Weather data from every planet

[PicnicDoctor]

TL;DR Summary

How feasible is it to track the weather on every planet at the same level of detail we do for Earth.

I was curious about how much we could advance planetary science with the amount we are spending (and planning to spend) on the SLS. Specifically, I want us to increase the number of climates we study from basically Earth to every planet in the solar system.

It looks like polar orbiting satellites (https://en.wikipedia.org/wiki/Weather_satellite#Polar_orbiting) would be the most efficient to monitor a planet. If they can act as communication relays or help with coordinating future probes, all the better. Seems like 4 is a good number of these for earth. Looking at JPSS-1 the mass is 2294 kg. The math lines up pretty good so that 4 satellites for 1 falcon heavy mission, given my assumptions that follow.

16,800 kg payload to Mars expendable * 0.70 to factor in reusable instead = 11760 kg. Assuming a payload to Mars would be about the same with gravity assists to anywhere else in solar system. Falcon heavy launch cost of approximately $100 million reusable.

So assuming 4 is the minimum and then extrapolating linearly we get:

planet	radius	# of satellites	number of falcon heavy missions
Jupiter	139,822 km	44	11
Saturn	116,464 km	36	9
Uranus	50,724 km	16	4
Neptune	49,248 km	16	4
Earth	12,756 km	4	n/a
Venus	12,104 km	4	1
Mars	6,780 km	4	1
Mercury	4,780 km	4	1

That comes to 31 falcon heavy missions with launch costs of 3.1 billion dollars. The JPSS program on Earth seems to cost about $1 billion a year to operate, I'm going to assume it will be more efficient scaled up and be ~ .5 billion per planet (.5 * 7) - so total operating/building costs of 3.5 billion a year.

I made a lot of assumptions (and some numbers totally up), but it does seem like monitoring every planet in our solar system at Earth like weather detail, is in the same cost order of magnitude as the SLS program ($35 billion estimate to 2025?).

Would love to know: which of my assumptions are the worst; what you think of the idea; if you know of anyone who is proposing we do something like this - even to just say Mars. Thanks for reading!

 

[phinds]

what you think of the idea;

Right now that would be a HUGE waste of money for very little return when we have pressing needs here on Earth.

 

[Vanadium 50]

Would love to know: which of my assumptions are the worst

That would be hard to say.

One biggie is that most of our weather data on Earth comes from terrestrial sensors, not satellites. Another is that you just don't put up a rocket and whoosh! You have a probe orbiting another planet,. In a polar orbit, no less. It doesn't work like that - look at MESSENGER for an indication of how hard it would be.

A better estimate of cost is to scale up MESSENGER by 8 (twice the mass, and four times the number of probes) per mission and 31 missions, for a total of $94B (inflation adjusted), and since it lasted 4 years, you'd need to spend roughly $25B/year to do this. That's more than the entire state budget of Minnesota.

 

[Vanadium 50]

As a PS..it's also more than the entire NASA budget.

 

[PicnicDoctor]

Comparing the rockets flown

Delta II (https://en.wikipedia.org/wiki/Delta_II)
US$51 million in 1987
US$137 million in 2018 before retirement

Seems fare that messenger mission might be around the same $100 million range as Falcon Heavy in 2004.

The Payload capacity that is comparable is Payload to GTO
Delta II - 2,170 kg
Falcon Heavy - 26,700 kg

We can send 12 more probes per the same launch costs.

$450 million total cost of Messenger (so $350m for operations, construction) over at least 10 years.. that's $35 million a year

Operations obviously if we can't get more efficient would kill it at 44 billion a year, but if we develop 128 relatively similar probes, I'm guessing we can get some efficiencies for both construction and operations.

I don't see why polar orbits would be a significant setback seeing as how we are not coming from the target planet in question.

 

[Vanadium 50]

We can send 12 more probes per the same launch costs.

Whoosh! In orbit around Jupiter!
Whoosh! In orbit around Saturn!
Whoosh! Four in Orbit around Uranus, four around Neptune, one around Venus and three around Jupiter!