ExoMars landing today!

[Alien 13]

6 minutes ago, Knight of Clear Skies said:

each one is a prototype working in a hostile environment which is no recipe for reliability.

I do wonder why this should be the case, it would make far more sense to uses a tried and tested systems each time with incremental improvements if applicable.

There is equipment working happily on earth that has to withstand far harsher environments than space.

Alan

[johnfosteruk]

25 minutes ago, Alien 13 said:

There is equipment working happily on earth that has to withstand far harsher environments than space.

But there aren't systems working happily on earth that have to withstand far harsher environments than space which are also mars lander shaped and don't give failure alarms which are read instantly without an 8 minute delay, automatic failover systems, instant access by humans to troubleshoot/restart, site surveys prior to installation to enable full proofing against the local environment and all the other constraints that a Mars mission has.

The lander was after all at least partly a technology tester, so they'll analyse the data and all being well learn from it, iron out the problem and land a rover next time.

 

 

[Alien 13]

8 minutes ago, johnfosteruk said:

But there aren't systems working happily on earth that have to withstand far harsher environments than space which are also mars lander shaped and don't give failure alarms which are read instantly without an 8 minute delay, automatic failover systems, instant access by humans to troubleshoot/restart, site surveys prior to installation to enable full proofing against the local environment and all the other constraints that a Mars mission has.

The lander was after all at least partly a technology tester, so they'll analyse the data and all being well learn from it, iron out the problem and land a rover next time.

 

 

I realy hope they do learn and come up with a landing system that works but more importantly stick with the same concept once proven. As to earth based systems I dont think the electronics in an artillery shell gets a second go at working after is pulled 15000G

Alan

[Davey-T]

Another problem is that the financial constraints etc cause long lead times on these projects, some people spend their whole career on one thing, inevitably they get overtaken by technological advances leading to constant upgrading and changing things.

Watching the program on Nat' Geographic they said the planned lander mission is now nothing like it was originally so any time / money already spent on it was practically wasted.

Dave

[johnfosteruk]

7 minutes ago, Alien 13 said:

I dont think the electronics in an artillery shell gets a second go at working after is pulled 15000G

That's a fair point Alan, although it would be interesting to see reliability stats on ordnance - I'm sure they do fail.

[Alien 13]

Chasing the latest technology is never a good idea if it wasn't for the old Soyuz launch platform there wouldn't be much of a space industry. It would be far better to take a design concept and stick with it till completion after all most Defense companies design around older properly tested and coded parts in a design that will be in service for up to 25 years.

Alan

[barkis]

We mustn't cause any upset to anyone in this thread, and I'm pleased Piero accepted the apology from SM.
None of us can be critical of the people who put this project together. Of course we can, without doubt, under estimate the immense difficulties
in performing a job like landing a package softly on a body with a strong gravitational field. Every nation attempting this have failed at one time or another.
We are all mostly expressing our disappointment at this latest mishap, which  does appear to be the case  now.
We do fully support ESA's goals in furthering planetary research, and of course we want success, but it usually comes at a price,
and that price can be very high, in more ways than one. 
Our thanks must go to the engineers, scientists and many others engaged in this very difficult work, and we know
they will reap the rewards they deserve for their endeavours, and so will we.
 

[Knight of Clear Skies]

11 hours ago, Alien 13 said:

I do wonder why this should be the case, it would make far more sense to uses a tried and tested systems each time with incremental improvements if applicable.

Ideally, yes, but no such system exists - this is only Europe's second attempt to land on Mars.

[RayD]

As a consultant engineer (not involved in aerospace) I can say with some degree of certainty that all the calculations, measurements and designs would have been checked, checked again and then checked once more before launch.  I worked in Dungeness A nuclear power station for a long time, and there were even engineering failures there, and the results of failure in this environment were potentially extreme.  However, they happen, and in engineering and science, whilst greatly improved and reduced in numbers over the years, they will always happen; it's just a huge shame that it has happened on such a public event, and on such an important mission.

I'm sure all the engineers will be frantically looking at every piece of information they have to establish what happened, and can only hope that this is in order to understand and fix the issue for the future, not just to blame someone.  However, that sadly seems to be an increasingly adopted culture in the corporate environment today, so I suspect that unfortunately someone, organisation or otherwise, will be singled out.

So sad for the guys involved, right down to the bloke that made the valve for the flange (great word), and the Oxford University Professor who had his wind sensor on board.

Hopefully they will find and understand the cause(s) and push forward with another mission as it must have been feasible to have been funded initially. Most importantly, lets not forget the successful side of now having a satellite in orbit, which will be collecting data which will also be incredibly important.

 

[Stub Mandrel]

Think the worrying thing is that all three ESA lander missions: Mars Express/Beagle 2, ExoMars/Schiaparelli and Rosetta/Philae have all failed to land scuccesfully. Philae may have just about survived a triple bounce followed by wedging under a cliff but that wasn't the planned method of attaching to a comet.

A few less ambitious moon landings might have been a useful way to build experience.

Plus why does every new lander have to be different? Part of NASA's success is through developing designs over a long series rather than a small number of unique projects.

[Alien 13]

16 minutes ago, Stub Mandrel said:

Think the worrying thing is that all three ESA lander missions: Mars Express/Beagle 2, ExoMars/Schiaparelli and Rosetta/Philae have all failed to land scuccesfully. Philae may have just about survived a triple bounce followed by wedging under a cliff but that wasn't the planned method of attaching to a comet.

A few less ambitious moon landings might have been a useful way to build experience.

Plus why does every new lander have to be different? Part of NASA's success is through developing designs over a long series rather than a small number of unique projects.

I agree that each mission should build on the last and if a failure occurs then identify a solution and fix it rather than starting from scratch each time or better still copy a method that has already worked. I do worry that the next attempt will have the lander dangling off a giant bungee cord.

Alan

[RayD]

It's wrong of us or anyone to assume that the failure was as a result of new technologies or designs.  In January 1986 Space Shuttle Challenger exploded killing 7 people as a result of the failure of an O ring on a solid fuel booster.  Nothing new failed, in fact the opposite; this system had been used numerous times before, and it was a tried and trusted technology, but it failed with catastrophic consequences ( I know there were warnings issued etc. but the technology was old).

ESA don't know, therefore we don't know, what the cause of the failure was, but let's assume it was something like the parachute not opening fully?  Instruments show it deployed, but as it didn't open fully the rate of descent was lower than calculated, boosters fire far too late and for a shorter period as a result, and we have a problem.  The parachute is not a new technology, it's tried and trusted many times over.  This is an example and not an attempt at a diagnostic.

My point is, we don't actually yet know what the failure was or why it happened, but it seems there is an assumption that is must be by something that's been newly developed for this specific mission, and definitely not a tried and trusted system which simply, but unfortunately, on this occasion failed to operate as designed.

[Pluto the Snowman]

Is it harder to land on Mars or Venus? Didnt Venus have a few failures with landers? Conditions on Venus are so bad that even a successful lander only lasts and hour or 2. 

[DaveS]

Mars is a notoriously difficult planet to land on.

The gravity is too high for retro rockets all the way down, while the atmosphere is just high enough to require a heat shield but not high enough to make a parachute an easy option.

[RayD]

I think one of the hardest challenges, as someone has mentioned previously, must be the 8 minutes or so delay in receiving information.  This means absolutely every emergency system must be fully automated to deal with every possible scenario, as nothing can be triggered manually.

I have an absolute passion for technical and precision engineering, but I don't envy the pressure these guys must be under, as any failure at all carries such huge consequences.

All of a sudden our Moon seems so close and reachable.

[Paul M]

I'm a believer in tried and tested technology, particularly when the stakes are high. And keep it simple!

It's a relief that no one is actually trying to put a man on the Moon right now, even the US with the brilliant track record of Apollo.

Apollo's success, I feel, was very much down to solid mechanical engineering and some awesome guys flying by the seat of their pants! If they sent a man now, the craft would have many similarities but would be packed with modern electronics. I think that's the weak point. Too many lines of code and too many systems cross talking. Much more room for failures.

Am I right to think Apollo might have been less successful (in terms of the number astronauts lifting off = the number splashing down) if had been engineered to today's technological standards?

 

 

[Stub Mandrel]

I would agree, if NASA hadn't managed to land two mini-sized Viking landers in 1976.

Yes they had two failures in the 1990s plus the deep space probes which were a gamble anyway (they didn't use any form of braking as they were meant to penetrate the soil at high velocity, and may just have hit rocks), but they can be balanced against four successful rover landings - Sojourner, Spirit, Opportunity and Curiosity.

<edit> And Phoenix!

8 minutes ago, Paul M said:

Am I right to think Apollo might have been less successful (in terms of the number astronauts lifting off = the number splashing down) if had been engineered to today's technological standards?

You're right to ask the question! Apollo 11's success must have been largely due to Buzz Aldrin's skill as the computer was away with the fairies for much of the descent because it kept trying to point an aerial that meant it kept running out of memory.

[RayD]

5 minutes ago, Paul M said:

Am I right to think Apollo might have been less successful (in terms of the number astronauts lifting off = the number splashing down) if had been engineered to today's technological standards?

I don't know but I suspect you could be right.

Many would probably have been abandoned by watchdog or supervisory monitoring i.e. temperature, vibration, humidity, timing and other very sensitive sensors.  I don't think the Apollo missions were devoid of electronics though, but not too complicated by today's standards, but certainly cutting edge then.

I imagine that monitoring nowadays would extend more to the actual astronauts also.

[symesie04]

4 hours ago, Stub Mandrel said:

Think the worrying thing is that all three ESA lander missions: Mars Express/Beagle 2, ExoMars/Schiaparelli and Rosetta/Philae have all failed to land scuccesfully. Philae may have just about survived a triple bounce followed by wedging under a cliff but that wasn't the planned method of attaching to a comet.

A few less ambitious moon landings might have been a useful way to build experience.

Plus why does every new lander have to be different? Part of NASA's success is through developing designs over a long series rather than a small number of unique projects.

I would imagine the difficulties of landing on a comet are vastly different to landing on Mars hence why those probes were different. Regarding Beagle 2 and Schiaparelli if you look at them they are not actually that different in landing technologies. Probably the biggest difference is the last stage of the landing which in Beagles case used airbags and in Schiaparelli case thrusters. The thing is Beagles solar panels failed to deploy possibly because of the deflated airbags causing problem so they it would seem that this time the plan was to do away with the potential and very uncontrollable element and use thrusters instead. But it seems to me that there are some calling for using the same technology but fixing the problems and yet when ESA do this they are accused of not sticking with tried and trusted technology. Im a little confused i must say.

[RayD]

18 minutes ago, Paul M said:

Apollo's success, I feel, was very much down to solid mechanical engineering

I really don't think the mechanical engineering has changed very much.  In fact, with technologies now perfected such as fusion welding, new alloys and new machining techniques, scanning and testing techniques etc. it's almost certainly now much better (in this industry) than its ever been, but admittedly much smaller and lighter.  Perhaps this gives a perception that it's not as big and strong as it used to be, but materials such as manganese when used in modern alloys for example, are incredibly strong and light, and certainly far stronger than any steel. I believe on these earlier missions they used a lot of titanium, which in those days was revolutionary, but by today's standards even that is now classed as heavy.

I guess an example would be to look at telescope mounts now.  They used to be made from machined or cast steel, big and strong, but not necessarily extremely refined or accurate by today's standards.  Most are now made from aluminum, whether this is CNC machined billet or cast, it's equally as strong in this application, but significantly lighter and won't rust.  Aluminium has only been available to us as a usable alloy for about 200 years or so, and in a precision machined form far less than that.  The faces, bearings and couplings are also much more precise than they used to be as machining and measuring equipment is just much better now.

I did my apprenticeship in tool making back in 1982 using mechanical lathes, mills and saws etc. and at the time thought the precision was amazing, but now things can be made far more precisely to much more controlled and tighter tolerances than anything that was possible even only back then, and annoyingly, totally automatically!

Most of the issues it seems to me come from electronic equipment and associated software, and the fully autonomous nature of these missions.  The electronic equipment is often susceptible to things such as EMI and such like, which of course with a good old switch wouldn't be an issue at all.  Problem is if you are reading a peak in EMI 8 minutes after it's happened..........too late.

Ultimately can you really roll back technology for a mission who's prime objective is to research and advance technology and our understanding of the universe?  And in reality would you actually get the funding for it if you were proposing to do just that?

 

[symesie04]

6 minutes ago, RayD said:

 Perhaps this gives a perception that it's not as big and strong as it used to be, but materials such as manganese when used in modern alloys for example, are incredibly strong and light, and certainly far stronger than any steel. I believe on these earlier missions they used a lot of titanium, which in those days was revolutionary, but by today's standards even that is now classed as heavy.

 

 

Hmm googles Pinarello Manganese Dura Ace racing bike! 

[RayD]

2 minutes ago, symesie04 said:

Hmm googles Pinarello Manganese Dura Ace racing bike!

HOLY COW!!!!

Forgot to mention, manganese is also very expensive 

[symesie04]

1 minute ago, RayD said:

HOLY COW!!!!

Forgot to mention, manganese is also very expensive 

Booooo but what a bike <droools like a rabid dog>

[symesie04]

Had to laugh the prospect of Manganese made me google what other frame variants are available other than the usual suspects and cam across this in wiki about frame materials:

Beryllium[edit]

American Bicycle Manufacturing of St. Cloud, Minnesota, briefly offered a frameset made of beryllium tubes (bonded to aluminum lugs). Given the toxic nature of the material and the pricing ($26,000 for frame and fork), they never caught on. Reports were that the ride was very harsh, but the frame was also very laterally flexible.^[52]

errrr ill just by a car i think

 

Ooops i seem to have gone off thread   "stay on target"

[RayD]

1 minute ago, symesie04 said:

Beryllium

Lol I can't see that taking off, especially in aerospace.  Beryllium is quite strong, but very brittle.  In fact Ping used it in some Beryllium/Copper golf clubs many moons ago, which were lovely, but they were expensive and they wore out pretty quickly and needed refacing practically every season.  However, If you hit a stone they just broke in to chunks.

There will be something else discovered, not necessarily a new element of course, but an alloy mixture, which I'm sure will surpass every current material with regards to lightness and strength.  May not even be an alloy, it may be a new version of something like carbon fibres, or another means of bonding them to make them even stronger?

Who knows.