[James.Denholm]

Oh, now, don't do something just for little old me... *blush*

I like the idea of a MX though, but wouldn't the calculations be a bit difficult?

Either way, keep doing what your doing. You have my respect, let me tell you! Just one question about the Anake: Is there anyway to actually winch/unwinch (or whatever) the cables? Because I think that could potentially make rendezvous a lot simpler: More like stepping onto a slowly moving travellator, rather than trying to jump onto a Japanese Shinkanzen going hell for leather.

[n0mad23]

14 June 08 (5:15 GMT)

We've got 149 Ananke downloads at Orbit Hangar, and 79 downloads of the Ananke Scenarios.

This is awesome, gang! Thanks to those showing interest.

Linguofreak -

I've been thinking a lot about your questions/critique and have to admit I agree with you. Ultimately I'd love to see us pull off a HASTOL system and incorporate it into the transportation system. Hopefully by the time we pull off the cislunar transport system, we'll be up to the task - but honestly at this stage it makes me shudder to even contemplate it. It's going to be hard enough pulling off interceptions in LEO for the time being! Can you imagine the difficulties of doing this in Earth's atmosphere?

If you'd like me to pass along the HASTOL documents that I've got in my collection, shoot me a PM. It's one of the things I really love about this community - the free exchange of useful information.

I thought I'd also reiterate the origin of the ZTC-Ltd. Ananke briefly as well, as the project itself comes out of an entirely unrelated project. This platform, and my derelict space station, are in fact elaborate scene studies for some fiction that I've been picking away at. In discovering Orbiter, to my delight and surprise I found that I could actually create simulations of the platforms I was writing about, and then test them to see if they'd work the way I'd imagined.

It's probably no surprise, but what I've learned here has significantly changed what I originally wrote.

So the cislunar transportation system you see being developed here is somewhat restrained by what's come before. In the first story, Arias in C Minor, the Ananke/Khronos system is supported mostly by LEO craft that are initially air-launched by dual C-5C TSTO systems. At this point, I've only nodded at a developing HASTOL system in the story, and haven't dealt with it further than that.

If you've tried our prototype, you might have noticed that the date is 2021. This is no accident, and we've tried to only use materials that are currently straight "off the shelf." One of the problems with a HASTOL system is in creating a catcher that can withstand the forces of hypersonic speeds. Again, with the leapfrog nature of developing technologies, hopefully I'll find some solutions to this problem by the time we're ready to develop it. And if you or any others have some thoughts along these lines, I encourage you to share them with us.

So, in conclusion - I'm with you. Have patience and eventually we might just have what you're looking for.

[James.Denholm]

The thing I've noticed about the Anake is that it dosen't act like it's made of cables. Fair enough, that would be near-impossible to do in Orbiter at the moment, but realy, wouldn't there be a bit of drag, bowing the cables slightly or something, as they slice through the extreme upper atmosphere? Wouldn't there be a bit of a worry that the whole thing might colapse? Further more, if the whole thing is almost all cables, how would it start spinning in the first place?

[n0mad23]

Originally Posted by James.Denholm

 The thing I've noticed about the Anake is that it dosen't act like it's made of cables. Fair enough, that would be near-impossible to do in Orbiter at the moment, but realy, wouldn't there be a bit of drag, bowing the cables slightly or something, as they slice through the extreme upper atmosphere? Wouldn't there be a bit of a worry that the whole thing might colapse? Further more, if the whole thing is almost all cables, how would it start spinning in the first place?

Well called, my clever young friend.

I've been kicking around the idea of writing something for the next Delta-V addressing these very issues. I bet your teachers both love and hate you, don't they? You're the guy that anticipates where the lesson's going and asks the question just before it's time! Kudos for that.

Right. There are a lot of aspects of this project that need to be faked. Cable behavior is certainly a point of "willing-suspension-of-disbelief." Did you try the initial ACME tether test? When undocking from that one (the 95km version) the cable wobbled crazily upon undocking. I had the point of origin wrong on that one, and I suspect this behavior was solely due to this fact. As far as the cables collapsing, try tying a weight to a string and then spin it around your head. The centrifugal force makes this a non-issue. In terms of safety (from a cable being severed by a meteor), the implementation of 4 sets of cables adequately addresses this issue.

The ED propulsion system's going to have to be faked. Orbiter doesn't have a working ionosphere, and it's something we really need. Luckily Computerex's Starwars MFD might be tweaked in such a way that we can emulate magnetic repulsion.

The Ananke is a modular system, and in my design has to be assembled in orbit. The initial rotation is done with thrusters, and then the series of cables (in the spools) are unreeled. Tblaxland and I have discussed putting together a version where this will actually happen in real time, and we certainly plan on adding animations to support this. As the system loses energy upon catching and releasing payloads, the reeling/unreeling is important for re-energizing the system. We certainly plan on animating this as well as writing the code that will change the center of mass to support the physics here.

We're also planning on making the solar panels track the sun. But like Linguofreak's suggestion to create a HASTOL system, we're going to have to learn to walk before we can run.

Hopefully this addresses some of your concerns. A thanks for giving me the opportunity to attempt an explanation here.

[Linguofreak]

Originally Posted by n0mad23

 14 June 08 (5:15 GMT)

We've got 149 Ananke downloads at Orbit Hangar, and 79 downloads of the Ananke Scenarios.

This is awesome, gang! Thanks to those showing interest.

Linguofreak -

I've been thinking a lot about your questions/critique and have to admit I agree with you. Ultimately I'd love to see us pull off a HASTOL system and incorporate it into the transportation system. Hopefully by the time we pull off the cislunar transport system, we'll be up to the task - but honestly at this stage it makes me shudder to even contemplate it. It's going to be hard enough pulling off interceptions in LEO for the time being! Can you imagine the difficulties of doing this in Earth's atmosphere?

No need to do it in atmosphere. Just because you're slow doesn't mean you're low. You can do a suborbital trajectory that reaches up to 200 or 300 km and extend the tether to accomadate whatever ground-relative capture speed you want. Granted, you'll lose a bit more DV in the climb than you might otherwise.

As to doing the math for the intercept, maybe you should start talking with the Launch MFD guys and see what can be worked out there.

[Bullethead]

Originally Posted by James.Denholm

 You know, I've been thinking... I wonder if you could use a big (as in, really, really big) version of this instead inter-planetary ejection burns. Get to Mars with over 80% fuel left... in a Shuttle.

IIRC, there was an early scenario for the original 95km version of Ananke that had the oomph to do just that. I seem to recall crossing Mars' orbit in one of the early scenarios. No attempt was made to actually intercept Mars, just see if it could throw you that far.

[Bullethead]

Glad to hear you made it. I'll drink to that!

Originally Posted by n0mad23

 I am not a desert person.

I dunno, I like having fields of fire that extend 10-15 miles.

I live in the woods now and feel very claustrophobic. I lived much of my adult life in Tornado Alley and developed the habit of scanning the horizon for bad weather every few minutes this time of year. But here, even though tornados are rare, they still happen, and you can't see them coming until it's too late due to all the damn trees

I've never seen an adequate design or description for the RotoVatoR dropping and picking up a payload on the same pass, but some of the literature suggests it's possible to do. I've thought it might be possible with the right catcher design, but have yet to have that creative flash where I see how it can be done. I'm sure open to suggestions here.

I'll put my mind to it, for what that's worth .

[Bullethead]

Originally Posted by Linguofreak

 With a suborbital launcher you do a launch abort like you would with an orbital launcher that suffered engine failure during launch and try another launch at the next window. If you halve the DV of the launcher, my bet is that you well more than halve the cost and I think you may be able to double the reusability. So two launches of your suborbital launcher are likely to be cheaper than one of your orbital launcher. As long as you can get a better than 50% capture rate, you come out ahead.

What if you used the Terra-based equivalent of the Ananke flinger: the Lofstrom Loop? in one of its various versions? That gets the payload to LEO, and then Ananke gets it to the moon, and all the fuel the payload needs is for MCC.

I'd like to see a Lofstrom Loop add-on. Since n0mad23 is into colossal engineering projects, this seems up his alley .

[tblaxland]

Originally Posted by Bullethead

 I'd like to see a Lofstrom Loop add-on. Since n0mad23 is into colossal engineering projects, this seems up his alley .

My thought also when I saw that page a few weeks ago. I didn't want to distract him though . As an electrical engineer, that project has a lot of aspects that I find very interesting so I call dibs on the simulation code

[Bullethead]

Originally Posted by tblaxland

 My thought also when I saw that page a few weeks ago. I didn't want to distract him though .

Nor do I. Definitely something for the far future. I was just offering it as an alternative way to get the payload to LEO, since this discussion was getting into the economics of the initial launching from Earth.

Of the various Lofstrom Loop designs, I prefer the giant Ferris Wheel type over the linear type shown at the link above. I figure that's got 2 practical advantages: it would be easier to model in Orbiter, and in real life requires less real estate and right-of-way acquisitions .

[James.Denholm]

Originally Posted by n0mad23

 Well called, my clever young friend.

I've been kicking around the idea of writing something for the next Delta-V addressing these very issues. I bet your teachers both love and hate you, don't they? You're the guy that anticipates where the lesson's going and asks the question just before it's time! Kudos for that.

Meh, I'm not realy that smart, just a thinker.

<lie>Most of the time I don't realy pay attention in class, that's probably why I don't know html yet.</lie>

Right. There are a lot of aspects of this project that need to be faked. Cable behavior is certainly a point of "willing-suspension-of-disbelief." Did you try the initial ACME tether test? When undocking from that one (the 95km version) the cable wobbled crazily upon undocking. I had the point of origin wrong on that one, and I suspect this behavior was solely due to this fact. As far as the cables collapsing, try tying a weight to a string and then spin it around your head. The centrifugal force makes this a non-issue. In terms of safety (from a cable being severed by a meteor), the implementation of 4 sets of cables adequately addresses this issue.

Unfortunatley, I never had the pleasure of doing so. But surely, if one of the cables broke, that would throw the whole thing out of kilter (as in, with REAL cables)? Wouldn't they bend back on themselves and collapse, even if only for a moment before the counter-weight and payload pull them back into shape?

The ED propulsion system's going to have to be faked. Orbiter doesn't have a working ionosphere, and it's something we really need. Luckily Computerex's Starwars MFD might be tweaked in such a way that we can emulate magnetic repulsion.

I know, I will face a similar problem with my up-coming Bussard Ramjet based addon. Still in development...

The Ananke is a modular system, and in my design has to be assembled in orbit. The initial rotation is done with thrusters, and then the series of cables (in the spools) are unreeled. Tblaxland and I have discussed putting together a version where this will actually happen in real time, and we certainly plan on adding animations to support this. As the system loses energy upon catching and releasing payloads, the reeling/unreeling is important for re-energizing the system. We certainly plan on animating this as well as writing the code that will change the center of mass to support the physics here.

Remember, if you make the spooling fast enough, people will be able to "cheat" and reel it in during the "up" rotation, hence speeding them up, and then unspooling during the "down" rotation, or something to that effect.

That's a good thing though! Like the idea of a modular system, though.

We're also planning on making the solar panels track the sun. But like Linguofreak's suggestion to create a HASTOL system, we're going to have to learn to walk before we can run.

Hopefully this addresses some of your concerns. A thanks for giving me the opportunity to attempt an explanation here.

We all must walk before crawling.

Yup, finaly, an Ocean's 11 refrence on O-F!

[Bullethead]

Originally Posted by James.Denholm

 But surely, if one of the cables broke, that would throw the whole thing out of kilter (as in, with REAL cables)? Wouldn't they bend back on themselves and collapse, even if only for a moment before the counter-weight and payload pull them back into shape?

Each big "cable" is actually a bunch of parallel thin cables all laced together. The idea is that if one of the component strands breaks, the lacing will do 2 things: it will transfer the load around the break, and it will hold the severed ends in place.

If the whole big cable assembly is severed, though, you'd have a problem. The end toward the hub would recoil a little from the tension release but would soon straighten back out. However, the end toward the payload I'd expect would fold back toward the payload, at least as far as it could reach given where the next outboard spool set was. If it was part of the outermost section, it might whack the payload itself. And the whole rig would probably be thrown somewhat out of true by the changing load and would no doubt be vibrating somewhat.

I don't see a way to lace all the big cables together to prevent this, because then you'd have 1 big cable that would require really mondo spools. OTOH, the whole reason for the making the cables multi-strand is to keep this from happening as much as possible.

[n0mad23]

Originally Posted by Bullethead

 I'd like to see a Lofstrom Loop add-on. Since n0mad23 is into colossal engineering projects, this seems up his alley .

Honestly I've had more affairs with microscopes than telescopes. The colossal engineering projects are a complete accident, though I'll admit I'm finding the challenges hard not to take on. I'm a stubborn man, and I hate being told that things can't be done.

What the , the Lofstrom Loop is now officially on my list of upcoming projects.

How's that?

But first, I'm going after a HASTOL system.

Then after I've done enough massive projects to make the Wall of China look miniature, I'll turn my attention to the nanobots.

[Linguofreak]

Now, "HASTOL."

Before I read anything on it, am I correct in thinking that the "HASTO" part is "Half a stage to orbit"?

[Bullethead]

Originally Posted by n0mad23

 What the , the Lofstrom Loop is now officially on my list of upcoming projects.
How's that?
But first, I'm going after a HASTOL system.

Fine with me .

Then after I've done enough massive projects to make the Wall of China look miniature, I'll turn my attention to the nanobots.

Be careful there. Many people have died over those things :D