It looks like the Ingenuity helicopter is not yet deployed.

NASA's Ingenuity Mars helicopter clears tests, inches closer to historic first flight in April


So how did the Ingenuity helicopter clear tests even without being deployed on Mars?

  • $\begingroup$ Why not look at what the tests involved? $\endgroup$ Commented Mar 25, 2021 at 22:27

3 Answers 3


As of today, the debris shield has been dropped. The "tests" discussed in the article are electrical, computer, and sensor tests. Nothing mechanical (other than dropping the shield) has been done yet; the helicopter is still attached to the bottom of the rover.

The official NASA article dated today explains that the rover is now on its way to a safe flight zone to drop the helicopter:

Before Ingenuity takes its first flight on Mars, it must be squarely in the middle of its airfield – a 33-by-33-foot (10-by-10-meter) patch of Martian real estate chosen for its flatness and lack of obstructions. Once the helicopter and rover teams confirm that Perseverance is situated exactly where they want it to be inside the airfield, the elaborate process to deploy the helicopter on the surface of Mars begins.

See this answer for more details on the flight zone.

It then takes six sols (if things go right) to drop the helicopter (described in detail in the article). The NASA article also states that the first flight will be "no earlier than April 8", and that it will take 3 sols after the first flight just to download all of the flight data and images.

So be patient.

  • 15
    $\begingroup$ Patience is a virtue when it comes to Mars rovers. They move at a snail's pace, quite literally. $\endgroup$ Commented Mar 24, 2021 at 3:19
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    $\begingroup$ @DavidHammen "Patience" might be a good name for a future rover... $\endgroup$ Commented Mar 24, 2021 at 14:45
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    $\begingroup$ @DarrelHoffman "Perseverance" is pretty close in meaning, I'd think. $\endgroup$
    – Graham
    Commented Mar 24, 2021 at 15:25
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    $\begingroup$ @Graham Close, although "Perseverance" implies working tirelessly to meet a goal, while "Patience" implies just sitting around while someone/thing else works tirelessly to meet a goal. It's more passive. Less inspirational maybe, but seemingly more true to reality in this case. $\endgroup$ Commented Mar 24, 2021 at 15:42
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    $\begingroup$ Reading the article, I get the impression that the long delays are simply because the data return and command update cycles run daily. So it's "cut the bolt, then make sure that happened right; release the arm, then make sure that happened right..." It just sounds funny to say each little step is scheduled for a different day. Imagine them making a PBJ sandwich: Monday, unscrew PB lid; Tuesday, translate and invert lid to nearby surface, Wednesday... $\endgroup$
    – JDługosz
    Commented Mar 24, 2021 at 22:12

So How did ingenuity helicopter clear tests even without being deployed on Mars?

The linked article claims that Ingenuity has "cleared multiple system checks". By way of analogy, human pilots of aircraft on Earth perform or monitor all kinds of systems checks on the planes before the pilots even think of starting an aircraft's engines. Then they perform even more systems checks before they throttle up to take off.

Human pilots have the advantage of being right next to the aircraft. The remote operators of Perseverance and Ingenuity do not. They have to wait 20 minutes between the time a command is uploaded and the report of command reception is received on Earth. This 20 minute (or more) round trip light speed time means that devices sent to Mars operate slowly. Very, very slowly.

It will take about a week between passing the initial system checks and the initiation of deployment, and then it will take another week before the Ingenuity makes its first tiny hop. There are many reasons for that slowness. I've mentioned one, the long time it takes for a signal to go between Earth and Mars and back. Another key reason is that the deployment will inevitably involve several irreversible actions.

If some future Ingenuity systems check does indicate a potential problem, mission controllers on Earth might be able to delay Ingenuity operations until the problem is resolved. This remains a possibility until the point in time when key irreversible actions are taken. This in turn means that controllers on Earth will proceed slowly. Very, very slowly.

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    $\begingroup$ There's also a tiny possibility of copter deployment failure causing damage to the main rover, right? Obviously their plans and procedures will minimize that, but waiting gives the main rover a chance to get some of its primary goals done before taking even a tiny risk of having a copter crash into it or have something get stuck during deployment. (As well as delaying reducing those eventual risks by having more time to do more careful testing and see how everything is working.) $\endgroup$ Commented Mar 24, 2021 at 15:00
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    $\begingroup$ @PeterCordes I think it's the other way around. The copter is slung under the rover, so it could get in the way and reduce ground clearance. It's also currently taking power from the rover, I believe. And the rover's primary mission is drilling rocks, which has a non-zero chance of debris damaging the rather fragile copter. As I understand it, the idea is to dump the copter at the earliest possible opportunity, before the rover gets going on its own mission. $\endgroup$
    – Graham
    Commented Mar 24, 2021 at 17:19
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    $\begingroup$ @PeterCordes ... The main risk to the rover which they're concerned about is the copter flying into it (or given the winds on Mars, being blown into into it). Once the copter is dropped off, of course there are a lot of preflight checks to be done. But the primary concern is getting the rover to a reasonably safe distance away. $\endgroup$
    – Graham
    Commented Mar 24, 2021 at 17:23

The question now asks how Ingenuity was able to "clear tests" before being deployed to Mars. Both previous answers have discussed some of the testing regimes, but neither addressed actual flight tests...which was actually the OP's original wording.

The Wikipedia article on Ingenuity says Ingenuity made test flights in a simulated Martian environment, but the citation for that assertion does not reference any flight testing. I wandered through the many other citations at the bottom of the Wikipedia article, and found this one from JPL, which reports on actual flying tests. The text is:

In late January 2019, all the pieces making up the flight model (actual vehicle going to the Red Planet) of NASA's Mars Helicopter were put to the test.


"Gearing up for that first flight on Mars, we have logged over 75 minutes of flying time with an engineering model, which was a close approximation of our helicopter," said MiMi Aung, project manager for the Mars Helicopter at NASA's Jet Propulsion Laboratory in Pasadena, California. "But this recent test of the flight model was the real deal. This is our helicopter bound for Mars. We needed to see that it worked as advertised."

While flying helicopters is commonplace here on Earth, flying hundreds of millions of miles (kilometers) away in the thin Martian atmosphere is something else entirely. And creating the right conditions for testing here on Earth presents its own set of challenges.

"The Martian atmosphere is only about one percent the density of Earth's," said Aung. "Our test flights could have similar atmospheric density here on Earth - if you put your airfield 100,000 feet (30,480 meters) up. So you can't go somewhere and find that. You have to make it."

Aung and her Mars Helicopter team did just that in JPL's Space Simulator, a 25-foot-wide (7.62-meter-wide) vacuum chamber. First, the team created a vacuum that sucks out all the nitrogen, oxygen and other gases from the air inside the mammoth cylinder. In their place the team injected carbon dioxide, the chief ingredient of Mars' atmosphere.

"Getting our helicopter into an extremely thin atmosphere is only part of the challenge," said Teddy Tzanetos, test conductor for the Mars Helicopter at JPL. "To truly simulate flying on Mars we have to take away two-thirds of Earth's gravity, because Mars' gravity is that much weaker."

The team accomplished this with a gravity offload system - a motorized lanyard attached to the top of the helicopter to provide an uninterrupted tug equivalent to two-thirds of Earth's gravity. While the team was understandably concerned with how the helicopter would fare on its first flight, they were equally concerned with how the gravity offload system would perform.

"The gravity offload system performed perfectly, just like our helicopter," said Tzanetos. "We only required a 2-inch (5-centimeter) hover to obtain all the data sets needed to confirm that our Mars helicopter flies autonomously as designed in a thin Mars-like atmosphere; there was no need to go higher. It was a heck of a first flight."

The Mars Helicopter's first flight was followed up by a second in the vacuum chamber the following day. Logging a grand total of one minute of flight time at an altitude of 2 inches (5 centimeters), more than 1,500 individual pieces of carbon fiber, flight-grade aluminum, silicon, copper, foil and foam have proven that they can work together as a cohesive unit.

Sounds like "flight testing" to me, or at least as close to "flight testing" as might be actually achievable here on Earth.

  • $\begingroup$ Yeah, this is what I had in mind when I read the question title originally, too. We actually have some pretty cool test chambers at various NASA and USAF facilities for doing these sorts of tests. I used to work at an Air Force base that did a lot of aerodynamics testing (both for military and commercial hardware, space and air) and we had several test cells that could simulate all sorts of conditions. Hot, cold, sandy/dusty, rain, hail, snow, ice, pressures from sea level to near-vacuum, collisions at low Earth orbital velocity, re-entry heating, etc. $\endgroup$
    – reirab
    Commented Mar 25, 2021 at 18:52

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