Differences

This shows you the differences between two versions of the page.

--- blog:articles:science:landing_mars2020 [2019/07/02 09:10] – created Phil Ide
+++ blog:articles:science:landing_mars2020 [2019/07/13 08:00] (current) – [What This Means] Phil Ide
@@ Line 1: / Line 1: @@
 ====== Landing the Mars 2020 Rover Safely ======
 {{:blog:articles:science:landingmars2020.gif?direct&400 |}}
-Autonomous landings are always fraught with danger. One of the most dangerous terrains any landing might occur on is a boulder field. Not only would the impact of the landing on these hard objects be a threat, but the boulders are likely to be jagged too. Another threat are the steep cliffs of the crater - not falling off them (although that's a possibility), but crashing into them.
+Autonomous landings are always fraught with danger. One of the most dangerous terrains any landing might occur on is a boulder field. Not only would the impact of the landing on these hard objects be a threat, but the boulders are likely to be jagged too. Another threat are the steep cliffs of the crater - not falling off them (although that's a possibility), but crashing into them. //(click on the image to the left to see the animation)//
 The landing ellipse for NASA landers on Mars is typically around 20km (12mi) long and 7km (4.3mi) wide. Jezero crater, where Mars 2020 is due to land in Feb 2021, is 49km (30.4mi) across. This means there are probably going to be a variety of terrains within that ellipse. Mars 2020 has a solution to prevent landing in a poor location.
@@ Line 38: / Line 38: @@
 A landing ellipse is 20km by 7km. Jezera is 49km in diameter. If we look at NASA's most recent landing - InSight - we can see a problem. InSight was meant to land at a longitude of 135.974°E, but it actually landed at 135.6234°E. Let's do some maths:
-,344 km (circumference of Mars) / 360 (number of degrees) = 59.288 km
+,344 km (circumference of Mars) / 360 (number of degrees) = 59.288 km per degree
 .974 - 135.6234 = 0.3506 (degrees)
 .288 * 0.3506 = 20.786 km.
-Insight missed its target by 20.786km. What this means is the landing ellipse is 20km long, with a 20km variance of hitting the actually intended landing site. I'm pretty sure NASA can do better than that (perhaps a 10km variability or less), but at this sort of accuracy Jezera, at 49km wide, is pushing the limits of safe landing. Internally, Jezera is riddled with hazards. This new landing system is in effect a game-changer.
+Insight missed its target by 20.786km. What this means is the landing ellipse is 20km long, with a 10km variance of hitting the actually intended landing site. At this sort of accuracy Jezera, at 49km wide, is pushing the limits of safe landing. Internally, Jezera is riddled with hazards. This new landing system is in effect a game-changer.
 Mars 2020 is taking a helicopter with it too. I'm pretty  excited about Mars 2020. Aren't you?
+~~socialite~~
+~~DISCUSSION~~