Don Lee: Perseverance lands on Mars after ‘seven minutes of terror’

Published 8:00 am Tuesday, March 9, 2021

Back to space this week.
I have had some health issues for a couple of weeks, but it seems to be alleviated now. That is a way of life for older people. I am sorry I am so late on writing about the landing of the Mars Perseverance rover.
I think I can tell you a few news items about it that have not been in the evening news or in the newspapers.
The goal of this $2.7 billion project was to determine if there has been any life on Mars a few million years ago. The rover will be looking for microbes that would indicate earlier life there. The rover weighs a little over a ton and is the size of sport utility vehicle.
It was launched July 30, 2020, and successfully landed on Feb. 18, 2021.
The rover will be collecting dozens of samples of soil and rocks to be returned to the earth in subsequent years.
The expectation is that the chalk size samples will be stored in a place where the next craft can pick them up and return them to earth. That will be decades in the future, although funding has been approved for the engineers to start planning for the trip.
The Feb. 19, 2021 issue of The Wall Street Journal had a lot of information on the trip and landing of the rover.
It traveled 292 million miles to catch up with Mars, which was a very spectacular feat, especially when you realize that it takes 11 minutes, 22 seconds for the instructions to be sent from Earth to Mars in its current position.
The engineers said there were seven minutes of sheer terror, which was the time it took from the last transmission before it entered the Mars atmosphere until it landed.
It was traveling at more than 10,000 miles per hour and used the braking of the Mars atmosphere to slow it down to 940 miles per hour, when the 70-foot diameter parachute deployed to further slow it down to 200 miles per hour.
The sky crane then took over as the parachute was detached.
At that time, the retrorockets were fired to slow down more and, when it was 21 feet off the surface, it lowered the rover on cables and then, when it touched down, the crane disconnected and moved away.
The engineers expect they will be starting to move the rover in a couple of weeks.
They have given it a nickname, Percy, which I mentioned a few weeks ago since I can’t spell Perseverance.
There were so many systems that had to work perfectly for the landing to be a success.
For the landing sequence, there were over two million lines of computer code.
As the rover descended the camera took pictures and with artificial intelligence, it was able to direct the rover to a suitable place to land.
This was during those seven minutes of terror mentioned above.
The Chinese have a space craft in orbit around the planet Mars and intend to make their first landing in May of this year. There is not much information on the goals of the Chinese craft, but they are spending a lot of time and money to catchup with the U.S. effort.

Don Lee, a pilot flying out of Lawrence County Airport since 1970, has been in charge of equipment and grounds maintenance for the last several years. He can be reached at

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