# Combat in Space

dinosaurus
Science 07 Aug '08 00:35
1. 07 Aug '08 00:35
I have been looking for a good game to use while I teach my some some more math. I found a three dimensional space combat game that is very interesting. The creators of the game are very proud of the physics behind the game and its overall accuracy. However, while looking at the details, I realized space combat will never look anything like what we believe from reading novels or watching space movies. The number one reason is because the power requirements are too enormous.

I did a quick check of the amount of time and power it takes to accelerate a decent spaceship of ~250,000 lbs (w/o fuel) and the answer is phenomenal. One of the biggest problems I see is that a human can not withstand many G-forces. For example, accelerating from 0 m/s for one minute at 4Gs only gets you to about (1/2) x (4 x 9.81 m/s^2) x (60 sec)^2 = 70,600 meters with a final speed of (4 x 9.81 m/s) x (60 sec) = 2354 m/s. One minute at 4G might be a terrible strain on the body, but it is peanuts compared to the vast distances that will be involved.

Using reasonable estimates, you are likely to detect an approaching ship days before it could fire a shot at you. Under these conditions it appears space combat would be decided by the fellow with the longest range weapons assuming he can target them well enough. If this is correct, the whole engagement might be decided by the first shot from extreme distances.

Has anybody been curious about the real possibility of space combat enough to run any numbers as I have? I would appreciate it if some folks could run their own numbers to check mine.

Also, has anyone else found a good 3-D space game I could use for a guide while teaching my son more about math? Thanks.
2. AThousandYoung
West Coast Rioter
07 Aug '08 00:41
Originally posted by dinosaurus
I have been looking for a good game to use while I teach my some some more math. I found a three dimensional space combat game that is very interesting. The creators of the game are very proud of the physics behind the game and its overall accuracy. However, while looking at the details, I realized space combat will never look anything like what we bel ...[text shortened]... nd a good 3-D space game I could use for a guide while teaching my son more about math? Thanks.
The first thing that comes to mind is the US Air Force deciding dogfights would never happen again because long range missiles made them obsolete.

They were wrong.
3. sonhouse
Fast and Curious
07 Aug '08 01:56
Originally posted by dinosaurus
I have been looking for a good game to use while I teach my some some more math. I found a three dimensional space combat game that is very interesting. The creators of the game are very proud of the physics behind the game and its overall accuracy. However, while looking at the details, I realized space combat will never look anything like what we bel ...[text shortened]... nd a good 3-D space game I could use for a guide while teaching my son more about math? Thanks.
In Photonics magazine, there is an article about IR sensors measuring the temperature of space engines, variable thrust ion engines with a specific impulse rating from 3000 to 5000, about ten times the SI of H2 O2 chemical rockets. The engine they were evaluating had a "High Thrust' of several newtons, maybe 10 pounds or 20 pounds of thrust, something like that. But the killer was the power requirement, 200,000 watts! Now a car on a track with perfect mechanics, zero friction and 100 percent traction, could accelerate 555 pounds at 1 G, taking 32 HP do do so. 32 times 746 is about 24 kw. So the comparative efficiency of a normal car accelerating on a strip is several thousand times more efficient at turning mechanical force into acceleration. The gist of that is, we can pretty much forget deepspace combat for now, any deep space craft would be defending with high power lasers or Xray lasers or some such because there would not be enough power with present technology to accelerate a ship enough to be able to do the dodge and fly tactics of modern fighter jets or even WWII dogfights. You can imagine the power requirements of an ion rocket to give some decent accel #'s to a 300,000 pound craft, lets say a 555,000 pound craft to compare to my previous numbers, on the ground, it would take 32,000 Hp to accel that much weight to 1 G. 32,000 Hp is 24 megawatts. Now multiply that times 2000 or so, you get 48 Giga watts to accel that same craft in space. And that is only one G, 4 G's like you mentioned would be more like 170 Gigawatts. I don't know if you could get that kind of power even with fusion reactors. Maybe matter-antimatter but that is like on earth, 170 Chernoble type reactors. (typically one Gw per reactor)
4. 07 Aug '08 05:56
Godsfire is the only 3-d space board game I've ever played. It's out of print and was almost too complicated to play. Starfleet Battles is probably the most popular space combat game on the market. It's low on physics, but has plenty of rules. As the name implies, it's based on Star Trek, and each ship has 'X' amount of energy that you must allocate each turn (from Warp Reactors, Impules Engines, APR, and batteries). All movement must come from warp energy (except 1, which can come from elsewhere--never did understand why). You can allocate the rest to movement, shields, weapons, transporter, tractor, even a cloaking device, and of course you never have enough energy to do everything you want. A good space combat game that's been around since the 70s. Then there's the out-of-print game, Dark Stars. I owned it once, but the rule book looks like it would require a degree in astorphysics to learn the game.
5. 07 Aug '08 12:15
Originally posted by dinosaurus
I have been looking for a good game to use while I teach my some some more math. I found a three dimensional space combat game that is very interesting. The creators of the game are very proud of the physics behind the game and its overall accuracy. However, while looking at the details, I realized space combat will never look anything like what we bel ...[text shortened]... nd a good 3-D space game I could use for a guide while teaching my son more about math? Thanks.
What is the game?

For realistic spaceflight simulation, you can't do much better than Orbiter (www.orbitersim.com). It is a free (but not open source) simulator written by a professor at UCL.

--- Penguin.
6. 08 Aug '08 00:55
A few years ago, I bought a game called Vector 3 for less that \$5. It was cheaply made, but appeared to take a serious look at space flight and combat in a frictionless environment. It was not highly developed. The game was made by SPI and I do not think it is in print any longer. I have seen some advertised on eBay.

The other game that has my attention right now is called Attack Vector: Tactical. This game is clearly more highly developed but it is not easy to tell if it really meets my needs based on what I can learn on the Internet. It is definitely way beyond my son's ability right now. The problem there is if he is not blowing something up, he won't have the attention span for the math.

If any of the folks here know about either of these games, or another that requires you to understand and use the physics of spaceflight, please let me know.
7. shavixmir
Guppy poo
08 Aug '08 08:19
I saw a documentary once on space combat. It would seem the X-wing is a far better investement than a tie-fighter.
8. 08 Aug '08 22:44
Originally posted by dinosaurus
A few years ago, I bought a game called Vector 3 for less that \$5. It was cheaply made, but appeared to take a serious look at space flight and combat in a frictionless environment. It was not highly developed. The game was made by SPI and I do not think it is in print any longer. I have seen some advertised on eBay.

The other game that has my atte ...[text shortened]... nother that requires you to understand and use the physics of spaceflight, please let me know.
Don't know about those but I think Elite: Frontiers had newtonian physics. This did not go as far as modeling Gravity though, just mass and momentum.

It would also look very dated today!

--- Penguin
9. 09 Aug '08 03:05
Yes, I played the original Elite one summer when I was home from collage. I would get home from my summer job and sleep for an hour or two. Then eat and play Elite with my brother till we went to sleep. It was very addicting. I believe Elite has some good stuff in it, but it has a maximum speed, no gravity and some targeting "shortcuts" but a very addictive game.
10. AThousandYoung
West Coast Rioter
09 Aug '08 06:31
Originally posted by shavixmir
I saw a documentary once on space combat. It would seem the X-wing is a far better investement than a tie-fighter.
It depends. If you have a huge number of conscript pilots and capital ships like Star Destroyers, you go with the TIEs. If you only have a few precious pilots and no carrier ships, you need the X-Wing.
11. 11 Aug '08 22:36
After even more research, I stumbled on the website Howstuffworks, which I think is a great site. An article there about the US space shuttle gives even more information about fuel consumption. I believe the payload of the shuttle is 165,000 # unloaded with the ability to add 65,000 # to the shuttle as cargo. The whole shooting match on the launch pad is 4,400,000 #. This means less than 10% of the weight is real payload. However, another significant fraction is structure to hold the booster fuel and stuff, so it is not accurate to say 90% is fuel. But well over 65% is fuel!

On the plus side, this vehicle has to escape Earth's gravity and efficiency really changes once you leave the gravitational pull of the Earth. On the down side, it is difficult to capture the energy in the fuel in outer space. A lot of energy gets canceled out in the engine combustion chamber and nozzle. The website gave a reference to the next generation of ion engines which change the whole process from traditional chemical combustion approaches. I wonder what ratios of efficiency are possible?

I did some quick calculations and tried to convert the numbers into metric units so I could check against other references. If I recall (I don't have my pad with me) the energy output was something on the order of 3,333 N/kg of liquid fuel. The solid fuel was a much poorer performer in this measure. At launch, the vehicle is burning something on the order of 10,000 # of fuel per second to generate a little over 4,400,000 # of thrust. This includes both solid boosters and the main liquid fueled engines.

Given these numbers, does anyone think we will ever see a "Star Wars" kind of space battle? It appears the energy involved would power an entire country. We'll never have that kind of available resources.
12. Ponderable
chemist
14 Aug '08 15:30
Originally posted by AThousandYoung
The first thing that comes to mind is the US Air Force deciding dogfights would never happen again because long range missiles made them obsolete.

They were wrong.
In fact Space is differnt from earth since it's more or less empty. So while fyling a plane undetected on earth is not a problem, flying a space ship attack undetected could proove a problem.
13. AThousandYoung
West Coast Rioter
15 Aug '08 00:461 edit
Originally posted by Ponderable
In fact Space is differnt from earth since it's more or less empty. So while fyling a plane undetected on earth is not a problem, flying a space ship attack undetected could proove a problem.
A major reason dogfighting never went obsolete is because ROE demanded a visual ID. Would space change this?
14. 20 Aug '08 15:09
Originally posted by Ponderable
flying a space ship attack undetected could proove a problem.
"So'Ha' . . . peSuH!"
15. 21 Aug '08 17:33
One problem I read about when I played Starfleet Battles regularly was that someone had complained that there should be no "penalty" for going from "warp speed" to a very low speed (or even stopping). The argument was that since there is no friction in the vacuum of space, he could "slam on brakes" with impunity.
Not being a physics expert, I thought he had a good point. ðŸ™‚