IPB

Welcome Guest ( Log In | Register )

4 Pages V  « < 2 3 4  
Reply to this topicStart new topic
Arsia Mons Anomaly?, Recent Mars Express Imagery shows odd feature
ectoterrestrial
post Nov 16 2018, 06:02 AM
Post #46


Junior Member
**

Group: Members
Posts: 20
Joined: 22-February 06
Member No.: 688



Changing course...

Is there a limitation on conventional landings with chutes happening near one of the Tharsis 4? Atmosphere must be extra thin up there.

The huge flat caldera on Arsia seems to beckon for a lander or rover. The "spiral cloud" (caldera confined circulating aerosol suspension) might make things interesting as an engineering challenge.

What use is there for a high altitude station on Mars?


--------------------
UMSF Newbie since 2006.
Go to the top of the page
 
+Quote Post
mcaplinger
post Nov 16 2018, 07:08 AM
Post #47


Senior Member
****

Group: Members
Posts: 2504
Joined: 13-September 05
Member No.: 497



QUOTE (ectoterrestrial @ Nov 15 2018, 10:02 PM) *
Is there a limitation on conventional landings with chutes happening near one of the Tharsis 4?

https://marsnext.jpl.nasa.gov/scieng_eng.cfm says that the Mars2020 landing site, for example, has to be below -0.5 km MOLA elevation, with respect to the MOLA geoid. So you can forget about landing on the volcanoes unless you are using purely propulsive landing (no parachutes.)


--------------------
Disclaimer: This post is based on public information only. Any opinions are my own.
Go to the top of the page
 
+Quote Post
Guest_mcmcmc_*
post Nov 16 2018, 10:40 AM
Post #48





Guests






QUOTE (mcaplinger @ Nov 16 2018, 08:08 AM) *
https://marsnext.jpl.nasa.gov/scieng_eng.cfm says that the Mars2020 landing site, for example, has to be below -0.5 km MOLA elevation, with respect to the MOLA geoid. So you can forget about landing on the volcanoes unless you are using purely propulsive landing (no parachutes.)

why don't landers make aerobraking in orbit rather than landing directly? There would be much less energy to dissipate (just potential energy from 100km altitude rather than all the energy produced by the launcher).
Go to the top of the page
 
+Quote Post
Gerald
post Nov 16 2018, 02:06 PM
Post #49


Senior Member
****

Group: Members
Posts: 2346
Joined: 7-December 12
Member No.: 6780



The do, as far as possible, first with the heat shield, later with parachutes. But with a few hPa, it's hard to slow down to subsonic velocities by mere aerobreaking.
Go to the top of the page
 
+Quote Post
mcaplinger
post Nov 16 2018, 02:36 PM
Post #50


Senior Member
****

Group: Members
Posts: 2504
Joined: 13-September 05
Member No.: 497



QUOTE (mcmcmc @ Nov 16 2018, 02:40 AM) *
why don't landers make aerobraking in orbit rather than landing directly?

It would require a large engine and a lot of fuel to get into orbit first, but Viking did do that. You still need a parachute.

If you're talking about aerocapture to get into orbit, I'm not sure why you think it would help landing.


--------------------
Disclaimer: This post is based on public information only. Any opinions are my own.
Go to the top of the page
 
+Quote Post
ectoterrestrial
post Nov 16 2018, 09:28 PM
Post #51


Junior Member
**

Group: Members
Posts: 20
Joined: 22-February 06
Member No.: 688



QUOTE (mcaplinger @ Nov 16 2018, 12:08 AM) *
https://marsnext.jpl.nasa.gov/scieng_eng.cfm says that the Mars2020 landing site, for example, has to be below -0.5 km MOLA elevation, with respect to the MOLA geoid. So you can forget about landing on the volcanoes unless you are using purely propulsive landing (no parachutes.)


Hmm. Not much (unvisited) terrain left with those constraints.. A visit to Beagle 2 crater in Isidis? A slow climb up Elysium Mons maybe?


--------------------
UMSF Newbie since 2006.
Go to the top of the page
 
+Quote Post
atomoid
post Nov 17 2018, 02:00 AM
Post #52


Member
***

Group: Members
Posts: 866
Joined: 15-March 05
From: Santa Cruz, CA
Member No.: 196



QUOTE (mcaplinger @ Nov 16 2018, 06:36 AM) *
...If you're talking about aerocapture to get into orbit, I'm not sure why you think it would help landing.

aerocapture orbits take quite an extended time to slow the velocity and round out the orbit (adding operations cost to the budget), when that energy can be dispersed much quicker via the well-proven heatsheild method. I'd assume the orbital speed will still be high enough that you'd have use a heatshield for the orbital-to-atmopspheric entry anyways but i am only guessing... I was curious to find the relative velocities of direct atmospheric entry modes vs the slowest possible option for orbital insertion trajectories but ran out of time, here are some starter resources though.
Go to the top of the page
 
+Quote Post

4 Pages V  « < 2 3 4
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 28th March 2024 - 07:07 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.