Watch NASA’s Perseverance Rover Land on Mars!

[Shadowy Man]

True, from the videos I've seen just lift-off from Earth would put the payload through a lot of stress... sorta like putting an instrument on the end of a stick and shaking it back and forth as hard as you can.

I used to launch science experiments on suborbital rockets and you’d be amazed that coming back into the atmosphere put more stresses on it than launch.

On the way up speed is increasing while pressure is decreasing. On the way down they’re both increasing. The ride up is at high g, indeed, but relatively smooth.

 

[Treedbear]

Ingenuity has flown almost flawlessly through the red planet’s thin air and will now assist the science mission of the Perseverance rover.

[video]https://vp.nyt.com/video/2021/05/07/93521_1_07marscopter-video_wg_720p.mp4[/video]

“The plan forward is to fly Ingenuity in a manner that does not reduce the pace of Perseverance science operations,” said Bob Balaram, the chief engineer of the helicopter, in a NASA release after the flight.

Ingenuity is expected to make just one or two more flights this month, taking off when there is time amid Perseverance’s other activities.

But if that all goes well, Ingenuity could continue tagging along with Perseverance across the Martian landscape.

 

[lpetrich]

I have been very neglectful of reporting of the flights of the Ingenuity helicopter.

First Flight of the Ingenuity Mars Helicopter: Live from Mission Control - YouTube

Videos | Multimedia Section – NASA’s Mars Exploration Program

• Mars Report: Update on NASA's Perseverance Rover & Ingenuity Helicopter – NASA’s Mars Exploration Program - Mar 19 - Ingenuity was still on board Perseverance
• Mars Helicopter Prepares for Takeoff – NASA’s Mars Exploration Program - Mar 31 - lots of CGI video of the rover and the copter
• Mastcam-Z Captures Ingenuity's Blades Spinning – NASA’s Mars Exploration Program - Apr 13
• Mars Report: Update on NASA's Perseverance Rover & Ingenuity Helicopter (April 16, 2021) – NASA’s Mars Exploration Program - Apr 16 - mentioned the MOXIE O2-production experiment
• NASA's Ingenuity Mars Helicopter Successfully Completes First Flight – NASA’s Mars Exploration Program - Apr 19 - featuring the copter's operators at JPL
• First Video of NASA's Ingenuity Mars Helicopter in Flight – NASA’s Mars Exploration Program - Apr 19
• Enhanced Video Shows Dust During Ingenuity's Flight – NASA’s Mars Exploration Program - Apr 20
• Perseverance's Mastcam-Z Video of Second Flight – NASA’s Mars Exploration Program - Apr 22
• Perseverance Rover's Mastcam-Z Captures Ingenuity's Third Flight – NASA’s Mars Exploration Program - Apr 25 - the copter flies horizontally out of the field of view, and then returns
• Third Flight of NASA's Ingenuity Mars Helicopter is a Success – NASA’s Mars Exploration Program - Apr 25
• Fourth Flight a Success for NASA's Ingenuity Mars Helicopter – NASA’s Mars Exploration Program - Apr 30
• NASA's Ingenuity Mars Helicopter Fifth Flight Lands in New Airfield – NASA’s Mars Exploration Program - May 7
• Listen to NASA's Ingenuity Mars Helicopter in Flight – NASA’s Mars Exploration Program - May 7 - recorded by the rover and processed to enhance the copter's sounds

 

[lpetrich]

Ingenuity's blades spln at 2538 rpm or 42 Hz. But they are two counter-rotating ones, and they spin relative to each other at twice the frequency.

Mars Helicopter - NASA Mars including Helicopter Status Updates - NASA Mars

What We’re Learning About Ingenuity’s Flight Control and Aerodynamic Performance - NASA Mars

The copter was tested in a giant vacuum chamber at JPL that is used for testing spacecraft. It was used to simulate the Martian atmosphere, with its density at the surface of about 1% the Earth's atmosphere. It is a rather soft vacuum by Earth standards.

The surface pressure is about 6 to 7 millibars, comparable to that of the Earth's atmosphere at an altitude of 33.5 - 34.5 km (110 - 133 thousand feet). Sources: Aerospaceweb.org | Atmospheric Properties Calculator - 1976 Standard Atmosphere Calculator - calculators that use the 1976 Standard Atmosphere.

Ingenuity's blades are controlled like those of full-sized helicopters, with their pitch (tilt angle) having "collective pitch" (the same over a rotation, for going up and down) and "cyclic pitch" (varying over a rotation, for going sideways).

The copter uses a laser rangefinder and a camera to estimate altitude, using them only after reaching 1 meter altitude. Before that, it uses an "inertial measurement unit" (IMU) or accelerometer to estimate where it is. This is "dead reckoning", navigation by extrapolation and velocity and acceleration estimates, without direct updates of one's position.

For Ingenuity's first flight, Mars's atmosphere density at the copter is 0.0165 kilograms per cubic meter, or about 1.3% the Earth's sea-level atmospheric density.

 

[lpetrich]

 Ingenuity (helicopter) - the remote-controlled helicopter carried to Mars by  Perseverance (rover) nicknamed Percy

• Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) - NASA Mars
• MOXIE for Scientists - NASA Mars
•  Mars Oxygen ISRU Experiment
•  Solid oxide electrolyzer cell
• NASA’s Perseverance Mars Rover Extracts First Oxygen from Red Planet | NASA

On April 20, the MOXIE experiment produced some 5 grams of O2, enough to supply a typical astronaut for 10 minutes.

That experiment used solid-state electrolysis, doing

CO2 -> CO + (1/2)*O2

But that has a problem: separation of carbon monoxide and oxygen. Their boiling points are very close, meaning that it may be hard to separate them.

• CO: −191.5 °C, 81.6 K, −312.7 °F
• O2: −182.962 °C, 90.188 K, ​−297.332 °F

 

[lpetrich]

 List of missions to Mars
Here are the ones in operation:

1. Mars Odyssey - NASA - orbiter - L 2001 Apr 7, A 2001 Oct 24 - (2025)
2. Mars Express - ESA - orbiter - L 2003 Jun 2, A 2003 Dec 25 - (2026)
3. Mars Reconnaissance Orbiter - NASA - orbiter - L 2005 Aug 12, A 2006 Mar 10
4. Curiosity - NASA - rover - L 2011 Nov 25, A 2012 Aug 6
5. Mangalyaan - ISRO (India) - orbiter - L 2013 Nov 5, A 2014 Sep 24
6. MAVEN - NASA - orbiter - L 2013 Nov 18, A 2014 Sep 22
7. ExoMars Trace Gas Orbiter - ESA - orbiter - L 2016 Mar 14, A 2016 Oct 19
8. InSight - NASA - lander - L 2018 May 5, A 2018 Nov 26
9. Hope - UAESA (United Arab Emirates) - orbiter L 2020 Jul 19, A 2021 Feb 9
10. Tianwen-1 - CNSA (China) - orbiter, lander, rover - L 2020 Jun 23, A 2021 Feb 10
11. Perseverance - NASA - rover, aircraft - L 2020 Jun 30, A 2021 Feb 18

L = launch date, A = arrival date

• Orbiters: 8
• Landers: 1 (+1)
• Rovers: 2 (+1)
• Aircraft: 1

The (+1) is for the Tianwen-1 lander and rover, which may arrive on the planet this month or the next.

 

[lpetrich]

 Ingenuity (helicopter)

The copter has made seven flights so far:

1. April 19
2. April 22
3. April 25
4. April 30
5. May 7
6. May 23
7. June 8
8. (expected every 2 or 3 weeks until the end of August)

The sixth flight was the first flight to land in a different place from its starting site. Surviving an In-Flight Anomaly: What Happened on Ingenuity’s Sixth Flight - NASA Mars

Telemetry from Flight Six shows that the first 150-meter leg of the flight went off without a hitch. But toward the end of that leg, something happened: Ingenuity began adjusting its velocity and tilting back and forth in an oscillating pattern. This behavior persisted throughout the rest of the flight. Prior to landing safely, onboard sensors indicated the rotorcraft encountered roll and pitch excursions of more than 20 degrees, large control inputs, and spikes in power consumption.

What happened?

Approximately 54 seconds into the flight, a glitch occurred in the pipeline of images being delivered by the navigation camera. This glitch caused a single image to be lost, but more importantly, it resulted in all later navigation images being delivered with inaccurate timestamps. From this point on, each time the navigation algorithm performed a correction based on a navigation image, it was operating on the basis of incorrect information about when the image was taken. The resulting inconsistencies significantly degraded the information used to fly the helicopter, leading to estimates being constantly “corrected” to account for phantom errors. Large oscillations ensued.

But it nevertheless survived.

Despite encountering this anomaly, Ingenuity was able to maintain flight and land safely on the surface within approximately 16 feet (5 meters) of the intended landing location. One reason it was able to do so is the considerable effort that has gone into ensuring that the helicopter’s flight control system has ample “stability margin”: We designed Ingenuity to tolerate significant errors without becoming unstable, including errors in timing. This built-in margin was not fully needed in Ingenuity’s previous flights, because the vehicle’s behavior was in-family with our expectations, but this margin came to the rescue in Flight Six.

Such overdesigning is a common engineering practice:  Factor of safety

 

[steve_bank]

In reliability there is a tradeoff between environmental screening and inducing long term failures in the secreting.

'Shake and bake' vibration and temperature cycling.

There are probably instruments on the probe that would not stand up to extreme vibration testing.

Don't forget the Hubble mirror fiasco. Bad batteries were put on the ISS. Problems happen all the time. We only hear about the more visible ones.

 

[Treedbear]

In reliability there is a tradeoff between environmental screening and inducing long term failures in the secreting.

'Shake and bake' vibration and temperature cycling.

There are probably instruments on the probe that would not stand up to extreme vibration testing.

Don't forget the Hubble mirror fiasco. ...

Slowly I turned. Step by step.

 

[steve_bank]

In reliability there is a tradeoff between environmental screening and inducing long term failures in the secreting.

'Shake and bake' vibration and temperature cycling.

There are probably instruments on the probe that would not stand up to extreme vibration testing.

Don't forget the Hubble mirror fiasco. ...

Slowly I turned. Step by step.

The best laid plans of mice and men....

There used to ba site that listed all the probes and which ones failed and succeeded.

 

[lpetrich]

There used to ba site that listed all the probes and which ones failed and succeeded.

Is it really that difficult to search for such a site?

Wikipedia is a good place to look, though it should not be treated as a primary source.

•  Timeline of Solar System exploration
•  List of Solar System probes
•  List of active Solar System probes
•  List of Earth flybys
•  List of missions to the Moon
•  List of lunar probes
•  List of missions to Venus
•  List of missions to Mars
•  List of Mars orbiters
•  List of landings on extraterrestrial bodies
•  List of artificial objects on extraterrestrial surfaces
•  List of artificial objects on Venus
•  List of artificial objects on the Moon
•  List of artificial objects on Mars
•  List of Mars landers
•  List of artificial objects leaving the Solar System

 

[lpetrich]

Update: the Mars helicopter has made 28 flights as of the most recent version of  Ingenuity (helicopter)

• Maximum duration: 169.5 seconds (2.8 minutes, flight 12)
• Maximum altitude: 12 meters (flight 10)
• Maximum flight distance: 708.9 m (flight 25)
• Maximum ground speed: 5.50 m/s (flight 25)

 

[lpetrich]

NASA's Mars helicopter Ingenuity has flown its last flight after suffering rotor damage | Space - "The historic journey of Ingenuity, the first aircraft on another planet, has come to end."
and
'Bland' terrain likely doomed NASA's Mars helicopter Ingenuity | Space - "The sandy landscape offered few points of navigational reference for Ingenuity."

Ingenuity used large rocks and other features to get its bearings during its 72 flights on Mars. During the most recent four sorties, however, it found itself in a sandy patch that offered little in the way of navigational cues, mission team members said during a press briefing this afternoon.

"It's some of the hardest terrain we've ever had to navigate over," said Teddy Tzanetos, Ingenuity project manager at NASA's Jet Propulsion Laboratory (JPL) in Southern California. "It's very featureless."

Ingenuity had trouble in the area before: It made an emergency landing on Jan. 6, cutting Flight 71 short, apparently because it couldn't properly ground itself in its surroundings.

The same thing likely happened on Flight 72, Tzanetos said. But this time, Ingenuity apparently came in at an angle and struck the red dirt with at least one of its rotor

 Ingenuity (helicopter) - "Ingenuity weighs 1.8 kilograms (4.0 lb) and is 49 cm (19 in) tall. It is powered by six lithium-ion solar-charged batteries."
and
 List of Ingenuity flights - 72 flights over 3 years, far beyond the initial mission of 5 flights over 1 month.

If it seems like interplanetary spacecraft are often overdesigned, that overdesign is a necessity for making it very likely for them to carry out their primary missions. Once a spacecraft has done so, any additional mission time is pretty much for free in comparison to the time and expense of design, construction, and launch of it.

 

[Loren Pechtel]

If it seems like interplanetary spacecraft are often overdesigned, that overdesign is a necessity for making it very likely for them to carry out their primary missions. Once a spacecraft has done so, any additional mission time is pretty much for free in comparison to the time and expense of design, construction, and launch of it.

So long as it doesn't cost weight overengineering is a tiny percent of the total mission cost. Thus they usually use the most durable things they can for anything small. Big things are another matter--look how the rover wheels get beat up.

 

[lpetrich]

NASA Ingenuity Mars helicopter, broken and alone, spotted by Perseverance rover on Martian dune (photo, video) | Space

It's in the top left in that article's picture, beyond the rock field.

The rover ought to try to visit that helicopter, to get a better idea of what happened to it.

The Space Review: The case for a fleet of Martian helicopters

Ingenuity, which made 72 flights and traversed 17 kilometers prior to its recent retirement, weighed less than two kilograms. Ingenuity didn’t contain any rare or special materials, like plutonium radioisotopes or xenon gas, that would prevent manufacturing many such probes.

Suppose that NASA were to create a helicopter like this, but designed to be produced in large numbers and to enter, descend, and land on Mars independently, operating without a parent rover like Perseverance. They would instead communicate directly with satellites in low Mars orbit.

...
What could hundreds of Ingenuity-style helicopters accomplish on the Martian surface? A lot. While the scientific payload of such probes could only be measured in the hundreds of grams, this is enough to contain basics like cameras, thermometers, barometers, anemometers, and so on. And they would, like Ingenuity, make dozens of flights over tens of kilometers of traverse, each.

There are some activities that will be difficult for a Mars helicopter, however, like chemical analysis of soil or rocks.

 

[Loren Pechtel]

NASA Ingenuity Mars helicopter, broken and alone, spotted by Perseverance rover on Martian dune (photo, video) | Space

It's in the top left in that article's picture, beyond the rock field.

The rover ought to try to visit that helicopter, to get a better idea of what happened to it.

We already know everything we are going to learn.

Examining it visually won't show why it decided to do an emergency landing. It was destroyed because it did an emergency landing on uneven terrain and had a rotor strike. They know it's too unbalanced to fly safely and they certainly aren't going to command it into the air with a multi-billion dollar space probe close enough to be hit by flying bits of rotor--and they can't command it (it can only talk to the rover, not to Earth) into the air if the rover is far enough away to be safe.

 

[lpetrich]

The rover ought to try to visit that helicopter, to get a better idea of what happened to it.

We already know everything we are going to learn.

That's very, very dumb. We need to learn as much as we can about its failure, and getting pictures of it from the rover is a good way to do that.

 

[Shadowy Man]

JPL may have more to worry about right now.

JPL lays off about 8% of its workforce.

 

[Loren Pechtel]

The rover ought to try to visit that helicopter, to get a better idea of what happened to it.

We already know everything we are going to learn.

That's very, very dumb. We need to learn as much as we can about its failure, and getting pictures of it from the rover is a good way to do that.

The direct cause of the damage is obvious, we already know what happened. The exact mechanics don't matter, it would not be expected to survive a rotor strike. Something caused it's computer to an emergency landing but a camera isn't going to tell you what.

 

[bilby]

Something caused it's computer to an emergency landing but a camera isn't going to tell you what.

How can you be sure of this, until someone has pointed a camera at it, carefully studied the photo, and declared "Nope, no new evidence here."?

Visual examination of the machine could reveal something that could cause the computer to freak out. I don't know what that might be, but then, that's exactly why it's worth taking a look.

A recent example from Earth-bound aviation - an Airbus had to abort and return to Brisbane after its fly-by-wire computer system shut down and went into "safe mode" shortly after take off.

A close visual examination of the plane's exterior revealed the problem - mud dauber wasps had started to build nests in the Pitot Tubes, causing the airspeed information fed to the computers to go into wild and impossible swings.

The pilots, manufacturers, and accident investigators didn't expect a visual inspection would be of the slightest use, but they did it anyway, because it's part of the standard procedure for any incident. And, surprise surprise, it turned out to provide the critical information needed to understand the strange behaviour of the flight control computers.

All commercial aircraft that spend more than two hours on the ground at BNE are now required to have pitot tube caps installed (and to have them removed immediately before flight), to prevent wasps from filling the tubes with mud.

I strongly doubt that local wasps were the cause of the failure of the Ingenuity Mars Helicopter, but if they were, it would be fairly significant news