But clearly Orbiter has a mathematical basis on which it makes these calculations? Astronautix does have a lot of figures but not for new launch vehicles.

Not exactly sure where to put this, but how would I go about calculating the paylad of a given launch vehicle to LEO? I always see people saying things like, "well, this gives you x tons to LEO, add another SRB and you get 2 more" - how do I calculate this? Is there a program I could get hold of?

Here's the quote from the wonderfully vague 3rd-grade level NASA site:



I think Griffin said LOI is done with the CEV module; but this doesn't say how the CEV gets into lunar orbit. Note how it talks about how the lander docks with the CEV "and travels back to Earth" - also rather vague as to whether the CEV does the TEI burn, though I think Griffin pointed tha out also. The key thing is that here it says "after a de-orbit burn", when they're clearly talking about a lunar mission and they don't seem to be referring to TEI. Could it just be a mistake. I mean... you're not really in Earth orbit in the de-orbit burn sense, and you didn't need a burn to slow you down in Apollo, so I don't really know what they mean here. Clearly our ablative materials are at least as good as what we had then, and you shouldn't be going significantly faster.

I'm trying to extract details from the diappointingly vague press stuff:

Am I correct in stating that:
1. The Shuttle-derived EDS with two J-2Ss or SSMEs conducts the TLI burn
2. The CEV engine conducts the LOI burn
3. The CEV engine conducts the TEI burn

The way these really press-y articles are written it just says the astronauts "enter" and "leave" lunar orbit; you could read them as saying that the EDS does the LOI burn and the lander's upper stage does the TEI burn.

What's this about the 'deorbit' burn done by the CEV? Does that refer to the CEV 'deorbiting' the Moon or does it do a burn before reentry? I'm all confused here...

Sometimes I wonder about that - Lunar Orbiter, too; clearly there's some of the ice thing but I think it's just pork-barrel politicking.

I read this interesting article on the Space Review:
http://www.thespacereview.com/article/458/1

The author supports ISS completion to US Core only and an early Shuttle retirement, and if you support the plan I think the reasoning is sound. What do you think?

Could someone make an image highlighting these fill lines so I know exactly what you're referring to? It does look like a contact binary to me...

Hi everyone:
I'm wonder what the best general introduction is for various bodies in the solar system. I'm looking for stuff that's above the level of NASA press release stuff and Sagan-like stuff, but stuff that's not at the professional level of texts like the tome they have for each planet (like Asteroids III, "Neptune and Triton", etc.). I mean books like Mercury: The Iron Planet by Strom and Hartmann's A Traveller's Guide to Mars, and also the Neptune and Uranus books by Miner; are there other good books on this level for Venus, Jupiter, and Saturn? Or other good books on the other planets?

Sounds perfectly reasonable to me - where did you see this?

Honestly I'm getting really tired of people making fun of the idea and calling it the "Boomstick" and whatnot. It's safe, proven, cheap, and capable, and 3.8G is not at all unreasonable. Should be cheaper with greater lift capacity than the EELVs. And also man-rated and flown much more than the EELVs.

Even so I don't think it presents a problem. You can a) cut the fuel such that you don't get more than maybe 4 or 5 sustained Gs, which is uncomfortable but bearable, and b) even if you do have 9 Gs it wouldn't be for very long, and it certainly can be dealt with by tranied astronauts.

But how many times has that happened to the Shuttle SRBs inflight?

So what would the actual acceleration be from an unmodified SRB with regularly cut fuel?

So what would the actual acceleration be from an unmodified SRB with regularly cut fuel?

Just how much acceleration in G's would you get out of an unmodified SRB, assuming maybe a 20 ton payload plus the liquid-fueled upper stage?
Personally I think it's a good idea to use them if you can solve that problem - sure, you can't shut them down, but in reality how often do you shut off an engine during manned spaceflight? And it will be "simple", "soon", and inexpensive to develop. I would assume you can cut patterns in the fuel to keep the acceleration to an acceptable level.

Alan: What about Ceres and Vesta? Do you think that we should call them planets by virtue of their shape? Personally I agree with your scheme but I don't think it would be logical to call Ceres and Vesta planets instead of asteroids.

I understand what the complex is - I was asking what Bruce meant by saying "both the White House and Congress -- isn't even seriously pretending anymore that the manned space program has any real justification other than continuing to feed the Aerospace/Industrial Complex," whether someone in the White House or Congress had said something to the effect of "science is secondary".

Or at least just not in any more press releases or websites, because there are much much better ones? I'll list them with text to spare you the agony of seeing them again:

Full Earth, Apollo 17.
The Viking Mars mosaic with Valles Marineris in the center.
The Voyager Iapetus photo.
The Voyager "colorful Saturn rings" photo.
The Voyager Titan flyby with the orange haze on the right. This one is especially silly since there are fantastic but not-often-reproduced images from Cassini showing tons and tons of haze layers backlit by the Sun.
That Skylab photo with the huge prominence (although this one isn't as bad an offender).
Not that I have a problem with the photo itself, but that first color photo from Spirit is often used as the only photo out of the gazillion from MER. That panorama from Bonneville is also overused.
That ONE image of Ida and Dactyl that you always see- it's always THE SAME ONE. Galileo took lots and lots of photos of Ida and Dactyl and we always get that one with Dactyl in the right of the frame (you know the picture!) .
Similarly, there's always that SINGLE view of Gaspra.
The Halley image used as the only view of a comet nucleus, when we have one set of better images (Borrelly), one set of much better images (Wild 2), and one set of far better images (you know the one).
Pathfinder's "presidential panorama" is used way too much. There was all sorts of neat Pathfinder stuff- superresolution views of the Twin Peaks and such - and we always see the same one.
We never see Viking lander images other than the one panorama from each site.
The set of like 4 photos from Apollo 11's EVA that serve as the photos for any discussion of any Apollo mission, ever. When there are tens of thousands of much more interesting images.

It's a shame since there's tons and tons of cool stuff from these mission that most people never see. And how come we never see Soviet stuff, like Venera lander images? Whenever there's a Venus image it's usually that garish blue Galileo composite.

I love it - but I also find it to be infinitely more enjoyable when I have a window seat. There's so much to see (and if you look for something, you're far more likely to see it). Once I even saw a sundog from ABOVE it! It always amazes me how people can just get on a plane, close the window shade, and go to sleep.

But I do agree with you that these cuts are a waste. TPF and the Europa Orbiter and MSL and really valuable missions like them are being delayed for these useless ISS construction activities. Now that, I will agree to some extent, is flushing money down the toilet. But once we get out of LEO, and have manned lunar, NEO, and Mars flights, I think we'll see some real science out of them.

And to look at if from another perspective, we're going to have manned flights no matter how you look at it- better to be flying to a NEO than lapping the LEO racetrack. Interestingly, the period when there no manned flights at all, from 1975-1981, was perhaps the starkest period ever for unmanned spaceflight. The rising tide raises all the boats, as they say. The new moon-Mars initiative isn't what's killing MTO and company; it's the Shuttle RTF costs. And personally, I would be perfectly fine with retiring the Shuttle right now and sending to the NASM. But we're not going to do that, so we need to do the next best thing and retire them as soon as possible.

Pork-barrel poilitics is, of course, really bad. Sean O'Keefe and Craig Steidle's protracted, DoD-like procurement plan for the CEV would have stretchted it out endlessly and wasted billions, and generally made the pork-eaters quite happy. At least Mike Griffin knows what he's doing and will save billions of dollars and years of work on the CEV with his plan for acceleration. The cost of anything from a contractor isn't in hardware; it's people multiplied by time. Compared to labor costs the hardware itself is virtually negligible. So by downselecting early, you have one company working much faster, rather than two with endless amounts of time for CEV development, so you're saving billions of dollars that might otherwise have come from the unmanned stuff.

Again this isn't really a fair comparison. The only manned initiative with a price range in the hundreds of billions was SEI, and the current plan on the table certainly isn't going to cost that. The NASA Mars Reference Mission 3.0 - a manned mission - is only costed at $55 billion, and that's by the same group who did the jaw-dropping $450 billion SEI analysis. The Planetary Society did a detailed report (with Mike Griffin) showing the total cost of a manned Mars program over 30 years to be between $119 and $129 billion. A lot, but not ridiculous over so long a time period. The main issue is the up-front non-recurring investment in hardware. Once you do that, the cost of each individual mission shouldn't be much more than a sample return mission (and we'd certainly get way more samples, better picked, studied, and from deeper drill points than we'd get with a robotic MSR). Why do you estimate $300 billion? Over how long a time period would that be spent? - surely NASA's budget is not going to be increased by that proportion. (If it were, it could only help the unmanned missions).



If there are any real fossils, like stromatolites, I don't think the contamination issue is a problem. The problem with contamination is what it might do to studies of extant life. This is, of course, a problem that must be dealt with somehow. However, any extant life is likely to be in underground liquid water and therefore could probably be separated from direct human contact (which is not to say forward contamination should not be examined closely). But I think humans would be so much more effective at finding fossils than robots that they should be sent to search for fossils, not just to study what robots have already found. No robotic missions currently being funded could find unambiguous evidence of fossil life (certainly not extant life) without really enormous stromatolite-like structures.



What do you mean by this? Was there some specific action or statement by someone?

Bruce: I agree with Bob here. While I agree that the shuttle, and especially the ISS, is for the most part a waste of money (a COMPLETE waste of money as far as the ISS goes), I think that it's unfair for you to consider the manned program worthless. If we actually build a lunar- and Mars- capable CEV and follow through with the Moon-Mars initiative, we will see some genuine science that's orders of magnitude better than what we've been getting robotically.

Robots are fine on Mars (or anywhere) for orbital photographic surveys, long-term seismology and meteorology, and limited geochemical science. But searching for fossils, let alone extant life, requires intelligence and versality of an entirely different type. Fossil hunting requires both very heavy and very fine work. It also requires complex perception. MER and Sojourner- indeed, anything I think we can realistically expect before 2020 with the exception of MSR (and I don't expect to see that before maybe 2016 at the very earliest) has absolutely no manipulative capabilites whatsoever.

Zubrin, while controversial, has made the fair point that one could parachute thousands of MERs onto Earth, and it is a fair bet that they might not find any fossils, "at least not before the arrival of the next ice age, when they would be crushed by the glaciers which they would not be able to outrun."

Take an Apollo mission, Apollo 15. The ALSEP, for starters would unquestionably be way too complex for even the most advanced modern robots to set up. Could these same robots than explore the region? Remember everything the Apollo astronauts did; they traversed several miles over rough terrain, they carefully examined and photographed the terrain, found the "Genesis Rock", and were able to do other work like removing the stuck drill for the core sample to take back to Earth. In just three EVAs they explored a significant fraction of the Hadley area and collected over 200 lb of lunar samples. I think a robot would be hard-pressed just to land and try to take the drill core, let alone get it unstuck (if indeed it got stuck), and then somehow send it back to Earth.

It took Spirit almost 2 1/2 months to a reach a crater that was about 800 feet away from it. I think anyone on this board could probably walk 800 feet in about two minutes. That's the time factor; robots simply take forever to do whatever they are doing, at least compared with humans. Remember Purgatory Dune? I think that would make any self-respecting toddler who's played in a sandbox laugh as he lifted his foot up out of the dune.

Opportunity spent six months in Endurance exploring the rock outcrop. Considering the size of the outcrop, a trained geologist could probably completely cover the outcrop in an hour or two, with just as much or more thoroughness as Opportunity. More important, the scientists could do things Opportunity or even MSL could never do, such as drill deep into the outcrop and bring the samples back to a lab for (immediate) study. Plus, the scientists would probably not take a whole day to try to climb out of the crater if they failed the first time. Remember the Spirit/Opportunity trenching acitivites earlier in the mission? I could probably dig ten times that far with my bare hands in five minutes. Spend all the money you want on drills and robot arms, nothing beats a human with a drill and shovel for exposing geologic layers or drilling holes in a rock.

Now don't get me wrong here; the rovers are doing a phenomenal job. But they have the intelligence of watermelons when it comes to their usefulness in terms of exploring unassisted from earth.

The discovery of the unknown includes data collection, but it is not limited to data collection.

To quote someone from another board, "Even in Apollo there was a combination of automated and manual data collection. A camera is a camera, whether it's operated by an astronaut or by a robot. Either way you get a photograph. The difference is in the tight coupling of a human brain to the data collection process. It's not a matter of the ability to collect data, but the intuition to know where to look for data, and to adapt the study on the fly. Telepresence is just not good for that. A geologist can tell a lot about a rock by just how it feels when he bangs on it with his hammer. There are plenty of examples of expertise in observation that just aren't translatable to machine automation.

Now the point about making the best use of limited funds is certainly valid. I'm not saying manned exploration is better in all respects. It's better in the same way that hand-detailing is better than driving your car through an automated washer. You get a higher quality product, but you pay for it. Since space travel in all its forms is currently very expensive, and the willingness of the public to expend resources on it is limited, prudent financial management is the rule. But just because your budget forces you to eat mac-and-cheese six days a week doesn't mean you won't enjoy saving up for that 16-oz 30-day-aged steak on Saturday night."

So robots simply can't navigate and ambulate intelligently, make their own decisions about exploration, and analyze their findings the way humans can. Consider trying to use a MER, or MSL, to explore the Grand Canyon, or Disney World. It cannot be done.

Granted, we haven't landed people on Mars yet, and I would much rather see MTO than any STS mission, even Hubble servicing, which is probably the only real scientifically useful Shuttle activity undertaken with any regularity. However, I think it's unfair to dismiss manned missions out of hand. When we get a real, manned lunar and manned Mars program, with extended surface stays, we'll get some serious science.

Until then, of course, the loss of MTO is a great waste; the half-a-Shuttle-mission we'll get in return is not worth it in anybody's checkbook (except maybe the United Space Alliance).

Considering how important this is, has MTO been deferred or cancelled outright? Might it resurface? This is a decision we're going to regret later - and if we do end up sending people to Mars, we'll need something akin to MTO anyhow. I'd rather see them cancel the 2011 Scout or Scouts than MTO.

I'm a big supporter of Griffin ("rather dumb" to turn off Voyager ) and even of NASA's new Moon-to-Mars manned spaceflight focus (please don't throw any cans at me ). But still, I don't think this cut is worth it. I'd rather see MSL (two MSLs?) fly in 2011 if it meant that we'd get MTO. This may seem like it's convenient now but wait until MSL arrives with no MTO in orbit - we'd BETTER actually fly MSL in 2009 for this to be worth it.

And I was disappointed; I just looked at google Earth for the first time and was impressed. I had seen this thread and thought, "wow, this will be really great for the moon". And then... blah. It isn't THAT funny.

There was a serious theory in the 1950s that Venus had oceans of seltzer, because they would be heavily carbonated under pressure.