Tintin Forums

i am currently researching a physics project on the subject of whether Professor Calculus's moon rocket would ever have actually reached the moon, and the technicalities of it, its journey, etc. if anyone knows of any resources or information i would love to hear (about) it, or if anyone wants to know what i find out...
i recall there was a topic a bit like this a while back too - it fascinates
me!

Interesting subject...

I'd love to know what you find out, NASA may be a place to start. The TV series 'From the Earth to the Moon' (one of the early episodes) talked about how a single rocket (like the Moon Rocket) would be impractical to take to the moon. Hence they used the Lunar Excursion Module

Rik

jockosjungle
The TV series 'From the Earth to the Moon' (one of the early episodes) talked about how a single rocket (like the Moon Rocket) would be impractical to take to the moon.

I'm not sure I saw that, sounds like it could be good; however, I think that the single rocket theory is now officially "wrong", because the route that NASA took to get to the Moon by the end of the Sixties (as per JFK's pledge) involved the multiple-stage vehicle. It's 20/20 hind-sight, due to them riding rough-shod over the X-rocket, Chuck Yeager school of re-useable vehicles.
Tom Wolfe's The Right Stuff goes into this in some detail.

Also the Orion project, atomic-powered powered, single-stage, re-usable rockets, were at one point seen as the future of rocketry; only Freeman Dyson being unable to reconcile the environmental damage, and the inherant loss-of-life, caused the development to be halted (although some say it may be revived).

As I have said elsewhere, Calculus does not seem to be worried about the fall-out being vented along with the radio-active gasses from his ship... :-/

As to whether the rocket could fly aero-dynamically-speaking, well Harrock n Roll provided this information.

The moon rocket looks like one of those toys that people have shot into the air like what Homer Hickham did in "October Sky", so it could be quite aerodynamic.

The one big part of the moon journey that I didn't get was how the rocket reconfigured itself prior to landing while still traveling forward at very high speeds. The Space Shuttle could reconfigure itself (from flying upside-down to going right-side up prior to re-entry), but it could do that because it is not propelling itself at very high speeds (its motor is off while in orbit). But in the Tintin adventure, the rocket still speeds to its destination. I'd guess that a lot of fuel would be needed to turn on a rocket engine elsewhere on the craft so that it could change direction. How can the rocket do such a thing?

BTW, how do you think the rocket goes through re-entry? It doesn't look like it has protective tiles or enough on the surface so that the heat only burns away part of the cover...

I’m not sure I saw that, sounds like it could be good; however, I think that the single rocket theory is now officially “wrong”, because the route that NASA took to get to the Moon by the end of the Sixties

It was a HBO 13 part series, Tom Hanks was executive producer and was in/directed one episode. It was on Saturday lunchtimes on C4.

I agree with Snafu though, they did use far too much fuel than was necessary. Basically they fired it full until half way and then had to turn round and keep firing to slow it down again.

However it wouldn't require a lot of fuel to turn the rocket as there is no friction in space, a very small thrust would turn it.

Rik

report so far...

jock123
the route that NASA took to get to the Moon by the end of the Sixties (as per JFK’s pledge) involved the multiple stage vehicle.

the advantage of multistage rockets is that as one stage runs out of fuel, it can be fired off, which decreases the mass of the rocket, giving it a higher forward speed for the same amount of propellant(momentum = mass x velocity).

snafu
The one big part of the moon journey that I didn't get was how the rocket reconfigured itself prior to landing while still traveling forward at very high speeds.

you're right, it was travelling very fast (a good point, which i may find i have to explain), however they cut the motors to perform the turning operation, and as jockosjungle said, it would take only a small thrust to turn it owing to the lack of air resistance. although this brings rise to the question of if there is no air resistance to make turning difficult, then in theory, there will be no force acting on the rocket to slow it down once it has escaped the earth's gravity, so there should only be need to give the rocket an initial speed, which it would then be able sustain (no resistance, ergo no acceleration/deceleration) until it reached the moon.

hmmmmmmm
i see a lot to think about.
thank you all so far (and for the link, jock123).
watch this space!

wench
a higher forward speed for the same amount of propellant(momentum = mass x velocity)
Of course you are right here; however, speed isn’t the deciding factor really - you could have a really massive single stage rocket lift off really slowly if it could generate the force required. That was sort of the Orion approach.

although this brings rise to the question of if there is no air resistance to make turning difficult, then in theory, there will be no force acting on the rocket to slow it down once it has escaped the earth's gravity, so there should only be need to give the rocket an initial speed, which it would then be able sustain (no resistance, ergo no acceleration/deceleration) until it reached the moon. ~wench

That was more or less my concern. I mean even if the motor was off, there'd be insufficient air resistance to really slow the rocket. Tintin and Co. would still need a lot of fuel to slow down, turn around, and safely land, especially since this is a large craft. By contrast, the space shuttle never traveled so fast as to completely break from Earth's gravitational pull, and it was small enough to adjust into orbit. Furthermore, the Apollo craft were shipped into the Moon's gravitational field so they spun around it and slowed down prior to landing (not heading straight towards it as the rocket did). Well, that's great science fiction, though...

jock123
you could have a really massive single stage rocket lift off really slowly if it could generate the force required

Absolutely right. But motors with possibilities of reaching Mars (within a reasonable time-scale) would almost certainly need to be multi-stage, as they would have to fire part of the way there as well, so the greater thrust would be more necessary. The Moon rocket was single stage though, so I guess it doesn't really matter.

snafu
I mean even if the motor was off, there'd be insufficient air resistance to really slow the rocket. Tintin and Cº would still need a lot of fuel to slow down, turn around, and safely land, especially since this is a large craft.

I have often wondered how come it took so little time for the rocket to reach the Mon. As there is no resistance in space, and the rocket keeps it's engines running all the way there, it would in fact accelerate all the way there. Although the rocket is travelling at incredibly high speeds, it doesn't stop while it turns around, just drops to a steady speed raher than continuing to accelerate.
The effect is that when the engines are switched back on, they only have to provide sufficient reverse acceleration (thrust in the opposite direction to the direction of motion) to counter the speed which will not be taken up in landing.
A lot of speed will be lost when the auxilliary engines are switched back on. If you think about it, they are the engines used for take off, and so are incredibly powerful accelerators, which would make them incredibly good decelerators for landing on the moon.

I see I have only just scratched the surface of this topic. More when I know...

wench
motors with possibilities of reaching Mars (within a reasonable time-scale) would almost certainly need to be multi-stage

I don't think you could build a multi-stage rocket large enough for a trip to Mars which would be practical. Far more likely is a multi-part trip, with an ascent to space and then transfer to a ship built or assembled in orbit or on the Moon. Without the restraints of Earth gravity, a single "space-ship" type vehicle (or even a fleet of such), which would be as useful for the return as for the outward bound journey looks to be a better bet, and this might be atomic, like Calculus's is.