Recent content by indy91

I had written myself a function for it, too, it's basically the offset between TT and TAI (which is 32.184 seconds) plus the number of leap seconds. Slightly simplified and not giving exactly TDB, but, close enough. Was your idea for the Mission Editor similar?

Should be easy to add this to the FDO MFD. A mission specific constant that can be set on the config page. Just like the 64.18 value in this real screen from the FDO Console Handbook: We would keep using zero for this value until SSV has been changed in the same way.

As it turns out, when trying to implement a tool faithfully that the real Shuttle FDOs used, what we ended up with is something that requires a level of orbital mechanics knowledge of a real Shuttle FDO :D But I have also been thinking about this topic. We should really start a collection of...

Those generic plans are from the FDO Console Handbook, it's what they had prepared for different phase angles for STS-114. I would say it's quite representative of the rendezvous profiles flown in the last decade of the Shuttle, but not necessarily identical. I would think that one of the plans...

Then the rendezvous plan doesn't really work out for the specific orbits and phase angle. Either have to use a different plan or it needs some adjustments (e.g. number of orbits between some maneuvers). If you are using spherical gravity then they should be the same. With non-spherical gravity...

Yeah there is a problem with spherical gravity. Because of the required difference in LAN at insertion the optimum launch time is also different between spherical and non-spherical gravity. In an extreme case you would not even be able to use the historical launch time together with a state...

When using non-spherical gravity this sort of RInc after insertion can be completely normal. Both Shuttle and target are affected by nodal regression (longitude of the ascending node changing over time), but this effect is different at higher vs. lower altitude. So the Shuttle often had to have...

Sure, whatever works best for you. It's still easy to make a mistake with the MCT (e.g. changing an input in a wrong way and then not being sure what the value was before) and having files saved as backup can be helpful. Saving is optional though, just re-calculating the maneuver sequence before...

If you calculate the sequence of maneuvers before OMS-2, then generate Maneuver PADs for all of them and just perform them like that for the rest of the mission, without ever calculating the maneuvers again, then you would never reach your target. You would have to perfectly null the DV of all...

The day-of-rendezvous NC burn (usually named NC-4) would still be calculated by Houston. If it's a large burn then it can even be quite important to re-run the calculation after the NH burn, to take the actual trajectory into account. The NCC burn is the first one calculation onboard with SPEC 34.

With the 140 I hope, not 144. Your launch day (which the config page wants as input) is day 140 of the year, May 19.

You want to manually change it to 140. The intended workflow is for the case where you start a mission from launch (or at least the launch day). Then you can open the MFD, click the DLO button and leave the input blank. But your scenario is already on May 24, so it would not choose the right...

I'll clarify it in the MFD and in the manual. Just an unlucky case I guess, usually one can just leave the year/day blank and the MFD will automatically use the current day as launch day, but if the first attempt at using the MFD is with an on-orbit scenario and you have to manually input the...

Ah I see the problem. I guess that is not made clear enough, but the "day" input on the Config page of the FDO MFD needs the day of year, not day of the month.

Sadly the screenshot is not quite large enough to actually see the numbers in the MFD and Shuttle display. Almost, but not quite. I would say the most likely discrepancies would be the launch day or launch time in the FDO MFD or a mismatch between the selected landing site in the FDO MFD versus...