4 ms·

Wow! I just looked up the difference in pressure and found that the "air" pressure on the surface of Mars is 155 times less that of Earth (1013.25 mbar on Earth

Wow! I just looked up the difference in pressure and found that the "air" pressure on the surface of Mars is 155 times less that of Earth (1013.25 mbar on Earth, 6.518 mbar on Mars).

m4rtink 6y ago
Yeah, that was really not expected and only found via space probes. That's why you see gliders for landing in many of the early Mars mission concepts but not in the newer ones. Actually the atmosphere is too thin for full gliding or parashute landing but too thick to ignore it like we can on the Moon. Still twice the Moons gravity with no atmospheric breaking at all would also suck I guess.
- jillesvangurp 6y ago
  Basically means you need a lot more delta v too slow down. Which means burning a lot more fuel to first get below escape velocity (5km/s) and then slow down all the way to zero. Escape velocity for Earth is 11km/s. ISS flies at about 7.6 km/s. A typical Mars approach and landing starts at about 20km/s. Most of that is Atmospheric braking. So yes, that would suck.
- skykooler 6y ago
  From what I remember of playing around with X-Plane's Mars atmosphere model, you can glide, but at very high speeds (for most planes close to the speed of sound), you can barely turn, and it's horribly easy to stall.
  - m4rtink 6y ago
    Doesn't paint a good future for large scale aeronautics on Mars - even if you somehow can sustain those speeds in an atmosphere where you cant burn stuff for propulsion, landing the thing, somehow, at the destination would be very hard - possibly harder than landing the F-104 Starfighter!;-) That speed likely rules out any normal landing gear or runways, possibly with the exception of a maglev catcher cradle. Most likely the "aircraft" would need some sort of a robust long duration vertical landing capability, likely rocket based. No wonder you don't see any aircraft on Mars in The Expanse series - only hyperloop like pods on flimsy rails making use of both the low pressure and low gravity or full on spaceships or orbital shuttles.
    - imtringued 6y ago
      We need to "inflate" the atmosphere. That means digging up nitrogen deep in the soil.
    - skykooler 6y ago
      Yeah, the only real possibilities for landing on a runway are insanely long runways (dozens of miles!) or high-speed arrestor cables, like souped-up versions of those used on carriers. And even then, the super-wide maneuvering radius means flaring without stalling is practically impossible - you'd need to clear a long area in front of the runway so you can basically come in almost flat.

Wow! I just looked up the difference in pressure and found that the "air" pressure on the surface of Mars is 155 times less that of Earth (1013.25 mbar on Earth, 6.518 mbar on Mars).

m4rtink 6y ago

Yeah, that was really not expected and only found via space probes. That's why you see gliders for landing in many of the early Mars mission concepts but not in the newer ones. Actually the atmosphere is too thin for full gliding or parashute landing but too thick to ignore it like we can on the Moon. Still twice the Moons gravity with no atmospheric breaking at all would also suck I guess.

jillesvangurp 6y ago
Basically means you need a lot more delta v too slow down. Which means burning a lot more fuel to first get below escape velocity (5km/s) and then slow down all the way to zero. Escape velocity for Earth is 11km/s. ISS flies at about 7.6 km/s. A typical Mars approach and landing starts at about 20km/s. Most of that is Atmospheric braking. So yes, that would suck.
skykooler 6y ago
From what I remember of playing around with X-Plane's Mars atmosphere model, you can glide, but at very high speeds (for most planes close to the speed of sound), you can barely turn, and it's horribly easy to stall.
- m4rtink 6y ago
  Doesn't paint a good future for large scale aeronautics on Mars - even if you somehow can sustain those speeds in an atmosphere where you cant burn stuff for propulsion, landing the thing, somehow, at the destination would be very hard - possibly harder than landing the F-104 Starfighter!;-) That speed likely rules out any normal landing gear or runways, possibly with the exception of a maglev catcher cradle. Most likely the "aircraft" would need some sort of a robust long duration vertical landing capability, likely rocket based. No wonder you don't see any aircraft on Mars in The Expanse series - only hyperloop like pods on flimsy rails making use of both the low pressure and low gravity or full on spaceships or orbital shuttles.
  - imtringued 6y ago
    We need to "inflate" the atmosphere. That means digging up nitrogen deep in the soil.
  - skykooler 6y ago
    Yeah, the only real possibilities for landing on a runway are insanely long runways (dozens of miles!) or high-speed arrestor cables, like souped-up versions of those used on carriers. And even then, the super-wide maneuvering radius means flaring without stalling is practically impossible - you'd need to clear a long area in front of the runway so you can basically come in almost flat.