Flight Question Preparing fuel for interplanetary flight

[Richy]

Hi there

I'm new to the forum, but I'm flying (or do we say "falling") orbiter since many years.
As I get to know orbiter, I was impressed by the possibility of traveling throughout the entire solarsystem in a realistic manner.

So I get familiar with the physics needed for space travel, and, maybe like all of us, have installed thousends of addons into my Orbiter. So much about myself. :tiphat:

--

Now, I'm planning an insterplanetary flight. Altough the ability of interplanetar travel of the DGIV and the XR2, I don't want to use these as the main ride, but as landers with exclusive atmospheric abilities.

For the mothership, I validated many DSV available at orbithangar.com and finaly choosed the Descartes DSV.

Assume that it was assembled in space with empty tanks, I now face my first main problem:
How the **** should I bring 4000 tons of fuel into LEO?

• I look at the XR5, with the fuel-cargo addon. In optimum this may be about 400 tons fuel, but that means I have to fly 10 legs! (launching from and refuel in moon orbit would maybe save some fuel, but not much I think)
• And other idea is an space-elevator on the moon. Yeah I know, it's a little bit more unrealistic than the entire unrealistic scenarion, but my goal is it should be plausible, not realistic. ;-)
• I also searched for heavy lifters (Hercules, JupiterIII, Uni Launcher), this may be a conceivable solution.

What I mean, is there an other possibility of bringing huge amounts of fuel into space?
(Fuelspacestations are a possibility, but how the fuel get up there? We assume it can only be produced on accordingly equipped bodies like earth or moon (or maybe dedicated space facilities? but what?))

I hope, some of you have faced the same problem, and may know a solution or at least an advice, and that I don't accidentally dropped a brick or so (english is not my mother tongue).


btw: I often get a CTD while loading/unloading fuel with XR-Vessels or DGIV using fuelMFD. Is this a known issue (due to these vessels have ded. fuel management)?


Regards
Richy

 

[the.punk]

Hi there

I'm new to the forum, but I'm flying (or do we say "falling") orbiter since many years.
As I get to know orbiter, I was impressed by the possibility of traveling throughout the entire solarsystem in a realistic manner.

So I get familiar with the physics needed for space travel, and, maybe like all of us, have installed thousends of addons into my Orbiter. So much about myself. :tiphat:

to the forum.

Now, I'm planning an insterplanetary flight. Altough the ability of interplanetar travel of the DGIV and the XR2, I don't want to use these as the main ride, but as landers with exclusive atmospheric abilities.

For the mothership, I validated many DSV available at orbithangar.com and finaly choosed the Descartes DSV.

Assume that it was assembled in space with empty tanks, I now face my first main problem:
How the **** should I bring 4000 tons of fuel into LEO?

• I look at the XR5, with the fuel-cargo addon. In optimum this may be about 400 tons fuel, but that means I have to fly 10 legs! (launching from and refuel in moon orbit would maybe save some fuel, but not much I think)
• And other idea is an space-elevator on the moon. Yeah I know, it's a little bit more unrealistic than the entire unrealistic scenarion, but my goal is it should be plausible, not realistic. ;-)
• I also searched for heavy lifters (Hercules, JupiterIII, Uni Launcher), this may be a conceivable solution.

What I mean, is there an other possibility of bringing huge amounts of fuel into space?
(Fuelspacestations are a possibility, but how the fuel get up there? We assume it can only be produced on accordingly equipped bodies like earth or moon (or maybe dedicated space facilities? but what?))

When you want to simulate the fuel launching I think a heavy launcher would be an option when you don't want to fly several times into orbit. You mentioned the jupiter III. There's also JupiterV-X bigger than Jupiter III: http://orbithangar.com/searchid.php?ID=3672.
This is also very nice for transporing fuel into orbit: http://orbithangar.com/searchid.php?ID=4350
You can launch it with the energy project: [ame="http://www.orbithangar.com/searchid.php?ID=1036"]ENERGY project, release 4[/ame]
Or even a fuel station where you can dock your descartes. I think the above includes a winged tanker and a simple tanker.

btw: I often get a CTD while loading/unloading fuel with XR-Vessels or DGIV using fuelMFD. Is this a known issue (due to these vessels have ded. fuel management)?


Regards
Richy

it could be haven't tried it yet.

 

[TSPenguin]

to the forum!

Since you assume it was assembled in space, then 10 extra flights to provide fuel seems minuscule in comparison.

The XR Series ships can be used with FuelMFD when adjusting the config appropiately:

#--------------------------------------------------------------------------
# Enable or disable Orbiter's default auto-refueling behavior (i.e., when
# touching down on a landing pad.)  
#
# You should set this value to 1 (Orbiter auto-refueling enabled) only if you
# want to use an external refueling MFD (such as FuelMFD), or if you want Orbiter
# to automatically and instantly refuel you when you touch down on a landing pad.
#
# If you will only be using the XR2's built-in refueling features, leave
# this value set to its default of 0 (Orbiter auto-refueling disabled).
#
#   0 = Orbiter auto-refueling disabled (recommended)
#   1 = Orbiter auto-refueling enabled
#--------------------------------------------------------------------------
OrbiterAutoRefuelingEnabled=1

Happy Orbiting

 

[Richy]

Thx for these suggestions. I think the Hurricane fits best for my purposes.

Since you assume it was assembled in space, then 10 extra flights to provide fuel seems minuscule in comparison.

According to the Descartes' dry mass of 125 tons, I launched all the parts via an XR5 (MPM ~430t), an then let assemble it by an army of brave astronauts.

That with this XR-Config I'll try out. Maybe, it helps, thanks!

 

[PeterRoss]

Yesterday I've found that it's possible to launch another Greg Burch's ship - Gilgamesh - into LEO using Energia,release 4 and Buran-T attached to it. Gilgamesh fits perfect there and have dry mass of just 10 t. But, hell, it's fuel weight is 400 tons...

---------- Post added 12-09-09 at 09:45 AM ---------- Previous post was 12-08-09 at 09:51 AM ----------

• I look at the XR5, with the fuel-cargo addon. In optimum this may be about 400 tons fuel, but that means I have to fly 10 legs! (launching from and refuel in moon orbit would maybe save some fuel, but not much I think)

By the way, I've managed to deliver only 200 tons of fuel in a single flight at XR5 (expert settings) to LEO. The heavier the payload the bigger the fuel consumption. Numbers you've mentioned where for standard XR5 settings, or am I doing something wrong? Have you tried to make such refuel flight by yourself?

Anyway, I'm thinking about 'building' and refueling ships at lunar orbit, producing fuel on Moon itself. Why not? It's much easier to lift fuel from low-gravity airless body like Moon.

 

[Richy]

I estimated these numbers. But with the XR5 on realistic settings, it matches very closely.

Refueling is now done by the fuel-tank on top of the Hurricane Rocket. It fits perfect on to the tail dock of the descartes.
Unfortunately, I chanced my DSV to the Total Immersion Descartes, and discovered inital that it needs four times the fuel of the old Descartes as a already was refueling it.
So I need to scrape some other hurricanes togheter and see, if I'm able to launch them from Baikonur, Kourou and KSC and bring the needed 12'000 tons up . A XR5 with empty cargo fuel tanks is also on it's way to the moon, to do the final refueling there. Man, it looks like the most challanging thing is to fuel up for that mission. ;-)

btw: I found out, way orbiter is crashing while I'm using FuelMFD. It was not XR2 nor DGIV, it turned out to be the Autosave-Module. I also have often CTD when saving manually while FuelMFD is on.
Seems as orbiter has problems saving fuel states in flux.

 

[PeterRoss]

I think FuelMFD is compiled for some older version of Orbiter like 2003 or something like that. No wonder why it crashes the process. It doesn't even appears on my MFD selection screen when I'm trying to use this module.

12000 tons, you say? Oh brother. I wanted to use DSV to explore Mars when I'll finish my work with Moon. It's not Total Immersion what makes its fuel capacity this big, but the renewed version of DSV by Greg Burch - DSV45. TI upgrade is intended for installing over DSV45.

 

[T.Neo]

For heavy lifting I would suggest Sky Captain's Hurricane class heavy lift rocket, which can lift around 2000 tons. Two launches should meet your 4000 ton goal. :thumbup:

 

[Tommy]

(launching from and refuel in moon orbit would maybe save some fuel, but not much I think)

Actually, it will save you a noticeable amount of fuel. Let's say that the interplanetary flight you are planning requires 10km/s dV from a parking orbit of 200k alt. If you start from the Earth, You need around 9.5km/s dV just to get into orbit (counting orbital speed and the losses due to gravity and atmospheric drag). That's a total of 19.5km/s.

If you start at the moon, you have much less gravity losses, and no drag losses. You can get down to a 200k Earth PeA (for a "slingshot") for about 3.5km/s dV from the lunar surface. Plus, you'll be travelling at around 10.5 km/s when you get there (instead of 7.5 km/s) so you only need about 6.5km/s more to make the journey. Result is around 11km/s total dV compared to 19.5km/s.

Now consider that you need quite a bit less fuel to achieve the required dV, which means you can bring less fuel, which means lower mass, which means even less fuel is needed to achieve the dV. You could be looking at half the fuel required.

The reason to sling off the Earth instead of leaving directly from the Moon is because the transfer burn will be more efficient if done closer to the Earth (this is known as the Oberth Effect, see Wikipedia for more details if interested). The IMFD Full Manual (available at OH) has an example of this type of slingshot using IMFD.

 

[the.punk]

For heavy lifting I would suggest Sky Captain's Hurricane class heavy lift rocket, which can lift around 2000 tons. Two launches should meet your 4000 ton goal. :thumbup:

Also sky captain made an even bigger rocket. http://orbithangar.com/searchid.php?ID=4070

 

[T.Neo]

Also sky captain made an even bigger rocket.

Yeah, there is also the Hercules and Hercules Med, but I thought that the Hurricane would be best suited to the job.

 

[the.punk]

Yeah, there is also the Hercules and Hercules Med, but I thought that the Hurricane would be best suited to the job.

Yes. I think you're right that the Hurriance is good. Because 12000ton is maybe a little bit too big.

 

[Richy]

@Tommy

That sounds really interesting. That was the next question I want to ask, how to do best sling-shots. So I'll read into that IMFD manual.
Thx

For the fueling challange, I try to stretch the fuel capacity of these Hercules tanks a bit, or else invent some lighter fuel. ^^
(yes, I know the mass/energy relation of fuel )