APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4206
Joined: Fri Dec 04, 2009 3:27 am

APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by APOD Robot » Mon Feb 15, 2021 5:06 am

Image Landing on Mars: Seven Minutes of Terror

Explanation: Starting Thursday, there may be an amazing new robotic explorer on Mars. Or there may be a new pile of junk. It all likely depends on things going correctly in the minutes after the Mars 2020 mission arrives at its new home planet and attempts to deploy the Perseverance rover. Arguably the most sophisticated landing yet attempted on the red planet, consecutive precision events will involve a heat shield, a parachute, several rocket maneuvers, and the automatic operation of an unusual device called a Sky Crane. Thursday's Seven Minutes of Terror echo the landing of the Curiosity rover on Mars in 2012, as depicted in the featured video. If successful, the car-sized Perseverance rover will rest on the surface of Mars, soon to begin exploring Jezero Crater to better determine the habitability of this seemingly barren world to life -- past, present, and future. Although multiple media outlets may cover this event, one way to watch these landing events unfold is on the NASA channel live on the web.

<< Previous APOD This Day in APOD Next APOD >>

User avatar
XgeoX
Ensign
Posts: 66
Joined: Tue Jun 30, 2020 12:57 pm
AKA: Idiot

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by XgeoX » Mon Feb 15, 2021 7:18 am

Mars has just enough of an atmosphere to really complicate landings...

Knight of Clear Skies
Ensign
Posts: 31
Joined: Mon Jul 25, 2016 9:02 am

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Knight of Clear Skies » Mon Feb 15, 2021 9:43 am

XgeoX wrote:
Mon Feb 15, 2021 7:18 am
Mars has just enough of an atmosphere to really complicate landings...
Yes, it certainly does, and air travel.
The tricky thing is that with so little atmosphere, to get any lift, you have to go fast. You need to approach Mach 1 just to get off the ground, and once you get moving, you have so much inertia that it’s hard to change course—if you turn, your plane rotates, but keeps moving in the original direction. The X-Plane author compared piloting Martian aircraft to flying a supersonic ocean liner.
Last edited by Knight of Clear Skies on Mon Feb 15, 2021 1:35 pm, edited 1 time in total.

De58te
Science Officer
Posts: 345
Joined: Mon Sep 30, 2013 6:35 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by De58te » Mon Feb 15, 2021 11:49 am

Is it just me but I don't think NASA is so much worried on Thursday that Perseverance goes fast enough to get enough lift off the ground, but that Perseverance slows down enough to land on the ground in one piece.

User avatar
orin stepanek
Plutopian
Posts: 6055
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by orin stepanek » Mon Feb 15, 2021 12:18 pm

I don't know what good it does; but at this point; just cross your fingers! :mrgreen:
Orin

Smile today; tomorrow's another day!

raschumacher

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by raschumacher » Mon Feb 15, 2021 12:28 pm

I hate that shaky hand-held Zack Snyder camera meme. It's supposed to provide a you-are-there quality, but any spacecraft actually vibrating or flailing around like that would be in very deep doo-doo. Bring back smooth old-school NASA style animation.

sillyworm 2

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by sillyworm 2 » Mon Feb 15, 2021 2:24 pm

The spacecraft with the crane..after it gets out of the way..is it landing or crashing?

User avatar
Chris Peterson
Abominable Snowman
Posts: 15655
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Chris Peterson » Mon Feb 15, 2021 2:40 pm

sillyworm 2 wrote:
Mon Feb 15, 2021 2:24 pm
The spacecraft with the crane..after it gets out of the way..is it landing or crashing?
It crashes.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
johnnydeep
Science Officer
Posts: 459
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by johnnydeep » Mon Feb 15, 2021 5:26 pm

Chris Peterson wrote:
Mon Feb 15, 2021 2:40 pm
sillyworm 2 wrote:
Mon Feb 15, 2021 2:24 pm
The spacecraft with the crane..after it gets out of the way..is it landing or crashing?
It crashes.
The "spacecraft" at this point is now just the rover, and by "crashing", I take you to mean the it simply falls after being released by the sky crane, as opposed to being further slowed by onboard rockets. Is that what you meant? What will the final impact speed be? I can't find that stated anywhere yet.
"To Boldly Go......Beyond The Fields We Know."

NGC3314
Telescope Nerd
Posts: 120
Joined: Thu Sep 23, 2010 5:15 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by NGC3314 » Mon Feb 15, 2021 5:44 pm

johnnydeep wrote:
Mon Feb 15, 2021 5:26 pm
Chris Peterson wrote:
Mon Feb 15, 2021 2:40 pm
sillyworm 2 wrote:
Mon Feb 15, 2021 2:24 pm
The spacecraft with the crane..after it gets out of the way..is it landing or crashing?
It crashes.
The "spacecraft" at this point is now just the rover, and by "crashing", I take you to mean the it simply falls after being released by the sky crane, as opposed to being further slowed by onboard rockets. Is that what you meant? What will the final impact speed be? I can't find that stated anywhere yet.
That response was about "the spacecraft with the rockets", which is not the rover. The rover is gently lowered on a cable until it registers contact with the surface, at which point it cuts the cable, and the rocket-crane stage tips and flies away until its fuel runs out and it crashes to the surface. After the Curiosity landing, the rocket stage crashed 650 meters away (seen in images from orbit.

User avatar
Chris Peterson
Abominable Snowman
Posts: 15655
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Chris Peterson » Mon Feb 15, 2021 5:45 pm

johnnydeep wrote:
Mon Feb 15, 2021 5:26 pm
Chris Peterson wrote:
Mon Feb 15, 2021 2:40 pm
sillyworm 2 wrote:
Mon Feb 15, 2021 2:24 pm
The spacecraft with the crane..after it gets out of the way..is it landing or crashing?
It crashes.
The "spacecraft" at this point is now just the rover, and by "crashing", I take you to mean the it simply falls after being released by the sky crane, as opposed to being further slowed by onboard rockets. Is that what you meant? What will the final impact speed be? I can't find that stated anywhere yet.
I believe the question is what becomes of the crane, not the rover. The rover is deposited on the ground by the crane, then the cables are released, then the crane increases the power to its rockets, flies up and over a few hundred meters, shuts down the engines (or exhausts the remaining fuel), and crashes.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

geoffrey.landis
Ensign
Posts: 53
Joined: Thu Aug 20, 2009 3:49 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by geoffrey.landis » Mon Feb 15, 2021 5:46 pm

Nice explanatory video, but do notice that this is an old video from before the Curiosity landing.
The new Perseverance landing animation can be seen here: https://astronomynow.com/2020/12/28/per ... -for-nasa/
(and I like some of the things they did on the new rendering-- the hardware is getting to be photorealistic.)

User avatar
johnnydeep
Science Officer
Posts: 459
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by johnnydeep » Mon Feb 15, 2021 7:00 pm

De58te wrote:
Mon Feb 15, 2021 11:49 am
Is it just me but I don't think NASA is so much worried on Thursday that Perseverance goes fast enough to get enough lift off the ground, but that Perseverance slows down enough to land on the ground in one piece.
You are correct. But the rover also hosts a small helicopter that I'm looking forward to seeing work well :ssmile: See https://en.wikipedia.org/wiki/Mars_Helicopter_Ingenuity:
Mars Helicopter Ingenuity[6][7] is a robotic helicopter that is planned to be used to test the technology to scout targets of interest on Mars, and help plan the best driving route for future Mars rovers.[8][9] The small drone helicopter is planned for deployment around 19 March 2021 (30 sols from landing date)[10] from the Perseverance rover as part of the NASA Mars 2020 mission.[11]

It is planned to make the first powered flight on any planet beyond Earth,[12] and is expected to fly up to five times during its 30-day test campaign, early in the rover's mission, as it is primarily a technology demonstration.[1][13] Each flight is planned to be at altitudes ranging from 3–5 metres (10–16 ft) above the ground.[1] In up to 90 seconds per flight, it could travel as far as 50 metres (160 ft) downrange and then back to the starting area.[1] It can use autonomous control during its short flights, although flights will be telerobotically planned and scripted by controllers at JPL. It will communicate with the Perseverance rover directly after each landing. If it works as expected, NASA could build on the design for future Mars aerial missions.[14]
"To Boldly Go......Beyond The Fields We Know."

User avatar
johnnydeep
Science Officer
Posts: 459
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by johnnydeep » Mon Feb 15, 2021 7:05 pm

NGC3314 wrote:
Mon Feb 15, 2021 5:44 pm
johnnydeep wrote:
Mon Feb 15, 2021 5:26 pm
Chris Peterson wrote:
Mon Feb 15, 2021 2:40 pm


It crashes.
The "spacecraft" at this point is now just the rover, and by "crashing", I take you to mean the it simply falls after being released by the sky crane, as opposed to being further slowed by onboard rockets. Is that what you meant? What will the final impact speed be? I can't find that stated anywhere yet.
That response was about "the spacecraft with the rockets", which is not the rover. The rover is gently lowered on a cable until it registers contact with the surface, at which point it cuts the cable, and the rocket-crane stage tips and flies away until its fuel runs out and it crashes to the surface. After the Curiosity landing, the rocket stage crashed 650 meters away (seen in images from orbit.
Ah, yes, thank you (and Chris), I now see the question clearly was asking about the crane. And thanks for the detail about the rover being lowered until it touches. Makes sense. I suppose it must determine contact when the weight drops to almost zero.
"To Boldly Go......Beyond The Fields We Know."

Aeroflake123
Asternaut
Posts: 2
Joined: Sun Dec 20, 2020 9:40 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Aeroflake123 » Mon Feb 15, 2021 8:56 pm

First, to our Canadian friends: Happy Canada Day, eh.
Now, I've been a follower and fan of both human and unstaffed space flights since John Glenn went up the first time. I shall be delighted if this mission survives landing and is fully functional.
But I must admit I do not understand the allure, or rationale, for human flights to Mars. As I see it (and do correct me if I'm wrong), sending people that far and to that uninhabitable place will be vastly more complicated and expensive than sending machines like this one (and the more advanced ones yet to be designed and built). These gizmos, while expensive, do not require food, drinks, clean clothing, medicines, shelter, etc. But they will probably be able to accomplish most of the scientific explorations humans would be able to, at a small fraction of the cost. And bear in mind that as we go forward the competition for available funding for such missions must include the Earthly demands that we fight pandemics, rebuild our own nation's infrastructure while trying to ward off and reverse the ravages of climate change, transition to a green economy, provide everyone with healthcare, etc., etc., all while our human population climbs toward 8,000,000,000 and counting.
Colonize Mars? Would you really want to go live somewhere where you'll never again walk through a forest or sit by a stream or waterfall or on a beach? Where to go outside you (and your children) must always put on a life-support suit? Never see a squirrel, rabbit, deer, whale go about its day? Please explain the allure of such a life.

User avatar
Chris Peterson
Abominable Snowman
Posts: 15655
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Chris Peterson » Mon Feb 15, 2021 9:20 pm

Aeroflake123 wrote:
Mon Feb 15, 2021 8:56 pm
First, to our Canadian friends: Happy Canada Day, eh.
Now, I've been a follower and fan of both human and unstaffed space flights since John Glenn went up the first time. I shall be delighted if this mission survives landing and is fully functional.
But I must admit I do not understand the allure, or rationale, for human flights to Mars. As I see it (and do correct me if I'm wrong), sending people that far and to that uninhabitable place will be vastly more complicated and expensive than sending machines like this one (and the more advanced ones yet to be designed and built). These gizmos, while expensive, do not require food, drinks, clean clothing, medicines, shelter, etc. But they will probably be able to accomplish most of the scientific explorations humans would be able to, at a small fraction of the cost. And bear in mind that as we go forward the competition for available funding for such missions must include the Earthly demands that we fight pandemics, rebuild our own nation's infrastructure while trying to ward off and reverse the ravages of climate change, transition to a green economy, provide everyone with healthcare, etc., etc., all while our human population climbs toward 8,000,000,000 and counting.
Colonize Mars? Would you really want to go live somewhere where you'll never again walk through a forest or sit by a stream or waterfall or on a beach? Where to go outside you (and your children) must always put on a life-support suit? Never see a squirrel, rabbit, deer, whale go about its day? Please explain the allure of such a life.
Sending humans to Mars, and for the most part to space at all, is fundamentally a political action, not a scientific one. We went to the Moon as part of the Cold War. And the Cold War never really went away, it just morphed into something with slightly different players. And sending men to the Moon and Mars is largely still a response to that. A big splashy way to show that America is better and greater than anybody else, so there!

We will probably have manned missions to the Moon and to Mars in the next few decades. Colonies? Very unlikely. All in all, a regrettable expense that will likely reduce the funding for programs that would deliver real scientific value. But such is the nature of things.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
neufer
Vacationer at Tralfamadore
Posts: 17852
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by neufer » Mon Feb 15, 2021 9:22 pm

Aeroflake123 wrote:
Mon Feb 15, 2021 8:56 pm

Now, I've been a follower and fan of both human and unstaffed space flights since John Glenn went up the first time. I shall be delighted if this mission survives landing and is fully functional.

But I must admit I do not understand the allure, or rationale, for human flights to Mars. As I see it (and do correct me if I'm wrong), sending people that far and to that uninhabitable place will be vastly more complicated and expensive than sending machines like this one (and the more advanced ones yet to be designed and built). These gizmos, while expensive, do not require food, drinks, clean clothing, medicines, shelter, etc. But they will probably be able to accomplish most of the scientific explorations humans would be able to, at a small fraction of the cost. And bear in mind that as we go forward the competition for available funding for such missions must include the Earthly demands that we fight pandemics, rebuild our own nation's infrastructure while trying to ward off and reverse the ravages of climate change, transition to a green economy, provide everyone with healthcare, etc., etc., all while our human population climbs toward 8,000,000,000 and counting.

Colonize Mars? Would you really want to go live somewhere where you'll never again walk through a forest or sit by a stream or waterfall or on a beach? Where to go outside you (and your children) must always put on a life-support suit? Never see a squirrel, rabbit, deer, whale go about its day? Please explain the allure of such a life.
  • The Conquest of Space requires white men planting flags... that's all there is to it :!:
    (The U.S. will never allow Red Chinese to plant the first flag on Mars.)
https://en.wikipedia.org/wiki/Conquest_of_Space wrote:
Click to play embedded YouTube video.
<<Conquest of Space is a 1955 American Technicolor science fiction film from Paramount Pictures, produced by George Pal, directed by Byron Haskin. The film's storyline concerns the first interplanetary flight to the planet Mars, manned by a crew of five, and launched from Earth orbit near "The Wheel", mankind's first space station. On their long journey to the Red Planet, they encounter various dangers, both from within and without, that nearly destroy the mission.

Mankind has achieved space flight capability and built "The Wheel" space station in orbit 1,730 km above Earth. It is commanded by its designer, Colonel Samuel T. Merritt. His son, Captain Barney Merritt, having been aboard for a year, wants to return to Earth. A giant spaceship has been built in a nearby orbit, and an Earth inspector arrives aboard the station with new orders: Merritt Sr. is being promoted to general and will command the new spaceship, now being sent to Mars instead of the Moon. As General Merritt considers his crew of three enlisted men and one officer, his close friend, Sgt. Mahoney volunteers. The general turns him down for being 20 years too old. Hearing that Mars is the new destination, Barney Merritt volunteers to be the second officer.

Right after the crew watches a TV broadcast from their family and friends, the mission blasts off for the Red Planet. The general's undiagnosed and growing space fatigue is beginning to seriously affect his judgement: reading his Bible frequently, he has doubts about the righteousness of the mission. After launch, Sgt. Mahoney is discovered to be a stowaway, having hidden in a crew spacesuit. Their piloting radar antenna later fails, and two crewmen go outside to make repairs. They manage to get it working just as their monitors show a glowing planetoid, 20 times larger than their spaceship, coming at them from astern. The general fires the engines, barely managing to avoid a collision, but the planetoid's fast-orbiting debris punctures Sgt. Fodor's spacesuit, killing him instantly. After a religious service in space, Fodor's body is cast adrift into the void.

Eight months later, the general is becoming increasingly mentally unbalanced, focusing on Sgt. Fodor's loss as "God's judgement". On the Mars landing approach, he attempts to crash their spaceship, now convinced the mission violates the laws of God. Barney wrests control away from his father, landing the large flying wing glider-rocket safely. Later, as the crew takes their first steps on the Red Planet, they look up and see water pouring down from the now vertical return rocket. Barney quickly discovers the leak is sabotage caused by his father, who threatens his son with a .45 automatic. The two struggle and the pistol discharges, killing the general. Sgt. Mahoney, who observed only the last stages of the struggle, wants Barney confined under arrest with the threat of court martial, but cooler heads prevail; Barney becomes the ranking officer.

Mars proves to be inhospitable, and they struggle to survive with their decreased water supply. Earth's correct orbital position for a return trip is one year away. While glumly celebrating their first Christmas on Mars, a sudden snowstorm blows in, allowing them to replenish their water supply. As their launch window arrives, they hear low rumbling sounds, then see rocks falling, and feel the ground shake violently. The ground level shifts during this violent marsquake. Their spaceship is now leaning at a precarious angle and cannot make an emergency blast off. To right the spaceship, the crew uses the rocket engines' powerful thrust to shift the ground under the landing legs. The attempt works and they blast off, the spaceship rising just as the Martian surface completely collapses.

Once in space, Barney and Mahoney reconcile. Impressed with Barney's heroism and leadership while on Mars, Mahoney concludes that pursuing Barney's court martial for his father's death would only impugn the general's reputation, tarnishing what previously had been a spotless military career. Better is the fiction that "the man who conquered space" died in the line of duty, sacrificing himself to save his crew.>>
Art Neuendorffer

User avatar
Chris Peterson
Abominable Snowman
Posts: 15655
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Chris Peterson » Mon Feb 15, 2021 9:28 pm

neufer wrote:
Mon Feb 15, 2021 9:22 pm
Aeroflake123 wrote:
Mon Feb 15, 2021 8:56 pm

Now, I've been a follower and fan of both human and unstaffed space flights since John Glenn went up the first time. I shall be delighted if this mission survives landing and is fully functional.

But I must admit I do not understand the allure, or rationale, for human flights to Mars. As I see it (and do correct me if I'm wrong), sending people that far and to that uninhabitable place will be vastly more complicated and expensive than sending machines like this one (and the more advanced ones yet to be designed and built). These gizmos, while expensive, do not require food, drinks, clean clothing, medicines, shelter, etc. But they will probably be able to accomplish most of the scientific explorations humans would be able to, at a small fraction of the cost. And bear in mind that as we go forward the competition for available funding for such missions must include the Earthly demands that we fight pandemics, rebuild our own nation's infrastructure while trying to ward off and reverse the ravages of climate change, transition to a green economy, provide everyone with healthcare, etc., etc., all while our human population climbs toward 8,000,000,000 and counting.

Colonize Mars? Would you really want to go live somewhere where you'll never again walk through a forest or sit by a stream or waterfall or on a beach? Where to go outside you (and your children) must always put on a life-support suit? Never see a squirrel, rabbit, deer, whale go about its day? Please explain the allure of such a life.
  • The Conquest of Space requires white men planting flags... that's all there is to it :!:
    (The U.S. will never allow Red Chinese to plant the first flag on Mars.)
https://en.wikipedia.org/wiki/Conquest_of_Space wrote:
Click to play embedded YouTube video.
<<Conquest of Space is a 1955 American Technicolor science fiction film from Paramount Pictures, produced by George Pal, directed by Byron Haskin. The film's storyline concerns the first interplanetary flight to the planet Mars, manned by a crew of five, and launched from Earth orbit near "The Wheel", mankind's first space station. On their long journey to the Red Planet, they encounter various dangers, both from within and without, that nearly destroy the mission.

Mankind has achieved space flight capability and built "The Wheel" space station in orbit 1,730 km above Earth. It is commanded by its designer, Colonel Samuel T. Merritt. His son, Captain Barney Merritt, having been aboard for a year, wants to return to Earth. A giant spaceship has been built in a nearby orbit, and an Earth inspector arrives aboard the station with new orders: Merritt Sr. is being promoted to general and will command the new spaceship, now being sent to Mars instead of the Moon. As General Merritt considers his crew of three enlisted men and one officer, his close friend, Sgt. Mahoney volunteers. The general turns him down for being 20 years too old. Hearing that Mars is the new destination, Barney Merritt volunteers to be the second officer.

Right after the crew watches a TV broadcast from their family and friends, the mission blasts off for the Red Planet. The general's undiagnosed and growing space fatigue is beginning to seriously affect his judgement: reading his Bible frequently, he has doubts about the righteousness of the mission. After launch, Sgt. Mahoney is discovered to be a stowaway, having hidden in a crew spacesuit. Their piloting radar antenna later fails, and two crewmen go outside to make repairs. They manage to get it working just as their monitors show a glowing planetoid, 20 times larger than their spaceship, coming at them from astern. The general fires the engines, barely managing to avoid a collision, but the planetoid's fast-orbiting debris punctures Sgt. Fodor's spacesuit, killing him instantly. After a religious service in space, Fodor's body is cast adrift into the void.

Eight months later, the general is becoming increasingly mentally unbalanced, focusing on Sgt. Fodor's loss as "God's judgement". On the Mars landing approach, he attempts to crash their spaceship, now convinced the mission violates the laws of God. Barney wrests control away from his father, landing the large flying wing glider-rocket safely. Later, as the crew takes their first steps on the Red Planet, they look up and see water pouring down from the now vertical return rocket. Barney quickly discovers the leak is sabotage caused by his father, who threatens his son with a .45 automatic. The two struggle and the pistol discharges, killing the general. Sgt. Mahoney, who observed only the last stages of the struggle, wants Barney confined under arrest with the threat of court martial, but cooler heads prevail; Barney becomes the ranking officer.

Mars proves to be inhospitable, and they struggle to survive with their decreased water supply. Earth's correct orbital position for a return trip is one year away. While glumly celebrating their first Christmas on Mars, a sudden snowstorm blows in, allowing them to replenish their water supply. As their launch window arrives, they hear low rumbling sounds, then see rocks falling, and feel the ground shake violently. The ground level shifts during this violent marsquake. Their spaceship is now leaning at a precarious angle and cannot make an emergency blast off. To right the spaceship, the crew uses the rocket engines' powerful thrust to shift the ground under the landing legs. The attempt works and they blast off, the spaceship rising just as the Martian surface completely collapses.

Once in space, Barney and Mahoney reconcile. Impressed with Barney's heroism and leadership while on Mars, Mahoney concludes that pursuing Barney's court martial for his father's death would only impugn the general's reputation, tarnishing what previously had been a spotless military career. Better is the fiction that "the man who conquered space" died in the line of duty, sacrificing himself to save his crew.>>
I note also the degree to which the mission is a military endeavor.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
neufer
Vacationer at Tralfamadore
Posts: 17852
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by neufer » Mon Feb 15, 2021 10:46 pm

Chris Peterson wrote:
Mon Feb 15, 2021 9:28 pm
neufer wrote:
Mon Feb 15, 2021 9:22 pm
Aeroflake123 wrote:
Mon Feb 15, 2021 8:56 pm

Now, I've been a follower and fan of both human and unstaffed space flights since John Glenn went up the first time. I shall be delighted if this mission survives landing and is fully functional.

But I must admit I do not understand the allure, or rationale, for human flights to Mars. As I see it (and do correct me if I'm wrong), sending people that far and to that uninhabitable place will be vastly more complicated and expensive than sending machines like this one (and the more advanced ones yet to be designed and built). These gizmos, while expensive, do not require food, drinks, clean clothing, medicines, shelter, etc. But they will probably be able to accomplish most of the scientific explorations humans would be able to, at a small fraction of the cost. And bear in mind that as we go forward the competition for available funding for such missions must include the Earthly demands that we fight pandemics, rebuild our own nation's infrastructure while trying to ward off and reverse the ravages of climate change, transition to a green economy, provide everyone with healthcare, etc., etc., all while our human population climbs toward 8,000,000,000 and counting.

Colonize Mars? Would you really want to go live somewhere where you'll never again walk through a forest or sit by a stream or waterfall or on a beach? Where to go outside you (and your children) must always put on a life-support suit? Never see a squirrel, rabbit, deer, whale go about its day? Please explain the allure of such a life.
  • The Conquest of Space requires white men planting flags... that's all there is to it :!:
    (The U.S. will never allow Red Chinese to plant the first flag on Mars.)
I note also the degree to which the mission is a military endeavor.
https://en.wikipedia.org/wiki/Per_aspera_ad_astra wrote:
In Kurt Vonnegut's _The Sirens of Titan_, "Per aspera ad astra" was quoted as both the motto of Martian Imperial Commandos, a unit within the larger Martian Army, in addition to being the motto of Kansas, U.S.A., Earth, Solar System, Milky Way. In Kenta Shinohara's _Astra Lost in Space_, it is inscribed on a plaque on the bridge of the ship that the crew subsequently decided to name the Astra.
To Kill a Mockingbird: Chapter 27 wrote:
The band played the national anthem, and we heard the audience rise. Then the bass drum sounded. Mrs. Merriweather, stationed behind her lectern beside the band, said: “Maycomb County Ad Astra Per Aspera.” The bass drum boomed again. “That means,” said Mrs. Merriweather, translating for the rustic elements, “from the mud to the stars.” She added, unnecessarily, it seemed to me, “A pageant.”
Chapter V : A Portrait of the Artist as a Young Man, by James Joyce wrote:
Stephen, disheartened suddenly by the dean’s firm, dry tone, was silent; and through the silence a distant noise of many boots and confused voices came up the staircase.

—In pursuing these speculations, said the dean conclusively, there is, however, the danger of perishing of inanition. First you must take your degree. Set that before you as your first aim. Then, little by little, you will see your way. I mean in every sense, your way in life and in thinking. It may be uphill pedalling at first. Take Mr Moonan. He was a long time before he got to the top. But he got there.

—I may not have his talent, said Stephen quietly.

—You never know, said the dean brightly. We never can say what is in us. I most certainly should not be despondent. Per aspera ad astra.
Per aspera ad astra (or, less commonly, ad astra per aspera) is a popular Latin phrase meaning "through hardships to the stars". The phrase is one of the many Latin sayings that use the expression ad astra, meaning "to the stars".
https://www.kshs.org/kansapedia/kansas-state-capitol-ad-astra/11742 wrote:
<<The design for the Great Seal of Kansas was submitted by John James Ingalls, a state senator from Atchison. Ingalls also proposed the state motto, "Ad astra per aspera." The Great Seal of the State of Kansas was established by a joint resolution adopted by the Kansas Legislature on May 25, 1861: "The east is represented by a rising sun, in the right-hand corner of the seal; to the left of it, commerce is represented by a river and a steamboat; in the foreground, agriculture is represented as the basis of the future prosperity of the state, by a settler’s cabin and a man plowing with a pair of horses; beyond this is a train of ox-wagons, going west; in the background is seen a herd of buffalo, retreating, pursued by two Indians, on horseback; around the top is the motto, 'Ad astra per aspera,' and beneath a cluster of thirty-four stars. The circle is surrounded by the words, "Great seal of the state of Kansas. January 29, 1861.">>
-----------------------------------
<<Few things in Kansas history have created such a long-standing controversy as "finishing" the Kansas State Capitol dome. The story begins more than a hundred years ago. In 1889 a commission was appointed to consider some of the finishing details, such as sculptures and reliefs, for the capitol. A design competition was held in which seven sculptors competed for the honor of having their work selected to crown the dome. J.H. Mahoney of Indianapolis submitted the winning design: a bronze sculpture of Ceres, the Roman goddess of agriculture.

By 1901 a proposal was finally submitted to Winslow Brothers Foundry of Chicago to cast the 16-foot statue. The estimated cost was $6,950. Word soon circulated and many balked at the high price for what some considered such a non-essential item. Others criticized the idea of choosing to honor a Roman pagan goddess. Victorian sensibilities being what they were had many questioning her morals, in particular, her liaisons with her brother Jupiter. Public outcry tabled the idea and thus, the statue of Ceres was to remain just a small plaster model. The model itself would be moved around the building from closet to closet until it finally found a home in the collection of the Kansas Historical Society.

In 1984 the legislature appropriated funding for a yet-to-be determined statue but stipulated that it could not be a god or goddess. Late in 1988 a design competition was held from which three finalists were selected. Ultimately, Richard Bergen's bronze sculpture of a Kansa warrior succeeded in claiming the honor.

The title of the statue, Ad Astra, is taken from the state motto, Ad astra per aspera, which translates "to the stars through difficulties." The selection committee cited several reasons for choosing Ad Astra, principally the statue honored the state's American Indian heritage, created a unique and distinct profile, and conveyed the ideas of aspiration and inspiration.

The next step was to begin fundraising efforts to pay for the casting and the transportation of the statue from Salina to Topeka. The legislature paid to have the cupola on the dome reinforced to hold the extra weight of the statue. After 14 years the statue was finally cast in June 2002. The statue is hollow cast of silicon bronze, consisting of 95 percent brass and trace elements of silica, tin, manganese, and iron. It is quite sturdy and designed to sway no more than one inch in an 80 m.p.h. wind. Ad Astra is 22 feet 2 inches tall and weighs 4,420 pounds.

With the assistance of a huge 450-foot crane, Ad Astra was finally secured in place October 10, 2002. The formal dedication took place November 4, 2002, with Governor Bill Graves officiating. Members from all four American Indian tribes including the Kaw or (Kansa) Nation participated in the ceremony by praying and singing blessings for the statue. Today you can stand in many locations in Topeka and see Ad Astra from miles away or you can get up close by climbing to the top of the dome and standing on the cupola's railed balcony 23 feet below the magnificent statue. Either way, you are a witness to the resolution of one of the lengthiest battles in Kansas history.>>
Art Neuendorffer

Sérgio dos Santos

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Sérgio dos Santos » Tue Feb 16, 2021 1:53 am

Roger perseverance.
Tomara de tudo certo no pouso.
Só acho que nunca devem trazer de bus a terra qualquer amostra de Marte ou outro planeta sob o risco de alguma contaminação sem precedentes na terra.
Já pensou vir de Marte um vírus que corroe ferro em segundos.

Sérgio dos Santos

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Sérgio dos Santos » Tue Feb 16, 2021 1:57 am

Rover perseverance.
Tomara que de tudo certo no pouso.
Só acho que nunca devem trazer a terra qualquer amostra de Marte ou outro planeta sob o risco de alguma contaminação sem precedentes na terra.
Já imaginaram vir de Marte um vírus que corroe ferro em segundos.

nam888id
Asternaut
Posts: 9
Joined: Mon Jan 06, 2020 8:44 pm

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by nam888id » Tue Feb 16, 2021 4:08 am

There doesn't have to be any terror. Very smart, thorough and creative people have systematically approached this project. There are unknowns/scenarios that have been programmed to be handled. A seemingly huge task breaks down into manageable tasks. And the laws of physics are the laws of physics. I assume real time data on what is happening will be transmitted, so if something does not go right, there will be learning. I assume there is some chance involved, but great work has been done to minimize that.

User avatar
Chris Peterson
Abominable Snowman
Posts: 15655
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Landing on Mars: Seven Minutes of Terror (2021 Feb 15)

Post by Chris Peterson » Tue Feb 16, 2021 4:35 am

nam888id wrote:
Tue Feb 16, 2021 4:08 am
There doesn't have to be any terror. Very smart, thorough and creative people have systematically approached this project. There are unknowns/scenarios that have been programmed to be handled. A seemingly huge task breaks down into manageable tasks. And the laws of physics are the laws of physics. I assume real time data on what is happening will be transmitted, so if something does not go right, there will be learning. I assume there is some chance involved, but great work has been done to minimize that.
Missions like this are decadal. A single mission can represent a significant part of many scientists' and engineers' careers. And Mars has eaten half of all the probes sent there.

I can guarantee you that every critical moment, from launch, to separations, to orbital insertion burns, to correction burns, to the landing sequence, everyone is standing around with sphincters tighter than you can imagine. "Terror" describes it very well!
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com