Why do we still do exploration the way we did in 1960s Options

[karolp]

So, in the 1960s we did it like that:

1. sending single, big spacecraft of very limited, one purpose capability and limited lifespan
2. not being able to re-use the spacecraft for other targets
3. no means of controlling the situation when something goes wrong at landing etc.
4. not being able to see the spacecraft from orbit
5. designing each spacecraft from scratch instead of reusing and further developing existing designs

All in all, this resulted in:

A. a lot of failed missions and wasted money and effort
B. only limited scientific results which usually required follow-up missions which still were inconclusive
C. very expensive missions that took years to develop and perished in seconds if something went wrong

We may have made some progress in some points with missions like MRO which can see ground spacecraft from orbit or even take snapshots of spacecraft landing in progress (Phoenix). However, this is still occasional "byproduct" and not a change in philosophy. Therefore, I'd like to suggest creating a more general thread about the specific issues listed in the first paragraph.

Let's face it, we still do relatively expensive planetary probes which still provide us only with limited "beachhead" kind of scientific results and do not have a lot of maneuvering capability nor planning flexibility.

Here are a few suggestions which I would love to see discussed by people who know more than me about space exploration technology:

1. first and foremost: no more single, big and expensive, heavy spacecraft

Instead of taking one big rover on board, we could take one small rover, one small airplane and a cluster of microbots designed for specific purposes - each providing valuable data in many areas simultanously and if one is dead, there are still plenty of others to continue the mission.

2. a spececraft already there is better than one on the drawing board

No more short lifespans. Each mission should be designed while keeping in mind that money for future missions and follow-ups may not be available. Accumulating a lot of data over a lot of time gives us insight into how things CHANGE over time on a given target.

3. no more fly-by expendable spacecraft

Flying by a planet to see what it looks like and letting the spacecraft then fly into oblivion may have been a good idea back in the early days but not any more. I tend to regard this kind of approach as extremely short-sighted, providing only short-term gains which do not balance the cost and effort involved. I think we need spacecraft that is finally able to MANEUVER itself, meaning it has its own propulsion of some kind, be it only a weak ion thruster.

This way we could actually GO PLACES rather than select one target and writing off an entire spacecraft after this target is examined. Reusing Stardust and Deep Impact were good examples of this approach. However, I think this should be a default capability of every spacecraft rather than counting on pure luck and coincidence in selecting additional targets.

Imagine the Voyagers being able to come back to their previous targets or Galileo setting itself free of Jupiter's gravity and going out to explore asteroids instead of plunging into its fiery demise.

4. no more single-spacecraft "hope it works" approach

Instead of sending just one orbiter or one lander, we should send a lander and an orbiter simultanously so that we have the possibility of tracking spacecraft as it lands and inspecting it afterwards. No more "lost spacecraft stuck somewhere". We could aim at making spaceraft COOPERATE not by coincidence but from the start.

Let me give you a nice example: imagine we might send a new orbiter and a new lander to Titan. Obviously the orbiter will provide data link capability and some basic radio tracking. But would it not be wiser to actually fit it with a decent camera that allows it to actually SEE the spaceraft if something goes wrong?

I shall go into more detail on that in another thread:

http://www.unmannedspaceflight.com/index.php?showtopic=5820

Do not worry, I won't fill the forums with lots of my threads of this kind, just this one and another one for some of the things that had been on my mind for some time now.

And finally:

5. no more reinventing the wheel each time we go somewhere

Of course each mission has its specific goals, but modifying an existing design might actually be cheaper in a lot of cases. And most of all: there is nothing wrong in sending identical spacecraft to two different asteroids

[dvandorn]

This has been discussed a number of times here, and most all of your points have been addressed. And, I must say, there are several areas in which you are not correct in your assumptions.

First, you're generally incorrect about "how we did it in the 1960s." The first successful American planetary probe, Mariner 2, was a Ranger Block II spacecraft fitted with a large parabolic antenna and some alternative sensors to those generally carried by the early Rangers. It was not custom-designed for a mission to Venus, and nearly succumbed to the increasing solar constant as it approached our nearest planetary neighbor.

We planned entire series of spacecraft for given missions back in the 60s. Each of the first three American attempts to reach Mars were designed as dual-spacecraft missions. Mariners 3 and 8 never even got into Earth orbit, but there were originally to be flotillas of Mariners 3 and 4, 6 and 7, and finally 8 and 9.

Ranger, Lunar Orbiter and Surveyor lunar probes were designed as a series of missions to be flown by the same base spacecraft, with minor changes to the sensor packages between flights. And this was even rather program-specific; all five Lunar Orbiters were nearly identical, the Surveyors only differed in the various experiments attached, and Ranger went through five spacecraft iterations, only one of which (the Block V) actually succeeded.

Even into the 70s, we sent pairs of spacecraft on every mission. Vikings 1 and 2, Pioneers 10 and 11, Voyagers 1 and 2. And as for not knowing what's happening during critical events such as landings, our ability to monitor such things back in the 60s had a lot more to do with limitations of communications and data processing techniques. Once we developed ways of monitoring these mission segments, we started doing it.

It wasn't just the pairs of spacecraft on a given mission that shared design elements -- Mariners used the same octagonal spacecraft bus starting with Mariner 3 and ending with Mariner 9, and even the Voyagers house their "guts" in octagonal buses that are similar in size to the first Mariner ever designed.

By saying "never re-invent the wheel again," you put on blinders that don't let you take advantage of new developments in a variety of engineering and scientific fields. It makes absolutely no sense to be forced to carry forward antiquated power, imaging, data processing or propulsion technologies. And trust me, it's not just a matter of "Hey, just fly Cassini or MER or Galileo again and just update whatever has been improved in the meantime." Once you factor in such technology advances, you end up re-engineering a "carry-forward" design so much that you're essentially designing a new vehicle every time.

Now, I'm speaking primarily of the American program. If you want to argue any illogic to the progression of the Soviet planetary exploration program, you need to read up on how the Soviet system worked -- there was little to no actual planning in terms of progressions of missions, each building upon the last. Each Soviet probe was an engineering demonstration championed by a specific design bureau, or most often by the little kingdom-holder of a given design bureau. As with many things, the Soviet space program reflected a nearly Byzantine maze of personal relationships and antagonisms more than it did a well-thought-out plan for planetary exploration.

So, I would agree that we ought not do many of the things you say we ought not do, Karol. The problem is, we didn't do those things back in the '60s. Please read your histories a little more thoroughly...

Why don't we send things in twos any more? Without exception, it's because of cost. When your launch vehicle accounts for a good 40% to 60% of your total mission cost, you just often can't afford to use two of them. And the MER experience tells you pretty solidly that it *does* take nearly twice as much money to make two of something as it does to make just one.

As for your insistence that we only send little tiny probes, micro-robots, things with limited resources, but with robust designs, well, that really limits what you can get out of a mission. If you're going to spend $100 million for a booster, you need to get as much as you can out of the spacecraft you're delivering. And the best example of a "small" rover vs. a "big" rover would be Sojourner vs. MER. I don't care if you landed three Sojourners at each of the MER landing sites, you would *never* have gotten the amount of science out of them that you've gotten out of the MERs. (In general, "small" means more limited, less able to handle adverse or unforeseen conditions, less capable -- be wary when recommending such approaches, as far too many *failed* missions have ascribed to that philosophy.)

-the other Doug

[ElkGroveDan]

oDoug has made a huge number of important points here. In short my question to the original post would be: Why do you think things have been done the way they have ? Because our engineers were Ignorant? Careless? Lacking vision?

In a nutshell, each mission was designed -- at the time -- to accomplish a goal that was there -- at the time -- with the resources that were available -- at the time -- using the most cutting-edge emerging technology available, or that could be developed within the project time frame -- at the time. Omniscient central planning has a great allure to back-seat drivers who have the benefit of viewing events in retrospect, but in most cases, we do what we do, the best we can, with the information and resources we have, -- at the time.

[karolp]

ElkGroveDan said while I was editing my reply:

"Why do you think things have been done the way they have ? Because our engineers were Ignorant? Careless? Lacking vision?"

As much as I admire them, we still sort of lost track, didn't we? I mean we keep sending new spacecraft (for now) but are we making any PROGRESS? We kept getting inconclusive data from each mission in the 1960s and still what we have about things like life on Mars is inconclusive. We have hints at something that may or may not be microorganisms emitting methane, buried deeper in the ground or even in underground liquid water reservoirs. Wouldn't a MER fitted with a drill or rather some advanced tethered penetrator do the job? All we need is a piece of an advanced technology for getting deeper underground and seeing what is there. Would a MER be so incompatible with such a device, even if the penetrating tool were small and largely independent? If I am not mistaken MSL was supposed to have a drill or a laser but its budget run over and it will have none. Wouldn't such device fit on a MER?

Sure resending spacecraft is cheap but not innovative and completely redesigning s/c is innovative but expensive. But can't we balance those two things? Why can't we fit a MER with AI, RTGs and better cameras and just send it there? You might say we would still have to redesign it so far that it would make it a completely new spacecraft. But couldn't we compromise somehow? We have MSL and look, it missed the upcoming launch window and run over its budget. Wouldn't an upgraded MER be better than no mission at all?

Now on to the original reply to Doug's post:

This is exactly the kind of reply I was hoping to get. I was fully aware that certain details needed to be corrected and I may be wrong in many of my assumptions. Still, I think we might need a place to think outside the box about what really is expensive and what is not and how we can really move on to something new instead of doing pretty much the same thing in terms of the level of thinking. Einstein once said:

"Problems cannot be solved at the same level of awareness that created them."

And this is why I started this thread - to try to think of how we can change our entire thinking rather than keep hitting the same wall for decades (and by the wall I mean budget constraints and limited scientific gains).

I also do realise that this kind of topics has been brought up before and some of them have been already "discussed to death". Still, a lot of things changed since then and the actual designs even apporached some of the points mentioned, they are just not quite there yet.

So let's just make this thread into a place where we can finally summarise all ideas of this kind scattered in many different places all over the forum and perhaps make them even more specific.

I see some contradictions in the current approach. You said:

1. we no longer fly s/c in twos because it is expensive

but

2. we do not re-use designs even though it saves money

And I am not talking about all those instances where you cannot send a Mars-type spacecraft to Venus because it will get fried by sunlight. I am talking about things like re-using Stardust and Deep Impact or having MRO take snapshots of the landing of Phoenix. We did it because there was an opportunity to do that but it still largely happened by chance, meaning Stardust was simply still operational after completing the first comet fly-by and MRO just happened to be at the right place at the right time. What I mean is, why don't we do that INTENTIONALLY and from the start and EVERY TIME we go somewhere rather than by chance?

After establishing the general philosophy I would like to go as specific as possible and ask for actual examples like the ones you already provided and direct our attention to very specific issues with reference to current projects. So, I would like to ask specific questions:

1. We know a MER sent to the Moon would not be of much use as the temperatures are different and real time navigation is possible on the Moon. It does not make sense to send un-protected Mars-type s/c to Venus etc. However, would it be possible to simply divide Solar System bodies into separate classes depending on the landers and orbiters suitable and just go ahead and send identical hardware there?

2. Could someone possibly tell my why spacecraft still do not have any maneuverability but go one place and just stay there? Would it not be fun (and a huge money-saver) to redirect missions like Stardust not once or twice but almost indefinitely? Deep Space 1 had ion propulsion but it was very weak since it was a prototype. Now imagine you want to explore three asteroids in the main belt. You do not need 3 spaceraft but one which could go to all of them. We have Dawn you might say - but it still is very limited because the ion propulsion is still weak and therefore the transfers are so sloooow. My question is: why is ion propulsion still so weak and why are not all spacecraft fitted with them?

You might say there is not enough energy but we are even planning to have solar panels on Juno going to Jupiter and on the ESA orbiter possibly going in orbit around Ganymede - so why not just give a spacecraft six pairs of those instead of just two and go ahead with a more powerful engine? Because it would make it heavier - but what is more expensive - a more powerful launcher or a separate new launcher for each of the new spacecraft going to different targets to perform pretty similar tasks?

3. Why is there no AI in our spacecraft? We have a bunch of engineers working in shifts and not getting enough sleep just to make sure two rovers go a few centimeters a day and not get stuck in dunes or tip over rocks. Of course some of the navigation is done in an autonomous way and they are there to get the rovers out of really bad trouble. But still, would it not be much better to have rovers that reeeeeally go places like real cars and not just 10 miles a year (I do not recall the exact figure, please correct me here but I hope you see my point). Just think of it - Mawrth (one of the possible landing sites for MSL) is not that far away from Opportunity and Gale is not that far away from Spirit. This may still be a couple of hundred miles (please provide the exact numbers if possible) but that is how far we can normally go by car, isn't it? If we had AI and reasonable speed on Mars rovers, we could gain a lot more within the 5 year mission however vast our current achievement might be.

4. Finally let me correct one statement: I do not mean we should start launching only tiny things like Axel or ExoFly. But I still wonder why we did not send additional mini-spacecraft with the MERs. Budget constraints? Maybe, but we are still not planning to send anything of this sort with the MSL either. And why? Because it has already run over its budget. And why this happened? Because we decided to design a whole new thing yet again rather than fitting another MER with better instruments and RTGs...

[Greg Hullender]

There is no "AI" on the spacecraft because no one today knows how to do such a thing. The popular impression of the state of the art in "AI" is very far from the reality.

Where is the AI that can drive your car? That's a much, much easier problem, with a much, much bigger payoff, but despite a lot of effort on the problem, it's nowhere near the marketplace.

--Greg

[nprev]

Karol, just to add a little more to oDoug & EGD's replies, you also must remember these factors:

1. Technological obsolence. Unless you buy a LOT of parts upfront, it's unlikely that you'll be able to procure them at all in just a couple of years. This places a major constraint on the cost-effectiveness of mass-producing spacecraft.

2. Additionally, space-qualifying even common components like processors is an extremely time-consuming & arduous process, and with good reason. The environment(s) are harsh, and you can't fix it after launch. This is one major reason why AI isn't even a dream yet, quite aside from the fact that any software of that level of complexity would add an incredible amount of mission assurance risk; I think that they still haven't space-qualified anything more advanced than 80486s yet.

3. Project planning timelines are usually at least several years long for both the previous reasons stated, the necessity of very rigorous system engineering, integration and testing, and, one HUGE item: almost inevitably variable funding & schedules.

Trust me, there's lots & lots of reasons why UMSF is done the way it is.

[mcaplinger]

If I am not mistaken MSL was supposed to have a drill or a laser but its budget run over and it will have none. Wouldn't such device fit on a MER?

You are mistaken. MSL will have a laser (ChemCAM) and it will have a drill, and neither of those would have fit on MER.

[karolp]

Greg Hullender:

I am not talking about the marketplace. I am talking about DARPA and its "Grand Challenge" competition and things like that. A lot of technologies are not available not because they do not exist but because it is more beneficial to keep them in the hands of the military. I am certain users knowledgable in military topics can provide plenty of examples for that. I will provide one that ceased to be a military thing: the GPS. Now we have GPS receivers in our phones. But back in the mid-1990s the accurate measurement was reserved to the military and we got a downgraded signal. And why? Because it was considered a threat to national security. But somehow they got over it or have an improved technology now and released the older version to the wider public.

Similarly, a car fitted with AI that would be widely available in the market would give some advantages to criminals, terrorists etc. This is why there is no AI in your car. But that does not mean the military do not have it yet or are not on their way to getting one. If anyone has any details on the current state of AI in vehicles and aircraft (anything that HAS been in a public release) please provide the details.

nprev:

This is what I am after - a way around obsolence, availability of parts, variable funds etc. Sometimes we ommit very straightforward solutions because we do not think "outside the box". I know a space-related joke (I do not know if it is actually true) but it goes like that: Astronauts needed something to write with in microgravity because normal pens wouldn't work. The Americans developed a new pen for microgravity at a cost of a million dollars. The Russians used a pencil This kind of thing - maybe we could "use a pencil" but keep omitting this kind of a solution which would let as get around budgetary and technical issues and start getting vastly superior amounts of more CONCLUSIVE science out of our planetary missions.

mcaplinger:

This is why I asked for correction if necessary. And still, even if the drill and the laser have been kept:

A. it is not certain that MSL will get off the ground even with the best of intentions
B. if it does, it will NOT use the laser nor the drill to look into the question where the methane is coming from because we need a new piece of technology for that which does NOT have to be big nor MER-incompatible


Now I would like to thank all of you for picking up the subject in this thread. After only a couple of answers I can formulate my ideas more clearly and boil them down to just a few words for everyone who would like to comment. This by the way is what a "regular" person might tell you when you tell them about the current state of the art in planetary exploration:

1. why aren't the MERs going as fast as regular cars (the AI thing)
2. why spacecraft go to one place and stay there (the ion propulsion thing)
3. why do we build new spacecraft for each new target (the balance of building upon existing designs and innovation)
4. why can't we see everything spacecraft does and why is NASA losing spacecraft and wasting money (sending in twos, redundancy, "the network approach" that I discussed in the Titan thread)

This is what I'd like discussed in more depth now. We have some examples for 1 and 3 (and some addtional comments to make) and not so much for 2 and 4.

[dvandorn]

A few general replies:

- We may not re-use a lot of hardware designs, but we re-use information, and that saves a lot more money than you might think. For example, the Viking program ran hundreds of millions of dollars' worth of tests on its entry vehicle shape and dynamics, and of its parachute system. Every successful landing on Mars since then has re-used the Viking developmental data, thus saving hundreds of millions of dollars in developmental testing.

- You can design a general spacecraft bus for destinations with similar environmental characteristics, true. But how many destinations have similar environments? The Moon is unique in terms of thermal environment, as are each of the rocky planets. Vacuum operations are the same on the Moon and on asteroids, but there are large differences in how much you can rely on gravity between the Moon and an asteroid -- gravity not only helps you move around (it keeps your wheels in contact with the ground), it also keeps your lander from flying off the surface if you use, say, a pneumatic drill or a rock chipper. Also, power systems must differ drastically depending on periodicity of insolation, degree of insolation, etc., and that's just when you're using solar power.

- Again, if you're going to find the money needed to launch a fleet of probes, then yes, it makes sense to make a bunch of the same probe and send them all over a period of a year or three. That was proven in the American lunar probes of the 60s. But a fleet of probes means a fleet of launch vehicles, and launch vehicles are the most expensive single part of the equation. You want to send five probes using Atlas V or Delta IV as launch vehicles? Then you need to add at least a half a billion dollars to your budget, just for the launch vehicles. Even if Falcon 9 works the first time and every time and you can buy one for only $50 million as opposed to the $100 million for an Atlas V, then your five probes still require a quarter of a billion dollars for launchers. And, it can be asked, why did you need to have five probes when one could have given you 90% or more of the data returned by all five?

- You seem to think that ion propulsion is the overlooked savior of sending huge probes all over the solar system cheaply. The only reason the existing ion engines have been successful in sending small probes around a variety of locations is that they are very low thrust engines, and thus require a relatively small reaction mass. (Ion engines work like any other rocket engine in that they expel mass out of a nozzle to make the spacecraft go the other way, so your total amount of delta-V is limited by the reaction mass you can carry with you.) Ion engines are low-thrust affairs, it's not just a matter of "Hey, let's scale this up and make ourselves a big, powerful ion engine that still only needs a couple of hundred kg of fuel to go from here to Mars!" That violates the physics of how ion engines work; if you want big, powerful engines, you really need to carry a lot of reaction mass, whether you use chemical, nuclear or electrical energy to force that mass out of a nozzle. There's no current way around that.

- You say we've spent all this money but not made any real progress on understanding Mars. I beg to disagree. We have a tremendously greater understanding of Mars than we did even 10 years ago. Yes, we don't understand entirely what might be happening in terms of life on Mars, but we *do* understand that life is not widespread, that if it exists it evades detection sensors that would detect even a devastated ecology, and that if it does exist, it must be hiding in places so well-protected from inimical factors that it will be difficult to well-nigh impossible for easily-affordable probes to find and study. I'd say that's an understanding several orders of magnitude more sophisticated than we had when we launched Mariner IV 35 years ago, and that understanding has been refined by only six successful landers and nine or ten orbiters (depending on how you classify some of the Soviet orbiters in terms of adding to our information). Just because they haven't found what you wanted them to find doesn't mean that these spacecraft have made no progress. They've not found what we were looking for in all cases, true -- but, far more importantly, they've found what is there.

- The MERs are fitted out with the best AI we've been able to design, in terms of what AI is useful for on a MER-like mission. The girls have even gotten smarter as the missions have progressed, thanks to upgrades to their AI-like autonavigation capabilities. That's what AI is right now, and the MERs have it. And as Dan asked, in what way does AI enhance your mission? Does it make it cheaper? If so, how? I don't care how good I think I have made an AI, I'd want to monitor it, improve it, and make sure it doesn't do something stupid pretty much constantly. There is literally no way to make AI any better than it is right now; increases in computer power and the subtlety of programming languages has not brought us nearer to, say, allowing AI routines to run our cars or our air traffic control networks. It would have to get at *least* that good in order to be useful on a space probe, right? And, trust me, the economic advantages of AI that can run air traffic control, or drive you car, are such that those types of applications are already driving AI development. This isn't a case where you can develop AI for your favorite Titan lander and then make up the trillions of dollars you need for your exploration plans by selling your AI to the car companies -- you are *much* more likely to adapt whatever AI DARPA, or the airline industry, or the car companies come out with for your space probe, and consequently will need to find the trillions of dollars you need for your exploration plan somewhere else.

-the other Doug

[nprev]

Well, to answer your last: I see your point, but how do you think that it's possible to direct innovative thinking?

The only possible managerial means I can see is already employed as a secondary feature of cost caps; designers have fixed resources, so of course they're going to try to come up with the best ideas they possibly can to achieve the mission within cost, schedule & performance constraints.

[ElkGroveDan]

As much as I admire them, we still sort of lost track, didn't we? I mean we keep sending new spacecraft (for now) but are we making any PROGRESS? We kept getting inconclusive data from each mission in the 1960s and still what we have about things like life on Mars is inconclusive.

I see. You want a hard fast answer to the question of "Is/was there life on Mars". Well as I tell my children, most of the time in life there aren't a lot of easy answers. You have to work hard for anything that's worth learning.

As far as your question of are we making progress, you have got ot be kidding. What we know about Mars, compared to what we knew when the the Vikings landed is immense. What we learned from the Vikings, Pathfinder, MGS , Odyssey, MERs, MRO, Phoenix could fill entire libraries of printed volumes. I'm sorry the lizard or centipede you expected to crawl by in one of the images hasn't shown up, or a fossil appeared under a the rat brush, but you know there's a whole lot more to what we are doing there, in the quest for understanding this amazing planet, than what you hoped to see the easy way.

In answer to your question, no we haven't lost track. Not at all.

[djellison]

Sorry - this thread isn't going to go anywhere positive. It's covering ground that's been covered previously, and is skirting around the edge of a banned subject. The place for big long "Where's my flying-car dammit" rants is your own blog - not a discussion forum