Scenario (Jarvis HLV) Verrazzano Moon Mission (how-to?)

[Pipcard]

original title: "Rendezvous with a station orbiting another body (e.g. Moon)"

I can rendezvous with a station (orbiting the same body as me).
I can do a lunar transfer.

But I can't transfer from Earth-Moon and then rendezvous with a station in lunar orbit (especially if it's about 100 km from the surface). So how can you do that? I'm also worried about running out of fuel.

Specifically, this has to do with the "Verrazzano Moon Mission" scenario that comes with the [ame="http://www.orbithangar.com/searchid.php?ID=4527"]Jarvis HLV[/ame], but it can apply to any scenario that involves what I mentioned above.

 

[garyw]

But I can't transfer from Earth-Moon and then rendezvous with a station in lunar orbit (especially if it's about 100 km from the surface). So how can you do that? I'm also worried about running out of fuel.

Perform an off-plane intercept. Target the moon first then perform an MCC to target the orbit of the space station then sync up to it the same way you'd do in Earth orbit.

Break the mission down into steps. First the moon, the stations orbit and finally the station. If you go for the station as the first step you'll just give yourself too big a problem to handle

 

[Pipcard]

How would I target the station with TransX in order to do the MCC?

And I think this is more of a problem about running out of fuel.

 

[garyw]

How would I target the station with TransX in order to do the MCC?

I don't know, I've only used IMFD for this when I docked at the ISS during a return from the moon.

And I think this is more of a problem about running out of fuel.

Take more?

What is your dV budget for this mission?

 

[Pipcard]

What is your dV budget for this mission?

It's supposed to be about 1.37 km/s (for lunar orbit insertion and rendezvous) according to the .pdf. Although I have less than that (long story), probably around 1 km/s.

 

[Quick_Nick]

How would I target the station with TransX in order to do the MCC?

And I think this is more of a problem about running out of fuel.

If you know the target inclination (ecliptic I think) and orbit radius, TransX gives you the expected inclination and periapsis that the maneuver will result in.

 

[Pipcard]

The main reason I can't do it is actually because I don't have enough fuel.

I think it's because I'm supposed to burn to an elliptical orbit first with the Jarvis-H second stage, before the TLI where I burn with the third stage (to take advantage of the Oberth effect). But when I plan my TLI in TransX after that initial burn to elliptical orbit, the time I should burn is not at the periapsis (where I am fastest).

 

[Cras]

Jarvis H? If you are going to the moon, you are going to need the Jarvis-M for that.

as for getting into the right orbit. I would recommend using IMFDs map program.

Pull it up, set it to max accuracy, and then adjust your course with a TLCC or two to get your orbit in line with what the station, module, or what ever you are aiming for.

I am still working on the best way to go about this myself (actually for a trip from the Moon to an orbiting space station in LEO), I will let you know if I develop a solid procedure.

 

[Pipcard]

Jarvis H? If you are going to the moon, you are going to need the Jarvis-M for that.

Actually, the scenario has the Jarvis-H. The Verrazzano for the lunar mission weighs 29 t, and the Jarvis-M is too much (48.6 t to LTO).

 

[fausto]

This mission is not easy to accomplish.. i can tell you that imfd is not the proper tool for the job because when it computes the trajectory it doesn't take in account the lowest delta v budget. At first you have to choice a good moment for the transfer. This occours tipically 3-4 days before the moon reaches the node between lunar orbit and earth orbit. The only tool capable to perform this kind of lunar transfer is transx

 

[NukeET]

This mission is not easy to accomplish.. i can tell you that imfd is not the proper tool for the job because when it computes the trajectory it doesn't take in account the lowest delta v budget. At first you have to choice a good moment for the transfer. This occours tipically 3-4 days before the moon reaches the node between lunar orbit and earth orbit. The only tool capable to perform this kind of lunar transfer is transx

Nonsense, IMFD is capable...so is LTMFD.

 

[Pipcard]

Nonsense, IMFD is capable...so is LTMFD.

I tried IMFD with the Jarvis upper stages. Orbiter crashed when I tried to use the autoburn. The burn vector view points me in a completely wrong and nonsensical direction.

 

[garyw]

I tried IMFD with the Jarvis upper stages. Orbiter crashed when I tried to use the autoburn. The burn vector view points me in a completely wrong and nonsensical direction.

I think there might be an issue if you've still got stages attached.

Was the burn vector wrong or was the information given wrong? I've never had an issue with IMFD when going to the moon.

 

[Pipcard]

I think there might be an issue if you've still got stages attached.

Was the burn vector wrong or was the information given wrong? I've never had an issue with IMFD when going to the moon.

The burn vector, when it's time to burn, points me to a direction near orbit-antinormal (but not exactly). As I burn, the vector keeps moving around a lot.

 

[NukeET]

The burn vector, when it's time to burn, points me to a direction near orbit-antinormal (but not exactly). As I burn, the vector keeps moving around a lot.

Please post the scenario. I've run this twice already and haven't seen what you are describing.

 

[Pipcard]

Just one question first: Are you supposed to do the TLI burn with the second and third stages or just the third stage?

 

[Quick_Nick]

Know your dV.
[ame="http://www.orbithangar.com/searchid.php?ID=4439"]Trajectory Planner[/ame]

 

[NukeET]

Just one question first: Are you supposed to do the TLI burn with the second and third stages or just the third stage?

I've successfully done it both ways. Better if you run the 2nd stage bone dry during the TLI. Leaves you more dV for later.