Question MFD to a specific orbit?

PaulG

New member
Joined
Sep 12, 2008
Messages
159
Reaction score
0
Points
0
Ok, lets say I want to launch to a specifc orbit. At a particular Inc, LAN, etc.

Is there an MFD, or a combination that I can use to arrive to a particular orbit most efficiently?

Or, should I use the scenario editor as my calculator to figure the orbital parameters out and place a LaunchProbe there? Is that cheating?

Thanks.
 

tl8

Addon Developer
Addon Developer
Tutorial Publisher
Joined
Oct 16, 2007
Messages
3,645
Reaction score
25
Points
88
Location
Gold Coast QLD
I believe IMFD can do that
 

Zatnikitelman

Addon Developer
Addon Developer
Joined
Jan 13, 2008
Messages
2,302
Reaction score
6
Points
38
Location
Atlanta, GA, USA, North America
LaunchMFD can also do a great job of putting you in a specific orbit even through an atmosphere! It's manual all the way, but even with my inaccuracies and whatnot, I still parked my own launch vehicle in a 200 x 190 orbit first time at a near-perfect inclination!
 

tblaxland

O-F Administrator
Administrator
Addon Developer
Webmaster
Joined
Jan 1, 2008
Messages
7,320
Reaction score
25
Points
113
Location
Sydney, Australia
Ok, lets say I want to launch to a specifc orbit. At a particular Inc, LAN, etc.

Is there an MFD, or a combination that I can use to arrive to a particular orbit most efficiently?
TransX and IMFD will both give you launch headings and times for flight plans they have calculated.

Launch MFD will also take as an input either a target vessel, an equatorial inclination or an ecliptic inc/LAN pair and will give you a launch heading and time to launch.

Or, should I use the scenario editor as my calculator to figure the orbital parameters out and place a LaunchProbe there? Is that cheating?
Not in my book, I do that sort of thing all the time. In fact, LaunchMFD does exactly that if give it a target inc/LAN (look at the vessel list, its called LaunchMFD-probe, or something like that).
 

PaulG

New member
Joined
Sep 12, 2008
Messages
159
Reaction score
0
Points
0
Thanks. So, lets say I wanted to reach an orbit, for example, a geostationary one. So, the inclination in the equatorial frame is 0. But now, lets say I wanted to be stationary over a particular longitude. How exactly do I got about doing that?

I guess thats what led me to the LaunchMFD-Probe idea.
 

Andy44

owner: Oil Creek Astronautix
Addon Developer
Joined
Nov 22, 2007
Messages
7,620
Reaction score
7
Points
113
Location
In the Mid-Atlantic states
Thanks. So, lets say I wanted to reach an orbit, for example, a geostationary one. So, the inclination in the equatorial frame is 0. But now, lets say I wanted to be stationary over a particular longitude. How exactly do I got about doing that?

I guess thats what led me to the LaunchMFD-Probe idea.

Launch MFD won't work if you're trying to get an orbit whose inclination is lower than the latitude of your launch site.

For example, trying to get to geostationary orbit (GEO) whose inclination is zero degrees from Cape Canaveral, whose latitude is about 28.6 degrees. You cannot launch directly into GEO from the Cape; you need to launch into a 28.6 deg orbit, then inject yourself into an elliptical transfer orbit. When you reach apogee at GEO altitude, you need to do a plane change to lower your inclination to zero degrees. On the next pass, burn prograde to circularize your orbit in GEO. (If you're hot you can combine these last two burns.)

Once you're in a near-GEO orbit, you can "drift" to your desired longitude by slightly increasing or decreasing your sma, which will cause you to shift longitude. Once you reach your longitude, adjust your orbit sma so that your period is the same as Earth's rotation.
 

tblaxland

O-F Administrator
Administrator
Addon Developer
Webmaster
Joined
Jan 1, 2008
Messages
7,320
Reaction score
25
Points
113
Location
Sydney, Australia
Thanks. So, lets say I wanted to reach an orbit, for example, a geostationary one. So, the inclination in the equatorial frame is 0. But now, lets say I wanted to be stationary over a particular longitude. How exactly do I got about doing that?

I guess thats what led me to the LaunchMFD-Probe idea.
Geostationary? Just use the scenario editor to place your probe at the particular longitude using the scenario editor (make sure your reference frame is the rotating one) and 42164km altitude, 3074.6m/s velocity. Launch with LaunchMFD and then fly to your probe with IMFD (or TransX).


-----Post Added-----


Launch MFD won't work if you're trying to get an orbit whose inclination is lower than the latitude of your launch site.
Ah yes, a bit of a brain fade there on my part. I need to :coffee:
 

Hielor

Defender of Truth
Donator
Beta Tester
Joined
May 30, 2008
Messages
5,580
Reaction score
2
Points
0
For example, trying to get to geostationary orbit (GEO) whose inclination is zero degrees from Cape Canaveral, whose latitude is about 28.6 degrees. You cannot launch directly into GEO from the Cape...

Technically, you could do a dog-leg, but it's not exactly efficient.
 

PaulG

New member
Joined
Sep 12, 2008
Messages
159
Reaction score
0
Points
0
Thanks all.

I think I got my answer. My first impression was to use the editor as a calculator for exactly where I wanted to place the orbit and where/when I wanted the spacecraft to be.

It seems best then, to use LaunchMFD-Probe, and the appropriate mix of MFDs to reach that position, since reaching a specific orbit is essentially the same as a rendezvous.

How would you use IMFD to reach a particular orbit?

Thanks again.
 

agentgonzo

Grounded since '09
Addon Developer
Joined
Feb 8, 2008
Messages
1,649
Reaction score
4
Points
38
Location
Hampshire, UK
Website
orbiter.quorg.org
Thanks all.

I think I got my answer. My first impression was to use the editor as a calculator for exactly where I wanted to place the orbit and where/when I wanted the spacecraft to be.

It seems best then, to use LaunchMFD-Probe, and the appropriate mix of MFDs to reach that position, since reaching a specific orbit is essentially the same as a rendezvous.

How would you use IMFD to reach a particular orbit?

Thanks again.
Unless you are wanting to be in a specific point in the orbit at a specific time (for rendezvous with the ISS or geostationary orbit) you don't need to rendezvous with the LaunchMFD-probe. You can just get into the same orbit as it. LaunchMFD will give you all the information you need to achieve this. If you do need to this, then launch into a slightly lower (or higher) orbit in LaunchMFD and then use SyncMFD or RendezvousMFD to rendezvous with your target.
 

markl316

XR2 Ravenstar Commander
Addon Developer
Tutorial Publisher
Joined
Mar 30, 2008
Messages
450
Reaction score
1
Points
18
Andy44 said:
(If you're hot you can combine these last two burns.)

Can IMFD do this?
 

C3PO

Addon Developer
Addon Developer
Donator
Joined
Feb 11, 2008
Messages
2,605
Reaction score
17
Points
53
You could have a look at this thread.
 
Top