Time to accelerate to 1% c at 1G

apoc527

Mongoose
Ok, I'm feeling dense. Is it even possible to use reaction drives to accelerate to 1% of lightspeed? I'm working on a Star Frontiers conversion and I need to know if that's even possible. If not, I'll just use the jump drive and call it good.
 
I'm figuring it takes about 85 hours at a constant 1G acceleration to reach that 1% lightspeed figure (assuming about 3 million m/s).

Hmmm...with the HG reaction drives, not really doable.
 
Depends on your starting velocity! ;)

Let's see... 300,000,000 m/s divided by 10 m/s*s divided by 3600 s/hr would reduce to 300,000 divided by 36 hrs or 8 and 1/3 thousand hours for ~c => a bit under 83 hrs 20 minutes for 1% from 0 m/s (ignoring relativity, etc.)

So, in general, you are correct => no, not practically.

(Star Frontiers was a fun game, though I can't remember any of its mechanics... perhaps an Alternative Drive along the lines of the Warp Drive would be a better fit...)
 
OK, that just looked wrong. Way too short. I'm too tired to do it but found a simple Newtonian/non-relativistic calculator on the web (if it's to be trusted) to plug numbers into:

http://www.cthreepo.com/lab/math1.shtml

(right at the top of the page, there's relativistic stuff below if you want it... )

I'm not even sure in my current sleep deprived and alergy stuffed mind I did that much right so do check me on it.

Plugging in your 1G and working towards 1% of c (3,000,000 meters/second) x60 x60 for 18,000,000,000 meters/hour (since I used hours for the input time).

I ended up narrowing it down to 18,000,000,144 m/h as close enough. Getting 509,684 hours (some 58 years) of acceleration and covering some 16,513,761,732,110,094 km.

I have no idea if that is right. I suspect not but I've already screwed up some basic math once, caught it (hence the quick delete and not so quick redo)... unless this correction is the screw up and I was right before when it was "only" some 21 days of time (that seemed way short too). I don't even know anymore. I shouldn't even be trying right now. I need sleep...

...somebody with a dozen brain cells to rub together check me or do it :)
 
STar Frontiers used 3 types of drives, Atomic, Ion and Chemical. Only Atomic and Ion drive ships were able to enter the void, so I wouldn't worry too much about reaction drives except for system ships. Atomic and Ion were never really defined, except Ion required "units" of hydrogen to operate and Atomic required "fuel pellets" to run - one consumed in each jump (which made the Assault Scout rather useless as a scout - jump in, take some readings and... oh, no fuel to get home again...).

I'd also point you towards

http://www.starfrontiers.us/node/370

and

http://starfrontiersman.com/downloads/starfrontiersman

G.
 
GJD said:
STar Frontiers used 3 types of drives, Atomic, Ion and Chemical. Only Atomic and Ion drive ships were able to enter the void, so I wouldn't worry too much about reaction drives except for system ships. Atomic and Ion were never really defined, except Ion required "units" of hydrogen to operate and Atomic required "fuel pellets" to run - one consumed in each jump (which made the Assault Scout rather useless as a scout - jump in, take some readings and... oh, no fuel to get home again...).

I'd also point you towards

http://www.starfrontiers.us/node/370

and

http://starfrontiersman.com/downloads/starfrontiersman

G.

Ho hum. Of course you'd also be aware that each engine actually carried 3 fuel pellets, not the 1 you mentioned.
Ok, Star Frontiers was more 'D&D in space', but I still like it as a game!
 
far-trader said:
...somebody with a dozen brain cells to rub together check me or do it :)
c = 299,792,458 meters/sec
1% of c = 2,997,925 meters/sec
1 G acceleration = 9.80 meters/sec/sec

time = change in velocity/acceleration
time = 2,997,925 / 9.80 = 305,911 seconds
time = 85.0 hours = 3.54 days

all strict Newtonian (non-relativistic) calculations to 3 significant figures.
 
Solomani666 said:
.

Err... Anyone see DFW?

.

Right here Sol.

Anyway, I got

304,922 seconds = 84.7 hours = ~3.5 days, for a vel. of 2,991,284 m/s.

On an interplanetary journey of moderate length you would reach this. But, I doubt with Trav reaction drives due to reaction mass requirements.
 
Thanks all. Good to know my basic physics skills aren't rusted entirely through. I've decided to use a jump drive based mechanic to enter the Void. It's just easier that way. :wink:
 
Rick said:
GJD said:
STar Frontiers used 3 types of drives, Atomic, Ion and Chemical. Only Atomic and Ion drive ships were able to enter the void, so I wouldn't worry too much about reaction drives except for system ships. Atomic and Ion were never really defined, except Ion required "units" of hydrogen to operate and Atomic required "fuel pellets" to run - one consumed in each jump (which made the Assault Scout rather useless as a scout - jump in, take some readings and... oh, no fuel to get home again...).

I'd also point you towards

http://www.starfrontiers.us/node/370

and

http://starfrontiersman.com/downloads/starfrontiersman

G.

Ho hum. Of course you'd also be aware that each engine actually carried 3 fuel pellets, not the 1 you mentioned.
Ok, Star Frontiers was more 'D&D in space', but I still like it as a game!

Class B did, and class C carried 10, but IIRC correctly, type A - which the Assault Scout had two of, only had one. You also had to do an overhaul on the engine after every jump. How does that make the assault scout ideal for hit and run attacks?

Anyway, I love the game. I did the covers for two of the Star Frontiersman webzines.

G.
 
GJD said:
Rick said:
GJD said:
STar Frontiers used 3 types of drives, Atomic, Ion and Chemical. Only Atomic and Ion drive ships were able to enter the void, so I wouldn't worry too much about reaction drives except for system ships. Atomic and Ion were never really defined, except Ion required "units" of hydrogen to operate and Atomic required "fuel pellets" to run - one consumed in each jump (which made the Assault Scout rather useless as a scout - jump in, take some readings and... oh, no fuel to get home again...).

I'd also point you towards

http://www.starfrontiers.us/node/370

and

http://starfrontiersman.com/downloads/starfrontiersman

G.

Ho hum. Of course you'd also be aware that each engine actually carried 3 fuel pellets, not the 1 you mentioned.
Ok, Star Frontiers was more 'D&D in space', but I still like it as a game!

Class B did, and class C carried 10, but IIRC correctly, type A - which the Assault Scout had two of, only had one. You also had to do an overhaul on the engine after every jump. How does that make the assault scout ideal for hit and run attacks?

Anyway, I love the game. I did the covers for two of the Star Frontiersman webzines.

G.

It's 3, 6 and 10 for the types of engines, lol! Yeah - SF was the first game I ever ran and I've still got the rulebooks, great stuff.
 
Friends don't let friends calculate drunk (or otherwise impaired like I was with insomnia and allergies last night :) ).

You (the rest of you) are of course correct in your calculations. I was too wiped to do the math last night and trusted the first online calculator google spit out. It has an error in the units output that produced the above.

Your results looking short is probably down to me usually working in fractional g's for such STL trips and not having a high enough functioning brain to realize that last night.

I'm a little better this morning, but still probably shouldn't operate FTL equipment ;)
 
far-trader said:
Friends don't let friends calculate drunk (or otherwise impaired like I was with insomnia and allergies last night :) ).

Due to the late rains this Spring, my allergies have been a nightmare this year.
 
A Reaction Drive wouldnt be good, but it would be childs play for a Gravitic Drive to accelerate at 1G for 3.5 days straight, right?
 
zero said:
A Reaction Drive wouldnt be good, but it would be childs play for a Gravitic Drive to accelerate at 1G for 3.5 days straight, right?

Yep. SOP for Traveller interplanetary travel. Higher G craft go even faster on long trips between planets.
 
Assuming a 0.01c speed limit, not unreasonable for particularly busy systems, it will take over a week to get from the Earth to Saturn. If the fuel is available, you might just want to jump.
 
GypsyComet said:
Assuming a 0.01c speed limit, not unreasonable for particularly busy systems, i.

No reason in the world to limit speeds. These mid point speeds. Space is a lot bigger than you are imagining...
 
In the abstract, sure, but most travel is going to be in a system's main orbital plane, where things are a bit busier. If my midpoint was anywhere near some other body or came close to another gas giant's trojan clusters, I would not want to be zipping along at several percent of c with very little course change warning or ability.

Think of it as a plot device to either slow your players down or force them incommunicado for the week of jump.
 
GypsyComet said:
In the abstract, sure, but most travel is going to be in a system's main orbital plane, where things are a bit busier. If my midpoint was anywhere near some other body or came close to another gas giant's trojan clusters, I would not want to be zipping along at several percent of c with very little course change warning or ability.

Think of it as a plot device to either slow your players down or force them incommunicado for the week of jump.

Wouldn't happen. Pilots don't plot courses through dangerous zones any more than you would aim for the guard rail while driving on the freeway. Space is a LOT bigger than you imagine. Totally unrealistic as a plot device if your players have any concept of space. If they don't, sure go for it.
 
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