To the moon first... - then to Mars and asteroids...

Earthman · 2004-01-10 13:28:34

I have no faith in the curent administration's words. Only financial motives have been policy. Maybe they want a "deathray" base? Let's leave the dark side for tourism and the full moon can have a military-industrial gunbarrel.

dickbill · 2004-01-10 15:07:44

that's right there is no dark side per se on the moon, but a side that never see the earth and is free of earth radio and light interferences. I think it's called, maybe improperly, the "dark side of the moon". Whatever, the important thing is that I remember stories to install a radio or even visual interferometers there, at least since the eighties, if not before.
So i's not new, and launching a human mission to set up a telescope interferometer there would make some sense. But staying there ? I am not sure if it's necessary since robots could deal with the maintenance of such an observatory.

Mars is a different story. We should go to Mars not just for the sciences, Mars is a human adventure which overtakes the scientific aspect. Maybe the only chance for humankind to develop further the Homo Sapiens is on Mars. I know that this is not a widespread idea in the public but I am confident that the concept of a second place for humanity will slowly impose by itself. And I really mean by itself.

RobS · 2004-01-10 16:52:35

Nuclear power for ion engines is unnecessary inside the orbit of Mars; solar panels take less mass. Consider the Mars Direct reactor, 3.5 tonnes and 100 kilowatts of power; the same mass of solar panels can make maybe 400 kilowatts in earth orbit. Prometheus seems to be aiming for 25 kilowatt nukes, or so a JIMO article I read recently hinted at.

As for Ariane, the media reports I've seen have specifically mentioned Ariane, much to my surprise; but Delta IV Heavy is almost as good, and it could probably be made into a Delta IV heavy heavy, with 5 first stages instead of three.

I'm encouraged by the international cooperation aspect.

--RobS

RobertDyck · 2004-01-10 17:52:10

You have to scale up the ion engines on Deep Space 2 or the European moon probe about 200 times, but that's not hard.

I'm going to get nit-picky this time. The ion engines were on Deep Space 1. The Deep Space 2 probes (2 of them) were the impact penetrator probes on Mars Polar Lander. They haven't been heard from since they separated from MPL.

I think it's called, maybe improperly, the "dark side of the moon".

Actually, it's called the far side of the moon.

Mad Grad Student · 2004-01-10 18:19:38

I don't think what we need to go to Mars is a new superbooster. Developing an even more powerful rocket will only drive the cost up and make everyone averse of going into space. What is needed is a more efficient way to get into space. I like ion engines because they're up to ten times more efficent than chemical rockets, but their problem is that their thrust is measured in grams, not tons. If we could find a way to make ion engines make several thousand times as much thrust without reducing efficency that would really allow space exploration to take off.

In the short term, however, we'll need something else to pull a Mars mission off. The cheapest way I can think of to launch such an endevour (Spelling?) would be to hook up an Energyia stack to some other smaller rocket, such as a Centaur upper stage. This naturally limits your payload to sub-200,000 lbs, but that could be doable. This would, of course, necessitate a base being set up ahead of time, as in Mars Direct, but be cheaper than the "Battlestar Galactica"-style mission.

One of the biggest problems I've seen with Mars Direct or any Mars mission is how do you send enough food and supplies for the mission? A solution I thought of is perhaps placing several supply depots in heliocentric orbits on the way to and from the red planet.This would mean that every two or three months the crew would get some fresh food, spare parts, and other necessities. What do you think?

Euler · 2004-01-10 20:05:58

Going back to the moon is a pointless diversion of time and resources that will simply delay a Mars mission. Most of the equipment involved in a moon mission would be completely different from equipment used on a Mars mission. "Testing" Mars equipment on the moon would not really be very useful as Martian environment can be simulated on Earth much more closely than it can on the moon. Furthermore, the moon does not provide the type of experience the NASA is most in need of: manned interplanetary travel.

The moon is not really that interesting, scientifically. Unlike Mars, there is little reason to suspect life might exist on the Moon. We have already sent astronauts to the moon, and studied the rocks they brought back. China, India, Japan, the ESA, etc. are also sending missions to the moon, so any scientific data that might be collected will likely be redundant.

There is also little reason to go back to the moon for nationalistic purposes. With all the other space agencies launching moon missions, many of which will get to the moon before the proposed American missions start, going back to the moon would just make it look like all of the other space agencies have caught up with NASA. For the American space agency to maintain its prestige, it must look to other targets and stay ahead of the curve.

If NASA needs intermediate goals before launching a mars mission, than it should probably send astronauts to near earth asteroids, gradually working its way up to asteroids farther and farther from Earth. This sort of mission would be in many ways easier than a moon mission, while at the same time being far more interesting to scientist, and they would give valuable experience working outside of Earths gravitational field.

clark · 2004-01-10 20:14:09

Bill, the CEV will be an updated Apollo capsule.

GOM · 2004-01-10 21:01:28

that's right there is no dark side per se on the moon, but a side that never see the earth and is free of earth radio and light interferences. I think it's called, maybe improperly, the "dark side of the moon".

Sorry. That term is one of my few pet peeves....

Call it the far side, as opposed to the near side. Call it the away side. Call it the back side. But don't call it the dark side.

Please.

Thank you.

Bill White · 2004-01-10 21:49:53

Bill, the CEV will be an updated Apollo capsule.

Launched on what? An EELV, right? A steroid-fed Apollo is also a lousy way for astronauts to travel to Mars.

Scrap the orbiter? Sure, should have been done yesterday.

Scrap the ISS? Sure, so long as we find a way to satisfy the ESA, Russia, Canada and Japan. Yesterday is over due as well.

Yet shuttle derived boosters remain the cheapest way the US is moving large amounts of mass into LEO - - until/unless we pay for a new starting from scratch HLLV.

I do like that RS-68 idea. Add expendable Delta engines to the main tank and SRBs and attach a variety of payloads.

Palomar · 2004-01-10 22:21:50

*There is just so much uncertainty, rhetoric, doublespeak, and general blah-blah-blah coming from the government that I'm really getting fed up with it. I mean particularly as regards manned missions to Mars. It's like a situation wherein my dad would say, "It (whatever) is like a dog going round and round, chasing its tail."

I feel like telephoning the White House and yelling "Do Something About It!" into the receiver <laugh>

Sorry...it's been a long day and I'm exasperated.

--Cindy

jabe · 2004-01-11 17:17:06

out of curiousity...Any official response from Zubrin since this announcement?

Josh Cryer · 2004-01-11 18:31:41

Robert Zubrin, president of the Mars Society, agreed the moon should be a milepost toward the bigger mission. If Bush proposes a return to the moon and an expedition to Mars ? "someday" ? then Mars may well lose out.
But for the moment, he said he is "happy and preparing for battle."

I personally am wondering what Zubrin is going to say. I think what he says will really tell us how much interest Bush and his team have in Mars. And what our chances are of seeing real Mars development.

Scott G. Beach · 2004-01-11 19:07:59

We could ask NASA to plan to use Luna as a place where people practice building model structures for permanent Martian settlements.

This might involve (1) sending nuclear reactors to Luna, (2) using the reactors to melt Lunar rock, (3) pouring liquid rock into molds to form building blocks, and (4) assembling the blocks to form habitable structures. Once we have mastered these building techniques, we could do the same thing on Mars. This would facilitate the establishment of permanent human settlements on Mars.

On Luna, we might start by creating an "open pit mine" that is 50 meters across and that has a straight access road that gradually slopes down to the bottom of the pit. The material from these excavations could be melted to form building bocks. Those blocks could then be taken down the access road to the bottom of the pit and assembled into a dome. Additional blocks would then be used to transform the access road into a tunnel. The dome and access tunnell could then be buried. An airlock could be constructed inside the access tunnel. Then a sealant could be applied to the interior of the dome and airlock and the dome could be filled with air.

Stacking building blocks up to form a dome can be a tricky task. However, I have conceived of a way to hold blocks in place during construction that does not require a support scaffold. This technique requires that the blocks have a special shape. Fortunately, it would not be difficult to give the blocks this special shape. The shape of the mold would determine the shape of the blocks.

RobertDyck · 2004-01-11 20:28:25

I do like that RS-68 idea. Add expendable Delta engines to the main tank and SRBs and attach a variety of payloads.

What about using RD-0120 engines with Zenit boosters? That would retain Merritt Island and Michoud, and the Russians appear to be inexpensive.

As for any response to these leaks about a new space initiative, let's wait and see what George W. Bush himself actually says. I've heard there is a scheduled press conference 3:00pm EST Wednesday, and it'll be aired live on NASA TV.

Cobra Commander · 2004-01-11 21:20:31

Hmm. I just have to ask, am I the only one having this absurd vision of George W. Bush standing on the moon in front of a "Mission Accomplished" banner while some CNN pundit complains about him showing up in a spacesuit?

GCNRevenger · 2004-01-11 22:29:52

A space nuclear reactor's output depends largely on its efficency of conversion, the reactor that Dr. Zubrin had in mind probably wasn't the modern helium/turbine converter type, where a relativly small reactor like that could make hundreds of kilowatts, perhaps more... though they will need some more engineering done on them. Nuclear ion will clearly be the more robust technology in the end.

Speaking of nuclear reactors, you don't need to use a super-high-temp reactor to melt rock to make lava bricks or anything, since a focused blast of microwaves will sinter the metal-bearing Lunar soil into a hard material nicely. A microwave generator on a robot arm and means to pour sifted soil where you want it for easy automated construction of simple forms, just like a giant version of laser/polymer "3D printers" today that make solid objects from plastic.

Now about those ion engines... Although they have great efficency, they still don't provide enough thrust for time sensitive (human, living, cryogenic, radiation-sensitive, etc) payloads, and this isn't going to change. Ion engines have low thrust by their nature, and you can't stack them up without running into trouble with the mass of fuel and the power requirements. If you want to use chemical engines for the initial kick out from Earth that might get pretty heavy/pricey, especially being expendable, and you would have to spiral out from Mars for a long time if you didn't likewise carry another kick-stage, which would make the craft pretty heavy... unless you want to throw the whole thing away on each trip out. Oh yes, and since the ion drive has to operate continuously to work its magic, you can't spin the spacecraft on a cable or anything, and thats a big problem if an ion vehicle will take a while to get there.

My money is on hydrogen nuclear thermal

The US ought to use RD-68 engines for the SDV because they are actually in production unlike the RD-0120, whose factory has been essentially gutted. Russia doesn't have any other cryogenic engines of that scale. Frankly speaking, I don't think that international cooperation on a project of this magnetude is a good idea in the first place for lack of technical integration and all the comprimises in design that are sure to happen.

Euler · 2004-01-11 23:02:48

Ion engines have low thrust by their nature, and you can't stack them up without running into trouble with the mass of fuel

Do you mean the mass of the engines? Adding engines to increase thrust increases power and engine mass requirements, but the fuel mass should stay the same.

Oh yes, and since the ion drive has to operate continuously to work its magic, you can't spin the spacecraft on a cable or anything, and thats a big problem if an ion vehicle will take a while to get there.

If the cables are rigged correctly, there really shouldn't be any problems with running the engine while the spacecraft is rotating. The engines have a low enough thrust that they should not disrupt the spacecraft too much, and the spinning motion would stabilize the spacecraft.

RobS · 2004-01-11 23:42:45

The ideas I have seen to use ion engines involve cargo only, or involve moving the heavy parts of the human spacecraft before the humans need them. One can move people from LEO (low Earth orbit) to L1 (lagrange between Earth and moon) in three days, so they can make that journey in a capsule. The delta vee to L1 from LEO is 3.2 km/sec, which requires about the same amount of fuel as the payload and structure to be moved. A 24 tonne to LEO EELV can launch a capsule and a boost stage, and three days later the capsule is at L1 with the crew.

There the crew would rendezvous with all the heavy stuff they need to fly to Mars, land on the surface, and survive there. An ion-powered vehicle will take six months to get the stuff to L1, but the payload can be about 75 to 80% of the total mass. You can launch 24 tonnes of payload into LEO, dock it to a solar electric vehicle massing eight to ten tonnes (including engines, panels, and propellant) from a previous launch, and it'll be at L1 six months later. If at L1 the payload is also greeted by a vehicle with lunar LOX and liquid hydrogen, then the 24 tonnes of payload from Earth doesn't need to include trans-Mars injection fuel. A lunar-based vehicle can take slightly more than half of its fuel to L1; the mass ratio is about 0.7 tonnes of fuel to 1 tonne of payload, including structure. At L1, the delta-vee to Mars for a six-month flight is 1.5 km/sec if one fires the engines when one is flying close to Earth, which means 0.4 tonnes of fuel can push 1 tonne of payload to Mars. So in essence any plan using ion engines and lunar fuel looks something like this:

Four EELVs put 24 tonnes each into LEO. One of the four contains one or more solar-powered ion tugs plus their fuel. The other three have 24 tonnes each (72 tonnes total) of stuff bound for Mars.

Six months later we have 72 tonnes of Mars-bound stuff at L1. This is about the mass of Mars Direct when one includes aerobraking, landing parachutes, landing fuel, etc.

A fifth EELV launches the crew in a capsule with a LOX/LH2 stage. They reach L1 in three days. The mass of capsule and consumables they bring (including themselves) can total about ten tonnes, so we now have 82 tonnes at L1. They will need a few days to a few weeks to set up the Mars-bound vehicle, moving things around, deploying aeroshields, testing, etc.

To push 82 tonnes to Mars at a fast trajectory from L1, we need about 33 tonnes of lunar fuel, which take another 30 tonnes of lunar fuel to be launched to L1. If the 82 tonnes of stuff are placed in one vehicle, we need one stage with lunar fuel to dock to it. If it is split between two (hab and ERV) we need two lunar-fueled vehicles. Possibly the ERV tanks could store enough fuel for the trans-Mars injection and could be fueled at L1.

The lowest-energy route to a close-Earth flyby from L1, I think, is via the moon. It takes about 0.2 km/sec to swing around the moon and use it as a gravity assist to fly past the Earth, where you fire your engine to go to Mars. If you go directly to a close-earth flyby from L1 the delta vee is 0.5 km/sec in addition to the 1.5 km/sec for trans-Mars injection. The direct delta-vee from L1 to Mars is 5 km/sec for a six-month flight, so you don't want to try that.

One does not need to use solar-power ion tugs. One can also used solar-thermal rocket engines, which use liquid hydrogen and give an Isp of about 800 seconds. Their thrust is low--a few dozen pounds--which is still a lot more than ion. So you conduct a series of "perigee kicks" to raise the apogee to L1. A solar-ion tug can raise about sixty percent of its total mass to L1; in other words, a 24-tonne payload would require 12 tonnes of liquid hydrogen plus tanks (about 2 tonnes) and solar mirrors (huge in size, but only a few kilos of mass) and a solar thermal engine (a big block of graphite heated by the mirrors massing a few hundred kilograms). Think of this as a poor man's nuclear engine: not quite as good performance, but no radiation issues, no complicated testing facilities, and no political headaches. NASA's developing solar thermal engines right now, but none have been tested.

-- RobS

RobertDyck · 2004-01-12 00:47:44

The US ought to use RD-68 engines for the SDV because they are actually in production unlike the RD-0120, whose factory has been essentially gutted. Russia doesn't have any other cryogenic engines of that scale. Frankly speaking, I don't think that international cooperation on a project of this magnetude is a good idea in the first place for lack of technical integration and all the comprimises in design that are sure to happen.

Tell me GCNRevenger, do you work for an American aerospace company with interest in nuclear engines? You appear very biased in this regard.

The official response from the manufacturer on October 10, 2003, was

Concerning the current status, to the 1st of November?03, nine engines RD0120 with various residual life-time are available at KBKhA, and we may prepare them for hot-fire tests on our?s own. These engines are at different degree of readiness for hot-fire tests and slightly vary in design. Due to this, certain co-ordination of potential testing program for each of these engines is required in order to make possible their use in the programs you?ve conceived.
Moreover, KBKhA has a few more incomplete engines (some components are lacking) but they may be fully assembled by involving the manufacture (our old subcontractor), Voronezh Mechanical Plant. The tooling required for RD0120 engine manufacturing is principally retained, but to resume the production of these engines, it will be necessary to acquire modern equipment and to make certain refurbishment of our production facilities along with the due refurbishment of our suppliers? production.

From your comments, I suspect you're not aware of NASA's plans to use VASIMR for a manned Mars mission. The idea was to use low-thrust/high-Isp to slowly spiral from LEO to high orbit, then transfer astronauts to it via capsule and a conventional chemical rocket. To depart, they would use VASIMR in high-thrust/low-Isp mode. High-thrust for VASIMR is would be medium for a chemical rocket, but it's enough to send astronauts to Mars with a reasonable departure delta-V. Furthermore, they would use VASIMR in low-thrust/high-Isp mode during cruise to Mars. That would result in reduced trip time. The electrical power necessary for that much thrust will require a 10 megawatt nuclear reactor, but at 9,000 seconds in high Isp mode it is more efficient than nuclear thermal. This is a form of nuclear electric propulsion.

A nuclear thermal rocket could also do the job, and it would launch from LEO. Mars Direct explains how to do it with chemical propulsion. The truth is there are many engine systems that could get you to Mars.

RobS · 2004-01-12 15:35:07

Robert, this is fascinating information, and I don't know enough about VASIMR. Can you recommend a web page or two about the topic?

-- RobS

Josh Cryer · 2004-01-12 15:43:09

Robert mentions several ways to get to Mars, and I think Dusty-M2P2 is one of the most interesting ways to ship stuff to Mars, very cheaply, and very very fastly. Better in very many regards than every other system as of yet devised, at least in the inner solar system.

But I don't mention it that much because I feel like I'm intruding in threads, but I figure why the heck not just this once. There was a paper written late last year that I only recently discovered... link.

Rxke · 2004-01-12 15:55:02

Interesting, definitely, but the timeframe... 30 years of development...
It's good to look forward, though, and adapt plans with state-of-the-art stuff in mind.
For this sail to get developed, there will be a need for it, so maybe it's a good thing when people start cursing the inefficiency of chemical rockets, driving research towards Dusty, Vasimir etc...

RobertDyck · 2004-01-12 16:02:33

The NASA web page on their Design Reference Mission was last updated July, 1997. However, the addendum page isn't working today, and that's where I read about use of VASIMR. The entire Mars section of NASA's manned spaceflight web site has been taken down. Maybe they'll bring much of it back now.

Scientific American had an article about Mars a few years ago, and it listed all sorts of engines, including VASIMR. NASA does still have a web site about VASIMR here, and another one here.

If you want to read my correspondence with Russian companies, you can find it at the Winnipeg Chapter web site. You can find out more about the Russian companies KBKhA, Energia, or Molniya (manufacturer of the Buran orbiter).

Ad Astra · 2004-01-13 22:24:18

I'm partial to some type of nuclear-electric propulsion for the Mars mission, either VASIMR or ion. In my mind, it dramatically improves the abort options for the mission. Reduced transit time would also be good in the event of an emergency. Sure, chemical propulsion would be quicker to develop, but I like to say "Do you want to do Mars fast, or do you want to do it right?"

Changing gears...

What is the significance behind making Wednesday the date for the speech? Friday would be more significant, being the first anniversary of Columbia's final launch. The State of the Union address would be a perfect time, because that's after both Mars rovers have arrived. At least by skipping Dec. 17, the President avoided the embarassment of proposing the Moon-Mars plan and then potentially witness both rovers fail. But I'm at a loss to see what's so important about Wednesday, Jan. 14.

RobS · 2004-01-14 00:02:17

Interesting question about timing. Friday wouldn't be good; you'd be linking the new plan with a disaster. Besides, the Iowa caucases are Monday and will dominate the weekend news. I suspect the State of the Union is regarded as too important a speech for this, especially since the space speech probably has to go into details inappropriate for State of the Union (costs and such). And you don't want two major speeches too close to each other in time because they compete for media time. So this speech can't be after Opportunity's landing; it would be pushed off the front page by state of the union. Finally, there's politics. The Democrats are squabbling in Iowa and the President is acting; they're duking it out in NH and the President is making the State of the Union; etc. It's part of a strategy to portray the Prez as a man of action and vision.

-- RobS

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#26 2004-01-10 13:28:34

Re: To the moon first... - then to Mars and asteroids...

#27 2004-01-10 15:07:44

Re: To the moon first... - then to Mars and asteroids...

#28 2004-01-10 16:52:35

Re: To the moon first... - then to Mars and asteroids...

#29 2004-01-10 17:52:10

Re: To the moon first... - then to Mars and asteroids...

#30 2004-01-10 18:19:38

Re: To the moon first... - then to Mars and asteroids...

#31 2004-01-10 20:05:58

Re: To the moon first... - then to Mars and asteroids...

#32 2004-01-10 20:14:09

Re: To the moon first... - then to Mars and asteroids...

#33 2004-01-10 21:01:28

Re: To the moon first... - then to Mars and asteroids...

#34 2004-01-10 21:49:53

Re: To the moon first... - then to Mars and asteroids...

#35 2004-01-10 22:21:50

Re: To the moon first... - then to Mars and asteroids...

#36 2004-01-11 17:17:06

Re: To the moon first... - then to Mars and asteroids...

#37 2004-01-11 18:31:41

Re: To the moon first... - then to Mars and asteroids...

#38 2004-01-11 19:07:59

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#39 2004-01-11 20:28:25

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#40 2004-01-11 21:20:31

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#41 2004-01-11 22:29:52

Re: To the moon first... - then to Mars and asteroids...

#42 2004-01-11 23:02:48

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#43 2004-01-11 23:42:45

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#44 2004-01-12 00:47:44

Re: To the moon first... - then to Mars and asteroids...

#45 2004-01-12 15:35:07

Re: To the moon first... - then to Mars and asteroids...

#46 2004-01-12 15:43:09

Re: To the moon first... - then to Mars and asteroids...

#47 2004-01-12 15:55:02

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#48 2004-01-12 16:02:33

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#49 2004-01-13 22:24:18

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#50 2004-01-14 00:02:17

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