Iron Hill Project Thread

[BruceJohnJennerLawso]

It is:yes:
You'll have to walk some distance to get there. And make sure you put all the team members aboard Chronus...

---------- Post added at 03:59 PM ---------- Previous post was at 03:54 PM ----------

You ain't jokin'...the launch burn took twelve minutes, and the insertion burn took about twenty. Discovery is in a roughly equatorial orbit around Earth...about 23 degrees from the ecliptic, I think.

That's exactly what we did. IMFD's Planet Approach program is very handy for that kind of thing. I just had to enter a 90* inclination and a periapsis of about 350 km, do the burn from waaaay out, and bingo, we were already set up for insertion when we got there

I'll PM you the playback, so you can see exactly what we did But that will probably happen tomorrow, as my schedule is going to be a little crazy tonight.

Hmm, given the inclination, Id imagine a preflight boost to a high-orbit, then a plane change, then a circularization at the apoapsis, would make sense. We can probably do this "remotely", ie send commands to the Arrow flight computer while still on earth. Given that, I was thinking maybe I could take the IHP scenario out for a spin sometime in the next couple days. I was wondering where our required addons list is?

Do you like the mercury orbital station idea?

 

[TMac3000]

The required addon list can be found in the first post of B-Crew Sign-Up thread.

Hmm, given the inclination, Id imagine a preflight boost to a high-orbit, then a plane change, then a circularization at the apoapsis, would make sense. We can probably do this "remotely", ie send commands to the Arrow flight computer while still on earth. Given that, I was thinking maybe I could take the IHP scenario out for a spin sometime in the next couple days. I was wondering where our required addons list is?

I assume you're talking about Chronus's rendezvous with Discovery, right?

 

[BruceJohnJennerLawso]

The required addon list can be found in the first post of B-Crew Sign-Up thread.


I assume you're talking about Chronus's rendezvous with Discovery, right?

Ah, no this would be a pre-crew arrival maneuver where commands sent to the computer boost discoveries orbit to a fairly high point (200-300 M) at an ecliptic node, correct inclination to match the ecliptic, then circularize back at the low point. Correct me if Im wrong, but it should be the most DeltaV economical way to get into the appropriate orbit for our Earth ejection. That being said, our XR ferry will have to expend slightly more fuel for rendezvous when the crew arrives, but the XR-5 should be able to spare that, whereas Discovery (and Odyssey for that matter) might need every last kilo of fuel we can spare at some point during the mission. Later today, assuming I have time, Ill start work on the Discovery skin, so that we can add it to the list for our users

 

[TMac3000]

Wait, when you say 200 - 300 M, do you mean 200,000 to 300,000 km?

Okay, so you want to set up Discovery's orbit from the ground, by remote?

 

[BruceJohnJennerLawso]

Wait, when you say 200 - 300 M, do you mean 200,000 to 300,000 km?

Okay, so you want to set up Discovery's orbit from the ground, by remote?

Yes, pretty much anything that doesnt leave her in lunar orbit, or more deltaV than we save. 150-200 M sounds optimal on second thought.

Space Stations You like?

 

[TMac3000]

A Mercury space station? I do like
It's going to add quite a bit to our payload. Are you planning to do this for the B-Crew mission in December?

---------- Post added at 04:53 PM ---------- Previous post was at 04:50 PM ----------

And BTW, I can send you a back up copy of the Iron Hill Project scenario if you want...

 

[sorindafabico]

Safe landing on Wideawake!

 

[TMac3000]

Well done!:thumbup:
Sorry I couldn't be there for the touchdown, but I spent the evening at a friend's house.

Now we're ready for November!

---------- Post added at 09:52 AM ---------- Previous post was at 12:20 AM ----------

Okay, Felipi, it's up to you now
Here's what you need to do:

1) Take me and RickD with you on the Azure Rover. You will need to load the relay and the drill.

2) Drive out to Scopas and set up the equipment. Make sure you get a screenshot of us examining the machinery.

3) Move us into the small life module nearby. We'll spend the night at Scopas, then I will drive us back to Iron Hill the next day.

No pressure on this. You can do it whenever you are ready, but try to get it done before the end of September. We haven't done Longevity or Tenacity yet, and we only have about a month before the next launch window.

 

[sorindafabico]

Playback of the Chronus flight:

https://rapidshare.com/#!download|737p2|4086130071|Chronus test flight Sep.12.zip

 

[TMac3000]

Yes, pretty much anything that doesnt leave her in lunar orbit, or more deltaV than we save. 150-200 M sounds optimal on second thought.

Space Stations You like?

I just reread your post, and NOW I see what you're getting at...You want to go way out, like halfway to the Moon, align with Mercury, and then return the orbit to a circular LEO.

That's ballsy:thumbup: Assuming of course, that it saves more delta-v then it uses...

Today I've been kicking around the idea of remotely putting Discovery in a geosynchronous orbit. What do you think about that?

---------- Post added at 08:58 PM ---------- Previous post was at 06:43 PM ----------

And Sorindafabico, you handled that mission very nicely:thumbup:
That takeoff was gutsy, using rockets and scrams all the way, accelerating at 25 m/s^2 and running the hull temps in reentry territory.

The landing was also very interesting to watch. When you started doing those S-turns, at first I though, "Cool, he's doing the HAC!" :lol:

:tiphat:

 

[sorindafabico]

My idea was to approach and land straight from the descent (my descent heading was the same of the runway) until I saw I was passing OVER Wideawake :rofl:

---------- Post added at 07:30 AM ---------- Previous post was at 07:20 AM ----------

About the inclination of Discovery prior to injection: I found the best inclination with IMFD. It saves about 1000 m/s of delta-v, if i did everything right (if you intend to do the injection at 23.3 eq). You can find it in "surface launch", which gives you the "best launch location", where you launch with a heading of 90 degrees. The inclination is 49.136 degrees (equatorial).

 

[BruceJohnJennerLawso]

My idea was to approach and land straight from the descent (my descent heading was the same of the runway) until I saw I was passing OVER Wideawake :rofl:

---------- Post added at 07:30 AM ---------- Previous post was at 07:20 AM ----------

About the inclination of Discovery prior to injection: I found the best inclination with IMFD. It saves about 1000 m/s of delta-v, if i did everything right (if you intend to do the injection at 23.3 eq). You can find it in "surface launch", which gives you the "best launch location", where you launch with a heading of 90 degrees. The inclination is 49.136 degrees (equatorial).

Not sure I follow what the plan is entailing. My specialty sort-of in interplanetary navigation is with Transx (truly want to shoot whoever came up with that awkward name), and I dont think Ive evre used IMFD. Are you suggesting simply sticking with the current orbit for ejection, or are you suggesting a new launch inclination to set with our maneuver? My guess is (and please correct me if Im wrong), but even if we eject off-plane, and it does work, it will still use more fuel than a properly aligned orbit, since we're expending delta-V changing Discoveries solar orbit reference plane.

(ie youre standing on earth revolving at a particular speed, but you also have velocity relative to the sun, and youre in plane with the sun, and youre orbiting the Milky way Galactic core... but thats an issue for another day :lol

Could I get some suggestions for the station were transporting? so long as its not a public release package, I assume I can use any meshes I find usefull to code for, then post the package on here? (having required downloads for SC3 and outdated version vessels is a pain)

1 last thing:
I dont have any real issue with WI as a base for now, but I was wondering if we could decide on a unique hub of operations for our VSA? As far as launch sites go, look at a globe/map & draw a horizontal line at +/- 20-30 degrees latitude, then look between the 2 bars for sites you like. Anything at 23 N/S is perfect for an ecliptic launch (but as the moon is 5 degrees off the ecliptic, 18-28 degrees will also work for lunar launches. Took me a while before it dawned on me why KSC is located where it is :lol

 

[TMac3000]

Are you suggesting simply sticking with the current orbit for ejection...

Really, that's what I would do. Discovery is in a roughly equatorial orbit, only a few degrees out of plane for a Mercury launch, so the THI delta-v is negligible.

The real challenge will be the TEI on the return trip, due to the fact that we'll be in a polar orbit around Mercury. I expect that burn to take between 10 and 15 minutes.

---------- Post added at 10:47 AM ---------- Previous post was at 10:45 AM ----------

Could I get some suggestions for the station were transporting? so long as its not a public release package, I assume I can use any meshes I find usefull to code for, then post the package on here? (having required downloads for SC3 and outdated version vessels is a pain)

I'll sit down and come with a design tonight

 

[BruceJohnJennerLawso]

Really, that's what I would do. Discovery is in a roughly equatorial orbit, only a few degrees out of plane for a Mercury launch, so the THI delta-v is negligible.

The real challenge will be the TEI on the return trip, due to the fact that we'll be in a polar orbit around Mercury. I expect that burn to take between 10 and 15 minutes.

---------- Post added at 10:47 AM ---------- Previous post was at 10:45 AM ----------


I'll sit down and come with a design tonight

I would prefer a wetworkshop approach to the station, but I can work either way. If you could refresh my memory, where does the SAS place the spare docking ports on the arrow? If the modules are placed at a rather odd angle do you think the superstructure COG will be out of line enough to make Discovery hard to control?

Yeah, that TEI plan is a headscratcher. I figure best solution would be to launch to a polar orbit that acts as a tangent to Mercuries prograde direction (ie down either terminator really) Should the mission plan call for a insertion burn returning to earth, or will we partially aerobrake? In theory, maybe the return trajectory could employ a reverse slingshot around the moon, in order to slow our encounter V a little bit?

 

[TMac3000]

If the modules are placed at a rather odd angle do you think the superstructure COG will be out of line enough to make Discovery hard to control?

It could be a potential problem if not handled well. Docking ports are located: 1 on the bottom of the ship, close to the stern; 1 on either side amidships, and of course the docking bay. We need to keep the bottom one clear so Chronus can dock. If we use all three of the other ones, with modules of equal mass, spaced evenly, it shouldn't be too much of a problem.

Oh, and about the B-Crew Roster: Interceptor dropped out, which leaves us 4/5. We need one more person for the Geology team. No one seems too eager to volunteer, so I propose a recruiting drive: we each PM two people we think might join.

---------- Post added at 11:31 AM ---------- Previous post was at 11:27 AM ----------

Yeah, that TEI plan is a headscratcher. I figure best solution would be to launch to a polar orbit that acts as a tangent to Mercuries prograde direction (ie down either terminator really) Should the mission plan call for a insertion burn returning to earth, or will we partially aerobrake? In theory, maybe the return trajectory could employ a reverse slingshot around the moon, in order to slow our encounter V a little bit?

I did a practice TEI yesterday. It wasn't hard to execute, it just took a huge amount of delta-v. I don't see any way around that. We'll just have to eat the cost.

Negative on the aerobraking. The Arrow has no heat shield
A slightshot around the moon might be a workable idea, though

 

[TMac3000]

Here is a very rough, makeshift concept for the Mercury polar space station. I'd like to add some solar panels to either side.

I attached a Dragonfly to the end to give it a little maneuvering capability

 

[sorindafabico]

@Bruce: I did the measurements empirically. It seems strange, but the inclination of 49 degrees relative to the equator costs less fuel than the inclination of 23 degrees. I will test with zero degrees later.

The "BLL" indicator on Surface Launch screen gives you the best launch site to your desired hohmann transfer, i.e., the site where you can use 90 degrees of heading to get the, I presume, the best parking orbit inclination before the injection.

 

[BruceJohnJennerLawso]

Here is a very rough, makeshift concept for the Mercury polar space station. I'd like to add some solar panels to either side.

I attached a Dragonfly to the end to give it a little maneuvering capability

umm, how can I view it? I dont recognize what module1 & module2 are pointing to. Forget any files ? :lol:

@Bruce: I did the measurements empirically. It seems strange, but the inclination of 49 degrees relative to the equator costs less fuel than the inclination of 23 degrees. I will test with zero degrees later.

The "BLL" indicator on Surface Launch screen gives you the best launch site to your desired hohmann transfer, i.e., the site where you can use 90 degrees of heading to get the, I presume, the best parking orbit inclination before the injection.

I think you need to hit FRM on OrbitMFD. Equatorial inclination will change constantly over the year, but ecliptic inclination (our solar systems plane) is more or less fixed. earth is inclined 23 degrees to the ecliptic, but an orbiting objects inclination is independent of the equatorial frame (at least outside the atmosphere anyways). I cant guarantee that it will save more delta-v total to align with the ECL before leaving than it uses, but when Chronus rendezvouses with us, we might be able to crossfeed some of its fuel over to cover some of its losses. Burning the TMI off-plane might still work, as the V added in the normal (changing our orbital plane) direction only bends us off-plane slightly, given how tiny it would be compared to our solar reference velocity, but it wastes fuel that we could use for prograde/retrograde acceleration.

Basically, the manuever can probably save us a fair bit of fuel in the long run, importannt because whenever you travel to/from mercury, you need a lot of Delta-V. Just dont want us to get stuck running out of fuel later in the trip if we can save it in Earth orbit-not many gas stations on the way :lol:

 

[TMac3000]

umm, how can I view it? I dont recognize what module1 & module2 are pointing to. Forget any files ? :lol:

Shift focus to "engine" to control it
If it still doesn't work, here's a pic

 

[BruceJohnJennerLawso]

Shift focus to "engine" to control it
If it still doesn't work, here's a pic

Not bad, Im just picturing the main modules as SSBB. Maybe a robotic arm would be good too? Just 2 things:

I hate to drag things to a halt, but every time I have ever tried to access VC in the Dragonfly I get a CTD, no clue why. In my package for the shuttleD, theres going to be a support vessel, basically the UCGO lander without landing gear & descent engine, but having 2 UCGO slots & a docking port. maybe we could use that for RCS station keeping?

And I thought I saw Shuttle-A PLs in the original file. Maybe those could be clustered around the node module for non-simulated consumables storage