ReentryMFD Reentry MFD not working with Orbiter 2010?

[Scared Bunny]

Sorry for cross posting this from Dan's Orbiter Page, but as seems this forum attracts more English speaking people, so:

Hi,

After a two year break I'm revisiting Orbiter and I can't understand why I left.

Anyway, in the past I used reentry MFD as a tool to estimate my required deceleration to land on planets and moons with no or almost no atmosphere. Very useful, but I just tried a landing on Brighton Beach, the Moon and as far as I can tell Reentry MFD seems to think Brighton Beach is 50 kilometers north of were it actually is.

When I approach the base at the suggested deceleration it is not enough to make a full stop above the base. If I maintain the suggested deceleration I pass above the base at about 500 m/s, and once I pass the base Reentry MFD still suggests that I decelerate at the present orientation, as if the base were in fact several tens of kilometers farther along my route.

Any ideas?

---------- Post added at 07:49 PM ---------- Previous post was at 07:13 PM ----------

I did some more checking on the forum and found this:

http://orbiter-forum.com/showthread.php?t=16243&page=2

It seems Aerobrake MFD has a similar problem.

 

[Tommy]

My understanding is that the planetary rotation model is a bit different in 2010. I myself haven't had any real problem with Aerobrake - it's not designed to get you all the way to ground. Even in the 2006P1 version you needed to "offset" the landing indicator a few kilometers to leave room for approach.

 

[jarmonik]

It is possible that the problem causing this will be fixed from the Orbiter but nothings been confirmed yet. If the source code of reentry mfd is available it should be pretty easy to "fix" the issue by code modification.

 

[hribek]

Aerobrake MFD works on Earth and Mars in Orbiter 2010, but make sure you are close to the surface, or in a low orbit. Opening the MFD near a body without atmosphere, like the Moon, can cause a crash.

 

[Hasso]

It seems Aerobrake MFD has a similar problem.

...as reentryMFD

Hard to say...

I couldn't find it anywhere. But i remember, i have tried it long time ago.
A MFD that provides a little + on the direct approach line, but without HUD?

It isn't listed in OH - or my eyes hardly need service:blink:

However, is the misleading 2.39° to south on mars? Then it may be the same behaviour - i can't test without the MFD.

But there might be an other solution to approach:
Place something fire-proof on (or near) your desired landing-site and catch it with DockingMFD to HUD. Now you got two speed-vectors (against and toward) you can point to. Then use [ame="http://orbithangar.com/searchid.php?ID=585"]ArriveMFD[/ame]

ArriveMFD tells how much thrust is needed to stop right on target.
It may also help to hover to zero AGL at target (if a ground-base is targeted)

I have had two succesfully landings at Brighton Beach with ArriveMFD in Orbiter2010. We should drop a line to IronRain (http://orbiter-forum.com/showthread.php?t=16177) if somebody has tested this at other places.

 

[Scared Bunny]

Thanks for suggesting ArriveMFD, Hasso. I tested it with the vanilla Delta Glider Brighton Beach scenario. One launch in an easterly direction, once around the moon, landing back at the same pad, and another launch and land in a southerly direction. ArriveMFD worked like a charm, but...so did reentryMFD.

The scenario I did that made me doubt reentryMFD's compatibility with Orbiter 2010 was a launch with a DG directly into a TLI using IMFD. I used IMFD's baseapproach to align me with Brighton Beach and then used reentryMFD to guide me down, only to discover that reentryMFD's deceleration numbers were completely off the mark.

The only difference I can see at first glance is that reentryMFD worked when I launched from the Moon and landed back on the Moon, but didn't work when I launched from Earth and landed on the Moon.

Any thoughts?

Just to be sure I'm going to recreate the Earth-Moon mission.

---------- Post added at 01:36 AM ---------- Previous post was at 12:13 AM ----------

Well, at least I'm not delusional. This is an image of ArriveMFD on the left and reentryMFD on the right, and as you can see the required deceleration on the left is much higher than on the right.

But when I did this run I approached at an altitude of 100 kilometers.

So, I thought perhaps the approach altitude was a factor, because the two moon-to-moon experiments I did earlier had approach altitudes of 1 kilometer.

I did another moon-to-moon experiment with a much higher approach altitude and this time I did replicate the difference between ArriveMFD and ReentryMFD.

As I see it, ReentryMFD takes the absolute distance between the ship and the base, while ArriveMFD takes the distance as measure on the ground (horizontally). This makes ReentryMFD think the base is farther away than it actually is horizontally speaking.

As far as I can remember ReentryMFD did not have this problem in the past. Anyway, ArriveMFD doesn't have this problem, so in a way my problem is solved.

Thanks to all the repliers!

 

[jarmonik]

If the problem is caused by the rotation model the error in the Moon is pretty small. In the Europa it's probably highest.

 

[jarmonik]

This problem should be fixed from Orbiter 100721 Beta. Can someone confirm this ?

 

[Hasso]

This problem should be fixed from Orbiter 100721 Beta. Can someone confirm this ?

Seems to be OK now.

Aerobrake shows a distance of around 2m instead of 140km on Mars if you are direct on target (measured near equator) :thumbup:

And ReentryMFD starts to go wild (infinite Decel req) if the vessel is landed on target.
I haven't tested the approach yet.

:tiphat: