Why can’t you fly by Venus, and use it to change your trajectory to aim for the Sun? (As long as you don’t need to be in orbit once you get there.)
Yeah - I’d think the “easiest” solution would be to calculate a series of slingshots from other orbits. How’d that work out, Chronos?
NASA is planning to do that with Solar Probe+ (assuming it’s still planned, I dunno). It’s supposed to pass by Venus several times to bend it’s trajectory closer and closer to the sun. 7 million km is the closest it will get. That’s still pretty far but if we can send something that close, isn’t the rest just a matter of tweaking the trajectory?
Well, yes, but then, if you’re doing flybys, you can use those to get anywhere else, too.
And I’m not actually sure about the center of the Galaxy-- I’ll run the numbers on that tomorrow.
All her scenes got cut; the Hollywood suits just didn’t get it.
Orbiting the earth:
The space shuttle orbits around the earth at about 17,400 MPH. All those engines and all that fuel are required in order to achieve that orbital velocity. When it’s time to come home, they only need to slow enough to modify their orbit a bit so that their new orbit intersects the atmosphere. That doesn’t take a whole lot of effort, and then the atmosphere is where they end up bleeding off all of that kinetic energy; that energy manifests as heat during reentry. Anyway, that’s how hard it is to get into orbit around the earth, and how easy it is to fall to earth.
Escape velocity from the earth:
(the starting speed you would need at ground level in order to leave the earth and never fall back down) is about 25,000 MPH. You need to provide that much starting velocity, or use rockets to provide that energy-equivalent over a non-zero period of time, in order to leave the earth. This is what the Saturn rockets did for the Apollo program. They were much, much bigger than the space shuttle. Pound for pound, it takes twice as much energy to escape the earth as it does to achieve low earth orbit.
Going to the sun:
We (the earth) are currently in orbit around the sun at a speed of 66,705 MPH. If you want to fall to the sun, you have to not only achieve escape velocity from the earth, you have to completely counteract that orbital velocity. If you only partially counteract that orbital velocity, you won’t fall into the sun, you’ll just fall into a different (probably highly elliptical) orbit around it. Unlike the shuttle in earth orbit, there’s no atmosphere you can use to bleed off orbital velocity; it has to be done entirely using rockets, or using gravitational slingshotting via Venus and/or Mercury. Pound for pound, if you want to hit the sun, you need to provide nearly 17 times as much energy as you would to simply achieve low earth orbit.