NASA next mars rover launch delayed again

[GDRRiley]

Summary

The next Nasa Mars rover Perseverance an improved and heavier version of Curiosity launching aboard a ULA Atlas 541 is again having issue. the rover is fine but the rocket upper stage is having problems and already half of the launch window to mars is gone. if this gets delayed it will be over 2 years and hundreds of millions if it misses this launch window

Spoiler

 

Quotes

Quote

NASA says it will be forced to delay the launch of its multibillion-dollar Perseverance mission to no earlier than July 30. The Mars-bound large rover must launch on an Atlas V rocket from Cape Canaveral Air Force Station in Florida before the middle of August, or it will miss Earth's conjunction with the red planet.

 

A source in Florida indicated that the issue was related to the Atlas V rocket's Centaur upper stage, which is fueled with liquid hydrogen and liquid oxygen.

 

My thoughts

I'd like to see this launched this year and not pushed back years. next time maybe a falcon9 would be a better launch vehicle given they would in the 2-3 month window have spares available. ULA doesn't have time to remake the centar stage and they likely don't have any in the pipeline close to being done.

 

Sources

https://arstechnica.com/science/2020/06/nasas-mars-perseverance-launch-date-has-slipped-eight-more-days/

[sub68]

my uncle worked on preparing for it

[givingtnt]

34 minutes ago, BlueScope819 said:

Should've gone SpaceX! Seriously though, it is bad news as I was looking forward to it.

Why ? That makes no sense.

 

SpaceX currently doesn't have the proven capability to go to mars, much less when the project was being planned (several years ago).

 

The Atlas rocket has an incredible reliability record and ULA has a much bigger history with NASA.

[givingtnt]

34 minutes ago, BlueScope819 said:

1.  

They can fit an extra SRB still (its allowed 5)

 

Either way. These things are planned so let ng in advance NASA would have never bothered with a potential offer from SpaceX lol

 

SpaceX has no experience with getting things out of low earth orbit / geostationary yet tho. 

 

And don't forget to add up previous rocket launches too

 

 

[givingtnt]

1 minute ago, BlueScope819 said:

Yup, totally agree on both counts. Seems like NASA suffered a case of buyers remorse in this case.

Not if they launch. It's not entirely off yet.

[GoldenLag]

7 hours ago, givingtnt said:

And don't forget to add up previous rocket launches too

And dont forget other rockets that could also have done the same job

 

7 hours ago, BlueScope819 said:

• It's cheaper
• SpaceXs Falcon Heavy has the required parameters in order to insert it onto the proper orbit. It's not about the Falcon Heavy or any other rocket going to Mars, it's about it's ability to insert it into the correct transfer orbit. The only additional complexity is relighting the engine in LEO to push it to Mars, which they did with their test launch of the Falcon Heavy

 

While SpaceX might be cheaper, its not the launch that is the expencive bits of these crafts. So just getting a reliable launch vehicles with the fairing capabilities and upperstage options are far more important. 

[GoldenLag]

1 hour ago, BlueScope819 said:

They gain more experience with Mars bound payloads to help solve some of the design problems with Starship

How does this help the rover guys?

 

1 hour ago, BlueScope819 said:

SpaceX hasn't had these types of problems with the rocket second stage having issues while on the pad.

Do they have a deep space stage that has been able to do corrections and be relitt multiple times?

 

1 hour ago, BlueScope819 said:

this is all a moot point

Well its also the case that spaceX may not offer what they were looking for, even if they were available

[dalekphalm]

11 minutes ago, GoldenLag said:

How does this help the rover guys?

It doesn’t help them specifically, but it does help NASA in general to have multiple Mars rocket options. 

11 minutes ago, GoldenLag said:

Do they have a deep space stage that has been able to do corrections and be relitt multiple times?

Yes. The second stage is capable of all of that. It has redundant ignition systems. 

11 minutes ago, GoldenLag said:

Well its also the case that spaceX may not offer what they were looking for, even if they were available

The Falcon Heavy on paper is 100% capable of this mission. 
 

Their maiden test flight launched a Tesla Roadster into a sun orbit (escaping Earths orbit). It was on a Mars injection trajectory but they didn’t bother actually moving it into Mars orbit. 
 

The roadster is currently in orbit around the sun and will remain there until someone collects it someday. 

[GoldenLag]

2 minutes ago, dalekphalm said:

It doesn’t help them specifically, but it does help NASA in general to have multiple Mars rocket options. 

Indeed it does, but its not as if its lacking in that department in regards to other rockets with similar capabilities. Even if those options may not sit strictly in the US

 

11 minutes ago, BlueScope819 said:

Long term.

Atm, its one vehicle. So while it mat help other launches. It doesnt help them now. I do see the point tho.

 

 

16 minutes ago, BlueScope819 said:

The thing that I'm talking about is jettisoned at 0:57 in the video.

Fair enough. 

 

9 minutes ago, dalekphalm said:

The Falcon Heavy on paper is 100% capable of this mission. 

Same with the Delta 4 heavy, or Proton M. 

 

Which both have far more launches under their belt

 

Seemingly the Ariane 5 can do it aswell, tho current active config is more for geostationary launches it seems. 

 

So assuming SpaceX was in its current state at the time of choosing. They still may not have been picked. 

[GoldenLag]

3 minutes ago, BlueScope819 said:

Delta IV heavy has 11 launches. Falcon 9 has 88

Falcon 9 heavy has 3........

 

4 minutes ago, BlueScope819 said:

This means that actually the Falcon 9 would be able to launch the rover, as it can launch 5 more tons to LEO than the Atlas V 541, which logically follows that it will be able to launch more mass to Mars.

Also doesnt change that other rockets could also have taken the payload instead. 

 

While the falcon 9 heavy is great and all. There are other rockets that can do the same, but with more launches under their belt.

[GoldenLag]

5 minutes ago, BlueScope819 said:

said Falcon 9, not Falcon 9 heavy.

I realize ive for some reason when lookign up rockets, managed to confuse the two when looking at specs. My bad. 

[seon123]

52 minutes ago, BlueScope819 said:

I couldn't find a spec sheet for the Atlas V 541 payload to mars

Well, obviously. The required C3 will vary, so the max payload mass will as well.

Here is the figure  "Minimum departure energies for Earth to Mars Ballistic Missions: 1990 to 2045" from "Interplanetary Mission Design Handbook: Earth-to-Mars Mission Opportunities 2026 to 2045" (2010).

Spoiler

From https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100037210.pdf

We'll just use a value of 14 and put it into the NASA Launch Vehicle Performance Website, and we immediately find that Falcon 9 Full Thrust ASDS is not even an option (using a C3 of 10 gives 2220 kg on Falcon 9 vs 4625 kg with the 541). Here are the plots for a C3 of 0, just to show. You can clearly see how the maximum payload falls much faster for the Falcon 9.

Spoiler

Plot generated using
https://elvperf.ksc.nasa.gov/Pages/Default.aspx

Using a C3 of 14, here are the launch vehicles capable of launching at least as much as the 541:

Spoiler

Plot generated using
https://elvperf.ksc.nasa.gov/Pages/Default.aspx

So the Falcon Heavy in recovery mode is barely able to carry more than the 541 (4600 vs 4270), and the 551 is able to carry more than that again (4680). Considering there have only been three launches of the Falcon Heavy, vs 84/84 successful launches of the Atlas V, the Atlas seems like a no-brainer to me ¯\_(ツ)_/¯

$90M vs $145M is just the cost of the launch itself, and the total cost of the mission is quite a lot higher.

52 minutes ago, BlueScope819 said:

This means that actually the Falcon 9 would be able to launch the rover, as it can launch 5 more tons to LEO than the Atlas V 541, which logically follows that it will be able to launch more mass to Mars.

I recommend studying the Tsiolkovsky Rocket Equation. The FT second stage engine has a specific impulse of 348s vs 450.5s on the RL-10.

https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

 

 

Edit: Obligatory "come on guys, it's not rocket science" joke

Edited July 1, 2020 by seon123
Something something

[cj09beira]

7 minutes ago, BlueScope819 said:

For all of the above, is there something that I am missing here? I know this is all just a theoretical discussion because Falcon Heavy wasn't ready when the mission was in the proper planning stages, but it's interesting to discuss anyways.

 

 

if i remember right it had something to do with the second stage engine being more efficient than the space x one, i could be wrong though

[Nicnac]

Nvm

[GoldenLag]

On 7/1/2020 at 7:24 PM, BlueScope819 said:

Is that the reason for the difference @seon123?

Yea i was about to return to comment the exact thing seon exlained. Im 2 days late tho.

 

The second stage hydrogen engine specific impulse is the reason why Delta 4 and Atlas 5 are far better at escape trajectory. 

 

There was apperantly plans for a "raptor" hydrogen upper stage for falcon, but seemingly got scrapped due to lack of funding. And morphed into the Raptor engine we know now. 

Spoiler

Reason behind me returning. Darn youtube recommendations didnt make me rewatch this untill today.