"[...] the helicopter executed the first half of its autonomous journey, flying north at an altitude of 16 feet (5 meters) for 466 feet (142 meters). Then a flight-contingency program was triggered, and Ingenuity automatically landed." #LAND_NOW
It is possible that during #Flight53 an anomaly occurred which may have led to #Ingenuity's disorientation or otherwise loss of ground reference. That could explain the low altitude of the flight (5m instead of 10m) and its much shorter duration and length. Resetting of the parameters used by the software to allow the IMU to substitute for the damaged inclinometer may be the reason for short #Flight54, "for heli localization".
So this question arises: if the plan for #Flight53 was to scout and cover 203m of ground, why did it do a straight line flight of only 142m? Even if this is a preliminary localization, still the flight seems rather abnormal.
If #Flight53 was indeed abnormal, then #Ingenuity did a marvelous job landing safely, and so did its team and the #Mars2020 team in resolving the situation AND localizing the heli.
#Ingenuity's landing 53 location which I posted yesterday was based on just one MastcamZ image and was not accurate. A more careful triangulation with ground features (rocks, sand dunes, terrain elevation) results in a much closer landing spot, about half the planned flight distance of 203m.
The above difference actually makes a lot of sense: the flight's purpose was 'scouting', apparently for #Perseverance to find a good path through the maze of rocks ...
1/
As with previous scouting flights, the flight would not be straight, but would follow a path designed for the #MarsHelicopter to capture images of the areas of interest.
The map above shows two possible flight paths in yellow dashed lines, covering different areas around the planned route. The old landing estimate is in red. Matching letters on the map and in the image below show the ground features used in the triangulation.
2/2
@mars_stu on Xitter, spotted #Ingenuity at its new landing 53, about 3 hours ago. Meaning, it's possible that the #MarsHelicopter had already flown #Flight53 when #Perseverance arrived at its RMC 42.1460 location on Sol 868, and that's why it didn't show up in the NAVCAM images.
New location of #Ingenuity after its #Flight53. No HELI_NAV images have been downlinked yet, so this is just a rough estimate of the landing spot; we also no not know when the flight occurred. More to come.
The map also shows the FOV of the image in the previous post.
On Sol 868 #Perseverance passed north of Snowdrift Peak and ended its drive at a new location, RMC 42.1460, just 90m away from #Ingenuity, inside the Fall River bank.
This localization is based on one image. The path shown with a double white dashed line is a guess. More to follow.
#Ingenuity has a 50m restricted no-fly zone, meaning that it shouldn't come closer than 50m to #Perseverance during a flight, to avoid risk of damaging the rover in case something goes wrong with a flight. At present this means that the heli will either have to fly within one or two sols from tosol, or wait until the rover drives away and clears the 50m no-fly zone in coming sols. That is, if the #MarsHelicopter hasn't already flown #Flight53.
The weather in Jezero, Mars, according to the MEDA instrument aboard #Perseverance.
Report Sol: 866
High temperatures ranged from -20C to -16.2C while low temperatures kept around -76C, rising as high as -75.1C on Sol 864. Atmospheric pressure kept its steep downward trend. Atmospheric density is about to dive below 0.014kg/m3, so #Ingenuity's #Flight53 will most probably take off with the rotor in high gear, 2700 rpm.
#Perseverance moved on to a new location, RMC 42.0776, ~95m to the west, 165m from #Ingenuity. Another ~35m to the west will bring it to a passage north of "Snowdrift Peak" (?) where it will be able to see the #MarsHelicopter from a distance of ~135m; that's perfect for a new video capturing #Flight53 😀 .
Well, that guessed path was ... close 😬 😳 I'll put a note here to #PDSAnalystNotebook, so I can revisit it when detailed reports get published (on Nov 27, 2023) and see what caused the strange drive; maybe RIFMAX again? Also to see why #Ingenuity has (probably) delayed its #Flight53, if it has indeed.
(guessed path in white, official path in dark brown double line)
What we don't know yet is whether #Flight53 has taken place as planned, last Saturday. Rising temperature and dropping pressure, both at night and during daylight, have decreased atmospheric density to below 0.0145kg/m3, the limit for low rpm rotor speed. Maybe this development caused a delay?
The weather in Jezero, Mars, according to the MEDA instrument onboard #Perseverance.
Report Sol: 859
It's possible that from now on, maybe even for #Flight53, #Ingenuity will have to use a higher rotor speed of 2700rpm to overcome the low atmospheric density, which has now reached below the limit for the low, 2537rpm rotor speed, which is 0.0145kg/m3.
This post by Håvard Grip, from the early days, explains why these changes are necessary:
The time in Jezero Crater, #Mars, is now 17:00 LMST, and the #Mars2020 Sol is 860.
By now #Ingenuity is expected to have completed its #Flight53; the first images from its landing should be coming in shortly, if the flight has indeed taken place. The radio link is expected to be good despite the #MarsHelicopter being out of sight behind a ridge of the Fall River bank (maybe called Snowdrift Peak?)
The map shows a rough estimate of the radio coverage from a possible landing location (red).
#Perseverance finished work at Ypsilon Lake and drove ~55m to WSW along the (guessed) planned route, where it stopped and took some pictures. One of them is attached below.
@PaulHammond51
:) If it doesn't disappear again behind a mountain or in a ditch, I think we'll get back to the good old days, with hundreds of HELI_NAV images coming a day or two after each flight.
And if it can get some of the dust off of its solar panels, then it may live to meet its relatives in '29 or whenever the #MSR mission occurs. 🙃
I'm feeling optimistic today 😀
Just to keep a long established habit live, the map shows my wild guess for #Flight53.
Two fresh #Ingenuity images were just downlinked. The date is yestersol and the time is in the morning, which both seem to indicate that the #MarsHelicopter is in good health, willing and able for its next #Flight53.
So, we're standing by for the announcement of the new flight 🙂
Now that newer details about #Perseverance's plans are known, here is a revised guess about the flight path of the upcoming #Flight53 and landing. The landing location is ~60m away from the anticipated route of the rover at closest approach. If the flight happens when the rover is about to enter the Fall River bank (marked with a circle), then #Ingenuity will be visible when it lands.
There is a spot along a path #Perseverance may take that has very good visibility to what lies about 500m beyond Fall River Pass, and includes a possible landing site of #Ingenuity's #Flight53. From that spot the rover could even take a movie of the #MarsHelicopter flying away, from a distance of about 135m.
This animated map shows that guessed path overlaid on a visibility plot. The interesting spot mentioned above is marked in red. Dark areas are not visible.
Now that #Perseverance has once again hit the road and #Ingenuity is (apparently) in good shape, here is a wild guess about a possible flight path for #Flight53:
Animated in sequence:
• plain map
• visibility from #Landing53
• estimated radio coverage from landing
• detail of landing location, zoomed in