How would you improve the Shuttle design?

[Fractal_UK]

Why will it need to happen? What could possibly happen to the earth to make it less habitable than, say, Mars?

Almost certainly nothing but that's not really the point. There is a limit to how large a population a given area can support as well as the economic opportunities that such a region can offer. We need to diversify resource availability in certain areas and those areas are only going to themselves increase with time. At some point, it's going to be optimal to move people closer to the resources that we are exploiting be that on the moon, mars or whereever else. Economic and population pressures will make this a natural result. We can either wait for that to become the only practical option or we can start now, invest, and reap the benefits early.

[drakesdoom]

On the manned vs unmanned exploration argument, what is the endgame of unmanned exploration? It is safer, cheaper, easier, but in the end it has always and will always be just a probe to see if and how we as people can get there. Exploration and knowledge has no value unless applied. I mean if safe, cheap, and easy are the only goals just sit on the couch and watch TV, who cares about space anyway?

[Fuzzy Dunlop]

To try and get the thread back on track, surely (if the shuttle was still flying) the quickest upgrade would be the ability to fly autonomously. If you are going to use the shuttle for any purpose that does not explicity require humans, it doesn't make sense to carry them along.

[DerekL1963]

It won't be clear if they'll be up to it? They've been doing it since 1970. There's some very simple arithmetic involved in which is cheaper; if I want to return a rock sample; do I return the rock sample, or the rock sample and a person, who has to be kept alive?

If by 'it' you mean automated sample return... Well, yeah, they've been at it since 1970... But again, apples and the thing most unlike apples you can imagine. No sample return mission to date has been even remotely as complicated as a Mars sample return will be.

And, no, the arithmetic isn't "simple" unless you willingly blind yourself to both the other scientific activities that humans can perform and their ability to do other things mentioned earlier.

If we lose ten sample return missions due to mistakes easily fixed by humans for every one that works, that'll still be value for money, easily. Looking at actual missions, we've achieved a lot better than that.

So long as you ignore everything but "returned random sample that happened to be in [robotic] arms reach at a [more or less random] landing sight" in your calculations, sure. But that's normally called a strawman, and isn't normally regarded as conducive to rational discussion. Once you start serious science and want targeted sample collection, things get very different very quickly.

Edited May 20, 2013 by DerekL1963

[DerekL1963]

Hum. I wonder how regular airplanes do it, then. Or blimps, if we take it to the extreme. And I've always been under the impression that low landing speeds were desirable, not a problem.

Regular airplanes are far more dense than internal tank (I.E. Faget type) orbiters. And still, they too, have problems with crosswinds. Blimps are even fluffier than internal tank orbiters, and they have enormous problems with crosswinds.

I never mentioned landing speeds - only susceptibility to crosswinds.

Seriously, dude, really? It's amazing what a guy can say defending the shuttle. I mean it looks cool, but that won't change physics any time soon.

I don't know about anyone else, but I'm not defending the Shuttle - I'm discussing engineering and fiscal reality and the consequences of engineering choices.

Separating crew and cargo makes sense, because both payloads have wildly different requirements. Using the same launch vehicle for both, however, can rapidly build up a flight history, which increases safety and lowers cost (i.e: Soyuz).

Not only Soyuz, but practically every other form of transport on this planet.

[RocketPilot573]

Moar Boosters!!!!

It would be awesome if the shuttle could go to Mars. And I would probably add a way for it to land on low gravity planets with little/no atmosphere.

[Kerbface]

If we lose ten sample return missions due to mistakes easily fixed by humans for every one that works, that'll still be value for money, easily. Looking at actual missions, we've achieved a lot better than that.

A manned mission to Mars or another body would undoubtedly be more complicated then just getting a couple or rocks and looking at them. It would allow a large number of samples to be tested in a short period as well as fast place exploration of the area of landing and it's surrounds, physical features and all that. Would you say that looking at a sample taken from the grand canyon is equally as informative as actually going to the grand canyon? I mean the Curiosity Rover is great, but it's got a very limited area to cover and takes a long time to do anything.

Edited May 20, 2013 by Kerbface

[Sof]

In my opinion, we either continue using rockets or we think outside the box and build some sort of ground based launch structure.

Apart from the discovery of a new type of engine, I'm not sure the costs of rockets is ever going to exceed the extra cost of launching all that landing gear, wings, maintanence and habitation compartments you get with shuttles. Earth is simply to hard to escape from.

[Canopus]

Moar Boosters!!!!

It would be awesome if the shuttle could go to Mars. And I would probably add a way for it to land on low gravity planets with little/no atmosphere.

That would make no sense at all.

[RRoan]

I would tell them not to waste exorbitant amounts of money on a flawed concept.

Slapping might be involved as well.

[DocSnuggles]

There is no reason for manned space travel. If you take a look at the progression that automation has taken and will take, why should you send an human to space. The only thing that can´t be explored by machines is the influence of space to humans . And being prepared for the day to encounter the overpopulation isn´t an argument in my opinion. I think there could live many more billions of humans on this planet well feedet by using all possibilities we have (aqua cultures, greenhouses in the desert by desalted water, reducing/cutting meat production and using alternatives.... ). At the end it´s only limited by the energy we have. And before we have to send out mankind to other planets because of the overpopulation there will be some cruel methods to safe fuel. Cut of the head and freeze it... send it to the mars colony and put it on an artificial body and reanimate it. But then human space travel also became an automated cargo operation and there´s no good reason to exercise manned space travel these days.

But damn... I also want to have the manned space programm alive. It´s like the "no speed limit on the autobahn". No good arguments for having it but if I had to decide to cut it... I wouldn´t do it.

Back to the main topic.

I would start the shuttles near the equator. There are some mountains that could be used for a kind of maglev system to accelerate the shuttle before using liquid fuel. Being 4000 to 6000 meters over sea level at 1000km/h before starting liquid engines should be a huge deal. From this point on a 2 stage system would take place with an shuttle/capsule mounted on the top. The command module would be more like an lifting body and the landing would be done by an controlled parachute (paraglider). If it would be possible to build and descending airfield with a kind of gliding surface the landing gears could also be dropped. A human wouldn´t be able to do this maneuver but a computer will imo.

[Rune]

Regular airplanes are far more dense than internal tank (I.E. Faget type) orbiters. And still, they too, have problems with crosswinds. Blimps are even fluffier than internal tank orbiters, and they have enormous problems with crosswinds.

I never mentioned landing speeds - only susceptibility to crosswinds.

You did say something about "sporty landings", as I quoted. But anyhow, the fact is both airplanes and blimps manage to fly routinely with much better safety records than the shuttle could ever have. So being a better glider can only be good regarding reentry... as long as the "price" you pay for it is cheap. Which is why I still maintain that having fuel tanks on the orbiter and using it as the upper stage makes for an easier reentry, not a harder one. By easier I mean the weight fraction of the reentry-dedicated hardware will be smaller. Which is kind of the point.

Rune. So better to have a tank already than putting wings on it.

[Nikolai]

Robotic sample return would still be far cheaper than sending humans anywhere.

Yes, if the only factor in a sample return were scooping up some surface material and returning it.

Part of the advantage of humans -- and also the reason that lunar astronauts were trained in graduate-level geology -- is that we have the ability to put findings in context. We can walk through an area and get a surface-level analysis of what happened to shape which geological features. We can use that to determine which areas require deeper study, and which samples within those areas are likely to offer answers to the questions we have.

This has proven fiendishly difficult to mechanize -- hence the sound bites that crop up every once in a while on the matter from people who are involved in robotic exploration, like Steve Squyres pointing out in Roving Mars that both MERs combined could "do in a perfect sol(*) [what] a human explorer could do in less than a minute". Apollo really showcased that. By necessity, contact with the lunar surface was tremendously short, but the return was immense -- leagues ahead of anything unmanned exploration could offer, or still can.

We also hope to live places other than Earth eventually -- well, some of us do, anyway, and it makes sense for the long-term survival of the species and/or its descendants -- and every little bit we learn about space travel helps that.

There is also some difficult-to-assess value in simply having a capability. While it's difficult to gauge exactly how much it's worth, what it means to industry, innovation, engineering capability, managerial capability, and technical capability can't simply be handwaved away.

It's also not simple and straightforward to assume that unmanned will always be cheaper. I invite you to look at the cost of, for example, Viking versus Pathfinder versus MER versus MSL versus MSR, expressed in constant dollars. Yes, each is growing in capability and sophistication, but that's the point.

Sure, there are all sorts of applications where robots are the only option -- and regardless, space is a hazardous environment, so you want to send robots first. But sending them "instead of" rather than "ahead of" is an enormously short-sighted mistake -- both in terms of the depth of science involved and in terms of the eventual future of our species.

(*) That is, a Martian day. And he knows whereof he speaks -- he was the project leader (the technical job title is "Principal Investigator") for the MER missions.

Edited May 20, 2013 by Nikolai
fixed incomplete fragment

[Kryten]

You can do that easily enough with a simple rover. Even something like curiosity would be a lot cheaper to send along (and, crucially, not bring back) than even a single human.

[Nikolai]

You can do that easily enough with a simple rover.

Evidence? People who've worked on rovers and have to know their top-to-bottom capabilities disagree with you; I quoted one.

Some might even point to the need to bring humans back in the early stages of exploration as a feature, not a bug; collection and prolonged study of contextualized samples is the real driver of scientific knowledge. You need some things to sit there; some things to bring stuff back; and after a certain point, you need some things that can recognize important things even when they're not expected or anticipated.

The case for space exploration, and especially manned space exploration, is multifaceted and requires the careful weighing of several interrelated factors. Attempting to handwave these things away by pointing out that machines can, in a limited capacity, mimic some of these same activities (as long as you don't examine the activities themselves too closely) is not convincing. After all, one could just as easily point out that remote observation is cheaper than sending spacecraft to the site; why not let all of our exploration be done with instruments in orbit(*)? At some point, the details of exploration make different methods of exploration relevant.

(*) Some actually argued this with respect to Voyager; as it was wrapping up its mission in the outer Solar System, ground-based and orbital observatories were making discoveries in advance of the probe.

Edited May 20, 2013 by Nikolai
Added "After all..."

[Kryten]

That they can do less than a human is absolutely not the same thing as saying they can't do enough for the mission to work. Doing analysis at the landing site isn't terribly useful anyway, you'd never be able to launch anything comparable to what we have in labs on earth. All you need is some photographs and quick spectroscopic anlyses (or just grabbing surrounding rocks as well), and you've put your sample/s into context.

[DerekL1963]

You did say something about "sporty landings", as I quoted.

Ah, forgot to expand that part... By "sporty" I meant that big fluffy aircraft like an internal tank orbiter likes to 'stick'/'float' when they enter the ground effect, I.E. the rate of descent suddenly and dramatically slows. This isn't very desirable, and it's easy to get into PIO (pilot induced oscillation) which can be hard to recover from and can lead to stalls or smacking the vehicle into the runway with extreme prejudice.

But anyhow, the fact is both airplanes and blimps manage to fly routinely with much better safety records than the shuttle could ever have.

In the portion of the flight that's relevant to this sub discussion, the Shuttle has a 100% safety record - precisely no failures on landing. (A couple of near misses/diving catches, but no failures.) Otherwise, if you're trying to argue that your landing mode is safe because airplanes and blimps are safe... that, again, is beyond apples and oranges. Airplanes aren't that fluffy, and blimps don't come in that fast.

So being a better glider can only be good regarding reentry... as long as the "price" you pay for it is cheap. Which is why I still maintain that having fuel tanks on the orbiter and using it as the upper stage makes for an easier reentry, not a harder one. By easier I mean the weight fraction of the reentry-dedicated hardware will be smaller. Which is kind of the point.

I never said being a better glider wasn't good for reentry. I just pointed out that a low ballistic coefficient, which is (as you correctly point out) very useful in the reentry phase, has drawbacks in the landing phase. You can't simply say "it's cool for reentry" and walk away... because the vehicle has to land too. In real life, engineering decisions have trade offs and consequences, and you can't make a rational decision without being aware of those and you can't simply handwave away all the other phases of flight.

[Nikolai]

That they can do less than a human is absolutely not the same thing as saying they can't do enough for the mission to work.

Of course not. But we're talking about costly missions here. One wants to get the maximum return for one's investment. That's why, as I mentioned above, you want different methods of exploration at different times.

Doing analysis at the landing site isn't terribly useful anyway,

Planetary geologists who choose landing sites would like to disagree with you. I'd also like to point out important, critical, and unexpected discoveries made by humans on the site, e.g., the Genesis Rock from Apollo 15.

you'd never be able to launch anything comparable to what we have in labs on earth.

True. I mentioned that myself, and even pointed out that that's advantageous.

All you need is some photographs and quick spectroscopic anlyses (or just grabbing surrounding rocks as well), and you've put your sample/s into context.

Patently false. If you pay attention to, for example, the scientists struggling to piece Gale Crater and Mount Sharp's history together as we speak, you'd see that it's not nearly as simple as you're pretending. They're not only trying to put together what's happened there, they're trying to reconcile what they're finding with measurements taken from Martian orbit.

Please stop making stuff up -- especially oversimplifying -- and pretending that you know exactly how capable a machines-alone approach would be.

[Kryten]

Why do you assume a rover wouldn't be able to find something like the genesis rock, for example? After all, it could have a lot more time at the landing site than any plausible human mission.

[Technical Ben]

You can do that easily enough with a simple rover. Even something like curiosity would be a lot cheaper to send along (and, crucially, not bring back) than even a single human.

Give it another 10 or so years and we could send a robotic android Asimo style. However, the 6 min delay would mean all actions need planning and waiting for updates.

[Nikolai]

Why do you assume a rover wouldn't be able to find something like the genesis rock, for example?

It's not just a question of what it is. It's also a question of context, of knowing what to examine where in more detail than mere pictures and spectroscopic analysis can provide but which don't require full-fledged labs. You need to be able to piece together processes, and where the key evidence of those processes would be located and what structures to look for when you get there, not just presence or absence of minerals.

Again, I recommend Roving Mars. The author goes into enough geological detail, minimal though it is for a lay audience, and shows some instances when pictures and Mossbauer spectra were decidedly deficient in providing the kind of in situ analysis and judgment-making that is trivial for an educated human, but which Spirit and Opportunity could not hope to duplicate.

Edited May 20, 2013 by Nikolai

[DerekL1963]

Why do you assume a rover wouldn't be able to find something like the genesis rock, for example? After all, it could have a lot more time at the landing site than any plausible human mission.

Given sufficient time, yes, a rover could find Genesis Rock. But a rover spending weeks carefully combing a small area hoping to find one special rock is cost effective... how? And given it's limited field of view, hoping to find it what driving by is pretty much an extreme long shot. In Roving Mars Steve Squyres goes into some detail the difficulties they had balancing between doing science (which mostly requires the rover to be still or moving on average very slowly) and actually covering ground to reach a destination. There's a reason why it's taken the rovers, combined, years to cover the ground that the Apollo astronauts covered in a single rover traverse in a single day.

Meanwhile, trained humans found Genesis Rock in a couple of hours while just walking by and keeping their eyes open. And they knew to keep their eyes open for this particular rock because of the analysis of the many pounds of rock previously returned told the earthbound geologists that it was something they should be looking for...

[Rune]

I never said being a better glider wasn't good for reentry. I just pointed out that a low ballistic coefficient, which is (as you correctly point out) very useful in the reentry phase, has drawbacks in the landing phase. You can't simply say "it's cool for reentry" and walk away... because the vehicle has to land too. In real life, engineering decisions have trade offs and consequences, and you can't make a rational decision without being aware of those and you can't simply handwave away all the other phases of flight.

Well, considering the whole flight envelope, I still maintain my assertion. Lower ballistic coefficient also means less dedicated weight to lifting surfaces, for example, and those are dead weight in the rest of your flight. If you go for runway landing, which I don't think would be my first option, because rockets ain't airplanes. And having big tanks in an orbital stage means you can refuel it to reach high orbits, adding a lot of functionality. Reentry would dissipate the same heat over more time, making the engineering problem a bit more manageable usually, though it depends. Plus, breaking up the flight to orbit on three stages like the concept I outlined does provides bigger margins for structural and system weights overall.

To balance that, you argue that ground effect and crosswinds make this option undesirable, and I just can't agree with that. It's a tiny detail that gets solved in other fields on a routine basis, IMO, not a show stopper.

Rune. Are we the only ones still talking shuttles?

[Kryten]

Given sufficient time, yes, a rover could find Genesis Rock. But a rover spending weeks carefully combing a small area hoping to find one special rock is cost effective... how?

Because that'll be what the entire rover'd be built around doing. It's the entire point of the mission; identify an area with samples you want, send a lander, and select them very carefully. Not like there needs to be any hurry about it.

[Fractal_UK]

Because that'll be what the entire rover'd be built around doing. It's the entire point of the mission; identify an area with samples you want, send a lander, and select them very carefully. Not like there needs to be any hurry about it.

And that's part of the problem, isn't it? You can design a rover to accomplish a specific mission and its capable of performing within the parametres of that mission. On the other hand, humans are capable of changing the parametres of their mission due to changing circumstances. Humans have the ingenuinity to reassess the progress of a mission throughout its operation period and if somthing does not appear to be paying off, they can act on the information they have to redefine the mission in a way that affords better results. A rover is only capable to the limits of what was already planned for on the ground.

There is no doubt that a rover can achieve adaquete scientific objectives and, in many cases, for now they are the only option for exploring certain bodies but as it becomes possible to have humans closer to the action, doing so is certain to result in a higher quality of research. That's before we even add the fact that placing humans and in space and doing it safely presents technical challenges that are worth exploring in their own right, something that could have positive benefits ranging from human colonisation and resource utilisation of other planets to sub-orbital passenger flight here on Earth.