Eve Ascent Question

[TerLoki]

So I'm using FAR, and I suddenly have the urge to do a sandbox mission to Eve for a manned landing. I built a simplified rocket to test various aspects (heat shield deployment, strut integrity, stability, etc.) and to my pleasant surprise it was able to make a 200km orbit flying manually without staging or using the last two stages (which had roughly 4km/s of dV between them).

My question to those who are more experienced with that purple orb than I is this: Does it sound like this would be enough to lift off from Eve and make a stable orbit for rendezvous? The dV readouts in the VAB say "no", but my gut says "yes".

Edited May 21, 2014 by TerLoki

[Captain Sierra]

FAR knocks about 1-1.5km/s of dV off what is needed to reach orbit on Kerbin assuming good aerodynamics. Now, Eve's thicker atmosphere means it will probably knock off more. I say go for it. If you really are concerned, change out any command pods/seats with a probe core so nobody dies.

[Taki117]

As long as your TWR is greater than 1 on Eve (Which might be an issue if this is a Kerbin Test) you should be fine (Though I wouldn't count on having much of that 4km/s left)

[Red Iron Crown]

Much depends on the altitude of your landing site, too. Landing on a mountaintop can reduce the dV requirements for an ascent by as much as a third (won't quote numbers as I only know them for stock aero).

[TerLoki]

Well right now the mission plan is more Mars Direct style, having the crew come later after the ascent rocket has already touched down. I'll probably include a rover as a second launch so that the crew can still get check out sea level and do ocean science regardless of landing site. And I totally agree there, higher is better.

As long as your TWR is greater than 1 on Eve (Which might be an issue if this is a Kerbin Test) you should be fine (Though I wouldn't count on having much of that 4km/s left)

Thank Kod for MechJeb including TWR on other planets, it's got around ~1.5 from the first stage on Eve and ~1.75 after dropping the first set of boosters. I designed the whole thing around that before taking it out to the pad for a test fit (had to make sure the heat shield was big enough), which then turned into an SSTO launch just to see what all that dV could do.

Sounds like I'm doing a sandbox "simulation" run then, sans-crew.

Edit: Good news! According to every test I've run this design should survive reentry and landing (6m heat shield, crapton of parachutes, still upright and operable after a 5m/s drop test). Bad news, the launcher for it is so utterly Whackjovian that my computer refuses to load it for launch. Any tips for getting 450 tons to orbit?

Edited May 21, 2014 by TerLoki

[Lukaszenko]

Any tips for getting 450 tons to orbit?

Yeah, don't ! Perhaps drain it of fuel before launching, and send the fuel later?

[Red Iron Crown]

Any tips for getting 450 tons to orbit?

A large asparagus-staged rocket made of SLS parts. Should be able to do it with a mass of around 2700t (payload included), part count for the lifter should be less than 200. A picture of the payload would help with providing more specific advice.

TL;DR: Moar boosters!

[TerLoki]

A large asparagus-staged rocket made of SLS parts. Should be able to do it with a mass of around 2700t (payload included), part count for the lifter should be less than 200. A picture of the payload would help with providing more specific advice.

Gladly:

Not the fully realized vehicle, but close enough. The main differences are the addition of parachutes (LOTS of parachutes), landing legs, a trio of crew capsules at the so I can use Crew Manifest to magic them up to the return capsule (cheaty, I know), and three heatshields rather than one.

Yeah, don't ! Perhaps drain it of fuel before launching, and send the fuel later?

Yeah, went with this suggestion instead. Managed to lighten the payload to 175 tons and strip about half the engines off the launcher in the process, while still getting a better margin of error.

I had to rearrange a few things, since I hadn't planned on orbital refueling the conventional fairings had to be swapped for interstage fairings leading up to a shielded decoupler. Hopefully TAC Fuel Balancer will help get that moving along while still keeping the fairings attached. Oh yeah, lots of fairings on this thing, three sets in fact. One for Kerbin ascent, one for Eve descent (just in case, keeps the parachutes a bit safer), and one little one at the top for the Eve ascent. This thing is actually too tall to fit in an interstage fairing o_o .

TL;DR: Moar boosters!

Way ahead of you. Now that I have something I can load (barely), I've moved on to the flight testing phase.

By "flight testing" I mean "MOAR STRUTS".

[Red Iron Crown]

Those are some good looking rockets, nice work.

Conveniently, the lifter you built for the payload should be able to refuel it in two launches.