[Pen and Paper Design] SLS and Falcon-Heavy Launched 570 day Mars Mission

[fredinno]

DISREGARD! GO TO POST #26 FOR NEW VERSIONS!!! (Page 3)

I decided to post my designs for a 570-day 6-person Mars Mission (and simultaneous 2-person Phobos/Deimos Mission) with a 360-day total transit time. It would be launched via 4 Falcon Heavy rockets, 2 SLS Block IB rockets, and 5 SLS Block II rockets.

I know it's not perfect, that's why I posted it here, to be criticized. I wanted it to be realistic and doable within a decent amount of money and science return.

Most of the information can be found on the images themselves. Sorry if you can't see the the writing very well (use the zoom tool at the top right hand corner to see it better)(My bad, I really should've used a pen:() I actually had a long explanation of the spacecraft all written out for you guys, but it got eaten by the Kraken!

Thanks in advance, and if anyone wants to post their pen and paper spacecraft/rocket blueprints here, than feel free to do so!

Edited May 17, 2015 by fredinno

[Dkmdlb]

That's a lot of launches. Reducing the number of launches is good.

[fredinno]

Where would you suggest I reduce the # of launches? For example, do you feel the Skylab II-C is too large? Thanks dude.

BTW, I'm kinda sad you're the only one who bothered to post here...

[Motokid600]

Interesting. I'd love to analyse it, but that site you uploaded the drawings too seems a bit sketchy. I can't click anything without a bombardment of ads. I'd like to be able to open the pic and zoom.

Never mind, sorry the sites just fine it seems.

Pretty good breakdown. To what extent did you do your homework? Are each of these modules the extent of the SLS and F9H payload capacity?

Because, yea your gonna need to do it with less launches. So some modules may have to be consolidated. And I'm a bit confused. Are you proposing a phobos lander as well? Or is Phobos just the name of the lander?

If not you may have to ditch the moons and focus just on Mars. Any missions to Mars's moons would have to be done separate.

Edit: Didnt see the part about the manned moon missions you mentioned. Yea imo that part of the mission would have to be done away with. You might be able to get away with a tiny probe instead however for Phobos or Deimos. Don't think you can hit both.

Edited May 8, 2015 by Motokid600

[Dkmdlb]

For example, do you feel the Skylab II-C is too large? Thanks dude.

To be honest, I looked at one picture and the bad handwriting and poor quality scan turned me off and I didn't look at anything else.

[Bill Phil]

I think you should increase the number of common components. Make them relatively small, too. That way if one fails, the next one is ready to go in a while already. Also make plans for more launches than necessary, allowing for failures.

[fredinno]

Interesting. I'd love to analyse it, but that site you uploaded the drawings too seems a bit sketchy. I can't click anything without a bombardment of ads. I'd like to be able to open the pic and zoom.

Never mind, sorry the sites just fine it seems.

Pretty good breakdown. To what extent did you do your homework? Are each of these modules the extent of the SLS and F9H payload capacity?

Because, yea your gonna need to do it with less launches. So some modules may have to be consolidated. And I'm a bit confused. Are you proposing a phobos lander as well? Or is Phobos just the name of the lander?

If not you may have to ditch the moons and focus just on Mars. Any missions to Mars's moons would have to be done separate.

Edit: Didnt see the part about the manned moon missions you mentioned. Yea imo that part of the mission would have to be done away with. You might be able to get away with a tiny probe instead however for Phobos or Deimos. Don't think you can hit both.

Regarding the Phobos landing, the lander was supposed to land the non-Mars landing components (fuel tanks, Skylab III) on Phobos to refuel, along with 2 people (the other six would go to Mars). My idea was that this would reduce the # of launches for the fuel. I'll replace it with a probe to produce the fuel necessary, and send the 2 astronauts to Mars.

Regarding the payloads, I did do my homework for the most part, but admittedly used high estimates on what the crew would need.

- - - Updated - - -

To be honest, I looked at one picture and the bad handwriting and poor quality scan turned me off and I didn't look at anything else.

Time to get off my lazy ass and redraw. Version 1.1 coming right up!

Edited May 9, 2015 by fredinno

[fredinno]

DISREGARD! GO TO POST #26 FOR NEW VERSIONS!!! (@ Page #3)

Here are the new links for the new spacecraft design: Now with fewer launches, and greater simplicity! (and much easier to read lol.)

Please provide constructive criticism for my design: I want it to be as realistic and doable within a 2030-ish time frame (without breaking the budget)

If anyone could also point out fundamental design flaws (if they exist), also please let me know!

Please and thank you in advance!

Edited May 17, 2015 by fredinno

[stupid_chris]

The thing that jumped to my eyes was that the whole return seems dependant on refueling the return craft at Phobos. While this *is* a good idea, this is also a very precarious one. Deep space refueling has never been attempted in any sorts, and this is entirely dependant on the availability of the required resources on the moon. Not only that, but this also means that if there is any malfunction with any thether or mechanism meant for the refueling, this could end up, very badly. This also sounds like a lot of spacewalking is required, and you'd really want to keep those at a minimum. This could easily jeopardize the whole expedition if anything goes wrong there. That's risky.

[Kryten]

There's also the minor niggling detail that the presence of ice deposits on or in Phobos is purely hypothetical.

Edited May 10, 2015 by Kryten

[meve12]

Interesting concept.

Personally, I would have gone with the Von Braun approach, and used two tugs-one for crew and one for equipment-both with reserve fuel. If the refueling fails, the crew tug can vampire propellant off the equipment tug for the burn home.

But, you know, higher amount of launches.

[ChrisSpace]

I like the plan. This could work. Just a few suggestions:

- I did not see any hard stats on the masses, Dvs, timing, radiators, solar panels, radiation shielding or even crew amount. As a start, try the following links:

Dv map: https://dannypagano.files.wordpress.com/2013/12/wgoy3qt.png

Launch windows: http://clowder.net/hop/railroad/sched.html

Dv calculator (if the nuclear engine is supposed to be a NERVA, set the specific impulse to 825): http://www.strout.net/info/science/delta-v/intro.html

If any of the spacecraft will be using artificial gravity, use this to find out how fast it should spin: http://www.artificial-gravity.com/sw/SpinCalc/SpinCalc.htm

Very important information about radiators, habitat modules and power sources: http://www.projectrho.com/public_html/rocket/basicdesign.php

Very important information about radiation and radiation shielding: http://www.projectrho.com/public_html/rocket/radiation.php

- Is there any way you can present this in a better format? pencil-and-paper is a bit hard to read and stuff.

Edited May 10, 2015 by ChrisSpace

[SciMan]

First thing that jumped out to me is the use of Nuclear Thermal rockets.

Nothing physical preventing it, but barring major changes in international law, those will never fly ever at all.

The 1963 Partial Nuclear Test Ban Treaty and it's follow-on comprehensive version, both prevent it. Even tho they were designed to prevent nuclear WEAPONS testing, IIRC the way they are worded also prevents the use or testing of nuclear reactors in space.

It would be nice if they could change the wording of that to allow nuclear reactors for power and propulsion uses in space, but I doubt that's going to happen anytime soon.

Politics preventing meaningful progression of human civilization yet again, nothing new there.

[Kryten]

IIRC the way they are worded also prevents the use or testing of nuclear reactors in space.

You recall incorrectly.

[SciMan]

You recall incorrectly.

That's one thing that I'll be happy to be wrong about!

So why is it that nobody's flown an NTR in orbit yet? Not even a small one? Or a nuclear powered ion drive craft, for that matter?

Is it just a matter of need? Massive PR flak from any attempt to launch something with the "N-word" (Nuclear) on board? Something else?

[Kryten]

No need.

[fredinno]

Interesting concept.

Personally, I would have gone with the Von Braun approach, and used two tugs-one for crew and one for equipment-both with reserve fuel. If the refueling fails, the crew tug can vampire propellant off the equipment tug for the burn home.

But, you know, higher amount of launches.

I considered this, but I'm probably going to use ion drives for going to and from Mars. My only worry is that the ion drives will not be powerful enough. Thanks for the suggestion though.

I like the plan. This could work. Just a few suggestions:

- I did not see any hard stats on the masses, Dvs, timing, radiators, solar panels, radiation shielding or even crew amount. As a start, try the following links:

Dv map: https://dannypagano.files.wordpress.com/2013/12/wgoy3qt.png

Launch windows: http://clowder.net/hop/railroad/sched.html

Dv calculator (if the nuclear engine is supposed to be a NERVA, set the specific impulse to 825): http://www.strout.net/info/science/delta-v/intro.html

If any of the spacecraft will be using artificial gravity, use this to find out how fast it should spin: http://www.artificial-gravity.com/sw/SpinCalc/SpinCalc.htm

Very important information about radiators, habitat modules and power sources: http://www.projectrho.com/public_html/rocket/basicdesign.php

Very important information about radiation and radiation shielding: http://www.projectrho.com/public_html/rocket/radiation.php

- Is there any way you can present this in a better format? pencil-and-paper is a bit hard to read and stuff.

I did include hard stats on the masses and listed the crew amount (8). I probably will include a stat page after this for all that other stuff though. Thanks for your help!

I probably can't present this in a better format, (w/o AutoCAD or other tools) sorry. Have you used the zoom tool on the upper left hand corner?

- - - Updated - - -

The thing that jumped to my eyes was that the whole return seems dependant on refueling the return craft at Phobos. While this *is* a good idea, this is also a very precarious one. Deep space refueling has never been attempted in any sorts, and this is entirely dependant on the availability of the required resources on the moon. Not only that, but this also means that if there is any malfunction with any thether or mechanism meant for the refueling, this could end up, very badly. This also sounds like a lot of spacewalking is required, and you'd really want to keep those at a minimum. This could easily jeopardize the whole expedition if anything goes wrong there. That's risky.

Where do you believe I would need spacewalking, stupid_chris? I'm thinking the connector struts between the modules, but I'm just checking. I'll probably make the use of ion drives to fix the refueling problem, though. (I'll probably need a fission reactor!) Thanks in advance.

Any more suggestions would be greatly appreciated! (V1.2 probably coming up sometime this week. Sort of busy.)

Edited May 10, 2015 by fredinno

[ChrisSpace]

I did include hard stats on the masses and listed the crew amount (8). I probably will include a stat page after this for all that other stuff though. Thanks for your help!

Oops. Okay, I did not see that. Anyway, I have a few more ideas/suggestions:

- I am pretty sure the mega SLS can only launch 130mT into low earth orbit, not 150. And the block I and IB only lift 70mT and 100mT, not the 100 and 130 you stated. So the exact module masses and launch vehicle types for them will have to change around a bit.

- You mentioned a Methalox-propelled SSTO lander using ISRU to refuel on the surface of mars. Entering mars orbit from the surface requires about 3650m/s of Dv, so a lander with a full mass of 40mT using a 'raptor' engine would need 25mT of Methalox fuel capacity, leaving only 15mT for the structure, habitat, engines, etc etc. Luckily this can be partially solved by the fact the falcon heavy can lift not 40 but 53mT into low earth orbit. Our 53mT lander will need 33mT of Methalox fuel, giving a slightly better 20mT for everything else. If we use the mega SLS, our 130mT lander can have a dry mass of 49mT, which will be enough for our 8-person expedition.

- Instead of using 'tin can' modules for the orbital vehicle, it would be a much better choice to use Bigelow Aerospace's BA 2100 module. It can easily be launched on an SLS, can accommodate the crew of 8 easily and is more radiation and micrometeoroid resistant than other designs. more info can be found at https://en.wikipedia.org/wiki/BA_2100

- I still cannot see any flight timeline. Using the launch windows link provided, what do you figure the (TMI, Mars arrival, Mars landing, Mars liftoff, TEI, Earth arrival) time schedule to look like?

- Are the sizes of the NTR propellant tanks just guesses, or are they based on the real density of liquid hydrogen?

- In case Orion can't be used, there should be a backup plan to use the SpaceX Dragon V2. Similarly, there should be a plan to use China's LM-9 (100mT payload to low orbit) as a backup for the SLS

[jfull]

The thing that jumped to my eyes was that the whole return seems dependant on refueling the return craft at Phobos. While this *is* a good idea, this is also a very precarious one. Deep space refueling has never been attempted in any sorts, and this is entirely dependant on the availability of the required resources on the moon. Not only that, but this also means that if there is any malfunction with any thether or mechanism meant for the refueling, this could end up, very badly. This also sounds like a lot of spacewalking is required, and you'd really want to keep those at a minimum. This could easily jeopardize the whole expedition if anything goes wrong there. That's risky.

I think the solution would be to extensively test the technology on a near-earth asteroid, then send the resource collector craft to Phobos long before the manned components of the mission are launched.

Only after it produces the fuel necessary for the return trip would the rest of the mission be launched to Mars

[fredinno]

Oops. Okay, I did not see that. Anyway, I have a few more ideas/suggestions:

- I am pretty sure the mega SLS can only launch 130mT into low earth orbit, not 150. And the block I and IB only lift 70mT and 100mT, not the 100 and 130 you stated. So the exact module masses and launch vehicle types for them will have to change around a bit.

- You mentioned a Methalox-propelled SSTO lander using ISRU to refuel on the surface of mars. Entering mars orbit from the surface requires about 3650m/s of Dv, so a lander with a full mass of 40mT using a 'raptor' engine would need 25mT of Methalox fuel capacity, leaving only 15mT for the structure, habitat, engines, etc etc. Luckily this can be partially solved by the fact the falcon heavy can lift not 40 but 53mT into low earth orbit. Our 53mT lander will need 33mT of Methalox fuel, giving a slightly better 20mT for everything else. If we use the mega SLS, our 130mT lander can have a dry mass of 49mT, which will be enough for our 8-person expedition.

- Instead of using 'tin can' modules for the orbital vehicle, it would be a much better choice to use Bigelow Aerospace's BA 2100 module. It can easily be launched on an SLS, can accommodate the crew of 8 easily and is more radiation and micrometeoroid resistant than other designs. more info can be found at https://en.wikipedia.org/wiki/BA_2100

- I still cannot see any flight timeline. Using the launch windows link provided, what do you figure the (TMI, Mars arrival, Mars landing, Mars liftoff, TEI, Earth arrival) time schedule to look like?

- Are the sizes of the NTR propellant tanks just guesses, or are they based on the real density of liquid hydrogen?

- In case Orion can't be used, there should be a backup plan to use the SpaceX Dragon V2. Similarly, there should be a plan to use China's LM-9 (100mT payload to low orbit) as a backup for the SLS

Regarding the SLS rocket payload sizes: "Oops".

The MAV is supposed to only launch the astronauts and a little more (samples, for example), so I'm thinking that the actual capsule minus fuel and fuel tanks would be ~10-15T. The relatively low weight of the MAV was intentional due to this low payload mass. Do you think doing this would be a bad idea?

I'll consider using the BA 2100. I'm actually aware of the inflatable designs, but I doubt I'll need so much space for the interplanetary flight (Skylab II is also relatively cheap and micrometeorite-resistant due to using modified fuel tanks. http://en.wikipedia.org/wiki/Skylab_II ). Probably I will end up using it to scrap the Skylab II lander modules, and just end up landing a single 100 mT BA 2100 on Mars (instead of 2 Skylab IIs). Thanks for the suggestion.

I forgot flight time-lines in V1.1. I originally intended the spacecraft to launch in the 2040 launch window, with orbital construction occurring over a year. I might have to completely recalculate everything though, now that I have Mars Launch windows.

Lastly, regarding backup systems, I'll list backup rockets, (though I'd rather not use them due to a smaller payload, and in the case of LM-9, less flexibility) but not backup return/launch systems(You could use almost any spacecraft that docks and holds crew, but you would need 4, rather than 2 launches, as only Orion's systems can survive deep space.

Thanks for the incredibly long list of suggestions.

- - - Updated - - -

I think the solution would be to extensively test the technology on a near-earth asteroid, then send the resource collector craft to Phobos long before the manned components of the mission are launched.

Only after it produces the fuel necessary for the return trip would the rest of the mission be launched to Mars

I don't think it would work, as the NEO selected could be different than the composition of Phobos. I'll stick to my original plan of changing the fuel type.

[ChrisSpace]

The MAV is supposed to only launch the astronauts and a little more (samples, for example), so I'm thinking that the actual capsule minus fuel and fuel tanks would be ~10-15T. The relatively low weight of the MAV was intentional due to this low payload mass. Do you think doing this would be a bad idea?

No, in fact it is quite clever. I was under the false impression the MAV would be where our crew lived for the whole surface expedition.

Other than that, everything seems good, I am still curious about the NTR hydrogen tanks. Are the volumes of the tanks just a random guess or are they calculated using the density of liquid hydrogen? And what kind of NTR is being used? A NERVA?

[Rune]

That's one thing that I'll be happy to be wrong about!

So why is it that nobody's flown an NTR in orbit yet? Not even a small one? Or a nuclear powered ion drive craft, for that matter?

Is it just a matter of need? Massive PR flak from any attempt to launch something with the "N-word" (Nuclear) on board? Something else?

The massive development cost, mostly (build the facility where you can test a nuclear rocket, mostly, including capturing the exhaust and the pieces of the very radioactive engines you test to failure like you should). Plus the lack of real need (they would sure be nice to have), and the fear of the N-word, of course.

As to design tips, well, capture at a highly elliptical orbit saves a lot, since you can save delta-v for the most massive components, namely the interplanetary Hab and the return stages. More of a job for the MAV, but that can refuel on the ground and do it in two legs. Then coming back from that barely-captured orbit is a breeze, which requires smaller return stages that can be chemical, which requires smaller stages to bring them to Mars in the first place...

Rune. Google the Von Braun Mars '69 plan, it's full of nice ideas.

[fredinno]

No, in fact it is quite clever. I was under the false impression the MAV would be where our crew lived for the whole surface expedition.

Other than that, everything seems good, I am still curious about the NTR hydrogen tanks. Are the volumes of the tanks just a random guess or are they calculated using the density of liquid hydrogen? And what kind of NTR is being used? A NERVA?

The tanks are a guess. I was planning on replacing them anyways, though. The NTR, though, was intended to be a NERVA engine, or a variant.

[ChrisSpace]

For the tanks, Wikipedia says molecular liquid hydrogen has a density of 70.85 kg/m3. So each 1mT of the stuff would have a volume of 14.114m3. If our tanks are 10m wide, this means each 1mT of propellant will add 0.1797m of height.

As for the NERVA, Atomic rockets says it has an isp of 825s, a thrust of 49kN and a mass of 10mT. This all sounds doable.

[ChrisSpace]

Okay, some more propulsion-related calculations:

Each vehicle has a 130mT nuclear propulsion stage using an NTR similar to the NERVA. the NERVA had a mass of 10mT, and the tank/docking/RCS systems will probably add another 10mT. This means our vehicles will each have 110mT of liquid hydrogen propellant, and tank dimensions of 10m wide and 19.767m long. According to the Dv map I posted, a transfer from LEO to low mars orbit requires 2440 + 680 + 90 + 390 + 670 + 340 + 400 + 700 = 5710 m/s of Dv. With 110mT of propellant and an isp of 825s, this means I should be able to calculate how much payload the mission can allow. I have been looking for a rocket equation calculator which uses propellant mass and Dv to find the dry mass, but all the calculators I find only use the wet/dry masses and not the propellant/dry masses. Can anybody help?