I'm interested in the environmental impact of launching many small rockets to put say one or two satellites into orbit vs the impact of a much larger rocket to launch many more at once.

Can anyone with more knowledge on the subject chime in on this?

Falcon 9 burns trough around 500t of propellant while Electron trough around 12t. So, you need roughly 41 launches of Electron to match one of Falcon 9. 41 Electrons can deliver max 10t of payload costing around 246 millions $, while single Falcon 9 more than 20t in expendable version costing less than 100 millions $.

But the issue with big rockets is that they can take a payload to pretty much a single orbit. You will never find 41 clients that want to go the same orbit. So, quite often big rockets are flying below their max capacity.

Also, rockets contribution to humanity CO2 emission is close to zero. I would not be surprised if some launches of agricultural satellites had positive net impact on environment due to more efficient usage of water, fertilizers and pesticides that monitoring from space allows.

If F9 fired 100 times a year and converted 100% propellant mass into CO2 (it actually produces a lot of water) it would be 0.0001% of world emissions.

A cool question, but you don’t need to have direct knowledge to see the answer. Economies of scale make bigger things more efficient.

But that’s just the rocket. I suspect the thousands of people working on it have a far larger environmental impact than the rocket itself.

I thought that maybe there could be something particular to how rockets work which would cause economies-of-scale to be irrelevant in the case of rockets, and so a bigger rocket wouldn't necessarily deliver a payload more efficiently (per kilogram).

Besides that though, I was also thinking about the ultimate goal of these companies. Presumably, both SpaceX and Rocket Labs (and others) want launching rockets to become a much more common day-to-day activity than it is now.

At that point, would it not be better for us to focus on bigger rockets to ensure that we're not creating unnecessary pollution with smaller rockets? Kinda the difference we could've made if the US for example had focused on large-scale public transit rather than urban sprawls where everyone has their own car. If we have the option now, it seems to be like we should push for the large-scale more efficient solutions now so that it doesn't come back to bite us later.

Either way, it's negligible compared to cars, concrete, aluminium production, and hundreds of other energy-heavy industries.

Well, negligible now, but isn't the entire purpose behind companies like SpaceX and Rocket Lab to make launching rockets much, much more ubiquitous?

And once rocket-launching is ubiquitous, should we not care that 100 smaller rockets are creating 10x more pollution as a single, massive rocket which delivers the same payload?

Or the carbon impact of the electrical bill for operating a big-box retail store, in a location where >85% of the power comes from a coal-fueled power plant.

I want these indie space companies to succeed as much as anyone else here but you are asking a valid and sober question and I don’t know why you are being downvoted for it.

He shouldn't be downvoted, I agree with you; his question was perfectly legit.

I suspect the downvotes might be because the question is effectively looking at a very small environmental footprint even in the worst case possible. I looked at the question that way, in fact.

Congrats to the people at Rocket Lab on another successful launch!

I'm so excited about these smaller and cheaper rockets making it practical to send much cheaper smaller payloads payloads into orbit.

Youtube launch stream: https://www.youtube.com/watch?v=sPwMuUxSrcA

The title of this post is deceptive; the actual title of the linked article is:

“Rocket Lab’s Modest Launch Is Giant Leap for Small Rocket Business”