Something funny

[eyu100]

I traveled from Earth to Mercury in an XR5, and once I arrived at Mercury I put myself in a nearly circular orbit with a perihermion (just got that from Wikipedia :lol of a few meters below the surface. When I tried to lower the landing gear, it said I couldn't because of excessive heat/excessive dynamic pressure, even though my hull temperature was at absolute zero and Mercury doesn't have an atmosphere :beathead:.

Oddly, I was able to make a belly landing at a speed of over 3000 meters per second without damaging my spacecraft--the first time I bounced off the surface back into space, but the second time I fired my retro thrusters as I was landing and managed to keep myself on the surface.

After I landed, I noticed something else odd: my rate of deceleration remained constant. Initially, the centrifugal force from my orbital velocity would be quite large, so the normal force from the ground would be small. As I slowed down, the centrifugal force would decrease, so the normal force would increase in order to support the weight of the spacecraft. Since my deceleration was being caused by friction, and (ideally) the force of friction is proportional to the normal force, my XR5 should have slowed down faster and faster, but this didn't happen.

Thoughts?

EDIT: Also, I was decelerating at around 30 meters per second squared. At low speeds, the normal force is equal to the XR5's mass times Mercury's surface gravity (3.7 meters per second squared). Dividing 30 m/s^2 by 3.7 m/s^2 gives the XR5's belly a coefficient of friction of over 8 :lollerskates:. Now if tires were made out of this material... :woohoo:! skidding wouldn't be a problem anymore.

 

[dbeachy1]

When I tried to lower the landing gear, it said I couldn't because of excessive heat/excessive dynamic pressure, even though my hull temperature was at absolute zero and Mercury doesn't have an atmosphere :beathead:.

That message means that the gear has already failed previously (e.g., during takeoff from Earth), and so the gear cannot be deployed. Are you sure your gear was working before you tried to deploy it? I just ran a quick test here with the XR5 in orbit around Mercury and the gear deployed just fine. Can you please post a scenario of your XR5 in orbit around Mercury? Then I can run it here and investigate.

Oddly, I was able to make a belly landing at a speed of over 3000 meters per second without damaging my spacecraft--the first time I bounced off the surface back into space, but the second time I fired my retro thrusters as I was landing and managed to keep myself on the surface.

The XRs model impact damage based solely on your your vertical speed at impact, which means that you can "slide" along the surface without destroying the ship as long as your vertical speed is low enough. TBH I never thought about belly landings at 3000 m/s.

After I landed, I noticed something else odd: my rate of deceleration remained constant.

That is all handled internally by the Orbiter core : all the XR vessel does is set the ship's surface friction coefficient due to a belly landing, which is a constant. I suspect that Orbiter (reasonably enough) does not factor in orbital velocities in its surface friction logic.

 

[statickid]

I don't know much about it, but I always felt that unless it's a runway or landing pad specifically, It seems like all planets are made out of ice. always been that way, at least on my installs.