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Old 07-15-2010, 10:59 PM   #106
fireballs619
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So it's official, no mining? I already took it out of the wiki, but i can easily re-insert it if we are mining other materials for some reason.
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Old 07-15-2010, 11:00 PM   #107
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Originally Posted by River Crab View Post
 As long as we're super careful about not losing Hydrogen and we bring enough extra to provide a degree of safety, I think we're good leaving out mining. There's also the matter of overcomplication, which is becoming more and more of an issue.

So I'm not decisively sure, but it seems better to leave it out.


Also, are we pretty much certain about the Sidemount for an HLV? The reference doesn't mention launches at all. Can that carry everything so far? And, relatedly, are we using the NERVA2?
Yes, I believe zero boil off is possible for cryogenic materials especially when you can hook a radiator directly to it while in space.

The launch vehicle is not really apart of the project 'build' team, its more of a vehicle used. That being said, I am saving it for the final version with the flight profiles in it.
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Old 07-15-2010, 11:03 PM   #108
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Originally Posted by Bj View Post
 NERVA2 uses LH2. Skycrane uses LOX/CH4. Yes that correct

Since we are using most of the elements found on Mars except for hydrogen, we will need to bring hydrogen with us. The conversion has a 62:1 weight gain ratio (ie 1 kg hydrogen turns to 62 kg LOX/CH4 ) and it happens to have the exact mixture necessary for our use.

The only part of the whole deal that is unrealistic is that it takes so much power, something like 66 kWh per kg for conversion so it would take months to make enough propellant for a single launch. Soooo I am just going to assume our nuclear generator has unlimited power and fuel can be produced every 2-3 days.
62:1? Wow, that's quite a figure.

Your reactor maxed what? 52kWh?

Yeah...let's just say it works out.
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Old 07-15-2010, 11:09 PM   #109
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I've began some blueprints, (well actually some blackprints), for a base on Mars after we have done our research on the Mars surface. I've included 4 landing pads I think for later missions to the "Red Planet".

I'll will later post the blueprints after I get them sorted out for the final time.
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Old 07-16-2010, 12:02 AM   #110
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Originally Posted by fireballs619 View Post
 So it's official, no mining? I already took it out of the wiki, but i can easily re-insert it if we are mining other materials for some reason.
Not at least for the first mission anyway. Mining might be the next step to getting goal 2 -independence from Earth, but I think it is stretching the difficulty of the project a tad. Iam going along the lines of the ALSEP where the first packages where not complete.

If we can harvest Hydrogen in whatever way possible, skycrane launches potently can be unlimited. However a method for extracting hydrogen has to be figured. Also the NERVA2 could use all its payload of fuel to get to Mars alone (in either a more speedy way, or with much more mass)




Before we get too far in this, can someone test something really quickly? (please post someone is working on it) I don't want this to turn into something like the Mars Climate Orbiter...

I want to change (make a backup) the Shuttle PB config to the equivalent of;

EMPTY_MASS=258000 // 42000 is empty + 2 droptanks + cargo of (200,000)
FUEL_MASS=174466
MAIN_THRUST=1500000
ATTITUDE_THRUST 320000
ISP = 16500

  • Start it in orbit ready to go to Mars.
  • Setup a flight to mars (transx or whatever) with total DV being less than 4.8km/s. Fly the mission to Mars.
  • It should start somewhere around 3.46 m/s acceleration and end at (while on Mars return trip, just empty of fuel) 5.81 m/s acceleration. When you reach Mars setup a trip back (you should have just a little less than half fuel left) Try to get it less than 3.4 km/s total for the way back
Let me know of any problems encountered. Remember when you get to Mars adjust the date leaving to somewhere 3-8 months ahead of time.

Make note of propellant left when(if) you get back to Earth. Also if you encountered any inefficient flying (ran beside the Moon or dodged Phobos or something...)

Thanks to all who try it


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Originally Posted by Izack View Post
 62:1? Wow, that's quite a figure.

Your reactor maxed what? 52kWh?

Yeah...let's just say it works out.
You read page 13 of the reference .9 right?

Quote:
Sabatier reaction then electrolysis: CO2 + 4H2 → CH4 + 2H2O → CH4 + 2H2 + 2O
Methane/LOX fuel chemical equation: CH4 + 2O2 → CO2 + 2H2O
LH2/LOX fuel chemical equation: H2 + O → H2O
CO2 + 4H2 → CH4 + 2H2 + 2O
2H2 can be reused so the only input is CO2 and 2H2 and the output is CH4 and 2O2. That just so happens to be the exact combination of CH4/LOX fuel.
So if we use 1 kg LH2
1000 x (1.00794) x (6.022 x 1023) = 6.06981468 1026 atoms
avogadros = 6.022 x 1023
atoms = grams * MolarMass * avogadros
grams = atoms/ avogadros /MolarMass
1 kg LH2 turns into 62.8313178 kg CH42O2
62:1
See page 14:

Stirling conversion GFS reactor predicts about 1,000 kWe.

Assume 50% efficiency, 66.6kWh/kg to create LOX/CH4 fuel.

so 66.6 * fuel we need = kWh required.

Though it has to be changed "37 days to make enough fuel to land a 5,000 kg lander" to 76,000 kg fuel for 20 tonne launch so that changes to "210.9 days to create enough fuel to launch a 25 tonne skycrane&cargo"

The only truly real way possible of making enough power is to build a real full sized nuclear power plant on Mars. Which in itself is pretty far fetched but not 'illegal' (see signature) What is 'illegal' is assuming our small generator has unlimited power.

Quote:
Originally Posted by Samuel Edwards View Post
 I've began some blueprints, (well actually some blackprints), for a base on Mars after we have done our research on the Mars surface. I've included 4 landing pads I think for later missions to the "Red Planet".

I'll will later post the blueprints after I get them sorted out for the final time.
You mean like this?

http://www.orbiterwiki.org/wiki/File:OFMMBase.png

When its done, should this sort of thing be in the reference? ..for base design? Looking forward to it.
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Old 07-16-2010, 12:04 AM   #111
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As far as the launch vehicles are concerned, I think we should do one of 2 things for the heavy lift vehicle. It all depends on what kind of modifications we want to make to the NERVA 2. We could either use the Ares V to launch all of our cargo (It can fit the NERVA 2) or we could use the Sidemount SDHLV to launch all of our cargo and modify the NERVA to fit within the payload shrouds. (That is, if the Sidemount can even get the NERVA into orbit.)

As for the crew launches, It would probably be best to use the space shuttle for two reasons:
1) We can take cargo to orbit in the same launches that take the crew to orbit.
2) It has the most crew transporting capacity of any existing launch vehicle.
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Old 07-16-2010, 12:19 AM   #112
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Originally Posted by Columbia42 View Post
 As far as the launch vehicles are concerned, I think we should do one of 2 things for the heavy lift vehicle. It all depends on what kind of modifications we want to make to the NERVA 2. We could either use the Ares V to launch all of our cargo (It can fit the NERVA 2) or we could use the Sidemount SDHLV to launch all of our cargo and modify the NERVA to fit within the payload shrouds. (That is, if the Sidemount can even get the NERVA into orbit.)

As for the crew launches, It would probably be best to use the space shuttle for two reasons:
1) We can take cargo to orbit in the same launches that take the crew to orbit.
2) It has the most crew transporting capacity of any existing launch vehicle.

Good points, I thought we where going for Ares V but it doesn't matter to me.

The Space shuttle can only carry 7, if 8 are going, that means we need 2 shuttle launches,

first - 2 STS crew + 4 MM crew
second- 2 STS crew + 4 MM crew

Also the shuttle is retiring, does anyone like being pulled out of retirement?

...and the shuttle needs to be UMMU compatable
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Old 07-16-2010, 12:30 AM   #113
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Originally Posted by Bj View Post
 Good points, I thought we where going for Ares V but it doesn't matter to me.

The Space shuttle can only carry 7, if 8 are going, that means we need 2 shuttle launches,

first - 2 STS crew + 4 MM crew
second- 2 STS crew + 4 MM crew

Also the shuttle is retiring, does anyone like being pulled out of retirement?

...and the shuttle needs to be UMMU compatable
A shuttle can carry up to 11 crew in emergency situations (ISS spontaneous depressurization, etc.). We will only need to make one shuttle launch.

As for shuttle retirement, well, I think we (and the shuttles) can pull it together for something as important as a Mars mission.

The 2010 version of shuttle fleet is Ummu compatible.
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Old 07-16-2010, 01:40 AM   #114
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If not the STS, one more option would be the XR2.

No, really! The realistic settings XR2, launched from the XL-70 or an SRB, carries 11 passengers+2 pilots, possibly UCGO cargo, and is actually pretty in tune with the realism of the rest of this project. Plus you can bet on having a skin to use, there's NASA skins and an X-15 type skin.
Just one more thing to consider.
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Old 07-16-2010, 02:10 AM   #115
Izack
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Originally Posted by Columbia42 View Post
 A shuttle can carry up to 11 crew in emergency situations (ISS spontaneous depressurization, etc.). We will only need to make one shuttle launch.

As for shuttle retirement, well, I think we (and the shuttles) can pull it together for something as important as a Mars mission.

The 2010 version of shuttle fleet is Ummu compatible.
I don't think we should use the emergency capacity of the Shuttle...

And wait, isn't the mission happening in 2003? (Yes, Bj, I read page 3 of the Reference...it's just that now is a good time to bring this up). There isn't much of a difference in spaceflight now than there was in 2003, certainly none on the scale of current spaceflight and a nuclear-propelled Mars Mission.
The record-breaking close approach of Mars in 2003 is an ideal time to fly there, for the same reasons (though not so colossal) as the Voyager missions in 1979 during the planetary alignment.

In 2003, Mars came within 55 760 000km of Earth. Nothing like that will happen until 2050 when it comes to 55 960 000km. The oppositions of 2012, 2014 and 2016 aren't that close by a long shot.

(From this page, which I think will be useful during planning anyway.)
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Old 07-16-2010, 02:25 AM   #116
fireballs619
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Well, we can launch the crew with the cargo (not actually with the cargo, but on the same flight). Perhaps we can use a Soyuz type craft with each cargo launch, so we can minimize the amount of launches needed.
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Old 07-16-2010, 02:38 AM   #117
Bj
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Originally Posted by Izack View Post
 I don't think we should use the emergency capacity of the Shuttle...

And wait, isn't the mission happening in 2003? (Yes, Bj, I read page 3 of the Reference...it's just that now is a good time to bring this up). There isn't much of a difference in spaceflight now than there was in 2003, certainly none on the scale of current spaceflight and a nuclear-propelled Mars Mission.
The record-breaking close approach of Mars in 2003 is an ideal time to fly there, for the same reasons (though not so colossal) as the Voyager missions in 1979 during the planetary alignment.

In 2003, Mars came within 55 760 000km of Earth. Nothing like that will happen until 2050 when it comes to 55 960 000km. The oppositions of 2012, 2014 and 2016 aren't that close by a long shot.

(From this page, which I think will be useful during planning anyway.)
2003 or 2010, whatever. I remember Urwumpe saying Earth-Mars orbits repeats themselves every what?... 2 or 17 years, something like that So if it makes it feel better, you can 'pretend' its 2 or 17 (whatever it is) years from when we start Orbiter

I am not really crabby about starting times, whatever you guys decide.
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Old 07-16-2010, 02:47 AM   #118
Izack
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Originally Posted by Bj View Post
 2003 or 2010, whatever. I remember Urwumpe saying Earth-Mars orbits repeats themselves every what?... 2 or 17 years, something like that So if it makes it feel better, you can 'pretend' its 2 or 17 (whatever it is) years from when we start Orbiter

I am not really crabby about starting times, whatever you guys decide.
I'm not really crabby either. As a simmer, I don't think I'd have a problem pretending anything. The only problem I'd really have would be if the date was too far away from Orbiter's most stable era, so as long as it's some time between 1970 and 2030 it should all be good.

P.S. It was soooo tempting to make a crab joke involving a certain member...
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Old 07-16-2010, 02:51 AM   #119
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Originally Posted by Izack View Post
 I'm not really crabby either. As a simmer, I don't think I'd have a problem pretending anything. The only problem I'd really have would be if the date was too far away from Orbiter's most stable era, so as long as it's some time between 1970 and 2030 it should all be good.

P.S. It was soooo tempting to make a crab joke involving a certain member...
Sorry, I didn't mean to imply that you where at all or anything against you, I guess 'stubborn' (for me) could be a better word

Does this certain member start with a 'B'?
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Old 07-16-2010, 03:02 AM   #120
fireballs619
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I say we pick the date that orbiter was first released- November 27, 2000. Sounds like a good time to me

I think this certain member begins with a 'R' and ends with a 'iver Crab'
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