Mars 2020 Mission, Perseverance Rover Launch

[doug]

Too bad they didn't have a forward camera on the Centaur stage.

I didn't see it during the launch coverage, but in the post launch briefing they showed video of the craft separation. You can see it around the 30 second mark of the video I posted above.

 

[bxr140]

Really cool frame or three on the massive recoil/oscillation at the base of the super long fairing.

A couple seconds after fairing deploy you can see half of the load reactor deploy too. That's the silly ring they add to the top of the upper stage to manage the ginormous fairing's lateral motion.

 

[mongo]

A couple seconds after fairing deploy you can see half of the load reactor deploy too. That's the silly ring they add to the top of the upper stage to manage the ginormous fairing's lateral motion.

That "silly" ring is also part of the load sharing setup I mentioned.

Payload clearance and vehicle structural stability are enhanced by the all-aluminum forward load reactor (FLR), which centers the PLF around the Centaur upper stage and shares payload shear loading.

https://www.ulalaunch.com/docs/default-source/rockets/atlasv-cutaway.pdf

 

[ecarfan]

Now that Perserverance is on its way, not much is going to happen until the “7 Minutes of Terror” when the vehicle enters the Marian atmosphere and then (hopefully) lands softly at an impact speed of less than 2mph. Here is a NASA video about that process. This video is about the 2012 Curiosity landing process (the first time the technique was attempted, and it worked perfectly) but Perseverance will land the same way. Apparently the supersonic parachute has been slightly modified and the software has been tweaked to adjust for local variations in Martian gravity; Curiosity touched down at 1.4mph and the engineers had expected it to be at 1.7mph. They later ascribed that to the landing area have a tiny bit less gravitational pull then they predicted. Perseverance also has something Curiosity did not: “terrain-relative navigation.” A camera on the spacecraft will take pictures of the landscape and match them with its stored maps. That will help it pick out a suitably flat spot free of large rocks. (Credit: https://www.nytimes.com/2020/07/29/science/nasa-mars-perseverance-rover.html)

 

[doug]

 

[ggr]

You can see the shadow of the smoke trail; at first I couldn't figure out what it was, thought it was a camera artifact.

 

[Electroman]

Look at the ice build up.. probably several cm think covering the whole outer shell top to bottom. And that is extra pounds it has to lift, not to mention the additional drag it induces.

 

[bxr140]

Look at the ice build up.. probably several cm think covering the whole outer shell top to bottom. And that is extra pounds it has to lift, not to mention the additional drag it induces.

It falls off pretty quickly and also represents mass efficient propellant, so it’s an acceptable trade off.

 

[Electroman]

It falls off pretty quickly and also represents mass efficient propellant, so it’s an acceptable trade off.

4 1/2 mins into the flight until the first stage separation much of the ice build exists.

"mass efficient propellant": Didn't SpaceX pioneer the usage of super-cooled LOX? And I don't recall seeing any ice build up, or not this much.

 

[Grendal]

NASA video:

 

[Nikxice]

Best of luck tomorrow for a successful landing to the mission 'Martians' at JPL!

Landing Toolkit: Perseverance Rover

 

[ecarfan]

On the sample return mission:
Ars said:
NASA and the European Space Agency are talking about jointly developing different elements of this mission, possibly for a launch as early as 2026. While there is some limited funding in NASA's budget for a new Mars orbiter, at present the complex plan to retrieve and bring the samples home seems more aspirational than real—we are hopeful that it comes to pass, but not expectant.
Something-something Starship something-something...

And three years later, Eric Berger reports that the costs for the Mars Sample Return mission have ballooned to the point that it is going to jeopardize NASA’s other planetary exploration missions.

According to two sources familiar with the meeting, the Program Manager for the mission at the Jet Propulsion Laboratory, Richard Cook, and the director of the mission at NASA Headquarters, Jeff Gramling, briefed agency leaders last week on costs. They had some sobering news: the price had doubled. The development cost for the mission was no longer $4.4 billion. Rather, the new estimate put it at $8 to $9 billion.

Moreover, this only represents the cost to build and test the different components of the mission. It does not include launch costs, operating costs over a five-year period, nor construction of a new sample-receiving facility to handle the rocks and soil from Mars. All told, the total cost of the Mars Sample Return mission is now about $10 billion.

NASA should put that mission on hold and wait to get a better estimate of when humans will arrive on Mars via Starship, because;

If NASA manages to develop and launch the Sample Retriever Lander by 2028, the samples could be returned to Earth in 2033. The problem is no one expects the lander to launch in 2028. At this point, even 2030 looks like a stretch goal.