Linked Questions

41 votes
4 answers
9k views

Why did multiple nations decide to launch Mars projects at exactly the same time?

There seem to be multiple Mars projects all happening at around the same time: The Emirates Mars Mission was the first of the three to arrive at Mars on 9 February 2021. Tianwen-1, an interplanetary ...
nycynik's user avatar
  • 763
13 votes
1 answer
1k views

Will Perseverance be captured into Mars orbit before descent or would it be a direct descent into the atmosphere?

Will Perseverance be captured into Mars orbit before descent or would it be a direct descent into the atmosphere similar to an aerocapture maneuver? It would be helpful if someone could add any ...
Bruce Vici's user avatar
14 votes
1 answer
2k views

Opportunity's last tau was 10.8; what does that mean and how is tau defined and measured?

@ahiijny added a direct link to the Sol 5110-5114 MER B Downlink Report. These are the final days that signals were received from Opportunity. The message "Tau Value is NOT a Typographical Error" ...
uhoh's user avatar
  • 149k
4 votes
3 answers
465 views

How long would astronauts' footprints on Mars persist?

The Apollo astronauts' footsteps can remain theoretically forever on the Moon as it has no atmosphere. Mars does have an atmosphere but a very thin one. Its pressure ranges from 72 Pa (0.0104 psi) on ...
Giovanni's user avatar
  • 389
13 votes
1 answer
644 views

Do Mars rovers protect optical windows during dust storms? Do they "avert their eyes" or do they just "grin and bear it"?

The question Did any lander or rover photograph the sun rising or setting during a Martian dust storm? makes me think of the images below showing the stuff blown around and on to martian rovers. I'm ...
uhoh's user avatar
  • 149k
5 votes
2 answers
686 views

Why would InSight's arrival date at Mars be fixed, and independent of the launch date?

Despite the 34 day long launch window, the day that InSight will arrive has already been chosen. See mars.nasa.gov's insight mission timeline below, a site I found linked in this answer. I'm not ...
uhoh's user avatar
  • 149k
2 votes
2 answers
1k views

how and why is image processing used on spacecrafts?

Electronics engineer here trying to dive into aviation and aerospace engineering. I was wondering which (advanced) image processing techniques are being used in satellites nowadays. And which purposes ...
privetDruzia's user avatar
7 votes
1 answer
724 views

How could the landing date of Perseverance Rover be fixed irrespective of 26 days launch window?

I am very much aware of this question from 2018 by @uhoh - Why would InSight's arrival date at Mars be fixed, and independent of the launch date?. I was led here by a similar question which arose in ...
OrangeDurito's user avatar
4 votes
4 answers
326 views

Alternative to GPS navigation for vertical landing, especially on other planets

Is the GPS data reliable or meaningful only on Earth or below the geo-stationary Earth orbit? For GPS navigation, does a rocket has to fly below the geo-stationary orbit? If GEO is a physical ...
seccpur's user avatar
  • 1,175
4 votes
1 answer
279 views

Have any systems on any Mars rovers failed (even partially) as a result of a dust storm? (besides loss of solar power)

Have any systems on any Mars rovers failed (even partially) as a result of a dust storm? There is the obvious problem of loss of solar power, but the failures there are the result of loss of power. ...
uhoh's user avatar
  • 149k
4 votes
1 answer
329 views

Why is 90 sols a standard mission duration for robotic spacecraft on the surface of Mars?

Several robotic Mars surface missions have a planned mission duration of 90 sols. I would like to understand why this specific mission lifetime is commonly used by mission planners. Below is a non-...
Armadillo's user avatar
  • 1,426
2 votes
1 answer
214 views

When did Curiosity land in the Martian Darian calendar?

The New York Times' Why Mars Needs Leap Days, Too “I daresay there have been more different proposals for Mars calendars than there are different calendars for the Earth,” said Michael Allison, a ...
uhoh's user avatar
  • 149k
5 votes
1 answer
187 views

Why are the gaps in MRO global images of mars so irregular and sometimes filled in?

Moderate Resolution Imaging Spectroradiometer (MODIS) images of Earth snow nice, regular repeating gaps in longitude where the viewing angle is too far for a given pass. But the large GIF shown in ...
uhoh's user avatar
  • 149k