Space - FOCAL Space Telescope

[Starbase1]

The modelling is done, so it's time for some finished renders!

Starting with some ortho views.

The FOCAL mission is a serious proposal to build a large space telescope and send it out to 550+ Astronomical Units, a lot further than even the Voyagers have got.

At distances beyond this, the Sun will act as a gigantic gravitational lens with the probe at its focus. So you send the probe to a point where a nearby star is (almost) directly behind the Sun, and you get an amplification in radio and light of 10^8, and enough magnification to pick up cars at the distance of Alpha Centauri.

Not science fiction.

It would also double as al excellent way of getting low powered communication between stars.

As far as I am aware, there are no detailed plans for the probe, so I came up with something that was a mix of the James Webb Space Telescope, and Voyager. It's kind of modular, so I can add copies of different booms / trusses, or move them around. This is my favourite configuration.

Nick

[Rigel]

Very nice!

[lonewriter]

I like it.

[Amras]

Nice model!

I think that mission would need more than just a few years.

[Starbase1]

Originally Posted by Amras

Nice model!

I think that mission would need more than just a few years.

Well, yes - but there's nothing really radical required in the hardware. With both Voyagers still working at huge distances and decades old, and Pluto Express heading out a lot faster than the Voyagers did, I think its clearly feasible.

There are issues with the trajectory - you want the probe to move directly away from the sun along the line of focus, so slingshots around planets won't help much - hough there are special cases, such as using the Sun for the final encounter, which do work.

The stuff that really excites me is the idea of getting a REALLY sharp look at worlds around other stars - I mean, this thing could produce something not far off "Google earth" for worlds around other stars. The Kepler probe is picking up thousands of planets, and they are getting much better at picking up smaller worlds. The holy grail is to get a spectrum of an earth like planet and find oxygen - generally considered a very firm indicator of life.

Once that happens, the desire to get a close look at a living alien world should be massive.

The people looking at interstellar probe feasibility tend to like this sort of thing a LOT - its MUCH easier to do, MUCH cheaper, far enough out to count as interstellar, and could give much better views than even a Daedalus flyby could.

There's a paper by Claudio Maconne here:
http://www.snolab.ca/public/JournalClub/alex2.pdf
(Somewhat technical)
A bit more friendly here:
http://www.spaceroutes.com/astrocon/...-AstroconV.pdf

And some more fun stuff on the excellent Centauri Dreams blog, such as this article:
http://www.centauri-dreams.org/?p=785

Nick

[JackN]

One problem is in getting it out there and stopping it where it needs to be...

Accelerating it at a constant increase only works for half the trip, then you have to decelerate at the same rate to get it to stop.

Darn physics anyway!

[Starbase1]

Originally Posted by JackN

One problem is in getting it out there and stopping it where it needs to be...
Accelerating it at a constant increase only works for half the trip, then you have to decelerate at the same rate to get it to stop.

Apparently no you don't - there's a range where it works, from 550 AU out to about 1100 from what I read, so as long as its on the right line, it will still work. Apparently it gets a bit better as you go out, as effects from observing through the solar corona are reduced

[Tony Gardner]

It's a fine model Nick and an interesting subject. It would be seriously impressive if something like this got built in real life

[Starbase1]

Well, they are looking at precursor missions seriously - they need to do things like map the solar corona effect on starlight coming through it, and test accurate station keeping techniques.

Apparently its ideal for a new propulsion method worked out a few years ago by a Fin - Electric Solar Wind Sailing. The idea is that if you spin out about a hundred very fine wires for a few kilometres and charge them up, the solar wind will push against them electrically.

Its less efficient than a solar sail - but the 'sail' only weighs a few kilograms, so it comes out ahead. Even an early model could shift a 1 ton spacecraft 5 AU outwards in a year, no fuel required!

Test satellites are scheduled I think, more info here for those who like such things:
http://www.electric-sailing.com/

Meanwhile back at the renders...

One of those diagram renders I like, a beauty shot with stars, and a probe spin. (I forgot to turn off the encoder info, hence the unexpected HUD!)

Nick

[Eden]

Very nicely crafted model, and even tho the gold foil is still not 100% perfect is a great improvement on the original...top job!!

[Starbase1]

A few more renders - in these the sun is correctly positioned, directly in front of the telescope. I was struggling a it on how to show the side away from the sun, and in the end went for a faint bluish spotlight with soft shadows, and strong radiosity for some bounce off the lit parts.

I ended up boosting the mid tones a bit too.

Not sure I got it right, but pitch black, though realistic, would not help much! (The darker ones don't show well in thumbnail, but please give them a look and tell me what you think...

[Phoenix]

One thing... the mirrors wouldnt have a sheen look to them, they'd be perfect mirrors and most likely couldnt be seen unless in a reflection against the black of space. I'd recommend changing that and then adding a LOT more stars so it can be siloutted. Would make more a dramatic image.

Oh and the last 4 images are the best.

[Starbase1]

Originally Posted by Phoenix

One thing... the mirrors wouldnt have a sheen look to them, they'd be perfect mirrors and most likely couldnt be seen unless in a reflection against the black of space. I'd recommend changing that and then adding a LOT more stars so it can be siloutted. Would make more a dramatic image.

Oh and the last 4 images are the best.

Thanks!

I agree about the dark ones, I wasn't sure if others would agree though.

For the mirror sheen, yes - I just always seem to be fighting the desire to show what things are clearly with what they actually look like! This item is definitely learning towards the former, which is also why I left some sag in the cables - unrealistic, but it makes them look like cables!

Stars are at maximum for my stars plugin - I dithered over layering up more, but some clever clogs generally spots it! If I am going for the look in this one though, maybe I should go the whole hog.

Must be something I can do... Photos of stars always look like photos, anyone got any other ideas for a REALISTIC ultra rich star backdrop?

[Starbase1]

I tried a richer version of the final image, tripled the star layer, and increased the brightness and size (slightly), for a more dramatic backdrop.

[Phoenix]

That star layer is excellent. What I do when working with single image renders is take a good photo of stars - and use clone tool in photoshop to make a backdrop to fit the image's size with stars at the scale I want them to be. Here, try it - this is where I get my stars from!

Also note: You can do it another way - goto photoshop, create image the size of the render, add noise, make 3 layers of the same noise, All layers screen or linear, adjust brightness/contrast of each layer to suite the size of stars you want on that layer (1-3, biggest to smallest - remember - VERY IMPORTANT - Doppler Shift for close/far stars). Collapse layers, do final brightness/contrast tweak and then copy whole compressed layer, paste into another layer, go screen - blur by 10pxl, tweak the fill to get a slight haze around stars - vuala! I'll post a small example shortly for ya.

[edit] added demo files - rar is after main layer compression but with the glow layers ontop of them to give ya an idea!

[Starbase1]

Thanks for that - I may not get to update for a couple of days, (as I have a new phone to play with!)

[Starbase1]

In the mean time I attach a big galaxy aligned image map I found, similar to yours, 9600x4800, so I had to zip it.

I think this has some great possibilities!
Nick

[Phoenix]

Well now, that'll be helpful! Thanks!

[JackN]

I've been looking for that kind of background for a while ... Thanks!

@ SB: I've been a bit busy the last two days, but I DO intend to get to them!