Exactly.

Too much is decided at levels above Griffin’s pay-grade to warrant getting angry at him.

= = =

EML-1 sure sounds like an important place for setting up shop, permanently.

“There are some drawbacks to that proposal. First, your Earth surface to low orbit spacecraft needs a thermal protection system as a backup, safety modality if the ascent has to be aborted.”

Good point, so what are some workarounds? Retaining the Escape Tower as a backup stage? Launching with parachutes? One of those European/Russian inflatables? Beefing up the on-board propulsion? C’mon, get creative.

“Since you’d have to send a heat shield to lunar orbit or libration point L1 for every lunar round trip, you might not save any fuel or simplify mission logistics.”

Um, why would we bolt on something in LEO to something going trans-LEO? The whole point is that you have a LEO staging to effect changes to the CEV. For the moment the heat shields would be launched in bulk from the Earth, but you’re also leaving open the door for heatshields made from Lunar processing slag or asteroid waste.

If you stage to EML-1 it doesn’t matter what your LEO inclination, it’s about the same delta-V, which means that we can use the ISS -for the time being- as a staging point, but with eventual designs on better facilities in more favorable inclinations. This is possible because the transport infrastructure trans-LEO can be the same for each additional LEO facility.

The only heatshields at EML-1 would be the ones coming from the Moon.

“Furthermore, your astronauts would be stuck if they missed the rendezvous with the heat shield, or if they failed to get it to attach properly. Your design would add to the list of critical potential mission failure events.”

Staging, man, staging. Why does everyone seem to think we have to launch to free orbit and rendezvous in the wilderness when we already have a LEO facility!?! Is it perfect? [No] Is it good? [No] Is it workable? [Eh, probably]. You have people there. You have robot arms. You have duct tape. (and nothing in this post should be taken as individually insulting in any way)

“why not dock the manned spacecraft to an exoatmospheric trans-lunar space tug/departure stage which has engines, fuel tanks, and cargo racks?”

Now that’s not a bad idea. I hope you’re not intending to launch that monstrosity all at once…

Besides, part of the problem is the delta-V requirements for travel in cislunar space. Until fuel depots are established you’ll need dV 6 km/s capable propulsion to get to/from anywhere of interest (as I regard the Moon as only one destination of interest). Once fuel depots are established in LEO, EML-1 and on the Moon you can drop that down to 4 km/s dV. Although it may end up that companies offer a number of propulsion kits (i.e. 3,4,5,6 &c. km/s dV add-ons).

“Why would that be better than having a reusable, refuelable, bespoke lunar landing and ascent craft, a.k.a. LEM? Your design would probably be heavier than a specialized LEM.”

Because I’m trying to avoid having special-use vehicles for each destination. Then folks are going to want a bespoke GEO vehicle (instead of just grappling arms and waldos), a bespoke NEO craft, a bespoke Mars vehicle (I’m actually in favor of constructing such at EML-1 and launching from there so that half the world can watch).

“Your design would not make a trip to the Moon simpler or more convenient than docking with a resuable LEM, since you’d have to stop somewhere in near-lunar space to get those legs and bolt them on.”

Right, you stop at the staging facilities at EML-1 which can also serve a lot of other traffic than just to the Moon. Earth to LEO, LEO to EML-1, EML-1 to Moon, GEO, HEO, MEO, LEO, NEOs, Mars, Ls 4&5, etc. EML-1 is our on ramp to the Interplanetary Superhighways, which opens up all kinds of instrumentation possibilities at the other libration points in the Solar system, not just SEL-1 & 2. EML-1 back to LEO, LEO back to Earth.

“Those bolt-on legs, would they be left on the Moon? If so, you’d have to keep sending up more bolt-on legs.”

No, just as you can get to anywhere on the Moon at any time for roughly the same dV from EML-1, you just do the same thing going back – launch to EML-1. If the CEV is then going somewhere other than back to the Moon (i.e. back to Earth for a D Check) then they would be taken off and used for the next CEV that needs them.

“That kind of one-use, throwaway accesorizing isn’t appropriate space systems design if the goal is repeated, routine travel to the Moon and back.

That type of accessorizing also implies a closed architecture — since your design lacks a separate lunar lander, anybody else’s spacecraft would have to rpovide its own means of getting down and up from the Moon.”

Hold up there, chief. Who said anything about throwaway. The whole point of my approach is that nothing is thrown away, but rather re-used at every opportunity. Except for the heatshields. I haven’t figured that one out yet. By staging at the appropriate places you can provide a location where assets can be stored, retrieved, and re-used.

“The point of a proper 21st century manned spacecraft for travel between Earth and Moon is to save money, improve safety, and make travel easier and more routine by being as airplane-like as possible, and by not emulating old-fashioned space capsules that strew disposable parts hither and yon.”

The point of the VSE is to open all space to all Americans, for science, security AND commerce. It’s not just about the Moon and the ESAS architecture does EXACTLY what you complain of.

“You overlook THE POINT that the hard part of travel to the Moon and back is getting up and down from low Earth orbit. That caplet stuff just doesn’t get to the main issue.”

But the bolt-on engines do, as does the provision for an EML-1 facility, and fuel depots.

“However, we might have some basis of agreement if you’d be interested in a design which called for a separate Earth to LEO and back aerospacecraft, a space capsule which only returned to Earth in case of emergency or for refurbishing after n-many Earth orbit-Lunar orbit trips, and a separate LEM.”

I’m actually highly in favor of t/Space’s CXV as a really-near-term solution to what you’re saying. It might even play a Much longer term role even after the advent of the CEV, be it capsule, caplet, lifting-body or other.

“I’ll concede one point. Your proposal calls for the spacecraft to ascend from the Moon and rendezvous with its heat shield near the Moon.”

No, no, no. The heatshields are all kept at/near ISS or other LEO facility. As noted above, the only heatshields I’m considering being anywhere close to the Moon are those coming FROM the Moon going to LEO.

“Your idea about bolting legs on to the the spacecraft for lunar landing — that does not sound very strong or very safe.”

Why would engineers design unsafe landing legs that couldn’t take the load? They know what they’re designing to: One CEV with dV 6 km/s propulsion add-on.

Oh, and I forgot to mention that on the Lunar surface I want to put the CEV in a cradle for surface use. Why not? We know the attach points and interface…

“I’d also like to ask if you intend to ascend from the Moon with these legs attached, so that the legs can be left in lunar orbit for re-use?”

Of course, see EML-1 above. Staging provides an entirely different logistics opportunity. We have to stop thinking in terms of going directly from the Earth’s surface to somewere and from somewhere back to the Earth’s surface. Having people and robot assets in space offers a lot more capability to handle missions and failures.

“But — do you then propose to go to another location, perhaps L1, to meet up with your heat shield?”

Again, no. The heatshields are in LEO at ISS or other facilities. If I start out by saying that putting heatshield mass beyond LEO is silly, why would I have my heatshields anywhere other than LEO?

If there are issues of being stuck in orbit without a heatshield that’s why you want to have lots of CEVs traversing around cislunar space, to render aid and assistance if they can. That’s the point of developing a robust and open architecture where a company can buy a CEV, have it launched to EML-1, and all they have to equip it with is propulsion and waldos. Not Lunar legs, not a heatshield, okay, maybe some cargo racks, but only those accesories that suit the purposes of the company, in this case servicing broadcast satellites and fixing all of those pesky BS-602s.

The first missions may include heatshields for shake-down purposes, but ultimately, like the ejection seats on the space shuttle, you want to ditch it as quick as possible because it’s holding you back.

The point is not to optimize to the minimal delta-V, or minimal time in transit, or any other individual parameter, but rather to optimize the overall system to serve America’s scientific, security and commercial interests.

And that’s my issue with the proposed ESAS architecture. Instead of providing a system that can get to all the destinations of interest between here and including the Moon, we’re going to be spending our money on a private system for NASA that only goes to the Moon a couple of times to get some science data.

I’m sure Mr. Griffin is a very nice and smart guy. But he’s saddled with an agency that can’t think creatively like it’s supposed to and by political and economic forces that are entirely beyond his control and he’s stuck with serving us a crappy plan that serves those interests. And I thought O’Keefe had it tough…

I do mean cross ocean travel, known for most of history as “deep sea travel,” which took thousands of years to develop, and several hundred years to learn to do well. Even you have to admit that it did ultimately prove of some use to humanity.

The same will be true of human space travel. But, only if we actually do it and stick to it with the same tenacity with which our ancestors insisted on crossing the oceans to no immediate benefit.

— Donald

If you mean cross-ocean travel, then yes, that has been useful.

So far human spaceflight has been a lot like Captain Nemo and nothing like Captain Columbus. If this is something that has to have a plan, where is your plan for colonizing the ocean floor?

To the contrary, it is “ludicrous beyond belief” to ignore the lessons of history. My point is, for example, that regular deep-sea travel did not deliver enormous benefits at first. Nor did an enormous market exist at first. It was developed for the greater glory of nation states — just like spaceflight today — and then, as trade began to develop, to defend that trade. Nothing is guaranteed, but if ESAS is persued to the point of deploying a lunar base that needs supplies, and if it can deliver oxygen for use by scientists studying the moon and in Earth orbit, than the seeds of trade will have been developed. leading to the “enormous markets” and “enormous benefits” you’re looking for.

You still haven’t told me your plan to get from where we are now to a spacefaring civilization, in the way that we got from a land-bound species to a sea-faring civilization. Government establishment of forward bases, leading to trade, is known to work, albit not as fast as most of us would probably hope.

Until you introduce a plan that can at least appear to work, you are only carping and not contributing anything constructive.

— Donald

Comparing ESAS to these is ludicrous beyond belief. All of these deliver enormous benefit, addressed markets that either existed or were close to existing. In all cases people were already traveling to many of the destinations that would be served by the newer technologies.

ESAS won’t provide anything remotely close to the payoff of these programs. No one is already going to the moon. No one besides NASA is going to use any of the launchers that are developed. The CEV is too big and expensive to be attractive.

No genuinely new industry starts out “economic.” For humanity to do things we haven’t done before, there must be “extra-economic” efforts, or we’ll only do what we’ve already done better (e.g., we’ll have the most efficient possible stone tools). We will never set up trade routes in the Solar System if we wait for it to be economically justified first.

— Donald

Direct lunar insertion implies that the spacecraft will have some sort of landing gear or feet. I suppose this landing gear could be sent to lunar orbit separately, attached to the spacecraft for landing, and then left behind after takeoff … or maybe left in lunar orbit for re-use.

I also suppose we could build a big direct insertion spacecraft with a large cargo hold for ten or twenty Earth ton payloads. But that sounds like too big a spacecraft. One might propose a separate, unmanned, cargo only direct lunar insertion spacecraft. But would this design be superior to having a specialized, reuseable lunar descent and ascent vehicle that could land human or nonhuman payloads? I’d go with the separate lunar vehicle.

What did Apollo do? The Project Apollo designers considered direct lunar insertion, but decided that a separate lunar module would allow smaller mass for the total Apollo mission set.

Your idea about bolting legs on to the the spacecraft for lunar landing — that does not sound very strong or very safe. We’d like to have a lunar landing vehicle that lands perhaps ten or even twenty earth tons on the Moon and be reused. One or two lunar-gravity-adjusted tons in addition to the mass of the spacecraft– that still implies more than spindly bolt-on legs.

I’d also like to ask if you intend to ascend from the Moon with these legs attached, so that the legs can be left in lunar orbit for re-use?

Also, if you descend to the Moon with the propulsion module that you’re going to use to depart lunar orbit and perhaps for braking as you approach Earth on the return, then you’re taking extra weight down to the Moon and back up. Therefore, I’ll make the assumption that you intend to separate from your propulsion module, descend to the Moon, then then re-attach to the propulsion module after ascending from the Moon.

But — do you then propose to go to another location, perhaps L1, to meet up with your heat shield? If so, that is another mission critical rendezvous, which adds additional risk to the mission.

Finally, as long as the lunar spacecraft is also the Earth ascent spacecraft — I assume it is in your proposal — that Earth ascent spacecraft must still depart Earth with a thermal protection system in place, as an emergency backup if the trip is aborted. Therefore, waiting until after departure from Luna to attach the heatshield is O-U-T, an unsatisfactory design.

There are some drawbacks to that proposal.

First, your Earth surface to low orbit spacecraft needs a thermal protection system as a backup, safety modality if the ascent has to be aborted.

Since you’d have to send a heat shield to lunar orbit or libration point L1 for every lunar round trip, you might not save any fuel or simplify mission logistics.

Furthermore, your astronauts would be stuck if they missed the rendezvous with the heat shield, or if they failed to get it to attach properly. Your design would add to the list of critical potential mission failure events.

To go to EML-1 you bolt on engines and fuel tanks, as well as cargo racks.

That’s possible, but why not dock the manned spacecraft to an exoatmospheric trans-lunar space tug/departure stage which has engines, fuel tanks, and cargo racks?

From EML-1 you bolt on landing legs for Moon landings…

Why would that be better than having a reusable, refuelable, bespoke lunar landing and ascent craft, a.k.a. Lunar Excursion Module? Your design would probably be heavier than a specialized Lunar Excursion Module.

Your design would not make a trip to the Moon simpler or more convenient than docking with a resuable LEM, since you’d have to stop somewhere in near-lunar space to get those legs and bolt them on.

Those bolt-on legs, would they be left on the Moon? If so, you’d have to keep sending up more bolt-on legs.

… The point is that the accesorizing is appropriate to the mission.

That kind of one-use, throwaway accesorizing isn’t appropriate space systems design if the goal is repeated, routine travel to the Moon and back.

That type of accessorizing also implies a closed architecture — since your design lacks a separate lunar lander, anybody else’s spacecraft would have to rpovide its own means of getting down and up from the Moon.

…. Digested to its basics, the point of the CEV is to keep a fixed number of people alive in space for a fixed period of time. Everything else is supplemental to that.

No, I don’t agree with that statement, which strikes me as rather double-talky. “Everything else is supplemental to that.” — Huh? When people make vague, open-ended sales pitches imbued with false certainty such as that, one wonders what else is one their agenda.

Your agenda seems to be a closed, tightly bundles spacecraft architecture. Sorry, but I don’t agree with that.

The point of a proper 21st century manned spacecraft for travel between Earth and Moon is to save money, improve safety, and make travel easier and more routine by being as airplane-like as possible, and by not emulating old-fashioned space capsules that strew disposable parts hither and yon.

… the point of the CEV is to keep a fixed number of people alive in space

You overlook THE POINT that the hard part of travel to the Moon and back is getting up and down from low Earth orbit. That caplet stuff just doesn’t get to the main issue.

However, we might have some basis of agreement if you’d be interested in a design which called for a separate Earth to LEO and back aerospacecraft, a space capsule which only returned to Earth in case of emergency or for refurbishing after n-many Earth orbit-Lunar orbit trips, and a separate LEM.