The main beef I have with the new Yahoo beta is that it is slow. Of course this is compared to Outlook, and I guess I won't ever expect a web-based service to be as fast as a client-side program. Maybe it's not any slower than the normal Yahoo interface, just that since it looks more like Outlook that I expect it to be faster too. I might have just gotten so used to getting around in the normal Yahoo mail using tabs in firefox to have messages load in the background and such, that it is taking me a little time to adjust my style to the new way they're doing it.
The problem with the 40*40*40 calculation is that that would be for volume not surface area. Also, it would be the volume of a 40 ft cube, not a shipping container. Imagine a semi towing one of those down the highway! As others noted the dimensions of a standard shipping container are more like 40 x 8.5 x 8 ft.
I'm sitting in Boeing's Mission Control Center right now. Latest news is that the launch has been cancelled for today, not sure when the next attempt will be.
I certainly was surprised to see this show up on the front page of slashdot. It's not a super big deal that Ariane is launching two satellites at once, they have done that before. I guess the capacity has increased from the sounds of it? One of the satellites onboard (Spaceway F2) will be one of the largest commercial satellites ever launched. It's sister satellite, Spaceway F1, was launched last April and was successfully delivered to the DirecTV customer this fall. They are both about 6100 kg when fully loaded with fuel.
Companies may be able to save some money by doing a dual-manifest launch but it can also be a real pain in the ass. This launch was originally supposed to happen in June but the other satellite had problems and had to get sent back to home base to be checked out thus delaying Spaceway F2 also. Plus when you get your own launcher you can have a lot more control over what orbit you are injected into and the launch window. Ariane provides a standard GTO injection with their ECA launcher, which is not the most desireable orbit for some satellites.
Yeah, I am a little suspicious of the government just trying to keep people gambling in Australia instead of blowing their money in offshore online casinos. The article mentions that "the Act is technically breached even by listing online casino sites in search results".
So it's not just the advertising that the government has a problem with. I can't really see google or yahoo going to the trouble to filter out gambling sites from search results.
As noted by parent, there's an easy answer, and a complex answer. For the basics of the problem, all you really need is the two-body equations of motion. A basic Hohmann transfer (an elliptical orbit connecting the near-circular orbits of the Earth and Mars) will get you there with a pretty close guess as to the fuel usage and mission duration. If you actually want to do the calculations, that's where you should start.
As for the procedure, for most missions to Mars, the launch vehicle takes care of steps 1-4, they pretty much happen within a few hours at the most. The Mars Reconnaissance Orbiter was separated from the launch vehicle and on it's way to Mars in a little over an hour after launch.
There's usually at least one mid-course correction manuever, and then a final braking burn to bring set the craft up for a landing, or multiple braking burns if you're just going to go into orbit around Mars.
As to how NASA actually models the trajectory, they probably use numerical integrators that take into account the basics (Earth, Sun, and Mars gravity), but also the gravity of the moon and maybe the other planets, and the solar radiation force. When you're calculating mid-course corrections these little things really start to matter (especially if you're going to be landing on the surface!). And if you're going to be orbiting Mars, then you would also take into account the fact that Mars is not a perfect sphere and how this affects your orbit. You could even use atmospheric drag to change your orbit like the Mars Odyssey spacecraft, cool stuff.
Also, you don't really need to worry about the inclination you get launching from the Cape for a Mars mission. Once you get away from the Earth you're pretty much in the ecliptic plane relative to the sun and your inclination relative to the Earth is moot. And the units you're looking for in the first paragraph of the parent post are km/s.
As others have noted, for the basics of the problem, all you really need is the two-body equations of motion. A basic Hohmann transfer (an elliptical orbit connecting the near-circular orbits of the Earth and Mars) will get you there with a pretty close guess as to the fuel usage and mission duration. If you actually want to do the calculations, that's where you should start.
As to how NASA actually does it, they probably use numerical integrators that take into account the basics (Earth, Sun, and Mars gravity), but also the gravity of the moon and maybe the other planets, and the solar radiation force. When you're calculating mid-course corrections these little things really start to matter (especially if you're going to be landing on the surface!). And if you're going to be orbiting Mars, then you would also take into account the fact that Mars is not a perfect sphere and how this affects your orbit. You could even use atmospheric drag to change your orbit like the Mars Odyssey spacecraft, cool stuff.
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The main beef I have with the new Yahoo beta is that it is slow. Of course this is compared to Outlook, and I guess I won't ever expect a web-based service to be as fast as a client-side program. Maybe it's not any slower than the normal Yahoo interface, just that since it looks more like Outlook that I expect it to be faster too. I might have just gotten so used to getting around in the normal Yahoo mail using tabs in firefox to have messages load in the background and such, that it is taking me a little time to adjust my style to the new way they're doing it.
The problem with the 40*40*40 calculation is that that would be for volume not surface area. Also, it would be the volume of a 40 ft cube, not a shipping container. Imagine a semi towing one of those down the highway! As others noted the dimensions of a standard shipping container are more like 40 x 8.5 x 8 ft.
I certainly was surprised to see this show up on the front page of slashdot. It's not a super big deal that Ariane is launching two satellites at once, they have done that before. I guess the capacity has increased from the sounds of it? One of the satellites onboard (Spaceway F2) will be one of the largest commercial satellites ever launched. It's sister satellite, Spaceway F1, was launched last April and was successfully delivered to the DirecTV customer this fall. They are both about 6100 kg when fully loaded with fuel.
Companies may be able to save some money by doing a dual-manifest launch but it can also be a real pain in the ass. This launch was originally supposed to happen in June but the other satellite had problems and had to get sent back to home base to be checked out thus delaying Spaceway F2 also. Plus when you get your own launcher you can have a lot more control over what orbit you are injected into and the launch window. Ariane provides a standard GTO injection with their ECA launcher, which is not the most desireable orbit for some satellites.
Does this extend to mean that only the sponsoring news organizations can report on olympic news. Sounds tricky.
So it's not just the advertising that the government has a problem with. I can't really see google or yahoo going to the trouble to filter out gambling sites from search results.
As for the procedure, for most missions to Mars, the launch vehicle takes care of steps 1-4, they pretty much happen within a few hours at the most. The Mars Reconnaissance Orbiter was separated from the launch vehicle and on it's way to Mars in a little over an hour after launch.
There's usually at least one mid-course correction manuever, and then a final braking burn to bring set the craft up for a landing, or multiple braking burns if you're just going to go into orbit around Mars.
As to how NASA actually models the trajectory, they probably use numerical integrators that take into account the basics (Earth, Sun, and Mars gravity), but also the gravity of the moon and maybe the other planets, and the solar radiation force. When you're calculating mid-course corrections these little things really start to matter (especially if you're going to be landing on the surface!). And if you're going to be orbiting Mars, then you would also take into account the fact that Mars is not a perfect sphere and how this affects your orbit. You could even use atmospheric drag to change your orbit like the Mars Odyssey spacecraft, cool stuff.
Also, you don't really need to worry about the inclination you get launching from the Cape for a Mars mission. Once you get away from the Earth you're pretty much in the ecliptic plane relative to the sun and your inclination relative to the Earth is moot. And the units you're looking for in the first paragraph of the parent post are km/s.
As to how NASA actually does it, they probably use numerical integrators that take into account the basics (Earth, Sun, and Mars gravity), but also the gravity of the moon and maybe the other planets, and the solar radiation force. When you're calculating mid-course corrections these little things really start to matter (especially if you're going to be landing on the surface!). And if you're going to be orbiting Mars, then you would also take into account the fact that Mars is not a perfect sphere and how this affects your orbit. You could even use atmospheric drag to change your orbit like the Mars Odyssey spacecraft, cool stuff.