Accelerating Spaceship: Newsletter Challenge (07/01/11)

If a ball bounces across a roadway and is hit by a car windscreen while the car is travelling at speed along the road, the wedge shape of the windscreen will impart a significant velocity change onto the ball, driving it upwards and forwards at a rate related to the inclination and speed of the windsceen.

The analogy is the spaceship being the ball and the planet being the car windscreen.

Something like that?

Well put.

Better run the algo again, zen. You forgot the inversion feild - could be a coupla blayswidth out, there. Think you may've also neglected the coheccular moemtum.

[And assuming that when you used the word "VOLSITY" in the expression "SPEED IN VOLSITY" you meant "VELOCITY", you are 360º of aparture wrong.]

Give up, and take some more meds. Have a nice quiet lie down in a dark room.

This was covered a while back ad nausium.

It is a simple transfer of momentum as JBTardis stated.

Also, the approach can either add velocity or remove velocity depending on how it is done. So you can gravity assist or use the other body as a mechanism to do an insertion orbit.

As was pointed out, this has been covered before. The key to remember is that acceleration can be in speed, direction, or both. In this case the change in direction yields an orbit with a total energy that would otherwise have required a tremendous increase in initial speed when launched from Earth, or a really large fuel supply expended after launch.

Yes - must conserve both momentum and energy.

[Edit: ... always remembering - momentum is a vector quantity)

I've seen a lot of weirdness about this, which I thought was pretty straightforward. So, here's a simplified sketch showing the idea of launching a spacecraft from Earth to Pluto directly (in one case, Energy E2) or by using a Hohmann least-energy orbit to first launch it toward Jupiter (Energy E1) to use Jupiter's orbital energy to then accelerate the spacecraft to Pluto.

The total energy of a solar orbit is given by E = -m*K/SMA, where m is the mass of the craft, K is a constant and SMA is the semi-major axis of the orbit. Note the minus sign. For elliptical orbits the total energy is negative. For a parabolic orbit the SMA is 'infinity' and the total energy is zero. For a hyperbolic (solar escape) orbit the total energy is positive. In the sketch below I ignore the constant K, but I demonstrate that a direct Earth to Pluto orbit requires 13.5 times the energy of the Earth to Pluto orbit. (This assumes a value for Pluto's SMA as 40 AU, and assumes a Hohmann least-energy orbit.)

Oops, slight correction needed:

I demonstrate that a direct Earth to Pluto orbit requires 13.5 times the energy of the Earth to Pluto Jupiter orbit. (This assumes a value for Pluto's SMA as 40 AU, and assumes a Hohmann least-energy orbit.)

I think it's sad that someone can crave attention so much that he/she will spend hours making up rubbish replies just to provoke responses. You're not funny, you're pathetic, and you're just clogging the site with meaningless, forgettable blather.

So, you've gotten a response from me.

So, see this: .............................................

-- that's me now ignoring you.

http://en.wikipedia.org/wiki/Chatterbot

I am not sure I am reading your answer correctly, but I think your answer is incomplete.

First, we must assume a frame of reference by which we measure the space vehicle's (SV) velocity. I.e., the Sun.

Second, the intersecting path between SV and the planet must be considered in the analysis of the outcome.

For instance, to gain a net velocity the SV can approach the planet retrograde to the planet's orbit, complete a half orbit, and exit on a trajectory that follows the orbit of the planet.

If you do that the resulting velocity for the SV will be the initial SV velocity plus the planet's orbital velocity.

If you reverse the situation and overtake the planet, then the planet's velocity is subtracted from the SV's velocity.

If the SV encounters the planet at some attitude in between the two scenarios described, the resultant velocity change will be less depending on the angle of entry, the direction of the partial orbit and the angle of exit (that exit is a hyperbola). In other words, it is more complex.

In the end, the planet will loose some momentum and the SV gains momentum (conservation of energy). Since the mass difference between the planet and the SV is extremely large, we tend to ignore the planet's loss of momentum.

The acceleration gained may well be lost BUT the new velocity of the spaceship is "centred" around the velocity of the planet doing the sling shotting.

This really seems confused. The primary acceleration to the spacecraft is its change in direction. That doesn't get 'lost'.

And what does 'the new velocity of the spaceship is 'centered' around the velocity of the planet' mean? Are you talking about a choice in frame of reference? That's a rather odd way to express that.

What if the planet were stationary? Would there still be a transfer of momentum?

I hope you understand these concepts better than you spell them. That was painful to read.

Zzzzzzz ... people, PLEASE!

The slingshot effect (that is, the INCREASE or DECREASE in speed) is caused by a spaceship's passing between a planet and one of its moons.

As the spaceship approaches the planet and moon from behind the moon ('behind' in the sense of the moon's and the planet's moving 'forward') and between the planet and moon the spaceship's gravity pulls on the planet and the moon, thus slowing them down and speeding up the spaceship. At the midway point, the spaceship shoots 'ahead' of the planet and moon and starts slowing down, but since it's going faster than before it spends less time being 'pulled back' than it was being 'pulled forward'.

The result: the spaceship will move faster 'forward'; the planet and the moon will move more slowly 'forward'; and the planet and moon will have acted as two branches of a slingshot.

The opposite can also be done: the spaceship can be SLOWED DOWN by a planet and its moon. That's accomplished by having the spaceship fly towards them so that the moon passes between the spaceship and the planet. In that case, the spaceship and the planet are the branches of the slingshot so that the planet and the spaceship 'slow down' and the moon 'speeds up'.

When planets don't have moons, there can be no planet-moon slingshot effect, only a trajectory change caused by the planet's gravity. The exception to this is if a planet is used along with the Sun to accelerate/decelerate a spaceship. I don't know if the Sun's gravity is strong enough to have a significant speed-change effect when a spaceship passes near an inner planet in our Solar system (so Mercury and Venus), but it will have some effect. That being said, passing near Mercury or Venus is done principally for trajectory change, and not so much for speed change.

Cheers! DZ

Hmmmm.....unless you are an expert in this area I am going to stick my head out and bet (nothing) that your explanation is wrong and that you don't need a moon planet combination, as you seem to claim, to get a sling shot effect !

Do we have a NASA person watching this thread?

Well stuck out - and totally safe.

You just need to know which way the planet is moving, relative in orbit, to incoming thing.

No NASA rocket surgeons required.

loud

"I have many fRiends at NASA..."

Ouch ! Name-dropping only works if you can name names (and hope they'll remember you).

Kinetic Energy (E_K) = ½ x mass x (velocity)². Momentum (P) = mass x velocity.

You can turn your fields up any which way you like, but

E_K(in) = E_K(out), and P_(in) = P_(out).^{[1] [2]}

And there isn't anything you can say or do that will change it. It's all in the sums.

[1] This is total: planet + spacecraft + moon(s) + sun(star) + the rest of the Universe (including all the dark matter).

[2] Potential energy will be conserved as well, but it won't change the sums.

There are no such words as incepionaly, apature, relavent, and yeild. Affect ≠ effect. So far there is no known way to run your "algo". Whether you are right or wrong is impossible to tell, because your compositions are too incoherent to be understood.

Couldn't you understand the part where he insinuated that John DG was a dog?

ok so your about insulting peple that have a higher I.Q THAN YOU FINE DONT RESPOND IF YOU DONT WANT TO LEARN FRACTIONAL SCIENCE.

I suppose it's possible for a high-IQ person to misspell every third word or so, but it's a bit rare.

So far you have failed to provide anyone a way to use your "algo", or even a decent explanation of what it does.

I sold my Bendix 15 back in 62

Flipper

Ok - "there is no slingshot effect"

Say I am approaching a substantially circular orbiting planet from the direction of its sun.

I wish to turn through 90⁰ of arc, or from a radial course, to a course tangential to the planets' orbit.

Now say I choose to go 'behind' the planet to make my turn - exiting in the direction of the planets' velocity - what happens to my exit velocity?

What happens if I choose to go 'in front' of the planet - exiting against the planets' velocity?

If you can demonstrate that the exit velocities are the same, relative to space, I will accept your leading statement.

_{I shall put this on topic in anticipation of you publishing your 'algo' results, for the enlightenment of all readers.}

What a hoot!

Perhaps you could explain "cohecular moemtum"?

Coheccular moemtum is the speed that a craft can induce when triangulating at the vector inherant potientaly at 1451.1 this next gen technolgy is comming you will see in the very near future. you guys are still into rocket power wait and see what the next gen propulsion is all about.

You've lost me, here (clearly my I.Q.^[1] is way too slow). Is that 1451.1 zeals or 1451.1 hexajewels? And for future reference, what's the conVERSION FACtor?

[1] Impetuous Quadrille.

In 12.8 minutes, a speed of 45,000 feet per minute will get you 576,000 feet, or about 109 miles. Pray tell how is this within the "orbital margen" [sic] of Mars?

IF you calculate the congluent yeild in the distance and take off that percentage you end with a top speed of 62,400 ft per min it is 84 billion multiplyed by the congluent yeild ,481987 multiplyed by 701 indistance factor, and divided into the distance traveled that can very depending when you go ,summer sulstace or winter sulstace your craft will acsend at the orbital margin of MARS in 12 min 18 sec approx.

How can you figure somthing like this out? I have not had any advanced courses in anything so I hardley understand anything anyone is saying half the time. It sounds very interesting though.

Fractional science is fasinating when your into it it takes yrs of reasearch to calculate these figures ,however Ihave been running algos for yrs and its about testing the theory advancing the inception and developing the technolgys.

Time is relative to where you are. ZEN M.L.D.

Just to clear things up, Ed, - when you refer to an "algo" - do you mean "algorithm"?

Whether or not this is the case, could you please define (your meaning of) "algo"?

you are correct sir.

So please define your meaning of "algorithm".

The algorithm is the advanced conjecture in apature involvement there are 2 kinds 1, is rhythmatic in conjecture the other is sustained rythm without fault many can be produced ,however not all can sustain.

Let's try to get some of your words straightened out. By "apature", do you mean "aperture"?

Does one need a congeminating sproggle to do this?

Google's Martian to Earthian translator stinks. S.M.

Try the Venusian one instead. It might do a better job.

I really gotta give it to you

this is a great gag

you haven't broken character once

Zen you are the most entertaining new member since

Moronic Bumble

here is his introduction

Deer College:

I am thanking you for bringing my post to this very good place. I will try to post it again under your general discussion. I am not a general, but I have served in our army, so I thought general would be best place. We have education in Phuket, and good education in Moronia. Maybe Education would be better place. I want to learn from CR4 and also want to share what we no. We have many things to say about the science and engineering of procreation. I want to learn more about CR4 before I tell you more, because we are better than you at this science. But. We don't want to be pully, or do you say pushy?

Some time politics and religion come into our procreation strategies, but I will not mention those parts, because I read the rules when I signed up for this institution.

Phuket!

Guru GARTHH,i don't understand your diploid insurrection but i sense you are of stiller mind and can appreciate the induction.ZEN M.L.D.

When morning comes you will be first to know. zen...

Yeah. Phuket!

He may mean "exajoule" = 10¹⁸ joules. But evidently his arithmetic is equal to his spelling. In one post he says 10¹² (in an awkward way), which is off by a factor of a million.

Hmm, that bit implying that 109 miles gets you into Mars' "orbital margen" seems to be off by a similar factor.

thank you

Nope hexajewel there are henceajewels as well that is a lower rate of induction.

I guess a "hexajewel" would be a suitable unit for describing a dilithium crystal. How it would be equivalent to "1,394 negitive [sic] ionic" (whatever that is) remains unexplained. And what is a "blayswidth", or 19401 blayswidths? This sounds like a distance, but then how does it apply to "induction"? Inductance is measured in henrys, but induction? We are owed an explanation, which we will probably never get.

Come on Tornado, you should know this stuff. A blayswidth is another word for a henway.

Zen never responded if he studied "quantum physics" and The Secret. If so, that would somewhat put things in perspective.

Don't ask him what's a henway.

Next thing ya know, he'll be asking about Grecian urns. _harrumph.

"That's all ye know, and all ye need to know."

--John Keats

(But our Zen neophyte needs to know a lot more than what we have seen thus far.)