Iron Hill Project Thread

[TMac3000]

Okay, we have somewhat of a problem. After doing a prediction, I found out that Mercury PeA is bad. Veerrry bad. If we make no changes, the MCC will take over 4 hours, which is very clearly longer than even an Arrow can burn.

In simulation, I was able to whittle it down to about 11 million km. Much better, but still waaay off. (Not to mention, the resulting trajectory would take us halfway to Mars orbit)

I could probably have whittled it down further, but I don't wish to do anything without consulting the team. Following is the latest state file, and a picture of the current situation in IMFD's map. If anyone can run a model that will fix this, please tell me and I will follow your instructions

Here is my idea: on our current orbit, we will reach aphelion on June 13 of this year. At that point, we should be able to just burn retrograde and get ourselves back on course. Any other ideas?

 

[Cras]

uh-oh

 

[Felipi1205]

Well, I could reach a periapsis of 293.6k, with several burns in different times. And the fuel is at 584k, enough for the orbit insertion...

 

[TMac3000]

And the fuel is at 584k

Sounds like plenty...what percentage is that (roughly)?

 

[Felipi1205]

Maybe 75%, but not sure...

 

[TMac3000]

uh-oh

Don't worry:lol: I've seen these guys in action, and they are very, very good

---------- Post added at 05:22 PM ---------- Previous post was at 05:21 PM ----------

Let's go to chat right quick, so we don't clutter up the thread...

---------- Post added at 05:40 PM ---------- Previous post was at 05:22 PM ----------

Okay, Felipi has a plan, and I have a plan. Any one else?

 

[Felipi1205]

What's your plan?

 

[TMac3000]

Wait until solar apoapsis on June 13, and burn retrograde.

 

[astrosammy]

For example, I try to grab an unpacked UCGO module and attach it to another one (I'm very picky about these things) But when I tell the UMMU to move in one direction--left, for example--He moves right for a second, back for a second, then starts moving slowly to the left.

Do you have [ame="http://www.orbithangar.com/searchid.php?ID=3251"]Deepstar 2.0[/ame] installed? There are two dll files in that addon that are not compatible with Orbiter 2010.

I've seen the same behaviour on Europa, maybe it's the same here.

 

[TMac3000]

No Deepstar
Tried my plan, and I think it's going to work, but it will skip the MCC and add another month to the mission...

---------- Post added at 07:57 PM ---------- Previous post was at 06:38 PM ----------

Okay, so both Felipi's idea and mine seem to work quite nicely Btw, Felipi, do you happen to remember what the encounter velocity with your plan was?

Mojoey is in command (I swapped him and RickD, who will be payload specialist), so it's up to him and Houston what happens next...

 

[Felipi1205]

Not sure, but I still could have a safe orbit insertion.
And we can slow down the spacecraft some hours before the orbit insertion, if the speed is too much high.

 

[TMac3000]

Houston, Odyssey. We'll wait on you.

 

[Felipi1205]

Just noticed something. If you burn prograde pointing to the direction 231 in the Orbit MFD (just turn the nose to the right, according to the scenario of the problem. The pitch doesn't need to be changed!), you can adjust the PeA to 300.000km, and is a big change! The fuel is still at 80%, so it's not a problem. And later, we can have a MCC to set the exact PeA....

 

[TMac3000]

That worked beautifully, Felipi!
It not only brought us (almost) back on course, but it eliminated the portion of our trajectory that was outside Earth orbit:thumbup:
I'll have to check on the arrival date (in 103 days) to see if its still in August, but so far everything looks great
Here's the latest state file, and the new IMFD situation

 

[Felipi1205]

Nice! Next destination : Mercury!

 

[TMac3000]

We now reach aphelion Thursday evening, so I'm going to do a short burn then to bring it down some more.

 

[sorindafabico]

I have a suggestion to fine-tune the trajectory: using the "Plan" tool of IMFD's Map screen and Delta-v tool of Course screen.

---------- Post added at 06:10 AM ---------- Previous post was at 05:22 AM ----------

Something like this:

One MCC and you're not only inside Mercury SOI, but ready for HOI (if the Eq. Inc is not a problem).

***If you don't get the same numbers, set "accouracy" to "1.000 (max)" in IMFD's Map MFD.

 

[TMac3000]

Thanks! I'll give that a try...

 

[TMac3000]

Aphelion estimated May 11 07:00 UTC

 

[TMac3000]

Houston, Odyssey. Sorry we're late, we had a radio malfunction. (Read: internet was down because of local construction work). Here's our weekly update. We're about 7 million km out now. I've managed to whittle the periapsis down to 205,000 km.