Flight Question Need help with TransX

[TMac3000]

Okay, so I tried to set up a Jupiter trip in TransX the other day.

Changing the eject date forward only made my Cl App even farther off (well over 1T), and clearly I can't leave before now:dry:, so I used Outward Velocity instead. That, combined with the other variables, got the approach value down to about 12 million kilometers, but after that I have to fight like mad for every meter. At that rate, I could be at Jupiter before I finish setting up TransX:facepalm:

Any solutions? Is there just no launch window to Jupiter available right now?

 

[MaverickSawyer]

The next best launch window for an ideal Hohmann transfer is August 10th, 2012. Arrival at about May 4th, 2015. You can adjust these dates with the use of increased dV.
and good luck!

 

[TMac3000]

Thanks for the well wishes Anyway, I think I have finally figured out how to use IMFD, so I'll be using that instead of that accursed TransX thing.

PS: What I'd really like to do is launch an XR-2, dock it to an Arrow, transfer the crew, send the XR-2 home, and take the Arrow to Jupiter.

 

[flytandem]

The other day my car broke down so I had to take the bus downtown. When I got to the bus stop I asked the folks where the bus was and I found out it had left about 5 minutes earlier. I considered running to catch up to the bus but it would have required running at over 40 mph. That was more speed than I was able to produce. I thought about waiting a couple of minutes before starting the run but to my surprise it would have meant running even faster. So in trying to find a solution to my dilemma, I got online and asked a friend. He told me that indeed I had missed the bus by 5 minutes but that they run every hour on the hour so I should wait 55 minutes and get the next bus. I really didn't want to hassle with learning how to read the bus schedule or hassle with remembering what time it was so I opted to enroll in the city's automated bus pickup system where I only have to say where I am and where I want to go. They automatically knock on my door, carry me out to the bus and deliver me to my destination. I could be blind, have no watch and no clue what direction it is to downtown, yet still make it there. Isn't simple great?

 

[n122vu]

Schooled.

 

[TMac3000]

The other day my car broke down so I had to take the bus downtown. When I got to the bus stop I asked the folks where the bus was and I found out it had left about 5 minutes earlier. I considered running to catch up to the bus but it would have required running at over 40 mph. That was more speed than I was able to produce. I thought about waiting a couple of minutes before starting the run but to my surprise it would have meant running even faster. So in trying to find a solution to my dilemma, I got online and asked a friend. He told me that indeed I had missed the bus by 5 minutes but that they run every hour on the hour so I should wait 55 minutes and get the next bus. I really didn't want to hassle with learning how to read the bus schedule or hassle with remembering what time it was so I opted to enroll in the city's automated bus pickup system where I only have to say where I am and where I want to go. They automatically knock on my door, carry me out to the bus and deliver me to my destination. I could be blind, have no watch and no clue what direction it is to downtown, yet still make it there. Isn't simple great?
Chicago - Does Anybody Really Know What Time It Is? - YouTube

Wow. Just...that is amazing. You know what's really fun? What's really fun is when you are having a problem with something, so you go to the pros for help, and instead of helping you, they mock and ridicule you.

Thanks for the help, flytandem and nv122u. At least I didn't have to pay you.

 

[agentgonzo]

Wow. Just...that is amazing. You know what's really fun? What's really fun is when you are having a problem with something, so you go to the pros for help, and instead of helping you, they mock and ridicule you.

Thanks for the help, flytandem and nv122u. At least I didn't have to pay you.

You know what's annoying? When juvinile idiots come to an internet forum asking for help but refusing to learn any of the simple concepts that go behind what they are trying to do and shunning the advice they get. Then whining about it when this is pointed out to them.

The folks on here are very helpful and kind, but if your attitude to not being able to get to Jupiter at a few clicks of a button is to throw a tantrum and blame the 'accursed' tools then feel free to not come back here. You won't be missed.

If you want to learn, then stick around, stop whining and try to understand why TransX was being problematic for you. You may want to read "Go Play in Space". After that, you'll likely understand why 'now' isn't exactly the best time to plan a trip to Jupiter.

 

[TMac3000]

You know what's annoying? When juvinile idiots come to an internet forum asking for help but refusing to learn any of the simple concepts that go behind what they are trying to do and shunning the advice they get. Then whining about it when this is pointed out to them.

The folks on here are very helpful and kind, but if your attitude to not being able to get to Jupiter at a few clicks of a button is to throw a tantrum and blame the 'accursed' tools then feel free to not come back here. You won't be missed.

If you want to learn, then stick around, stop whining and try to understand why TransX was being problematic for you. You may want to read "Go Play in Space". After that, you'll likely understand why 'now' isn't exactly the best time to plan a trip to Jupiter.

Okay, I had to go back and check on that...other than describing my problem, the closest I got to complaining was the use of the word "accursed" to describe TransX. I realise that there are many fans and proponents of TransX here, and I certainly meant no offense to any of them. I'm now hard at work on solving the problem myself by learning IMFD, which, while it has idiosyncrasies of its own, has many useful tools besides the course planner.

Again, I apologize if I offended anyone by trashing TransX. In fact, I have used it successfully many times before. I don't know why I'm having such trouble with it now.

 

[MaverickSawyer]

Orbital alignments. we just passed the window for Jupiter a few months back. Sorry

 

[TMac3000]

Orbital alignments. we just passed the window for Jupiter a few months back. Sorry

Got it. Too bad Saturn, maybe?

 

[MaverickSawyer]

Ideal Hohmann transfer: launch on 12/20/2011, arrive on 1/7/2018. Good luck!

 

[agentgonzo]

I don't know why I'm having such trouble with it now.

Take a look at the current solar system chart. Sun, Earth and Jupiter are pretty-much in alignment (Jupiter is at opposition). When doing interplanetary travel you have to necessarily start with the current position and velocity of the planet you are on (in this case Earth).

So your current velocity is tangential to the Earth's orbit. If you want to go to Jupiter from here, you need to (basically) turn 90° and head directly away from the sun. This is a massive change in velocity of about 40km/s, which is about four times as much as your standard Earth-->Jupiter TJI escape velocity. That's why you are having trouble at the moment. You need to wait until the Earth has gone around the sun and you can set up a [ame="http://en.wikipedia.org/wiki/Hohmann_transfer"]lower velocity[/ame] transfer.

 

[n122vu]

I don't want this to turn into any kind of flame war. I just want to explain this. It wasn't so much a matter of offense, for me anyway. It was the fact that you posted a thread titled "Need help with TransX." Then, after one post explaining that your issue was that you were outside the launch window, you, in a nutshell, posted that you were giving up trying to figure out why TransX didn't seem to be working properly and going to use IMFD instead. I don't think flytandem was as much offended by your choice of IMFD over TransX, and neither was I. It was the fact that you asked for help with TransX, then trashed it and said you weren't going to use it. It came off to me that you basically decided that figuring out why TransX wasn't working in this instance was too much work, so you were going to use IMFD instead, which does most of the work for you.

 

[Ajaja]

BTW, IMFD does very simple work while we searching launch window for optimal transfer. We choose eject time and intercept time - so IMFD have position and velocity of initial point (planet), position and velocity of target point. All math - it's to find elliptical orbit through this 2 points and to calculate deltaV. But in the TransX we need to set 4 values: eject time, prograde velocity, outward velocity, ch. plane velocity. For example, optimal trajectory to Jupiter next year is >8k prograde, >3k outward, >2k ch. plane (I do not remember exact values). Is it possible to find it without Trajectory Optimization Tool or IMFD? I don't think so.

 

[agentgonzo]

Is it possible to find it without Trajectory Optimization Tool or IMFD? I don't think so.

No, TransX won't find an optimal trajectory for you without you repeatedly tweaking your trajectory in a manual fashion.

---------- Post added at 13:54 ---------- Previous post was at 13:53 ----------

It was the fact that you posted a thread titled "Need help with TransX." Then, after one post explaining that your issue was that you were outside the launch window, you, in a nutshell, posted that you were giving up trying to figure out why TransX didn't seem to be working properly and going to use IMFD instead.

That's exactly the problem that I had.