Mars 9 tons at a time.

[j05h]

<i>> All the crew does not have to go in the same vehicle. And the way they go need not be the way they come back. </i><br /><br />Yes! 6 crew might fly to Mars orbit in 2 SunDancers (with or without prop. bus), descend together in a dedicated lander and return directly to Earth in 2-3 modified Dragon capsules with ascent stage. This also follows Rutan's "Flotilla" which just plain makes sense. Alternatively, they could fly orbit to orbit in a full "station" (assume Bigelow components) and descend in separate 2-seat reusable Landers. LEO assembly makes more sense long-term, but "Mars Lite" has an advantage in being able to start sooner and put people on Mars sooner than other options. <br /><br />In the 9-ton concept, several capsules could be thrown along with service/resource modules (SM, like SunDancer/FGB with more stores). The capsules dock with individual SMs, then dock during transit (or spin?). At Mars aerobrake, they are separate and can meet a growing complex in low orbit later. Crew descend in their transit capsule or other lander. A dedicated lander (also thrown singly at Mars via ELV) delivers standardized cargo modules (both pressurized and pallet), refuels on the surface and returns to the orbital base. <br /><br />(crew size assumption: 2-4 people per capsule-SunDancer stack for a Mars crew of 4-8, expected to serve a 5-year rotation minimum)<br /><br />The minimal configuration for a putative crew "Flotilla" is a surge-launch of X ELV-class payloads in a single Mars window (roughly 2 months). First, two provisioned SunDancers are launched TMI on ELV (pick one: Atlas, Delta, Ariane and Proton are roughly equivalent). A third is prepared and a fourth in backup. The two crew capsules (modified Dragon or similar) are thrown TMI, followed by the backup SunDancers and any other hardware before the window closes. At a minimum, this is 5 launches (3 SD, 2 Dragon) delivering 4-8 people to the surface. Roughly this would cost $1.25G in launchers, plus payload. <</safety_wrapper> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>> Sounds like some design questions can't be answered without more prospecting. I still like the idea of a commitment to sending a continual tonnage. </i><br /><br />Continual supply is a serious commitment. Either corporate or government mission, this says that it is sustained and won't be abandoned. In some ways this is a high-mass Mars mission - it just doesn't arrive all at once. 5-10 launches to Mars per 26 month opportunity is 45-90t on/orbiting Mars per window. That's almost 500t to Mars over a decade.<br /><br /><i>>How about some sort of robotic workhorse, in decent numbers... Phobos</i><br /><br />That's the plan. Pressurized crew/robotic rovers, a Dozer with attachments, smaller rover/dozer chassis. Generally, crew are there to operate remote machines in realtime. This can include mining, base-construction and exploration. With the right software, one person can operate several vehicles on routine tasks.<br /><br />"Mars 9 tons at a time" is conceptually related to my "Private Mars Mission" thread from a while ago: how do we start sooner, cheaper (and better)?? Tele-ops and water mining seem to be great "anchor" operations for a commercial firm. <br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>> Total crew size and therefore total crew mass is a vital aspect of the total mission mass. </i><br /><br />This makes more sense for a singular mission than a system for increasing Mars' population. <br /><br />For crew transfer, I'm more interested in getting specific vehicle enroute and docked than actual crew numbers, if that makes sense. Like an airliner, for conceptual purposes I'd rather set a baseline for crew per craft than total crew - going with the "Flotilla" concept. 4 light females might squeeze into the same space as 3 large men, but would challenge the life support system in some ways, especially CO2 and water use. In general I've assumed crew of 2-4 per capsule/SunDancer. We can specify better numbers if an actual capsule can be picked - but again choice is nice. A Soyuz capsule is in the range that ELV can throw TMI, as is Dragon and potentially "Excalibur-Almaz" systems. All would practically require a SunDancer or other cargo block during transit.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

Possible Mars Lite flight profile, through several flight windows. Assumption is that each payload is delivered to Trans Mars Injection by existing ELV. Generally, payloads are in the 5-9 ton range, following Delta IV Heavy's 17,600 lbs TMI.<br /><br />This mission is geared toward establishing a water-mining outpost at Elysium Planitia. The base is to host explorers and provide tele-operation for other Mars interests. In a single flight of 4 crew, two might be Company, two might be guests. <br /><br /><br />Flight Zero happens on a first opportunity. Flights 1-3 or 1-5 happen in the second opportunity. Flights 4-8 are in the third window. Flights 9-13 arrive at the fourth opportunity, delivering the first crew after 8 years of site preparation. Further flights can occur either in that window or ongoing, so the second capsule with crew can either be a month behind or 26 months behind. Crew missions are designed to overlap and the company encourages re-upping with generous bonuses.<br /><br />Flights Zero through 6 use direct entry at Mars, further flights use a mix of direct entry and multi-pass aerobraking.<br /><br />0 - Precursor: 9t direct-entry payload including rovers and scout/sample hardware. Ejection canisters put microsats into orbit. Tests direct-entry landing system. Scouts specific site, identifies local resources. Pre-places a landing beacon. <br /><br />1 - Beacon/SolarPV/ISRU - 9t direct entry payload delivers a more powerful beacon at final landing site. Rovers deploy PV. ISRU tests/intial LOX/CH4/H20 production. <br /><br />2 - Nuke<br />3 - Dozer <br />4 - Water mining hardware<br />5 - Rovers, dozer attachments<br />6 - power: nuke or PV<br />7 - reusable Lander/Ascender<br />8 - inflata-tanks (large capacity, expandable tank)<br />9 - supplies: food, kit, MPC suits<br />10 - Hab1: Surface SunDancer or tin-can<br />11 - Lander 2<br />12 - SunDancer/ERV "Lite"<br />13 - Crew 1 - Dragon capsule or Equiv.<br />14 - supplies: food, kit, MPC suits<br />15 - Airlock/Node<br />1 <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[JonClarke]

Probably better not to use the word "cycler" then, which has a very specific historic meaning. Reusable MTV might be better <img src="/images/icons/smile.gif" /><br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[JonClarke]

Certainly you can do that. However, since ascent and descent are the most dangerous part of the mission, increeasing the rumbers of launches and ascents per mission greatly increases the risk.<br /><br />You do need to have some idea on how you are goi9ng to get your crew to and from Mars, even if its not the main focus of your study.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[scottb50]

It is a cycler in that the Core Vehicle is used for multiple round trips.<br /><br />If I understand correctly the other cycler idea uses a vehicle that loops around Mars and Earth and doesn't enter orbit, the problem there is accelerating the payload to match speed with the cycler would take as much propellant as it would take to simply do the trip anyway. <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

In the literature the word cycler is very closely tied to the user of cyler orbits, which is why it is better not to use it for other types of mission.<br /><br />The problem you mention regarding cylers is correct, IMHO, and is just one difficulty. The main attraction of cyclers is their elegance from the view of orbital mechanics. From any other perspective, they are ugly.<br /><br />Jon. <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[j05h]

<i>> It is a cycler in that the Core Vehicle is used for multiple round trips. </i><br /><br />That's a reusable spacecraft, like Jon's suggestion of "MTV". A Cycler is a very specific concept. Referring to a reusable LEO-LMO craft as a "cycler" is going to keep getting you keyboard-jumped. It is the wrong word and you're just causing yourself pain repeatedly using it. <br /><br />No one is going to adopt your use of the term, since Aldrin's concept was first with the name. On top of that, we already have a word for what you describe, it's called a "ship".<br /><br />Can an in-space craft that departs LEO and safely carries crew and cargo to LMO a good idea? Probably. But it's not a "Cycler" nor the topic.<br /><br />Scott, you've got some good ideas if poor terminology. What payloads would you choose or build if the constraint was direct-throw using existing ELVs? <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

Scott, you've got some good ideas if poor terminology...<br /><br />And MTV is not associated with something completely different? Beavis and Butthead was good sometimes though.<br /><br />What payloads would you choose or build if the constraint was direct-throw using existing ELVs? />>><br /><br />I think they are too expensive to be used to place payloads into LEO.<br /><br />What I see is a fully re-usable Launcher and upper stages that then become construction material in LEO to build Vehicles and Stations where needed. If it costs $5,000 a pound to put something into Space it seems like a waste to throw thousands of pounds away to get it there.<br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[j05h]

<i>> Certainly you can do that. However, since ascent and descent are the most dangerous part of the mission, increeasing the rumbers of launches and ascents per mission greatly increases the risk. </i><br /><br />At first brush, it would seem safer to use multiple craft on the trip out and fewer on Mars ascent and transit to Earth. THis is simply because labor is at a premium on Mars and there is more check-out for the Earth launches. Outbound cruise has redundancy while a monolithic Mars Ascent has fewer engines to fail.<br /><br />Following the plan I've outlined, the crew would ascend from Mars in a reusable lander, then head back to Earth orbit in a stack of several SunDancers. This would probably be powered by a methane-LOX departure stage (unless nuke/Vasimr is avail). In the flotilla concept, the crew arrives with several SunDancers. These are leveraged several ways, as space station components (in LMO or Phobos/Deimos), as part of an Earth-Return system and potentially on the surface (though BA-330 has more potential there). <br /><br />How many ELVs do you think could reliably fly during a single launch window to Mars? 5? 8? 12? Also, what are your thoughts on sustained commitments of these sized payloads?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>> And MTV is not associated with something completely different? Beavis and Butthead was good sometimes though. </i><br /><br />In aerospace circles, "MTV" is almost universally understood as Mars Transfer Vehicle. It often implies a reusable craft. Are there others MTVs? Sure, but there are plenty of TLAs for ATM as well.<br /><br /><i>> I think they are too expensive to be used to place payloads into LEO. </i><br /><br />World launch markets are currently in a long slump or collapse, depending on who you ask. The US EELVs so far have had trouble attracting commercial interest. Markets and vehicles that looked promising (Volna ICBMs, Teledesic, etc) never played out. Flight frequency strongly affects cost and price in an open market. Decade-long contracts of dozens of launches would potentially be very cheap compared to current launch cost estimates.<br /><br />The only way for launch costs to decline is for flight frequency to increase. That means more payloads and more economic incentive to the rocket builders and operators to drive costs down, because they are building many more units. (It also means cheaper payloads and commoditization of various space activities - witness SpaceX and Bigelow)<br /><br />We aren't talking about using ELVs to deliver payload to LEO for staging - we discuss that all the time. This thread is about using ELVs to perform direct launch of payloads to cis-Mars space. Fully reusable launchers do not exist. Delta IV and Atlas V fly right now, fairly regular. Every rocket production facility on the planet is slack. Surge-launches to Mars would provide a lot of new business - while creating more opportunities for others. Why not concentrate on the parts of the equation that aren't readily available? This is supposed to be an exercise in studying a potential new approach and you are continually spoiling on it. <br /><br />An MTV that is reusable absolutely needs in-situ propellant at Mars. It doesn't matter if its' from Mars, trans-shipped fr <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

The only way for launch costs to decline is for flight frequency to increase....<br /><br />And the cost of increasing the number of flights is directly You have two years to prepare a Mars trip if it is staged in LEO. To use expendable rockets is ridiculous. To even mention direct launches is comical. 1500 pounds or so to Mars is not worth the effort. <div class="Discussion_UserSignature"> </div>

 

[kelvinzero]

Hi Scott,<br />I'd love to see reusable vehicles taking off but that really is a topic for a different thread.<br /><br />This also applies to people who want to violently disagree with Scott <img src="/images/icons/smile.gif" /> ..<br /><br />Hi JO5H, I dont have much to add compared to the experts, but just wanted to add I like this idea also because it might be able to survive politics better? You mentioned ten launches but perhaps it could also tick over during low funding periods with single launches especially if sharing a standard rocket design.<br /><br />So long as we keep poking around on mars we are bound to find more and more attractive targets to draw us there. And we still need a lot of practice landing on it, which this approach would give. <br /><br />(this is sort of like asking what if we had maintained our ability to land on the moon, using the same basic rockets for LEO too)

 

[j05h]

<i>> Hi JO5H, I dont have much to add compared to the experts, but just wanted to add I like this idea also because it might be able to survive politics better? You mentioned ten launches but perhaps it could also tick over during low funding periods with single launches especially if sharing a standard rocket design.</i><br /><br />Mars Lite would provide for periodic declines in shipments, it has natural redundancy. As far as politics, my goal is to present Mars Lite as a corporate effort instead. The company would mine water, provide tele-operation for their own and other's equipment and host various explorers and other guests. The goal is a private, for-profit base that claims Elysium Planitia and promotes further development planetwide. <br /><br /><i>> So long as we keep poking around on mars we are bound to find more and more attractive targets to draw us there. And we still need a lot of practice landing on it, which this approach would give.</i><br /><br />There are many interesting features on Mars, my short list is Elysium, Louros Valles and Juventae Chasma. Elysium and it's frozen equatorial sea guarantees simple access to other sites because of the ease of ISRU production. A Mars Lite architecture would provide vast experience in aerobraking, especially multipass aerobraking. A direct-descent approach works best for hardware, not crew, in this scenario. This points to using it for the "pallet" lander if that approach maximizes payload against multipass aerobraking. <br /> <br />Josh<br /><br /> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>> And the cost of increasing the number of flights is directly You have two years to prepare a Mars trip if it is staged in LEO. To use expendable rockets is ridiculous. To even mention direct launches is comical. 1500 pounds or so to Mars is not worth the effort.</i><br /><br />Scott, what is the cost of increasing flights directly related to? You started to answer but moved on. <br /><br />Loitering in LEO has issues for all sorts of equipment and propellant storage. Expendable rockets exist now, currently capable of putting 8.5 tons on course to Mars. It's expensive, but available, unlike every other solution. 1500lbs is a very low estimate, others are estimating the direct-descent could easily deliver up to 6t (12,000lb) to the surface. The other nice synergy to this proposal is that several near-term spacecraft are close to the TMI abilities of the EELVs.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[thereiwas]

Another thing to consider, not mentioned before, is that you don't <i>have</i> to wait 2 years between launch windows. If I understand the mechanics correctly, unmanned supply missions could be launched at any time - they just take longer to get there. An extra 8 tons every few months could be a big help to the people living there.

 

[j05h]

IIRC, the mass goes way down or time goes way, way up for chemical propulsion on non-Hohmann transfers. The best options are probably VASIMR or solar sails to follow this sort of plan. With current rockets and upper stages, this is going to mean erratic supplies or just plan for a 26 month cycle. Sort of like LEO staging, it probably works but might reduce flexibility by limiting long-range planning. To work best it requires significant research. At the current level of analysis, it's a lot easier to look to 26 month surge-launch cycles and longer crew missions than to model this kind of supply chain. If someone that knows orbital mechanics better can add to this, maybe it does work out. You can use either standard upper stages or high-impulse propulsion for the analysis. <br /><br />What can we reasonably do on Mars now, using current rockets? What can be done that adds to an eventual human base?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[spacester]

ThereIWas: "Another thing to consider, not mentioned before, is that you don't have to wait 2 years between launch windows. If I understand the mechanics correctly, unmanned supply missions could be launched at any time - they just take longer to get there. An extra 8 tons every few months could be a big help to the people living there."<br /><br />My understanding is that you can indeed launch anytime you want, and that there will always be a way to get to Mars, BUT not only will it cost a lot more in propellant, you will get there no sooner.<br /><br />My understanding is that with anything short of Star Trek capability, a continuous arrival of supplies from Earth is out of the question. Even spiraling trajectories don't seem to work, but perhaps my understanding is lacking. Orbital mechanics is a harsh mistress. <br /><br />That being said, I really like the premise of this thread, JO5H. My vision for Mars includes LEO assembly, so I've not had much to offer here, but my short answer to your latest question is: prove ISRU. Start making potable water and oxygen and rocket fuel ASAP and plan the rest of it around that. <div class="Discussion_UserSignature"> </div>

 

[j05h]

<i>> My understanding is that with anything short of Star Trek capability, a continuous arrival of supplies from Earth is out of the question. Even spiraling trajectories don't seem to work, but perhaps my understanding is lacking. Orbital mechanics is a harsh mistress.</i><br /><br />It's not really a solution. The "spiral" that is easy to envision works out more like a fireworks pinwheel in implementation. Your last line should be the title of a book (joke).<br /><br /><br /><i>That being said, I really like the premise of this thread, JO5H. My vision for Mars includes LEO assembly, so I've not had much to offer here, but my short answer to your latest question is: prove ISRU. Start making potable water and oxygen and rocket fuel ASAP and plan the rest of it around that.</i><br /><br />Thanks. My general vision includes LEO assembly as well, but I'm willing to explore the small-payload route because it provides such quick leverage and incremental development. ISRU has been demonstrated lab-level by Pioneer Astronautics - they've created suitcase size devices that can synthesize gasoline from Earth air and methane from Mars simulant. My solution for potable water is to start by developing an Elysium base. Heat the ice until liquid, extract and centrifuge, then filter. <br /><br />As an example of leveraging, a Mars ascender (either the lander or dedicated craft) would mass 6-8t empty while heading to Mars, then would mass 60-100t full of LoX and CH4.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[spacester]

Yeah, see that's the reason to do ISRU ASAP - we have every reason to believe it will work, we can put together flight hardware in short order (except maybe for the landing part), but no one really cares until you actually do it.<br /><br />Great way to jump-start public interest in Mars. <div class="Discussion_UserSignature"> </div>

 

[thereiwas]

The Sabatier process also needs a hydrogen feedstock, so that would come from indigenous water as well. Has anyone done the calculation for how many kilowatt-hours would be needed to convert X kg of ice, plus CO2, to Y kg of Methane?

 

[no_way]

"Jon and Guns - Any suggestions on how to maximize surface payload from such "small" chunks?"<br /><br />A bit of craziness, but i wonder if it would be possible to utilize single ( set of ) engines to do all the burns from LEO down to martian surface, i.e. powered landing with the same engines that you started out from LEO with.<br />Of course, you want to get rid of the weight of the tanks before the next burn, so use drop tanks, but place them at the top of the stack and get rid of them during the cruise phase.<br /><br />That would basically mean replacing the entire Delta upper stage with dedicated martian craft. Could RL10 do a martian landing ?<br /><br />

 

[jimfromnsf]

Not really viable. The upperstage is used to put itself and the spacecraft into LEO before the escape burn. The 1st burn is much larger than the escape burn. You would be compromising spacecraft and LV by mixing both

 

[j05h]

It's not just tankage, but the engines as well, that are somewhat redundant. Perhaps useful for robust, reusable craft, but the "mars lite" schema would use extremely minimalist transportation craft. IIRC, the number of engines is different for different task, so you are hauling extra engines around.<br /><br />Ideally, cargo modules would separate from their upper stage and complete Mars transit and aerobraking using built-in heatshielding, gyros and limited RCS. These modules are then brought to the surface by a reusable Lander. <br /><br />RL10 could do Mars landings, the engine has even been tested using liquid methane. Personally, I'd prefer dedicated VTOL using the same instead of another solution (like using the same engines from Earth orbit, in this context). Another consideration is wear and tear on hardware - some of this hardware needs to work after years in space or Mars surface.<br /><br />j <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>