You know you're addicted to Orbiter when...

[DanM]

Do I want to know how much ink that uses?

 

[jedimaster1214]

Do I want to know how much ink that uses?

Lots, but wasn't too bad... i had to let it dry for like 10 minutes, at the most. Paper came out a little wrinkled, but once it dried i put it between two thick books, and it's all fine now.

That's my schedule at the bottom corner, that's why i left a bunch of black space at the bottom.

 

[DanM]

When your friend pictures you as this

(guilty, my friend just sent me that)

 

[Columbia42]

You know you're addicted to Orbiter when every key of your keyboard is programmed to launch a different scenario.

 

[Grover]

when you design a car that can be controlled solely by a 3d joystick, 4 buttons and a throttle (in progress)

 

[Pipcard]

...you look through your Algebra II textbook to look for problems related to spaceflight.

 

[n0mad23]

The carrot you dangle before yourself during a 2.5 hour animation development session is taking your craft out for a 3 orbit spin.

 

[OrbiterSpore]

When your friend pictures you as this
SPAAAAAAAAACE!! - YouTube

(guilty, my friend just sent me that)

GUILTY
Happens to me all over the time. :LOL!:

 

[Cras]

In keeping with the recent trend, I took a look and all my Orbiter installations (4 of them), and my add-on download folder is 22.7 GB.

I did not expect it to be that large I have to admit.

 

[Columbia42]

All Orbiter installations plus assorted accessories (addons, tools, whatnot) totals about 24.7 GB.

 

[HAL9001]

Totals about 80 GB, around 10-15, each

 

[Pablo49]

GUILTY
Happens to me all over the time. :LOL!:

Must you use giant red type? It's a little bit of an eyesore.

 

[DanM]

When you're asked on what you'd bring to a desert island and you say "A computer with Orbiter and addons". Guilty for me today in school, teachers were doing some weird activity to help us know one another better.

 

[jedimaster1214]

Origami DG...

'nuff said.

 

[Pipcard]

About the Algebra II textbook I mentioned earlier, I actually found an example problem involving spaceflight (I haven't gotten to natural logarithms yet):
"A spacecraft can attain a stable orbit 300 km above Earth if it reaches a velocity of 7.7 km/s. The formula for a rocket's maximum velocity v in kilometers per second is v = -0.0098t + c ln R. The booster rocket fires for t seconds and the velocity of the exhaust is c km/s. The ratio of the mass of the rocket filled with fuel to its mass without fuel is R."

The example then gives some numbers for the variables and shows how to solve it (using a calculator). A caption beside the example problem states that escape velocity from Earth is 11.2 km/s. What do you think about this formula? Does it only apply to single stage to orbit rockets?

Here's another problem from earlier in the book:
"A space probe leaves Earth at the rate of 3 km/s. After 100 days, a radio signal is sent to the probe hailprobe. Radio signals travel at the speed of light, about 3 x 10^5 km/s. About how long does the signal take to reach the probe?"

I think 3 km/s is the average velocity?

 

[elephantium]

Did you calculate the radio signal's travel time in the second problem?

 

[jedimaster1214]

:lol:
I haven't had school in a few months, so my brain is a bit rusty....but i think i solved that second radio travel time problem.

First i calculated how far away is 3 km/s for 100 days, which i believe is 24,720,000 km
Then i divided 24,720,000 by how far light travels (which is, according to the word problem, 300,000 km/s)

[math]24720000/300000 = 83.3333333333[/math]

Which came out to a time of 83.333 seconds...

But i think it leaves out that the probe hailprobe travels a bit more distance during the time it takes for the signal to travel to it, so that would take a bit more for the travel time...

 

[Pipcard]

Did you calculate the radio signal's travel time in the second problem?

Yes I did, with my scientific calculator, and got the same answer as jedimaster1214 (83.333... seconds)

 

[HAL9001]

I got following:
3km/s*100days*24hours/day*3600seconds/hour = 25920000km
Than I let my scientific calculator solve the equation:
25920000km+3km/s*Xs = 300000km/s*Xs
wich found out hat X (the seconds the signal needs) is:
X = 86,40086401s
and the signal gets the probe at 25920259,2km, but I think it's periodic and my calculator shortened it, so I think X = 86,4008640086400864008640086400..... (86400 again and again) s
and the signal gets the probe at 25920259,2025920259202592025920.... km

I would have answered:
flying away from earth at a velocity of 3km/s is too slow - it isn't even in an Orbit, so it would crash down within the 100 days. So the time is depending from the radio stations postition and the probes crashdown-position, but not longer than: 12756km(earth diameter)/300000km/s = 0,04252s
:lol:

---------- Post added at 17:25 ---------- Previous post was at 17:19 ----------

About the Algebra II textbook I mentioned earlier, I actually found an example problem involving spaceflight (I haven't gotten to natural logarithms yet):
"A spacecraft can attain a stable orbit 300 km above Earth if it reaches a velocity of 7.7 km/s. The formula for a rocket's maximum velocity v in kilometers per second is v = -0.0098t + c ln R. The booster rocket fires for t seconds and the velocity of the exhaust is c km/s. The ratio of the mass of the rocket filled with fuel to its mass without fuel is R."

The example then gives some numbers for the variables and shows how to solve it (using a calculator). A caption beside the example problem states that escape velocity from Earth is 11.2 km/s. What do you think about this formula? Does it only apply to single stage to orbit rockets?

The formula is only right for rockets wich onlylaunch straight up from earth.

I would use the formula: deltaV=c*lnR for the exhaust speed I set in the efficiency in N*s/kg instead, because than it's also correct for air-breathing engines, and other special cases.
For multistage-rockets I calculate the deltaV for each stage seperately.
I fill in gravity ad air-drag when I find out how much deltaV the rocket needs at all.

 

[elephantium]

I got:

3 km/s * 60 s/min
180 km/min * 60 min/hr
10800 km/hr * 24 hr/day
259200 km/day * 100 days
25920000 km traveled in 100 days

25920000/300000 km/s (relatively inaccurate speed of light according to the problem text) = 86.4 seconds travel time.

Now, the probe still travels while the signal is in transit...but as Hal showed, the additional distance traveled is negligible.

If you use the true speed of light (299792.458 km/s), you end up with 86.46 seconds of transit time.