenews.com...

More detail:

www.thespacereview.com...