Flight 19 for NASA’s Ingenuity is set to take place on Sunday, January 23, 2022.
Mars’ atmosphere is far less thick than Earth’s; yet, the Mars climate has many characteristics as Earth’s, including seasons, shifting winds, ice clouds, and dust storms. As is valid for Earth, predicting weather occurrences is inherently treacherous. Scientists discovered while planning for Trip 19 that unexpected Mars weather may result in a sad situation here on Earth: a delayed flight.
Fortunately, Ingenuity does not transport people, and all of its baggage is “carry-on,” so the only consequence is that the scientists must wait for better weather.
Weather forecasting has become an essential component of Martian flight preparation, with 18 missions accomplished so far. Jezero Crater has gone through spring and into summer since the first flight on April 19, 2021.
The start of the fall on Mars begins on February 24. With the changing seasons came new problems, such as a drop in air density, which necessitated changes in how it flew.
The role of weather forecasters is to assess current weather conditions about flying needs. What are the criteria for excellent and safe flying?
Two fundamental factors are favorable circumstances: air density and wind speed. Although there aren’t many weather stations or circling weather satellites on Mars, as we have on Earth, there are various instruments to decide whether or not conditions are suitable for flight.
How Do They Know Weather On Mars?
The Mars Environmental Dynamics Analyzer (MEDA) – an operational weather station on board the Perseverance rover – is the most valuable forecasting resource.
The Mars Color Imager (MARCI) and Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) offer everyday updates on the status of the atmosphere, which is helpful for understanding activities outside of Jezero crater that might affect future weather.
As Mars enters fall, we can anticipate an increase in the quantity of dust in the atmosphere; levels will stay elevated until winter. This time of year is known as the “dusty season.”
The dust significantly impacts Mars’ environment, particularly critical for solar-powered surface assets like Ingenuity.
Atmospheric dust will reduce the sunshine that reaches Ingenuity’s solar panels, which charge the flight batteries.
Furthermore, dust in the environment is heated by sunlight and heats the surrounding atmosphere, causing the already low-density air in which Ingenuity must travel to become much lower. The operations team has been actively discussing the impending dusty season and how to adapt to the consequences of this shifting environment.
On the first day of the new year, a large regional dust storm developed, engulfing the Jezero crater just as scientists were about to launch Flight 19. This storm arrived extremely early — even before the customary start of the dusty season! A storm of this magnitude was never seen so early in the Mars year.
MRO obtained photographs of this expanding regional dust storm from orbit, which showed symptoms of expanding from the southern hemisphere towards the northern hemisphere — perhaps approaching Jezero crater. The weather prediction team had to decide whether or not to proceed with the flight.
Because the data astronomers examine from MEDA and orbital assets might have a latency of a few hours to a few days, they had to anticipate Flight 19 a few days in advance. There was no doubt that there was a lot of uncertainty on the horizon.
The weather team suggested postponing Flight 19, which the Ingenuity team eventually agreed upon. The choice to ground Ingenuity proved to be the correct one. The dust storm traveled across the Jezero crater days after the mission delay.
The most noticeable change was a substantial reduction in air density — roughly a 7% divergence from what was measured before to the dust storm. This measured decline would have lowered density below the lower threshold of safe flight, putting the spacecraft in danger.
We also noticed the impact of dust on the quantity of sunlight absorbed by Ingenuity’s solar array, which dropped significantly below usual “clear sky” values, a reduction of roughly 18%.
The dust storm has passed, and it seems that we will fly Ingenuity no early than this Sunday, January 23.
Future incidents are likely later in the dusty season, potentially evolving into global-scale storms like those seen most recently in 2018, 2007, and 2001.