Wonderful Photographs from Mars

[DataCable]

I think NASA are doing the same thing again that they did it the 1960's

If you mean actually travel to another stellar body to study it, what a coincidence, I think they're doing that, too.

I want them to succeed and show us something useful that we have not seen before.

Scientific exploration is not always necessarily "useful."

Surely the Curiosity is going to find something new.

Such as new elements? 

And stop calling us Shirley.

Why I am still shouting about the original hoax is because...

...you don't have any actual evidence of a contemporary hoax, so you're asserting a historic hoax to invoke guilt by association.

all the scientists in other countries have assumed that they did it...

Minor typo there, you misspelled "evaluated the mountain of evidence in favor of the Apollo program's authenticity and found it satisfactory, especially in light of the hoax theory's stunning lack of even a molehill's worth of supporting evidence."

Completely different ideas are needed like anti-gravity or using springs to get us into orbit.

Why?

[Jason Thompson]

Attention  sts60

Why him in particular?

I am here to respond to any oustanding points.

But you're not, because you haven't responded to a single point.

nobody has shot me down in flames.

You must be reading a different thread from the rest of us. Or, more likely, doing the 'fingers in the ears going "la-la-la"' thing that most conspiracy theorists do when confronted with rebuttals to the points they make. Tell me, is it conscious ignorance of what has been written in reply or do you genuinely just not see the myriad ways you have been shown to be wrong in even your most basic assumptions?

I think NASA are doing the same thing again that they did it the 1960's

So far you have yet to demonstrate they did anything other than what they say they did in the 1960s.

and give out far too much detail because thats what they think the American  public expect for the money spent

That is what people expect of a publicly funded organisation. Is there some reason this expectation is unjustified?

I want them to succeed and show us something useful that we have not seen before.

They have. For some reason you don't seem to realise that everything that we 'have seen before' was actually new when we saw it before.

But you don't even know what you really mean by 'show us something new we've not seen before', do you?

Why I am still shouting about the original hoax is because all the scientists in other countries have assumed that they did it

Justify the statement that scientists anywhere have assumed anything rather than concluding on the basis of the evidence that they did it. Science does not work by assumption, and if the evidence is so deficient that you can see it, then there is no way in hell a bunch of professional scientists all over the world would be fooled. Or do you really think you know more than them? Your knowledge of even basic chemistry is so lacking you think new elements should be discovered.

Completely different ideas are needed

Why?

like anti-gravity or using springs to get us into orbit.

You're not even trying to be serious, are you? Really, if you've barely got time to participate in this forum at all, why bother wasting time in this manner?

We have lost 50 years of innovation.

No, it just doesn't follow the path you expect. And since you are clearly ignorant of the relevant fields anywhere, we can safely discount your view of it as baseless.

[Echnaton]

nobody has shot me down in flames. 

Have you launched anything worth shooting missiles at?   All I have seen is a few under filled balloons without enough lift to carry their own weight.

[smartcooky]

Completely different ideas are needed like anti-gravity or using springs to get us into orbit. 
We have lost 50 years of innovation.

Oh, that is priceless! Springs to put things into orbit?

As for "anti-gravity". well, until someone changes the Laws of Physics, that isn't going to happen, so you can read "never" for that one.

As for losing 50 years of innovation, well that really is a preposterous statement. Since 1969 we have had...

1971 - Mariner 9 first spacecraft to orbit another planet, Mars, mapping the entire surface.
1972 - Pioneer 10 mission to Jupiter
1973 - Pioneer 11 mission to Jupiter & Saturn, Skylab launched
1974 - Mariner 10 dual-planet mission to Venus and Mercury.
1975 - Apollo 18 - Soyuz 19; the handshake in orbit
1976 - Vikings 1 and 2 on Mars. First soft landing on another planet
1977 - Voyager 1 & 2 on the "grand tour" mission to the gas giant planets
1978 - The Einstein Observatory (HEAO) an X-Ray imaging orbital observatory
1981 - First launch of the Space Shuttle
1989 - Galileo spacecraft mission to Venus, Minor planet Ida and Jupiter's moons. First launch of an interplanetary probe from Shuttle orbit.
1990 - Pegasus rocket is deployed from a B-52 bomber, and launched the Pegsat satellite. First satellite launched from an aircraft.
1990 - Hubble Space Telescope launch
1990 - Magellen spacecraft to Venus. Radar mapping of surface
1992 - Spacecraft Ulysses flies around Jupiter, on its way to the sun. (joint venture of NASA and the European Space Agency (ESA)
1996 -  Near-Earth Asteroid Rendezvous (NEAR) spacecraft launched
1997 - Mars Pathfinder becomes the first probe to successfully land on Mars including a separate roving robot probe (Sojourner)
1997 - Mars Global Surveyor arrives at Mars and begins the process of adjusting its highly elliptical orbit into a circular one using aerobraking
1997 - launch of the double probe Cassini/Huygens to Saturn.
1998 - Lunar Prospector is the first NASA mission to the Moon in 25 years
1998 - Space Technology EXperiment (STEX) satellite tests 29 new spacecraft designs, including a four-mile-long tether, advanced solar panels, and an ion engine test.
1998 - Deep Space 1, a technology test spacecraft evaluating 12 spacecraft designs. First use of an ion engine to leave orbit for and rendezvous with asteroid Braille.
1998 - Launch and Construction of the International Space Station begins
1999 - Stardust lifts off for a rendezvous with the Comet Wild-2
2001 - Mars Odyssey probe is launched to study Martian weather
2004 - Spirit & Opportunity
2004 - Cassini-Huygens orbits Saturn
2005 - Cassini-Huygens - soft landing on Titan
2009 - Kepler Mission is launched, first space telescope designated to search for Earth-like exoplanets
2011 - Messenger spacecraft orbits Mercury
2011 - Dawn spacecraft orbits the minor planet Vesta
2012 - Nuclear-powered NASA rover successfully lands on Mars to seek clues to past Martian life.

The last 40+ years has been nothing BUT innovation and exciting new missions into space. Ion engines, new launch systems, a return to the Moon & Mars. Not even listed above are the efforts of agencies other than NASA. They include a sample return mission to an asteroid (Japan), a huge Orbital Radio Telescope (Russia), an Ultraviolet to gamma ray spectrum orbital observatory (Russia, France, Denmark and Bulgaria), and numerous missions to Venus and Mars by the Russians.

[ka9q]

Oh, that is priceless! Springs to put things into orbit?

Well, springs are commonly used to separate spacecraft from upper-stage rockets after reaching orbit. The separation velocity is usually on the order of a half a meter per second to a meter per second. Considering a low earth orbiting satellite is moving about 7,000 meters/sec, it would only take maybe 10,000 springs to do the job.
 

[LunarOrbit]

The reason I have not responded is that I have been away from my desk for nearly three weeks of the six since I first put up my post.

No more excuses. If you had time to post that message then you had time to respond to us properly. Instead, all you did was repeat the same baseless claims you've made before. Just saying "NASA faked the Mars photos the same way they faked the Moon photos" doesn't make it true, you have to prove it.

So here's what I'm going to do: I'm going to place you under moderation. That means I will have to approve your posts before they can appear in the forum. I will approve any post you make, whether I agree with you or not, as long as you are responding to us and providing the proof you claim to have. Once you have responded to us satisfactorily I will take you off moderation and you can post freely.

[ka9q]

The last 40+ years has been nothing BUT innovation and exciting new missions into space.

To be perfectly fair, there has been significant innovation in some areas of space flight but little or none in others.

Apollo-era avionics are of course utterly obsolete now. Modern electronics is much smaller and lighter, uses far less power, and is (or can be) much more reliable. It can do things that weren't even conceivable during Apollo.

In stark contrast to avionics, chemical rocket engines have advanced very little since Apollo. We've seen some incremental improvements, mainly in the use of more advanced combustion cycles in larger engines, but we're still using the same propellants: RP-1/LOX, LH2/LOX, hydrazine/N2O4, and APCP (ammonium perchlorate composite solid propellant).

No new chemical propellants have matured despite some experiments with methane and a NASA-sponsored search for replacements for the classic hypergols that are less toxic and corrosive. Hybrids burning plastic or rubber with nitrous oxide were used on SpaceShipOne, but they have yet to find their way into orbital flight. SpaceX deliberately chose the low-tech combination of RP-1/LOX for all their engines to reduce technological risks.

And we've discovered that the basic Apollo spacecraft and mission design wasn't bad at all. That's why Orion (and the rest of Constellation, before it was cancelled) was essentially Apollo on steroids, using nearly identical engines except for the solid first stage of the Aries-1 (which was a really bad idea, IMHO). With the shuttle we discovered the hard way that a launch escape system and a protected heatshield are still valuable features.

Elon Musk (SpaceX CEO) is probably the latest to promise low cost through reusability, yet this has yet to be demonstrated (the shuttle being a spectacular failure in this regard).

The one big advance in reaction propulsion since Apollo is electric (ion and plasma). It's great for low-thrust applications like stationkeeping and some long-duration robotic exploration but not very relevant to human spaceflight.

But in my opinion, the single biggest advance since Apollo in space propulsion, broadly construed, is the gravity assist trajectory, including the use of chaotic trajectories involving Lagrange points. This became a demonstrated reality in the mid 1970s with Pioneer 11 at Jupiter and Saturn, Mariner 10 at Venus and Mercury, and of course the two Voyagers at Jupiter, Saturn and beyond. It's now a routine element of almost every robotic mission beyond earth orbit.

Like electric propulsion, gravity assist doesn't seem directly useful for human space flight because of the long times involved. But it could be useful for support flights delivering hardware and supplies for human flights to the moon, Mars or asteroids.

So I find it kind of frustrating that we've seen enormous advances in some fields related to space exploration but few in the one that actually gets us there: propulsion. I had hoped by now that we would have overcome our allergy to things nuclear and begun to use nuclear thermal rockets for human exploration beyond earth orbit. It's more than technologically feasible; working nuclear rockets were actually demonstrated in the early 1960s before the program was canceled. I don't see how we can have any kind of practical interplanetary human spaceflight program without it.

[Peter B]

Others have covered most of what Jockndoris has said, so I'll look at this bit:

...the money spent (some estimates show $7 for every preson in America).

Given a cost of $2.6 billion and around 315 million Americans, that's around $8.25 per person. :-O

Now, the cost of the Iraq War is, according to Wikipedia, $845 billion. That's $2682 per person.

Given that comparison, I think Curiosity's dirt cheap.

[cjameshuff]

Apollo-era avionics are of course utterly obsolete now. Modern electronics is much smaller and lighter, uses far less power, and is (or can be) much more reliable. It can do things that weren't even conceivable during Apollo.

Which influences other systems as well. Improved sensors and control electronics can detect engine trouble and do a safe shutdown...in the case of SpaceX's most recent launch, shutting things down before the vehicle leaves the pad and allowing quick troubleshooting leading to a successful launch a few days later.

No new chemical propellants have matured despite some experiments with methane and a NASA-sponsored search for replacements for the classic hypergols that are less toxic and corrosive. Hybrids burning plastic or rubber with nitrous oxide were used on SpaceShipOne, but they have yet to find their way into orbital flight. SpaceX deliberately chose the low-tech combination of RP-1/LOX for all their engines to reduce technological risks.

It's a really nice engine, though. 310 s vacuum specific impulse (quite good for a gas generator engine, close to what staged combustion engines get) and thrust to weight ratio of 150 for the Merlin 1D, beating the previous record of 137 for the NK-33. The RD-180 used on the Atlas only gets 78.5.

The lack of changes in propellant are really largely down to the existing ones being pretty much ideal. LOX is cheap, available, and reasonably easy to handle. RP-1 is cheap and dense. Hydrogen's a pain to work with, but you can't get a lower molecular mass. Most of the alternatives are a much bigger headache to handle, and/or much more expensive.

Methane seems like it could get some of the benefit of hydrogen while being much easier to handle, though. It unfortunately doesn't seem to get much attention, and projects using it keep getting canceled (JAXA's GX comes to mind).

So I find it kind of frustrating that we've seen enormous advances in some fields related to space exploration but few in the one that actually gets us there: propulsion. I had hoped by now that we would have overcome our allergy to things nuclear and begun to use nuclear thermal rockets for human exploration beyond earth orbit. It's more than technologically feasible; working nuclear rockets were actually demonstrated in the early 1960s before the program was canceled. I don't see how we can have any kind of practical interplanetary human spaceflight program without it.

I agree. There's one space reactor project (SAFE-400), and it's not even a major project. Even for robotic missions, practical ISRU will require a dense power source, and operations in the outer system will require something other than solar power. And reactors are far superior to RTGs in terms of handling and launch safety, as they don't have any highly radioactive components until they start operating.

[Mr Gorsky]

Isn't a rocket "anti-gravity" anyway?

[Glom]

Isn't a rocket "anti-gravity" anyway?

Depends on the thrust vector.

[ka9q]

Isn't a rocket "anti-gravity" anyway?

Not if it's pointed down!

I still remember watching the cheesy SF flick Crack In The World as a kid. There's a scene with a missile (closely resembling a V2, as they all did in those days) on a stand pointed down toward a hole in the earth. This carried the nuclear bomb that started the title problem. That seemed like a particularly stupid way to send a bomb into the earth. Why not just drop it in the hole?

[smartcooky]

I think rocket propulsion for getting off the planet is pretty much the only way we are ever going to to do this when we want to "launch" a vehicle into orbit. We may discover more efficient propellants, that give us more "thrust for our buck", but in the the end, the rough ratio of "tonnes of fuel to pounds of payload" is going to be around for a long while yet. Solid chemical rockets give us a much better ratio, but its their lack of controllability that is the problem. The two speed (stop and full thrust) aspect is always going to be the big drawback; after all, they are little more than a slowly exploding bomb. If some clever person can ever invent a way to build a variable thrust solid rocket motor they'll be set up for life.

Another idea has been the Air Launch (e.g. Pegasus). IIRC, the original idea for the Space Shuttle was to launch it off the back of a purpose built flying wing but the idea was quickly dropped as impractical. Other ideas have popped up from time to time, Maglev/Rocket Sled Launchers, flyback boosters, but they are beyond our technical capacity at this time.

The only other alternative I can see in the future is the Space Elevator idea (anyone who has read Arthur C. Clarke's "Fountains of Paradise" will know what I am talking about) We do not have the technical expertise or the advanced materials as yet to make this work, but it is something that needs to have some serious research done. It would the the cheapest system to operate (but the most expensive to build) with the least stresses on the payload; human or machine.

[ka9q]

Solid propellants actually have lower I_sp than most liquid propellants. The shuttle SRBs had an I_sp of 242 seconds at sea level and 268 sec in vacuum. The figures for the SSMEs (Space Shuttle Main Engines), among the most efficient rockets ever flown, were 363 and 452.3 sec.

Part of this was due to the use of hydrogen as fuel; liquid rocket engines burning hypergolic fuels typically get a little over 300 sec. Even those burning kerosene and LOX, often the lowest-performing liquid propellants, do better than solids. The F-1s used in the first stage of the Saturn V got 263 sec at sea level and the Russian-designed RD-180 on the Atlas V gets 311 and 338 sec.

The big advantage of solids is their simplicity and their ability to provide truly huge amounts of thrust. Each shuttle SRB produced 1.8 times the thrust of a single F-1. Thrust can be more important than I_sp at liftoff when the launcher is flying straight up and gravity losses are greatest.

[ka9q]

There actually is a controllable solid-fuel rocket. Well, partly solid: the hybrid rocket. The fuel is almost always the solid and the oxidizer is almost always the liquid. For small to medium hybrids, N₂O (nitrous oxide) is the oxidizer of choice. It's reasonably cheap and available, not terribly toxic, can be liquified under pressure at room temperature, has a vapor pressure high enough to flow into a combustion chamber without a pump or pressurant, and is a good oxidizer.

Fuels are various hydrocarbon polymers like a plastic or rubber. Because the fuel won't burn without an oxidizer, by shutting off the oxidizer feed you can throttle or shut down the engine.

For some reason hybrids have never been scaled up to the sizes required for orbital flight. (The SpaceShipOne used hybrids, but it only achieved 4% of the energy required to reach low earth orbit.) Among other problems, apparently the oxidizer stream can literally blow out the flame if it is fed too quickly into the combustion chamber in an attempt to increase thrust. One of the advantages of nitrous oxide for smaller hybrids would probably not apply to orbital launchers, as a tank strong enough to withstand its vapor pressure at room temperature would be far too heavy. You could cool it, but then you might as well use LOX and pump it.