Mars 9 tons at a time.

[keermalec]

lol, and if the ECLSS breaks down they can eat the rover. <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>

 

[JonClarke]

<i>Maybe I will have to assume the triconic aeroshell works. </i><br /><br />Quite a bit of work has been done on a range of long thin entry vehicles, and they work quite well. they are ideal for landing payloads on the surface.<br /><br />Jon<br /> <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>

 

[spacenutnewmars]

The real trouble though with the 9 tons to surface design thus far is how many launches are needed to support a human crew even being a single person. <br /><br />The number on launches needed in the short window of 2 months would also make for a design that could be made anywhere and not a single source so as to be launch from as many sites as possible.<br /><br />

 

[thereiwas]

The two month window only is for the least energy trip. You can launch any time if you do not limit to Hohmann orbits.<br /><br />Part of this proposal is that the intervening 2 years is spent getting things assembled so they are ready to go rapid fire when the proper alignment comes.

 

[j05h]

<p><em><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The two month window only is for the least energy trip. You can launch any time if you do not limit to Hohmann orbits. Part of this proposal is that the intervening 2 years is spent getting things assembled so they are ready to go rapid fire when the proper alignment comes. <br /> Posted by ThereIWas</DIV></em></p><p>Exactly. Assuming the Delta IV-H as starter, this could be up to 16 flights in the window. Eight would fly from Vandenburg, eight from Cape Canaveral. At current estimated launch costs it would be roughly $4 Billion per two-year cycle to purchase Deltas, but this could see major price reductions with extended commmitment. The intervening 2 years is spent getting everything ready.</p><p>16 launches places 80t or more of useful payload on Mars, an extra 40-60t of carrier hardware and over a dozen cruise-stage/comsats in orbit. Not a bad start for a&nbsp; base-camp, esp. starting with advanced robotics. The goal would be to scale operational costs down enough to keep flying like that. The autonomous lander we specced out in this thread points toward a likely design. </p><p>A crew flight might consist of 4 rockets launching a capsule with 3 crew, a service module/node and 2 supply modules, all meeting up after TMI. A full host would consist of 4 crews outbound totalling 12 people. This sort of configuration, with several crew in light craft, may be more robust (due to cross-rescue) than a single larger ship. This configuration assumes ditching the capsule on Mars or a very tough reusable or using a separate lander-ascender.</p><p>I don't discount electric craft or starting in LEO/L1 for this, but the simplicity of Mars Lite makes so much sense. It plugs right into current hardware with no modification. We ran the numbers for staging in LEO somewhere in this thread, and even with ion thrust its' only about 50% more payload to Mars orbit with attendent development/deployment issues. With direct-throw via Delta everything through TMI is handled by the upper stage, the payload only needs to work cruise and EDL.</p><p><br />Things to remember about this include Delta IV-H nearly being able to put a SunDancer (~10t) on course for Mars. Same for a Dragon<br />&nbsp;capsule, esp one with only 3 crew inside. For cargo an electric version of a light excavator or dozer can easily mass 5t or under. The two spacecraft mentioned are almost flying and a rocket to deliver them to Mars orbit is already flying.&nbsp; </p> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[ThereIWas2]

<p>This part about rendezvous of 4 vehicles after TMI needs some fleshing out.&nbsp;&nbsp; They would have to do their TMI burns carefully synchronized, without fail, and not bump into each other in orbit.&nbsp;&nbsp; Yet not be so far apart or such different velocities post burn as to require lots of dV to match up.</p><p>&nbsp;</p><p>One idea I had is to put the 4 vehicles into exactly the same orbit but spaced say 10 minutes apart.&nbsp; The lead vehicle does TMI first, followed by the others in order as they reach the same orbital point vis-a-vis the transfer orbit.&nbsp; Although vehicle-1 will gain a considerably head start, the others should catch up and be back in their 10-minute spacing enroute to Mars, never coming closer together than&nbsp; a couple thousand miles apart.&nbsp; Once stabilized enroute they then nudge toward the same spot, collapsing the "train" and docking.&nbsp;</p> <div class="Discussion_UserSignature"> <p><span class="postbody"><span style="font-style:italic"><br /></span></span></p> </div>

 

[ThereIWas2]

<p>By the way, I once tried something like this with Orbiter.&nbsp; I had two DeltaGliders at KSC on adjoining helicopter pads (about 200 feet apart) with identically programmed guidance computers, set to put them into the same orbit.&nbsp; With some fast clicking I managed to initiate the two launch sequences within a few seconds of each other.</p><p>&nbsp;</p><p>They both rose on their hover thrusters, one ahead of the other, then started main engines and took off toward the east.&nbsp; Over the ocean they pulled up into their almost vertical climb, with the one that started first gradually pulling away.&nbsp; I used the radar in the trailing ship to keep tabs on the separation distance.&nbsp; At one point they were about 20 miles apart as I recall.</p><p>&nbsp;</p><p>Finally the lead ship shut down and coasted.&nbsp; Since the trailing ship kept its engine going a couple seconds more, it made up the distance pretty quickly before it too shut down.&nbsp; They were now coasting a short distance apart and it was an easy matter to have the auto-dock program approach and line up for docking.</p><p>&nbsp;</p><p>I wouldn't cut it so close in the real world. &nbsp;</p> <div class="Discussion_UserSignature"> <p><span class="postbody"><span style="font-style:italic"><br /></span></span></p> </div>

 

[publiusr]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>16 launches places 80t or more of useful payload on Mars<br />Posted by j05h</DIV></p><p><br />&nbsp;By expending 48 RS-68 engines! Two or three Ares V can do that and more.</p>

 

[ThereIWas2]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;By expending 48 RS-68 engines! Two or three Ares V can do that and more. <br /> Posted by publiusr</DIV></p><p>But Ares V doesn't exist, and won't for years, maybe never.&nbsp; The Delta and Atlas exist TODAY, which is the whole point of this exercise.&nbsp; What could we do NOW?</p> <div class="Discussion_UserSignature"> <p><span class="postbody"><span style="font-style:italic"><br /></span></span></p> </div>

 

[j05h]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>But Ares V doesn't exist, and won't for years, maybe never.&nbsp; The Delta and Atlas exist TODAY, which is the whole point of this exercise.&nbsp; What could we do NOW? <br /> Posted by ThereIWas2</DIV></p><p>The issue is not how many engines it uses (who cares) nor how much initial mass on Earth it requires (who cares). The real issue is how much does it cost per unit of mass to get to the surface of Mars safely?&nbsp; In the grand scheme of things these are non-issues. The only real issue is how to get there cheap(er) and safer. I'm not saying that our "Mars Lite" idea is perfect, but it does present a path for getting people and advanced hardware onto Mars as soon as possible, because the ride already exists. Which is the whole point of this thread.&nbsp;</p><p>And thank you all for participating. Someday I'll write this into a real essay with Keermalec's numbers and everyones input&nbsp; but not just yet.</p><p>Josh </p> <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The issue is not how many engines it uses (who cares) nor how much initial mass on Earth it requires (who cares). The real issue is how much does it cost per unit of mass to get to the surface of Mars safely?&nbsp; In the grand scheme of things these are non-issues. The only real issue is how to get there cheap(er) and safer. I'm not saying that our "Mars Lite" idea is perfect, but it does present a path for getting people and advanced hardware onto Mars as soon as possible, because the ride already exists. Which is the whole point of this thread.&nbsp;And thank you all for participating. Someday I'll write this into a real essay with Keermalec's numbers and everyones input&nbsp; but not just yet.Josh <br /> Posted by j05h</DIV></p><p>There is also the posibility of putting a couple of Shuttle SRB's on a Delta or Atlas. I'm still&nbsp; a little unsure how much the recovery or the SRB's accomplishes, as far as re-use, but it might be a quick way to increase capacity.&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[ThereIWas2]

It isn't 9 tons, but this paper from SpaceX about lunar capabilities of the Falcon rockets has a little chart on page 7 saying that an F9 can put 904 kg into Mars transfer. <div class="Discussion_UserSignature"> <p><span class="postbody"><span style="font-style:italic"><br /></span></span></p> </div>