In 2016, we traveled to Scotland. A highlight of our trip was the week-long barge journey from Inverness to Banavie. It followed the route of the Caledonian Canal allowing us to traverse Lochs Dochfour, Ness, Lochy, and Oich from the North Sea to the Atlantic side of Scotland. The canal was finished in 1822. A fascinating part of the canal is the system of 29 locks used to raise and lower boats. The highest elevation reached is 106 ft above sea level. Our post is here about the lock system. Pictured below is one of the sets of lock gates viewed with Google Maps. The water level in the upper right is higher than at the lower left.
Last week, my friend David and I traveled to the Mississippi River at the Quad Cities to do a boat tour of Lock & Dam 15 conducted by two engineers with the U.S. Army Corps of Engineers. They explained much of the history of the river and early attempts to navigate boats through this region. They also described the maintenance of the dam and locks to further their useful life. They also discussed some of the history of the Rock Island Arsenal as we passed by.
The multiple gates of the dam are on the left in the next image. They control the river flow from upper right to lower left. There are two locks for river traffic just right of center. Our tour boat passed through the smaller of the two locks. Large tugboats and their barges pass through the larger lock.
The first video view of the flight of the Ingenuity helicopter on Mars was short and jerky. It lasted 13 sec. The initial video data omitted many frames in order to quickly confirm for scientists that the flight was successful. Since that time, the rest of the frames have been downloaded and compiled into this version of 57 sec. The camera used was on the Perseverance rover several meters away.
Things to watch for include spin-up of the rotors at 7 sec. Liftoff takes place at 15 sec. It reaches 3 meter altitude at 19 sec. It hovers and does a 90˚ turn at 24 sec. It holds that position for several seconds. During that time, notice how it drifts to the right and then left a little bit. The gentle Martian breeze that day caused the drift. Ingenuity regained its position correctly. It started to descend at 37 sec with touchdown 3 sec later.
Scientists at JPL used special video filtering to capture the faint dust cloud stirred up by the rotors of the helicopter.
“The Mastcam-Z imager aboard NASA’s Perseverance Mars rover shot video of the helicopter’s flight. The video is presented here in side-by-side formats that have both been enhanced to show a dust plume swirling during takeoff and again on landing. The view on the left uses motion filtering to show where dust was detected during liftoff and landing and the view on the right is enhanced with the motion filtering. Scientists use this image processing to detect dust devils as they pass by Mars rovers.”
While Ingenuity hovered, the camera on the bottom aimed straight down captured this image of its shadow. Imagine looking straight down from the height of a basketball hoop. The fast shutter speed froze the positions of the two counter-rotating rotor blades spinning at about 2500 rpm. The 4 legs of the copter are visible.
UPDATE: Flight 2 and images taken by Ingenuity in this video.
UPDATE: Flight 3 starts at the lower left. Lift-off at 10 sec. Cruises off screen to the right. Returns to view at 49 sec and then to touchdown.
Much of the excitement has settled now that Mars 2020 Perseverance Rover is safely on the surface of Mars after the 18 Feb 2021 landing. I gathered images and links to a collection of things I feel tell the story of this rover in a not too complicated way. The mission is very challenging. A primary goal is to find evidence that microbial life may have existed on the Martian surface in the past.
You might wonder where Perseverance landed and why is that place is important. Landing took place in Jezero Crater. The crater is about 49 km (30 mi) across. It is believed to have once been filled with water. This image shows a dried riverbed and delta of a water source that once flowed left-to-right and filled the crater. The colors are indicators of various types of mineral deposits and not actual colors. The rover landed in the lower right quadrant of this image just below the two side-by-side small craters on the flat plain and not far from the delta formation.
Ancient river delta into Jezero Crater | MRO | NASA
Scientists and space enthusiasts are excited about the upcoming landing of the exploration rover Perseverance on the surface of Mars on 18 Feb 2021. The NASA-TV broadcast from Mission Control starts at 11:15 am PST/2:15 pm EST.
The mission is designed to look for bio-signatures in a river delta of an ancient lakebed. It will harvest rock-core samples for analysis and possible return to Earth in a future mission. The rover will be joined by a small helicopter to extend its vision and reach around the area. This video (< 3 min) shows the basics of the rover design and plans for the mission. You are invited to explore more about the mission at this link.
Perseverance helicopter being examined by NASA engineers
Perseverance was launched in July of 2020. It took 7 months to coast to this meeting with Mars. On a collision course, it will enter the thin atmosphere at over 12,000 mph. The challenge is how to safely slow the vehicle and land it. This following graphic illustrates the overall plan, but not to scale.
The fast-moving craft in coast phase enters the atmosphere at upper left. A heat shield protects it and slows it down from 12,000 to 950 mph. A parachute deploys and the heat shield falls away. The craft scans the terrain to find the landing site.
At 180 mph and 1.3 miles altitude, the parachute is detached letting the vehicle fall. Rocket engines control the descent and slow it down to less than 2 mph and 60 ft. above the surface. The rover is lowered about 20 ft more by cables to touchdown on the surface. The cables detach and the rocket assembly flies far out of the way.
Lowering of rover by cables for touchdown | NASA
The technique has been done before in 2012 when the Curiosity rover landed on Mars. It was described then as 7 minutes of terror. Mars is far from Earth. By the time radio signals reach us more than 11 minutes later, events will already have played out, successfully or not. All actions are programmed. Curiosity is still functioning well on Mars today. Here is a recent selfie.
What will the Moon look like on any date in 2021? What will it look like on your birthday? Find out at NASA Dial-a-Moon. The example pictured below is for 16 January 2021. Set dates and see views for northern hemisphere and for southern hemisphere readers by following either link. Enter any month and day to see a high definition image. You may leave the universal time (UT) at the default value. If you wish, your local-to-Universal time conversion can be done at this link. Or, type ‘universal time’ into Google. Go back to Dial-a-Moon to enter the UT.
After visiting Dial-a-Moon, scan down that web page for a wealth of additional information about the Moon’s motions and appearance. The images of Dial-a-Moon are made from those of the Lunar Reconnaissance Orbiter (LRO) in low altitude orbit around the Moon since 2009.