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

[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...

[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.