[AAR] The Grand Tour - Voyage To The Planets

[BigOto2]

The only disadvantage I see is that it leaves you in an eccentric orbit going from low Jool to Ike orbit, at best. Which means engines or aerobraking for the rest of the way to Low Jool Orbit. But it's probably a lot less dangerous than going the full way! Although, it does mean losing the Kerbin free return window.

[TicTacToe!]

Dude, that was intense. I think Jeb's hallucinating, when he thinks Ned says: "Don't worry about me, old friend." Those are the exact words said by Bob to Jeb before he cooked himself on Eve, I definitely remember it from the Eve chapters, and I just checked.

Oh, and Insertion Burn, so they don't get grilled in an aero brake and they'll be on their way home if it fails.

[Cooly568]

Other option (combo approach, direct landing and rendez-vous et cetera)

This option might be a long shot, but I think it's worth consideration.

Before entry, they run computer models to see if a retro-prograde gravity assist would be possible after the path taken I describe below.

They would lower the perihelion to just bring the perihelion to an altitude where it would bring a aphelion to a place where the orbital path would be in a place where the orbit would intercept with Ike, decreasing the aphelion, making a LAMGML landing easier because of the decreased velocity.

Now this does have flaws, as I don't know of "Proteus's" current RCS totals, a retrograde Ike gravity assist may not be possible because of the nature of where it might be when they get there.

[The Error]

Another option... but I doubt it will work. Put Proteus on a trajectory that will slow down around Ike into a slingshot, sending it towards Duna. Before arriving at Ike, though, undock the LAMGML and go Duna-direct, so when Proteus comes around, they'll have had some time to land, look around, and prepare for ascent. But I don't think that would work, because it needs Ike to position himself correctly...yeah, right.

[Spuds]

Addition to Ike gravioli assist

Wow, a reply from the Grand Master himself! I'M ECSTATIC!

Anyway, I have an amendment to my plan. If you perfom the Ike assist, I think you should have a short retroburn at PE, emphasis on short, because you don't want to end up blowing Proteus to pieces and getting captured in Ike orbit. It will also reduce the amount of Delta-V needed to get captured in Duna orbit even further, with a high-atmo aerobrake and a short retroburn following the Ike assist. The emphasis has to be placed on making sure there is never too much stress on the Proteus, being an aging ship running Windows Vista and all

I dub this manuver combination PIERRE : Proteus Ike aERobrake REtroburn.

--Spuds

Edited February 9, 2014 by Spuds

[Patupi]

Love the way this is progressing Czokltemuss! As to the poll, I say go with an insertion burn, but plan it for a long, slow burn. Forget max utilization of the Oberth effect. As long as their refueller arrives fuel isn't too much of a problem. If they use the engines at 10% thrust for a longer burn there is less stress on the hull, less risk of overloading the engines, and less stress on the crew!

The Ike intercept idea is cool, but given what they've been through another tricky maneuver, with the planners of said maneuver already stressed out... I'd say stick with simple, even if it does use more fuel.

Of course this all assumes the fueller is still on course. I assume they'll check on it's status before the burn, right?

(EDIT: Oh, and as to sending a lander down ahead of Proteus then letting the main ship sling shot around and then pick up the lander... You'd have to be really picky. Just a standard de-orbit would be a quicker route because it would be sliding deeper into the gravity well, but it depends on the altitude Proteus is going to slingshot past is. My guess you wouldn't have enough time to land and take off again for a rendezvous. Another option is a powered orbit down. IE accelerating downwards as you go in, then aerobrake. That would need a lot of fuel during descent, but would mean you could pull ahead of the Proteus' orbit as she swings past.)

Edited February 9, 2014 by Patupi

[Tw1]

I vote for a combo approach. Utilizing a partial aerobreaking and then burning to get into orbit. It would lower the amount of stress on both the hull and the engines by this approach.

I also suggest a combo approach, but I'd do the burn first. That way, the demands of the aerobrake is reduced. They still may need some material left for Kerbin.

[Patupi]

I'm not sure I agree with partial. Any aerobraking is going to do quite a bit of stress on the hull, and with the ship in the state it's in... I'm not sure it could take it. I say minimize the stress as much as possible.

[Krevsin]

I'm not sure I agree with partial. Any aerobraking is going to do quite a bit of stress on the hull, and with the ship in the state it's in... I'm not sure it could take it. I say minimize the stress as much as possible.

But what about the fusion cores? Or do you suggest they use RCS (if they have enough)?

[popeter45]

everybody is partially copying my idea

i love it

do they have any communication with duna base?

[czokletmuss]

Dude, that was intense. I think Jeb's hallucinating, when he thinks Ned says: "Don't worry about me, old friend." Those are the exact words said by Bob to Jeb before he cooked himself on Eve, I definitely remember it from the Eve chapters, and I just checked

So someone did notice Congratulations!

But what about the fusion cores? Or do you suggest they use RCS (if they have enough)?

"Proteus" relative velocity to Duna is going to be 2-3km/s I think. I don't even want to think how much monopropellant you would need to decelerate ship so big as "Proteus"

Love the way this is progressing Czokltemuss! A

-snip-

Of course this all assumes the fueller is still on course. I assume they'll check on it's status before the burn, right?

(EDIT: Oh, and as to sending a lander down ahead of Proteus then letting the main ship sling shot around and then pick up the lander... You'd have to be really picky. Just a standard de-orbit would be a quicker route because it would be sliding deeper into the gravity well, but it depends on the altitude Proteus is going to slingshot past is. My guess you wouldn't have enough time to land and take off again for a rendezvous. Another option is a powered orbit down. IE accelerating downwards as you go in, then aerobrake. That would need a lot of fuel during descent, but would mean you could pull ahead of the Proteus' orbit as she swings past.)

I'm glad you like it! There will be more interactivity like this in the future it seems since I think it works

Uhm... They did check it few months ago. I guess they should check it once again

The main problem would be massive delta-v spending:

1. ~400m/s to get to Duna faster than "Proteus"

2. ~2000-3000 m/s to get into orbit

3. ~800 m/s inclination change

4. ~600 m/s landing (?)

5. ~1600 m/s getting in orbit

6. ~800 m/s inclination change

7. ~2000-4000 m/s acceleration to catch up with "Proteus"

= 8200 m/s in best case scenario

everybody is partially copying my idea

i love it

do they have any communication with duna base?

Longe range comms are dead. They will be in range during closes approach for sure however.

Sorry if I don't respond to everyone's comment but rest assured, I'm reading them all

Edited February 9, 2014 by czokletmuss

[popeter45]

it would be so heartbreaking if they find that all on duna are dead and they just end up using duna as a slingshot to kerbin

[Krevsin]

Well on the one hand, we have the possibility of a critical structural failure during re-entry, causing everything to either burn up or crash into the surface/get launched into the vast nothingness of space with no chance of survival, while on the other hand, we have the possibility of the fusion cores failing catastrophically, giving Duna a very brief second sun.

I vote... aerobraking. If they die, let them have a viking burial, their ship incinerated along with their bodies.

[RogueMason]

Under normal circumstances, I'd always go for aerobraking where possible to save fuel. However, Proteus has a free return to Kerbin from Duna, and if they need to get home, it's there. Ike does need to be in the right position, but it could be invaluable in making orbit around Duna, so I think I'd go for...

Orbit insertion burn, with a potential Ike assist. Just don't blow the ship up, ok?

[czokletmuss]

-snip- Just don't blow the ship up, ok?

Only time will tell

[Patupi]

But what about the fusion cores? Or do you suggest they use RCS (if they have enough)?

My suggestion was to minimize the burn. IE, go with a long, slow burn, with the reactors at 10%. You won't get the advantage of the Oberth effect as much, but as long as the fuel ship gets there OK they'll be fine... IE, as Czokltemuss just said, they really should check on it again

[czokletmuss]

Okay folks, so far we have:

Insertion burn - 10

Aerobraking - 5

Combo (aerobraking with Ike reverse gravity assist) - 3

Direct landing and rendez-vous with "Proteus" on escape trajectory - 1

Insertion burn + partial aerobraking - 1

Direct landing with aerobraking - 1

Proteus Ike Aerobrake Retroburn - 1

They may be some mistakes but I'll count the votes for real when the poll is over. Three most popular opiton underlined.

So yeah, it seem's that insertion burn it is. There are still ~30h left to vote so everything may happen

[Marksius]

Since they still have short range coms, wouldnt they be able to contact the base as they are going over the PE? If they get no response then they could just use that Kerbin window

[czokletmuss]

Yeah but what if there are problems with comms on Duna too? :>

[popeter45]

now your going to put THAT into the mix!

either way your going to the surface

maby the station in duna orbit was observing the signal too?

[Maxilica]

You know, I thnk that this will end a bit like "Europa Report"...

The crewmembers going down one by one, the cancellation of stuff, low crew morale, and of course extrakerbestrials.

[czokletmuss]

now your going to put THAT into the mix!

either way your going to the surface

maby the station in duna orbit was observing the signal too?

:dun dun dun:

You know, I thnk that this will end a bit like "Europa Report"...

The crewmembers going down one by one, the cancellation of stuff, low crew morale, and of course extrakerbestrials.

Dude, spoiler alert! It was a very good s-f movie and I'm sure not everyone watched it.

And of course I won't say anything about what's going to happen

[Patupi]

Weird. We watched it last night. It was... very well done. Wouldn't say it was 'very good' overall. The jumping back and forth in time early on, the constant static (and most of it was viewed through the ship's on-board cameras) got really annoying. Yes, it tried to represent things realistically, and did that very well, but it seemed odd, and (I won't go into details. No spoilers) the ending seemed abrupt and they didn't seem to finalize things, even with Mission Controls few post commentaries at the end. A lot of stuff left hanging for me.

Worth watching? I'd say yes, but I don't think it lived up to it's promise quite.

[czokletmuss]

What I mean by "very good" has to be understood in relation to other s-f movies. Sure, it wasn't "2001" but neither "Sunshine" or "Gravity" was. And considering terrible s-f movies like "Armageddon" or "Mission to Mars" or "Red Planet" and tiny budget I would say it was a very good movie

[Marksius]

Maybe they could use that Ike station for something?