Did Curiosity rover land on Mars?

Question

The Curiosity rover landed on Mars using an extremely complex system, system involving a sky crane and using pictures from the orbiter to maneuver to a flat landing spot. The 1 ton car (equivalent to 300 kg in Mars' gravity) was suspended from a hovering rocket platform, after parachute deployment (where the atmospheric density is 1% of Earth's). All this was done automatically since signals from Earth take too long to control the process.

The complex process is animated in this Jet Propulsion Lab video of the landing.

Such a complex system must have been tested extensively. But I have seen no video of testing on the Earth.

Videos from testing only show extremely simple procedures in the lab. Like the Sky Crane Full Motion Drop Test. That is the most complex test I have found. It was considered the major test and all staff was called in. That is not enough to risk billions of dollars sending it to Mars.

Nature World News quotes a "truther" who in turn attributes to others the idea that the landing was a fake:

He claims that there is a growing rumor that says NASA did not even send a rover to the red planet and the images and footages being released were filmed in Canada, according to a report.

Did the rover land on Mars?

Answer 1

Did you ever see a video of a proto-boeing-787 flying before the testbed version of a boeing-787 flew? No, you didn't. Why not? Here's a craft that is designed to fly in earths atmosphere, and they never even tested it before building it!

The answer is that computers and wind tunnels are fantastically good at reproducing the behaviour and environment of flight envelopes, so there is just no need to build a huge physical prototype outside of perhaps scale models for use in wind tunnels (even that is done by computer now).

Why do I talk about aircraft? There is a strong link between aviation and spaceflight, hence the name aerospace. A different atmosphere, a different environment, but that's just variables in a computer simulation.

As an aside, anyone who has ever played Kerbal Space Program can attest to just how realistic a "simple" game can be in reproducing most of the complexities of space flight and interplanetary travel/landing.

Back to Curiosity, there is a great youtube video which describes the process used to land Curiosity, it's the first 5 minutes, well worth a watch.

https://youtu.be/oNviFQpRvwQ

But you're right, it never shows a trial on Earth, and why would they? It's a different atmosphere, it would be hugely costly to take it to lower earth orbit only to drop it back down again in the wrong environment. And once again, a computer simulation can do it much better, and for a fraction of the cost.

All in all, as with any conspiracy theory we need to apply Occam's Razor. What's the simplest explanation? Did they:

• Fake the actual rover
• Fake taking it to Mars
• Fake land it
• Fake every picture and scientific discovery
• Silence all the thousands of engineers, scientists, mission controllers, etc etc
• Silence their critics (who would love to shout about how much of a waste of money space exploration is)

or did they:

• Use some really smart people
• Use some cool technology
• Actually land a small-car-sized bit of tech on Mars

It's actually simpler to just do it for real!

Answer 2

In my experience most testing isn't particularly exciting and worth recording and sharing with the public.

Nevertheless, the NASA shared a lot of videos and photos showing the more visually interesting aspects of the Curiosity rover being tested:

• First test driver of the Rover inside
• Test driving the Rover on Earth outside
• Four part series on testing the parachute
• Demonstrating sampling with a duplicate of the Rover on Earth
• Testing new drilling techniques with a duplicate of the Rover on Earth
• Testing the radar

• Testing the mast

• Test image from the camera

• Atmosphere testing

So, the contention that the complex system was untested because there is no evidence of testing is untrue.

Answer 3

Do you realize Curiosity has been on Mars and sending data ever since then? Do you think that if they were hiding it in Canada, there would be no kink in this story for nearly 8 years?

Are you saying all those photos movies from Mars (which NASA says were sent by Curiosity) are fake/CG? (Including the one with the flapping parachute on landing?) And if all those are [easy to] fake, what would a single [extra] test movie on earth prove?

Note that the Curiosity parachute, which was considered (quite) critical was extensively tested, but mostly in a wind tunnel because dropping it from a helicopter [which was done] turned out to be less informative as filming it at high speed (and up close) was the most important info collected. (Even for the newer 2020 rover [named Perseverance], a single real drop test of the parachute was performed--and not with the actual rover as load--because of the 100-fold difference in atmospheric density between Mars and earth.)

For the [Curiosity] crane retro-landing stage

Still, a real-world sky-crane landing has never been attempted, even on Earth.

"After extensive discussion, it was determined that the modifications needed to perform such a test in Earth gravity and atmosphere would result in extremely limited value from the test," Rivellini said. Mars's gravity is about a third that of Earth, and its atmosphere roughly 99 percent thinner.

So the radar that controlled when the rockets are fired was tested separately. The whole Curiosity retro-landing system was only simulated.

And that was indeed a chance they took. The same article discusses how Beagle 2 presumably failed to land properly although more recent data suggests that it failed to deploy properly (its antenna and/or solar panels) after landing. In general, the success ratio of lander missions to Mars hasn't been so good: "Two thirds of all landers sent there have crashed or lost contact with Earth, and half of the missions launched haven’t made it to the planet at all."

There a more in-depth Nat Geo video that discusses why the traditional alternatives (airbags, leg lander) were rejected for Curiosity. The 2020 rover will also use a sky crane, so I guess we'll find out how lucky the solution is/was. There was a separation test for the 2020 rover, but no real drop test, as far as I can tell (let alone one in which the retro rockets fired).

The much older Viking program also used retro-rockets to land on Mars, although not detachable ones (i.e. no crane, since the Vikings didn't have wheels so there wasn't a worry that the rockets can become entanglement points later). You might want to inquire about this further on Space SE, but it looks like a full landing test wasn't performed on earth for those either, only separate parachute (p. 11) or drop tests for the legs (p. 39) etc. Actually (p. 40) they did conduct four high-altitude tests (at 36 to 43 km high in earth's atmosphere) for the Viking vehicle's initial deployment of parachute etc. And a landing shock (drop) test for the fully assembled Viking lander was conducted 3 times (p. 48), but not with the retro rockets fired, but simply dropped from a height that would simulate its designed landing velocity. (This is quite similar to the video you saw for Curiosity). Additionally for Viking they conducted "pyrotechnic shock tests" to verify that nothing (internal) was disturbed by the firing of the rockets, but no actual landing under rocket power as far as I can tell.