Post central for information on CEV - iformation station for the spacecraft

Euler · 2004-03-31 21:55:10

Some of the artwork in that pdf file looks kind of strange. For instance, why does the nuclear electric propultion stage appear to have solar panels jutting out in every direction?

Based on the timeline it appears that a mars mission will not be planned until around 2030 at the earliest.

GCNRevenger · 2004-03-31 22:08:13

They aren't solar pannels, they are radiators, since Nasa seems hell bent on using low-temperature coolants for some technical or safety reason. Nuclear reactors can only convert 33% of actual thermal output into electricity, the rest of the heat has to be dumped overboard.

An awful lot of orbital transfers going on for the later-term reuseable arrangement, and I wonder if using a solar/ion vehicle that can come down to LEO (unsafe for nuclear apparently) would avoid the need for some of these orbital maneuvering stages.

Also not thrilled about building the system at any stage around the ISS, which won't even be in operation that much longer hopefully, to say nothing of the big bite out of payload capacity when launching from KSC.

Alot of launches by Delta-IV HLV or "Delta V" mega-EELV or the "Mini-EELV" mass-produced fuel launcher for the later-term system for small masses actually sent to the lunar surface, but the number is reasonable for an Earth Orbit Rendevous "Apollo II." I like the fuel depot/module/thing.

Michael Bloxham · 2004-03-31 23:27:13

Whats interesting here is the development timetable on page 14. The CEV is developed first (flight-ready by 2008, as Bush demanded), but the infrastructure required to make it useful are developed later. Odd... In my opinion, the CEV should either be an orbital space plane, or a genuine lunar exploration vehicle. NASA needs to decide which; an OSP should not be built presuming it can be later adapted for future lunar exploration. Though they don't explore the SDV option in detail, it is shown on the timetable to be a much quicker route to Mars, and therefore any real science payoff (BTW, what is 'Sustained Earth Neighborhood Access", for what other than the moon is in earths neighborhood?). An HLLV, whether shuttle derived, or all-new, is shown to be required for any Manned Mars mission. When will we see official documents exploring the SDV option? Why should we scrap our perfectly good Shuttle infrastructure (Remember, it is the Orbiter which plagues us), only to re-develop the infrastruture for a clean-sheet HLLV (all at considerable cost) only 10 years later? These preliminary plans seem much too complex, considering we will only gain the capability to send people to the moon (albeit on extended stays; but why...?), a feat which nearly became routine 3 decades ago. And when we finally get there, Apollo will be half-a-century behind us...

The last question asks: What Could the Future Look Like?

A lot like 1969, actually.

Bill White · 2004-03-31 23:31:04

Details of the augmented EELV are missing. Others have suggested it isnt really feasible to build a Delta V without considerable design expense.

Euler · 2004-04-01 00:26:18

BTW, what is 'Sustained Earth Neighborhood Access", for what other than the moon is in earths neighborhood?

They might plan to land on near earth asteroids, or possibly do something at GSO or the Lagrange points.

Other things I noticed about the timeline:

*Though ISS appears to be used in the mission architecture its funding dies out in fy16-17. The lunar landings would be fy15-28 or fy17-24.

*At the end of the lunar period all flights are stopped for several years while mars tech is developed. Contrary to what Bush has implied, it seems that the moon will not be utilized in a mars mission.

Rxke · 2004-04-01 11:24:18

That open cockpit idea is not new, seen it before (i think one one of the moon-settlement "DIY" sites, and IIRC they copied it themselves from somewhere else...)

clark · 2004-04-01 12:43:44

[http://www.upi.com/view.cfm?StoryID=200 … 5104-3165r]http://www.upi.com/view.cfm?StoryID=200 … 5104-3165r

CEV fly-off? Maybe...

Decision on the launch vehicle for the CEV to be made by the end of this year.

NASA sources told United Press International the agency has not yet made a firm decision on the fly-off plan.
For one thing, NASA engineers at Johnson Space Center in Houston are opposed to such a plan. They argue that the agency never has conducted a flying competition of alternative spacecraft designs in its 45-year history.
Other factors point to a fly-off, however. The military routinely conducts such competitions, as it did during development of the new Joint Strike Fighter.
Steidle's job, before coming to NASA, was directing the development of the JSF program in the Pentagon.
In addition, Boeing, Lockheed Martin, Orbital Sciences Corp. and Northrop Grumman, among other space industry firms, have expressed interest in competing to build the CEVs.
Meanwhile, Steidle has said he will choose a launch vehicle for the CEV by the end of this year. It could include new versions of the existing Delta and Atlas rockets, or an entirely new booster. An all-cargo version of the space shuttle, which replaces the winged orbiters with a cargo pod, also is under study to supplement the CEV with a heavy lifting, cargo-only capability.

RobS · 2004-04-01 12:56:31

I just saw this stuff. Wow, wicked super cool. . .

On page 11 it shows launches labeled 8 through 12 deploying a nuclear-powered ion tug and pushing a spare lunar lander and fuel to L1. Note that perhaps launch "2" put the fuel in orbit to push the nuclear tug to the nuclear safe orbit, so I suppose launch 1 was the nuclear tug. Launch 3 may show a prepositioned lunar lander and fuel at L1, so I guess that's what launch 3 did. But launch 4 was put into orbit on the rocket labeled "8" sitting on "Earth." So these power point slides are a little hard to understand!

Also note on page 13 it says that "At minimum, a 250 kw reactor with more efficient thrusters will be required. Solar Electric Propulsion (SEP) seems to be the superior approach in Earth neighborhood scenarios." That tells me the use of NEP on these slides is a bow to Project Prometheus, which doesn't want to be "dejustified" by SEP. But SEP they say is better, and one can quickly see why. It'll be cheaper to develop and won't require so many launches or orbits. Furthermore, on page 8 it says "Heavy Lift Launch Vehicles: The low-thrust propulsion systems require an upgraded Heavy ELV or shuttle-derived launcher for development." That is probably true of nuclear; reactors are heavy and can't be split up. But solar? I doubt it. Why not launch the ion engines with one launch and the solar panels on another? This strikes me as another strange compromise with Prometheus.

Watch out; Prometheus may eat the plan to send humans to the moon and Mars, rather than the other way around!

-- RobS

John Creighton · 2004-04-01 13:02:14

Nuclear electric has its advantages too? Right? More power? I think solar electric tugs will be developed by the private sector. I am sure both will be useful.

Euler · 2004-04-01 13:31:19

Nuclear electric has some advantages, and would probably be better than solar for a mars mission. The problem with nuclear is that it has to be done on a large scale to be efficient. In the 100s of kW range, the specific mass of the reactors (mass/power) decreases roughly by the square root of the amount of power. This means that a 400 kW reactor might only be twice the mass of a 100 kW reactor. In the several mW range that would likely be used for an NEP Mars mission, nuclear would have a specific mass at least as good as solar at Earth orbit and superior at Mars orbit.

I am not really sure about the whole nuclear safe orbit thing. Is it really necessary? I don’t know of any reason why nuclear power at ISS orbit would be especially dangerous.

clark · 2004-04-01 13:40:15

Perhaps the nuclear safe orbit has more to do with issues realted to orbital debris (don't want the reactor punctured by some stray chicken wing) and politcal considerations.

Bill White · 2004-04-01 13:49:51

This is cheerful information. A "fly off" could increase available R&D legacy for future private sector activity, correct?

I was also pleasantly surprised to see [http://www.space.com/goformars/]this link. Building public expectations for Mars is all good, IMHO, as it will then be more difficult to satisfy people with less.

Give me a plan that can garner bi-partisan support and actually get people off the planet (not merely support speeches about the moon and Mars) and things start looking up.

We still need a better name than PlanBush, however.

RobS · 2004-04-01 14:00:05

It seems to me with the new solar array materials being developed, solar must mass less at Earth orbit, and certainly costs less. A 100 kw reactor masses 3 to 4 tonnes and that's for the Martian surface where radiators can be smaller. Four thousand kilograms for 100 kw is 40 kg/kw. Change-Levine assumes VASIMR can be powered by large reactors in the 5-10 megawatt range massing 6 kg per kw; that's 60 tonnes for a 10,000 kw (10 mw) reactor! And he admits that a very optimistic projection. In contrast, solar panels that are 25% efficient long term are possible now; for Earth orbit, thats 4 square meters of panels per kilowatt. Panels mass 2 to 4 kilograms per square meter, so that's 8 to 16 kg per kw.

The plans for solar-powered tugs I've seen usually look at 400 to 500 kilowatts. That's still a big leap above Prometheus is size.

Returning from Mars, solar panels will generate only 40% as much power per square meter but the mass to be flown back is also less, because Earth departure would have to launch the return fuel as well (if you are assuming solar ion propulsion both ways; I favor solar-ion to lagrange and a chemical kick stage for trans-Mars insertion, perferrably using lunar-derived hydrogen and oxygen, and Mars-derived methane and oxygen for trans-Earth injection).

-- RobS

Bill White · 2004-04-01 14:29:23

RobS, we are getting off track, but anyway suppose you/we can buy Proton or Zenit-2 or Zenit 3SL and launch mass to LEO for between $1500 and $2000 per pound, what kind of cost figures are we looking at for supply drops to Mars?

Payloads of kevlar mats, aluminum trusses, powdered eggs & milk, powdered boron to mix with Mars-made polyethylne, stuff like that.

Solar ion out to L1 then chemical injection to Mars (just like in your book!) - - next, there is no need to send the solar tug to Mars, right? It can return to Earth LEO by lunar fly-by as well, correct? Maybe a deceleration burn and choose a fly-by trajectory that provides less speed as the SIP seeks LEO capture.

Even without lunar fuel (still a maybe, right? -> correct?) this architecture at $1500 per pound to LEO helps MarsDirect (or even a nuke Mars mission) quite nicely, no?

Just take the "Lo" road. . .

= = =

Left, right, correct? :;):

Ad Astra · 2004-04-01 16:39:45

Let's not forget nuclear-thermal propulsion. The Boeing design for the Mars ship has it (according to Aviation Week's analysis of the drawing, as well as my own.) NTR would be better for the initial acceleration out of earth's orbit past the van Allen belts.

My hope is that we build a real heavy-lifter out of the shuttle instead of stretching the Atlas and Delta core stages to launch 35 tons, as the PDF explains. I'm with Zubrin on this point: the more orbital assembly, the more difficult it is to get to Mars.

clark · 2004-04-01 16:48:11

Ah, but both architectures assume some HLLV to go to Mars. Even the SDV would need to be modified in later years for a Mars mission, versus a "clean sheet" approach if we go the EELV route.

First step is the Moon, and I think we may get more bang for our buck if we forgo the SDV now. The architectures assume a more robust lunar program with the EELV, where as the SDV diverts funds which reduce our ability to do much on the moon.

Bill White · 2004-04-01 17:06:49

Did you read Zubrin's "methane missive"

Moon First? Sure, okay, but sooner rather than later and Mars sooner rather than later.

But SDV is still joined at the hip with ISS IMHO. If ISS completion is a "must do" before Constellation then we need SDV because there is simply no way orbiter can finish ISS by 2010.

Besides, if we spend money on SDV to help finish ISS we can get a "2 for 1" deal on SDV design costs.

On the other hand, if we kill ISS now, then I am less insistent that SDV is the only way to go.

clark · 2004-04-01 17:12:31

What, or where, is Zubrin's speel on gas?

I can't disagree with your overall assesment Bill. Perhaps there is a horse trade in there somewhere?

Cancellation of the SHuttle post-haste, with a greatly reduced ISS (in comparison with current plans).

Free rides for the Euro crowd to the Moon may get them on board, as you have suggested before... it might make the nuclear aspect less of a politcal concern when it comes time to launch the radioactive birds too.

GCNRevenger · 2004-04-01 17:27:45

More robust Lunar plan with EELV? How so? The masses of actual lunar payloads reaching the Moon from this article seem pretty small, only two or three Lunar Lander payloads for 8 initial/5 subsequent "Delta V" launches? We'll never get much built on the Moon that way... Current EELV hardware is capable of getting people to the Moon and a minimum amount of payload, but the number of launches spirals if you want to do anything besides get people to & from with this architecture.

SDV or HLLV of some kind will have its uses for any Lunar expedition beyond a repeat of Apollo's capabilities, and since we will need it for Mars, it is a good idea to make the decision to build now so it is ready for larger Lunar or Martian expeditions or whatnot, let the current Delta-IV HLV do the first little Moon trips and spend as little as possible to use it.

clark · 2004-04-01 17:36:36

You answer your own question GNC, "We'll never get much built on the Moon that way... Current EELV hardware is capable of getting people to the Moon and a minimum amount of payload, but the number of launches spirals if you want to do anything besides get people to & from with this architecture."

We don't want much built on the Moon, remember.

We want the bare minimum for training for Mars. Tie their hands now so they don't get distracted. The larger the Moon base, the smaller the chances of going to Mars in anyone's lifetime. The larger the moonbase, the longer it will take to get to Mars.

If it means we have to approach this a little backwards, let's do it. Mars is the goal, the prize (yes, I get that ).

If NASA can launch Moonbase Gigantica, they will. Don't let em.

Bill White · 2004-04-01 17:40:47

Actually, I came to NewMars to post [http://www.news.cornell.edu/releases/Ap … y.deb.html]this link about lunar water and got sidetracked by the methane posts.

Okay, back to lunar water - read the link, it affects mission planning for Mars, IMHO. Especially the RobS scenario.

clark · 2004-04-01 17:44:43

Protected document... so I'm breaking the rules to free the speech. In the interest of the public, of course.

Text of the article Bill linked to

WASHINGTON, D.C. -- The discovery of accessible deposits of water on the moon would "profoundly" affect the economics and viability of a lunar base, Cornell University astronomer Donald Campbell told a House of Representatives subcommittee today, April 1. Unfortunately, he said, recovering water deposits will not be an easy task, since they are likely to exist in the bottoms of very cold, permanently dark craters at the moon's poles.
"For a permanent or reusable base, a local supply would be invaluable both for human needs in the form of water and oxygen and for production of rocket fuel," Campbell told the House subcommittee on space at a hearing on "Lunar Science and Resources" in the Rayburn House Office Building.
In January President George Bush announced a goal of returning humans to the moon by the end of the next decade and using a lunar base as a launch pad to Mars. The president said he would seek an additional $1 billion over the next five years to begin research on the program, and he directed NASA to divert $11 billion from existing programs to support development of technology needed to reach the moon and Mars.
Campbell is professor of astronomy at Cornell and associate director of the National Astronomy and Ionosphere Center, based at Cornell, which operates Arecibo Observatory, Puerto Rico, for the National Science Foundation.
A viable lunar base, Campbell told the committee, would enable further exploration of the moon and "has the potential to allow exploitation of lunar resources." These resources, he said, include a variety of minerals, such as oxides of iron and titanium, "and it is possible that these minerals can be utilized to provide resources such as oxygen to sustain an extended human presence on the moon." Campbell spent much of his testimony discussing the possibility that water is trapped below the lunar surface. Over the past decade, he said, there has been evidence from instruments on lunar orbiting spacecraft suggestive of the presence of water ice in the polar regions.
Suggestions of lunar ice first came in 1996 when radio data from the Clementine spacecraft gave some indications of the presence of ice on the wall of a crater at the moon's south pole. Then, neutron spectrometer data from the Lunar Prospector spacecraft, launched in 1998, indicated the presence of hydrogen, and by inference, water, at a depth of about a meter at the lunar poles. But radar probes by the 12-cm-wavelength radar at Arecibo showed no evidence of thick ice at depths of up to a meter.
However, Campbell told the committee, "While perhaps unlikely, the possibility still exists that there are thick ice deposits in the bottoms of some shaded impact craters at the lunar poles." There are definitely higher concentrations of hydrogen at the lunar poles compared with other areas of the moon, he said, "but both its origin -- and its current form -- hydrogen, ice or hydrated minerals -- is a topic of considerable discussion in the relevant scientific community."
He warned that "before we spend too much time making plans for exploiting water resources on the moon, we should determine whether there are any recoverable deposits of water, in what form -- distributed at low concentrations in the lunar soil or in concentrated deposits -- of what type -- ice or hydrated minerals -- and how accessible."
To do this, he said, it will be necessary to send one or more missions with these specific objectives.

clark · 2004-04-01 17:46:07

Sounds like a mission for the 2008 Moon probe...

Bill White · 2004-04-01 17:48:37

He warned that "before we spend too much time making plans for exploiting water resources on the moon, we should determine whether there are any recoverable deposits of water, in what form -- distributed at low concentrations in the lunar soil or in concentrated deposits -- of what type -- ice or hydrated minerals -- and how accessible."

RobS, light some candles, okay? Your mission architecture may well become THE mission architecture.

clark · 2004-04-01 17:53:57

[http://www.csmonitor.com/2004/0401/p14s02-stss.html]http://www.csmonitor.com/2004/0401/p14s02-stss.html

A new space race?

To put a man on Mars, US, Europe, and China face a stark choice: cooperate or go solo.

'UN' for space exploration
The International Academy of Astronautics is finishing a report outlining a range of approaches for cooperation on future space-exploration activities, says James Zimmerman, who for 12 years served as NASA's representative in Europe and currently heads a space-policy consulting firm in McLean, Va.
One possibility would be to establish an international body outside the United Nations framework, but modeled after ESA, that would coordinate an international moon-Mars effort, says Kevin Madders, a space policy consultant in Brussels.
Since 1958, NASA policy has forbidden the agency to go down what he terms this more "organic" road to cooperation in manned spaceflight, he says. "You've got to have a very good reason to change that track. Taking on the moon and Mars could provide such a reason."

Interesting article, and it does paint a rather bleak picture for NASA-international involvement, but it might be possible. Either way, ESA is planning on 2030 for a manned mars mission, so if nothing else, it provides an incentive for NASA to get off their duff and get out there.

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Re: Post central for information on CEV - iformation station for the spacecraft

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