Mars 9 tons at a time.

[no_way]

I dont see how number of engines has anything to do with anything here, as you can certainly do both powered landing and TMI burn for instance with single gimballed engine.<br />Apart from that, maybe engine sizes and thrust just wouldnt match up and thats a valid reason.

 

[j05h]

<i>> I dont see how number of engines has anything to do with anything here, as you can certainly do both powered landing and TMI burn for instance with single gimballed engine.<br />Apart from that, maybe engine sizes and thrust just wouldnt match up and thats a valid reason.</i><br /><br />Not sure about Delta, but the upper stage Centaur on Atlas uses different number of engines for different missions. All proposed upgrades to Centaur (per Lockheed's Atlas Evolved pdf) would use between 1 and 6 engines. Different orbits and uses require this, and the modular construction approach (like SpaceX) allows them to tailor the upper stage simply. Every pound saved increases available payload.<br /><br />An interesting note on both the Wide Body Centaur and some of the applications we've discussed lately. The line between upper stage and payload will blur as new needs come online. Centaur has gotten a lot of attention lately, Lockheed has tremendous heritage and operational experience to leverage. Turning that experience into restartable deep-space tugs, lunar landers and other tasks only makes sense. Their recent work with various new.space companies and the Lunar Lander study show that they understand the potential for this vast new market. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[aftercolumbia2]

I haven't read through this whole, rather monstrous thread, but I did an F3 search on every page for key words that should show any reference to what we're working on...none came up. It would appear that you are totally unaware of MarsDrive Consortium's work to solve the launch problem of Mars human exploration.<br /><br />Hmm...I'm not sure how to do this in any sort of way that doesn't look like I'm spamming this particular forum...so...mebbe...:literally scratches head:...sorry for spamming this forum. <img src="/images/icons/smile.gif" /><br /><br />MarsDrive Consortium has one completed study and one study in progress about how to launch human missions to Mars using smaller boosters, existing mediums if at all possible. The first plan was called Mars For Less, by Grant Bonin ( http://www.marsdrive.com/component/option,com_docman/Itemid,49/task,doc_view/gid,2/ ), and the second plan was originally called Mars For Way Less in honor of Bonin's original work, but is now called simply the MarsDrive Mission.<br /><br />The first one launched the two Mars Direct mission elements using six medium launches each, rather than one big launch. One launch was the payload, the second launch was the EDLS (layman: "lander") and the other four launches were all upper stages (later christened "Proteus" by Antonio Maia, who built the mission in the Orbiter spaceflight simulator.) Each Mars Direct equivalent launch was became one of these "trains".<br /><br />The second one is a team effort led by Terry Wilson (me) and has "SpaceNutNewMars" as a major participant...that was the fellow who alerted us to this thread (he must be dang near the best Internet sleuth in existence.)<br /><br />MarsDrive Mission recognizes that the choke point isn't the booster, but is actually the lander...getting from the end of your interplanetary trajectory to the surface of Mars safely...the terrifyi

 

[j05h]

AfterColumbia: I'm aware of the MarsDrive mission design, FrankMars posted about it. I signed up on the site but couldn't find the thread. I like MarsDrive's work and attitude, and also 4Frontier's older base design. I'd be interested in contributing to the MarsDrive plan but am somewhat pressed for time (except the past few days, on VACATION) You are welcome to mine this thread, Private Mars Missions or any of my others for ideas. <br /><br />I started this thread because it asks a simple question. What is the goal? The goal is not "build a huge rocket" or to satisfy a constituency. The goal is to build a viable outpost on Mars, to start sooner and make money doing it.<br /><br />A sweet realization has been that Sundancer, Dragon, Soyuz and Progress are all pretty close to what current (not upgraded) EELVs can throw trans-Mars. If you could launch 3 people in a Dragon (on Atlas V or Delta IV) and a SunDancer a week or two later (surge launch), the two craft would meet enroute, aerobrake together and provide a limited, expandable spacestation. As you point out, the hard part is still getting to the surface. <br /><br />Part of the solution is separating planetary capture from EDL. There should be an optimal number of aerobraking passes that limits heating greatly (I"m aiming at reusable craft). A dedicated Lander/Ascender is delivered for bringing payload from staging orbit to the surface. The only thing I'm proposing that does direct-entry is heavy equipment on unpressurized "pallet" landers. <br /><br />The idea is to get to Mars in such a way that everything adds to a growing base. It's initially laid out with precursor missions, so in some ways starts as a "robot base", with humans landing between 8 and 16 years after first robots. This is also an opportunity for orbiting crews to do tele-ops before a lander is available. <br /><br />Small packages are likely the way to go (for comparative early access), and provide the right size package for individual products from var <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[aftercolumbia2]

Er...you probably won't want to go cooped up in a little crew ferry for 6-8 months...where are you going to store your supplies?...and you'll need to give up your service module to aerocapture, then you last three hours when there's still about two years of mission to go...<br /><br />Not so simple, drat.<br /><br />There is a need to get to the surface, because the use of the Martian atmosphere is so important. You can make as much oxygen as you want (pick either RWGS, which uses hydrogen as a "catalyst" or direct electrolysis of carbon dioxide via a zirconium reactor...like Vozdukh.) If you can get water from Mars, so much the better. You won't get any of that if you stay on orbit...and you won't get much of it if you stay on Phobos (IMHO, that is a very silly idea...I think Buzz was buzzed when he endorsed that idea in Popular Science (about three years ago.))

 

[j05h]

Dragon and SunDancer together are plenty of room and resources for outbound transit. I don't know what the Dragon's lifespan is without it's SM, but it might be worth trying to aerocapture with the SunDancer attached. I'm just questioning the need for direct entry - nothing is simple.<br /><br />The surface is interesting, but hard to access right now. We have 99% of the tech to explore Mars from orbit. ISRU in all it's forms is critical, especially if the goal is to mine Mars. I don't understand the prejudice against Phobos on these boards. Water is available in select locations on Mars - the poles, Elysium and possibly in Marineris.<br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[spacester]

I agree JO5H, direct entry is not my idea of running routine operations in the Martian gravity well. If the goal of the settlement is also to build infrastructure, IMO we need to get used to orbital operations as the natural domain of true spaceships. IOW we need to bring enough fuel and engines with us to do the necessary orbital operations to support the rest of the program's activities. <br /><br />Among which should be Phobos. And of course we need Martian landers.<br /><br />I for one am not phobosphobic. It's just that it's an unconfirmed resource, and hard to envision as a centerpiece of a space architecture just because of that. <div class="Discussion_UserSignature"> </div>

 

[solarspot]

I have a slight concern about a MAV for a plan like this. What if it can't be designed with a dry-mass low enough to ship in one piece to the surface? Is there any way a modular vehicle could be assembled in orbit before decent or on the surface before launch, with the minimal infrastructure available? I'm uncertain about whether that rover/excavator would be able to lift parallel liquid boosters into place and attach it to the core vehicle... Would this be necessary?<br /><br /><br />

 

[j05h]

<i>> I have a slight concern about a MAV for a plan like this. What if it can't be designed with a dry-mass low enough to ship in one piece to the surface?</i><br /><br />A Mars ascender can be either SSTO or TSTO, the mass fractions for Mars are much, much easier than Earth. Roughly, at 5-8t dry mass, the craft will hold 50-80 tons of LOX and Methane and deliver several crew back to orbit. If it needs to be stacked on the surface, the first stage could be a "Fregat" type stage (short and squat) that a Dozer stacks the second stage onto. Parallel boosters are generally disregarded, if you look at most proposed missions, Mars ascent stages are simple, serial stacks of stages.<br /><br />Mars Lite generally will require splitting segments of the journey to achieve economic scales. Crew will travel to and descend to Mars in one vehicle, live in a different base, leave Mars on another craft and transit to Earth in yet another. I do think something like Soyuz or Dragon makes a good basic chassis for developing some of these craft.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>> I agree JO5H, direct entry is not my idea of running routine operations in the Martian gravity well. </i><br /><br />Thanks. It just seems to make sense to stage from orbit, especially as reusable lander and ascender craft become available. A space station or Phobos/Deimos base provides global access to Mars. Orbital operations greatly increase the effectiveness of ground-side ops. <br /><br />Each crew mission in this scenario leaves 1 or 2 SunDancer modules in Mars orbit. One or several precursor flights would deliver early orbital components like Martian moon explorers, comsats and probably a Node. <br /><br /><i>> I for one am not phobosphobic. It's just that it's an unconfirmed resource, and hard to envision as a centerpiece of a space architecture just because of that.</i><br /><br />The biggest question for either of Mars' moons is whether there is water. Did you read "Private Mars Missions" on this forum? We covered Phobos a bunch in that. My take is that worst case, both Phobos and Deimos are captured, depleted C-type asteroids. That usually only applies to surface features, it is reasonable to assume that there are hydrous materials at some depth on each body. Basing from Stickney Crater on Phobos would provide decent shielding, even if there is no water. <br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[solarspot]

"Parallel boosters are generally disregarded, if you look at most proposed missions, Mars ascent stages are simple, serial stacks of stages."<br /><br />I've noticed that. However most proposed missions have mass budgets much larger than 9t per launch. Also regarding serial stacks, could a dozer do this? I prefer stacked stages for Earth launch vehicles, but there are no cranes on Mars. I suppose tho, if predesigned with this in mind, a dozer may be able to lift an upper stage onto a squat first stage...<br /><br />"something like Soyuz" Would this be workable for a Mars plan? Soyuz craft have severely limited on orbit storage times... Perhaps this isn't a show-stopper for use certain concepts/components, but I'm not aware of any direct use for Soyuz hardware except carrying the crew into space, perhaps to a Sundancer on a trans-mars trajectory. But it would need to be discarded after that.<br /><br /><br />

 

[j05h]

<i>I've noticed that. However most proposed missions have mass budgets much larger than 9t per launch. Also regarding serial stacks, could a dozer do this?</i><br /><br />One possibility would be to use the same standardized cargo containers as parallel drop-tanks for the ascent craft. I've been assuming that it is a large, light craft instead. The Dozer would have a bunch of attachments for both a ground-level and turreted arm, it is closer to a small excavator than bulldozer. One or several dozers working in concert should be able to stack a launcher. <br /><br /><i>> <br />"something like Soyuz" Would this be workable for a Mars plan? Soyuz craft have severely limited on orbit storage times... Perhaps this isn't a show-stopper for use certain concepts/components, but I'm not aware of any direct use for Soyuz hardware except carrying the crew into space, perhaps to a Sundancer on a trans-mars trajectory. But it would need to be discarded after that. </i><br /><br />Energia's "MarsPost" would use regular Soyuz for Earth access and a Soyuz and Fregat derived Mars Ascender. It would be the familiar crew module, a service module as second stage and Fregat derivative for first stage. Long-duration modifications aren't to hard, especially considering the heritage of that hardware. My critique is that these concepts use fuels that aren't easily made on Mars. LOX and CH4 are the way to go IMHO. <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[spacenutnewmars]

Hi J05H you indicate that the MAV can be either SSTO or TSTO with a probable mass fractions for Mars of 5-8t dry mass, the craft will hold 50-80 tons of LOX and Methane and deliver several crew back to orbit.<br /><br />My question is how much from orbit would this be since we have difficulty landing even a few metric Tonnes to the surface with Parachutes, bouncing ball and maybe a skycrane for MSL in the near future?<br /> <br /><br /><br />Good to see you here aftercolumbia2, do not give up on this dream as it may prove to be a good parallel effort.<br /><br /><br />I do not have any images for the SunDancer of the internals, detail drawings or any other means at our disposal to work from but IMO this maybe the Strike one against an inflatable designed habitat for transit use. Until such information is available to allow determination aspects of this issue it could be the reason for not using inflatables other than on the surface of mars. <br /><br />All the panels, wiring ECT.. would have special needs for them to be adhered to the walls and protection from the crew as the wiring would most likely be in a plastic flexible conduit or pipe. But this will be an at risk hazard since there are no internal walls which would protect or hide the wiring from being used as a hand hold when moving about in 0g while in transit. Even the ISS had one incident where the vacuum line for the US built windows needed to have it replaced for that reason. <br /><br />There is also the need for water and this could be even more dangerous of a condition for the exposed plumbing as it could be in this module if its use is other than a habitat such as a green house hydroponics area. <br /><br />While the issue may have a mitigating solution of flat panel roll over strips being place over these areas the more wiring that is needed in the module to more the risk is increased. It is IMO a lesser problem for on mars surface use though since there is no free floating or at least less chance for this conditi

 

[thereiwas]

The external walls of a Bigelow structure are self supporting, but I doubt they are intended to be the final interior surface. The Genesis photos show too much exposed plumbing, wiring, and structural stuff. I expect there would be an inner wall to hide all that in a finished SunDancer. Just like the water tanks for radiation shielding get stuck in place after deployment (by the first occupants) I expect there would be a lot of "finish carpentry" to fit out the insides to meet the mission requirements. You wouldn't expect it to deploy from its squashed launch configuration and have all the cabinets, beds, toilets, and pool table already in place like a pop-up book. (Hmm - what would the zero-G 3-D equivalent of billiards be like?)

 

[spacenutnewmars]

I am wondering as well how well a various of the SunDancer would stand up to dust storms on Mars as well as another that in one kkattula2 of nasaspaceflight who posed the question on atmospheric pressure on Mars and A 400 kph sandstorm?<br /><br />Data equations in response were from another member A_M_Swallow of said same <br /><blockquote><font class="small">In reply to:</font><hr /><p>thrust T = V dm/dt <br />400 kph = 111 m/s <br />Mars air density = 0.020 kg/m^3 (significantly higher when carrying sand.) <br /><br />T = 111 * 0.02 = 2.2 N/m^2 <br /><br />Size of 6 berth caravan ( Sterckeman Star 486CE) <br />5.00 x 2.15, approx height 2.5 metres <br /><br />Total force 2.2 * 5.0 * 2.5 = 27.5 N <br /><p><hr /></p></p></blockquote><br /><br />But what can the unit withdstand?

 

[j05h]

<i>> My question is how much from orbit would this be since we have difficulty landing even a few metric Tonnes to the surface with Parachutes, bouncing ball and maybe a skycrane for MSL in the near future? </i><br /><br />The Lander would mass between 5 and 8.5t empty. Ideally it also fills the Ascender role. The Lander is sized to hold a standardized cargo pod, deorbit and land without dropping any parts. It then takes on many tons of LOX and CH4, berths a new pod (crew usually) and launches to Mars orbit. Rinse and repeat. <br /><br />Reusability and the modular system are probably for second-generation delivery. The first several flights to Mars using this idea would probably use variations on the "pallet" lander proposed for heavy equipment. A reusable Lander/Ascender and it's payloads would take a while longer to develop. There are extremely strong economic incentives to make every element reusable in some way, especially with ISRU methane and water available.<br /><br />The landing method is open to discussion. My preferred solution is a miniature of the "Mars Spider" craft I described recently - but that assumes the reusable Lander/Ascender. The "pallet" lander is proposed to use a Mercury-style dropping airbag with parachutes and maybe retros, perhaps this could be adapted to all the (non-reusable) landings. The issue is somewhat stagnant because it is both critical and flexible (as new items come online), so whatever works. <br /><br />The real issue, as I see it, with landing is whether the payload can go in direct-entry or needs to be staged from Low Mars Orbit. One can be done in a singular module or as a pod berthed to a dedicated Lander, the other is currently state-of-the-art but not good for crews or sensitive cargo. Generally I have disregarded the Bouncing-airbag method because of payload mass (to high) and the random-Gs from bouncing. Thoughts?<br /><br />Don't worry about the Bigelow habitats - examine their website and the patents for their hardware <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[solarspot]

Some potential issues in deceleration in Mars's atmosphere are covered in this PDF report <br /><br />I do not recall where I initially found the link to that report, so my apologies if it was linked to previously in this thread. My memory is not so detail oriented that I remember where I find every report I read... <img src="/images/icons/frown.gif" /> <br /><br />Could that affect plans for light weight crewed ascent vehicles?<br /><br /><br />

 

[thereiwas]

Very interesting paper. To me it says that entering orbit before landing is a very good idea, and that research into expandable very large 'balute' aeroshells could pay off big. The former reduces the initial entry velocity. The latter gets us away from the Earth launch vehicle setting a limit on aeroshell diameter.

 

[keermalec]

I fully agree. Ballutes are the way to go. A typical hard aeroshell weighs in at around 15% of a vehicle's mass, and a ballute much much less. Reducing by so much the mass that must be launched from Earth at 10'000'000 USD/ton... <div class="Discussion_UserSignature"> <p><em>“An error does not become a mistake until you refuse to correct it.” John F. Kennedy</em></p> </div>

 

[j05h]

How about a ballute that provides deceleration at Mars atmosphere, then becomes part of a ram-air airbag during landing? This would require a drop-down heatshield (that is not to heavy to negate) and one segment of the ballute tough enough to handle landing. It would use retros as well, where needed.<br /><br />This would be a potential method for greatly reducing the mass of EDL hardware for pallet landings and potentially crew landings. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[thereiwas]

I have seen designs for both leading and trailing ballutes. For what you suggest it would have to be the leading kind, that expends around and in front of the spacecraft. Then retros can be used early (like the rovers) or late (like Soyuz). I don't think you could combine a leading ballute/airbag with late-firing retros.<br /><br />It is probably easier at this point to treat the re-entry and deceleration problem separately from the safe touch-down problem.

 

[j05h]

This would be a leading ballute. There would be 2-3 options for retros: as part of a traditional backshell-tether combo or ejecting the outer part of the ballute or (very challenging) integrate the retros along the outer rim of the ballute. The solution I'm looking for allows delivery of either "pallet" or pressurized modules. <br /><br />My interest is in reducing the weight of the whole EDL package, to maximize, then standardize a delivery system. do you have suggestions? <br /><br />The Ballute-airbag would be a combination of these technologies:<br /><br />ILC Dover Ballute<br />Mercury Recap<br /><br />EDIT: If it's possible to land with the heatshield attached (afforded by lightweight metal HS?), then the whole package could be latched down and easily dragged without damaging the payload. This would require new HS tech.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[thereiwas]

Perhaps a hard central HS, which takes the worst of the heating then serves as a skid as you suggest, combined with an expandable ballute outside that to increase the area beyond what the launcher shroud can accommodate.<br /><br />Such a skid idea would put limitations on the sort of terrain you could use it on. The Vikings and Pathfinder landed in fields of coarse basalt boulders.

 

[j05h]

<i>> Perhaps a hard central HS, which takes the worst of the heating then serves as a skid as you suggest, combined with an expandable ballute outside that to increase the area beyond what the launcher shroud can accommodate.</i><br /><br />That's what I'm talking about. <br /><br /><i>> Such a skid idea would put limitations on the sort of terrain you could use it on. The Vikings and Pathfinder landed in fields of coarse basalt boulders.</i><br /><br />For "9 tons" these kind of landers are all landing inside a tight ellipse at a base. By definition the landing ellipse would be chosen for smoothness. Elysium has huge stretches of flat or undulating smooth terrain. There would also be beacons to aid in the drops.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[thereiwas]

Another complication then. Descent path corrections necessary for precise landing generally rely on some amount of L/D and attitude control for steering. That might require a more rigid sort of ballute, with edge flaps for steering. The image I posted from that Bill Stone TED conference showed something like that.<br />