2 ms·

Wow, that's really banged up! Wasn't that the thing the parachute was attached to? I would have thought that with a parachute the landing would be softer. Oh

Wow, that's really banged up! Wasn't that the thing the parachute was attached to? I would have thought that with a parachute the landing would be softer. Oh wait, Mars is almost a vacuum and the parachute is really just used to slow the lander as it's traveling at ridiculous speeds. Now I wonder what the terminal velocity was-- certainly higher than it would be on Earth, even with 1/3 the gravity? I wonder if there are good pics of the part of the delivery system that used rockets and didn't have a parachute? Did it fare worse?

isaacdl 4y ago
The caption for that first image says that it impacted at "approximately 78 mph (126 kph)".
namibj 4y ago
Mars's lower gravity, lower-density atmosphere, and different speed of sound (atmosphere mixture & temperature) happen to combine to similar aerodynamics in the high-subsonic region as the stratospheric region around 40 km altitude on Earth. I.e., a plane that can fly up there on Earth could fly on Mars at low altitude. Because gravity times travel distance is constant for constant aerodynamic efficiency and constant engine ISP, and Mars is both smaller than Earth and has significantly lower gravity, a hydrolox fuel-cell (driving electric props) flying wing should be able to do a "half-way around the planet" trip with reasonable cargo, followed by re-fueling oxygen, and flying back to the other place, before running out of hydrogen. (Alternatively, at less than 50% cargo capacity loss, it could collect the water exhaust from the fuel cell, to recover the hydrogen.) The main issue of such a plane would be that the lift-off speed on the runway would be about half the speed of sound. Maybe use the electric motors to drive fuel pumps and run hydrolox rocket engines for lift-off? Sounds like that could allow VTOL.

2 ms·

Wow, that's really banged up! Wasn't that the thing the parachute was attached to? I would have thought that with a parachute the landing would be softer. Oh

by crispyambulance 4y ago

isaacdl 4y ago
The caption for that first image says that it impacted at "approximately 78 mph (126 kph)".
namibj 4y ago
Mars's lower gravity, lower-density atmosphere, and different speed of sound (atmosphere mixture & temperature) happen to combine to similar aerodynamics in the high-subsonic region as the stratospheric region around 40 km altitude on Earth. I.e., a plane that can fly up there on Earth could fly on Mars at low altitude. Because gravity times travel distance is constant for constant aerodynamic efficiency and constant engine ISP, and Mars is both smaller than Earth and has significantly lower gravity, a hydrolox fuel-cell (driving electric props) flying wing should be able to do a "half-way around the planet" trip with reasonable cargo, followed by re-fueling oxygen, and flying back to the other place, before running out of hydrogen. (Alternatively, at less than 50% cargo capacity loss, it could collect the water exhaust from the fuel cell, to recover the hydrogen.) The main issue of such a plane would be that the lift-off speed on the runway would be about half the speed of sound. Maybe use the electric motors to drive fuel pumps and run hydrolox rocket engines for lift-off? Sounds like that could allow VTOL.