BBC Focus Magazine

[Shadowwolf]

Curiosity has had a successful launch, separation and is now on its way to the Red planet with the biggest rover yet. We'll have to wait until next August before the nail biting landing sequence is set for its debut.

A signal from NASA's Mars Science Laboratory spacecraft, including the new Curiosity rover, was received by officials on the ground shortly after spacecraft separation. The spacecraft is flying free and headed for Mars after separation from the United Launch Alliance Atlas V rocket that started it on its journey to the Red Planet. Liftoff was on time at 10:02 a.m. EST from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida.

http://www.nasa.gov/mission_pages/msl/index.html

[M Paul Lloyd]

I'll be up to my elbows before it lands.

[Lateralman]

Having looked at the sequence of events it has to perform to make a precision landing, Parachute decent, Heat shield separation, Radar activation and mobility deploy, Powered descent, Back shelf separation, Sky crane deploy, Fly away, Rover separation.

I would have thought that there would have been a far simpler way of getting it to land safely on the Martian surface.

[Healerman]

Yes, the deployment of the rover is a complex process, and that offers so many more opportunities for something to go wrong.

Still, here's hoping it all goes smoothly. Bon voyage!

[ChrisH]

Is the Rover too heavy for a simple parachute landing? Or would it likely get tangled up in the parachute on landing?

[Lateralman]

If the parachute was also designed to be a combination of a parachute and helium balloon for example, whereby helium was rapidly pumped up into the belly of the deployed parachute canopy, (or inner secondary skin,) as it descends. Would this not provide enough lift to slow the decent down sufficiently, if the helium were held trapped inside the canopy for a period?

FIRST STAGE. Parachute descent. SECOND STAGE. Parachute becomes helium balloon. THIRD STAGE. Gentle landing on heat shield. FORTH STAGE. Fly away, helium balloon parachute release, with observational cameras for further low-level viewing. FIFTH STAGE. Rover rovers.

I realise that this would involve a complete redesign of the Landers parachute systems along with countless other problems ect. However, it seems a simple cost effective idea to implement to me.

Is it too late to ask them to come back?

[M Paul Lloyd]

Its that old devil efficiency that spoils any plans for adding Helium to the mix as said gas would have to be stored in a container which would impose a weight penalty not only at launch but also in the descent stage with any marginal gain being lost in the total equation.

Personally I think the simpler the system is the less chance it has to go wrong and... well this rocket pack and trapeze wire arrangement worries me a bit I must say.

Is it too late to ask them to come back?

And well yes....... just a bit?

[Healerman]

I rather like the idea of the the helium parachute, Lateralman. A large twin-skinned parachute and maybe some retros for to cushion the last few metres.

Its that old devil efficiency that spoils any plans for adding Helium to the mix as said gas would have to be stored in a container which would impose a weight penalty not only at launch but also in the descent stage with any marginal gain being lost in the total equation.

My thought is, in the absence of oxygen, hydrogen could be used in stead of helium, chemically generated, so no weight penalty with a pressure cylinder there.
The amount of lift is open to debate and analysis, but it certainly deals with that problem of making sure the chute doesn't foul the lander. All in all, a much less complicated system than the one being used, and thus less prone to failures, statistically speaking.

[Lateralman]

The retro rockets take up space and use gas and it would do away with the crane trapeze device. The containers could be collapsible. Although something smaller in the way of retro rockets could be used for guidance and landing.

Okay forget helium, hydrogen, yes, great thought. We are off to NASA Healerman. Stand by your phone.

[M Paul Lloyd]

As much as I would love to endorse your careers in the aerospace industries chaps I'm afraid that the other rather inconvenient problem with 'balloots' as such twin skinned, gas filled, aerofoil envelopes are known is that the Martian atmosphere is so tenuous (it actually has more dust than gas molecules in it) that it would struggle to support even quite a massive device of such a design.
Landing on Mars is really quite complicated isn't it?

[Lateralman]

True Mr Lloyd, landing on Mars hanging from a crane is complicated.

Oh dear, we may have missed the boat anyway the Russians and the Chinese are knocking one up tonight and will be ready to launch tomorrow.

Then again, we could still pip them at the post, if they phoned ahead perhaps they could arrange for several little green men to catch the Rover in a big blanket before it hits the ground.

[Jamie]

I think I got my name on a chip on that one too! That's three spacecraft that I've managed to get my name on, although one did fly into an asteroid.

[M Paul Lloyd]

My daughters name is halfway to Pluto....... if that counts?

[Shadowwolf]

Oh dear, we may have missed the boat anyway the Russians...

I dunno, the last Russian probe appears to be going no where but back down - or shot down - instead of Mars. The Chinese appear to be going it alone so them teaming up with Russia seems unlikely at this point. There may be a Chinese probe along for the ride but I think that's a pay for ride and not intra-agency cooperation.

The only issue - apart from Mr M's point - I see with this alternate system is that it seems as complicated as the system already there, just different things to potentially go wrong.

I'd have thought a lander that actually lands then drops a ramp or the vehicle just drives out without cranes and landers flying safely away after detaching would have been easier. Probably a bigger craft though.

[M Paul Lloyd]

Given that the 'sky-crane' from which the Rover is suspended can hover on rocket power precisely enough to allow for this amazing trapeze contraption to work I'm left wondering why it could not actually put the thing gently down on the surface (Viking lander style) then fly off and crash?

[Lateralman]

Naa, that would be too simple Mr Lloyd. We want to see it fly off and crash.

Seriously, I mean why any of this multi dollar equipment has to fly off and crash is beyond me. They are not thinking this through, why doesn’t it fly off and plant a tree or open up a burger bar or whatever.

A straight landing without the use of a crane would be ideal but I guess that there is a reason why that is not possible.

I thought that the Viking Lander used some sort of multiple bouncy ball system.

[Shadowwolf]

It's only been the recent probes that utilised a balloon cushion, Viking landed under its own power after a chute retarded descent from what I recall; Viking was stationary with no vehicular component mind.

The only reason I can think of for not landing is that the craft required to physically land and then deploy the large rover would be too large for the launch vehicle.

[Lateralman]

Mr Wolf congratulations you have cracked it! Okay, forget bouncy balls, sky cranes and hydrogen-filled parachutes.

I think they should do something like you suggest, which is a more down to Mars idea, simply have it land, throw a bone and tell Rover to go and fetch.

That’s that sorted and now there is three of us off on a shuttle to NASA.

I have also been working on a cost efficient environmentally friendly way of getting a rocket into the earth’s orbit without using any rocket fuel. It is very simple and does not involve the use of a sky crane, a balloon or an enormous catapult. It is one of those, why didn’t we think of that one, ideas that is not rocket science. It is a sure fire Wernher von Braun winner.

Do you know anyone who is working on how to build a space rocket...Mr Lloyd?

[M Paul Lloyd]

Do you know anyone who is working on how to build a space rocket...Mr Lloyd?

Yes.
how-to-build-a-space-ship-a-beginners-guide-t9.html
Me.

[Shadowwolf]

I have also been working on a cost efficient environmentally friendly way of getting a rocket into the earth’s orbit without using any rocket fuel.

Technically not a rocket then

So, what's this new system.