How environmentally friendly is SpaceX's Starship?

[Admin]

SpaceX's Starship uses greener propellant than other rockets, but its environmental footprint could still be substantial if plans for hundreds of launches per year come to pass, experts warn.

How environmentally friendly is SpaceX's Starship? : Read more

 

[Mike from CT]

Does anyone really care about Starships environmental footprint? Im more interested in success and exploration, Starship is a game changer for space exploration.

Also curious why reusability isn’t discussed.

Overall a very poor article.

 

[24launch]

I was holding off on commenting.

Unfortunately Ms Pultarova has what appears to me to be an extreme dislike for Musk, SpaceX and Starlink based on her previous articles with similar critical viewpoints, especially of Starlink.

I have yet to see an article of hers with genuine concern about Amazon's planned constellation of thousands of satellites launched by initially all 100% throwaway rockets (hopefully eventually reusable with BO's New Glenn). Nor acknowledgement that Starlink, unlike Amazon, have been actively working with astronomers and the Int'l Dark Sky association to try to mitigate not only the reflectivity but the radio frequency impact of the Starlink satellites on astronomy. Amazon has thus far declined any such dialog.

And then there's China who are planning their own network of thousands of satellites.

I do agree there needs to be open dialog about such things, but pure opinion and hyperbole like, "environmentally conscious observers wondered whether the stainless-steel vehicle, perhaps containing hundreds of kilograms of residual fuel, could endanger marine life."

and even just subtitling the article as:

"Starship, because it's the biggest rocket ever built, is also one of the dirtiest."

really belong over on a doomsayer site like The Conversation and not here on a Space & Astronomy enthusiast site.

My US$0.02 for what it's worth.

 

[Unclear Engineer]

Seems like a lot of speculation on the potential for negative effects, without any speculation on the potential for positive effects. So, the article comes across as overtly biased.

For instance, the manufacture of reusable launch vehicles have a reduced carbon emission effect compared to throw-away vehicles. And refueling in space with affordable launches might be used to refuel and even update the satellites that the article decries for being deorbited and burning up in the upper atmosphere. And, about those particulates that will remain in the upper atmosphere "essentially forever", how does that compare to the proposals to intentionally put particulates into our upper atmosphere to cool the planet? Similarly, the water vapor that the article calls a "green house gas" may be a solid in the cold up there, providing reflective clouds that could also cool the Earth.

Those are speculations, too. But, why don't they get similar amounts of "ink" from this author?

 

[bleibold]

These environmental terrorists just won't give up.

 

[Cdr. Shepard]

Ms. Pultarova spends most of her time, writing not for LiveScience, Nature, Ars Technica, etc., but for SPACE.com, explaining why SpaceX shouldn't go into space, build things that might go into space, or, if already in space, reenter the atmosphere from it.

Does she have a counterproposal, other than Elon disbanding all of his ventures and retiring from the public eye?

The lecturing from certain overtly political and activist corners of journoworld (and from an incorrectly perceived position upon the moral high ground) is growing tiresome.

 

[JAS]

A few points for your consideration:
1) For those interested, Everyday Astronaut does a good more in-depth review of rocket pollution issues at the following link:

View: https://www.youtube.com/watch?v=C4VHfmiwuv4

2) I believe Musk plans to develop a non-fossil-fuel Methane source using the Sabatier Process for Star Ship. This would in essence make the fuel cycle a closed loop, sourcing CO2 from the atmosphere.
3) The dropping of metals into the ocean is just a short term effect with Star Ship development. Shortly, the prototypes will start making it home intact since the goal for Star Ship is 100% reuse.
4) While the number of satellites going to orbit is rising significantly, the size of them is dropping on average due to technology, and the fact that so many of them are being used in low (short duration) orbits.
5) The composition of satellites is changing also, with reductions in toxins, and with materials more compatible with safer destruction in the atmosphere. Lots of room for improvement still.
6) Satellites living in high orbits such as geo-stationary orbits are typically not brought down into the atmosphere, but instead are parked in a graveyard orbit. I imagine at a future date some smart cookie will build an orbital reclamation factory to reclaim all that valuable material sitting out there waiting to be 'picked up'.

 

[Helio]

Per the article...."According to Andrew Wilson, assistant professor in environmental management at Glasgow Caledonian University in Scotland, one Starship launch produces 76,000 metric tons of carbon dioxide equivalent (a measure combining different types of greenhouse gases in one unit). "

Is it possible that 4,600 metric tonnes of propellant can produce 76,000 metric tonnes of CO2? Call me dubious.

 

[Ken Fabian]

It will be important to continue to study and monitor atmospheric and ocean impacts of space launches, failures, returns, end of life burn up in atmosphere, especially if there are going to be a lot more of them.

Like every other industry rocket manufacturers/operators need to become zero emissions. Mostly it should come from a massive build of low/zero emissions energy, ie manufacturing and fuel production will draw on low emissions energy because that is what grids and energy supply companies are providing. I still expect industries doing things specifically based on combustion, like rocketry to face additional challenges but manufactured fuels made using electricity from a zero emissions grid seems reasonable, or possibly biofuels.

Being small isn't good enough reason to make an exception; every other "small" industry wants to be exempted too, lots of them, too many of them. But those too are going to reduce in emissions energy as more primary energy is low emissions.

Being important might exempt rocket launches if some overriding need can be demonstrated but I think ultimately should still be balanced with some kind of genuine negative emissions. Military need will rate important enough like it or not, but ISS, Moon and Mars aren't that kind of important. But there is no technical barrier to becoming a zero emissions industry.

 

[Unclear Engineer]

Is it possible that 4,600 metric tonnes of propellant can produce 76,000 metric tonnes of CO2? Call me dubious.

Helio, I am not going to try to verify or falsify the assertion. I am just offering a few relevant thoughts.

First, a ton of carbon composed of atoms with isotopic mass 12, each combined with 2 atoms of oxygen with atomic mass 16, means that ton of carbon makes (12 + 2 x 16)/12 = 3.7 tons of carbon dioxide.

Similarly, a ton of hydrogen oxidized to water produces ( 2 x 1 + 16)/ (2 x 1) = 9 tons of water, and the activists are probably including the water as a "greenhouse gas".

Finally, there is some methane leakage, and that is probably simply given a multiplier of 20 for its ratio of effects compared to carbon dioxide.

So, a ton of methane can make a lot of tons of "greenhouse gases". The ratio of "greenhouse gases" to fuel in the statement is 16.5. So that does seem like it might be a "stretch."

 

[Helio]

Interesting.

Lunar fuel production is looking a little better.

 

[Unclear Engineer]

Making rocket fuel on the Moon is another matter.

From what we know at the moment, there does not seem to be much carbon on the lunar surface. So, "rocket fuel" made there will probably be water that is separated into hydrogen and oxygen by something like electrolysis using solar energy as the power source. So, it would fuel rockets that use liquid hydrogen, such as the Centaur second stage currently used on the Atlas and Vulcan launch vehicles. (See https://en.wikipedia.org/wiki/Centaur_(rocket_stage) )

So, we have been using that technology since the 1960s, but, as Wikipedia says, liquid hydrogen "has significant handling difficulties." It needs to be a lot colder than liquid oxygen or liquid methane, and it has weird properties like climbing the sides of the tanks. It is also quite good at leaking through the tiniest openings, including pores in metallic walls.

The initial Centaur launches created some spectacular explosions during launches. And re-ignition of the engines did not always work, initially. So, making hydrogen propellant and using it on the Moon has some substantial risks.

But, "cold" on the Moon may be more easily done than here on Earth. And it is one of the most efficient rocket propellants. The exhaust gas is pure water, but being non-polluting probably has no value on the Moon.

So, if we really do find enough water on the Moon to expend it as rocket propellant, then our trips beyond will actually be done using solar energy, but first transformed into chemical energy.

 

[Questioner]

Envisioning atmospheric carbon skimmers so it can be exported to the moon.
Capture it then solar heat it in a transparent balloons might reduce the escape velocity...

Gotta feed a carbon hungry lunar economy.

Is there anyway of moving/lifting (ionized?) CO2 using a charged wire?

 

[Helio]

Making rocket fuel on the Moon is another matter.

From what we know at the moment, there does not seem to be much carbon on the lunar surface. So, "rocket fuel" made there will probably be water that is separated into hydrogen and oxygen by something like electrolysis using solar energy as the power source. So, it would fuel rockets that use liquid hydrogen, such as the Centaur second stage currently used on the Atlas and Vulcan launch vehicles. (See https://en.wikipedia.org/wiki/Centaur_(rocket_stage) )

Yes. There is likely a lot of ware ice on the Moon.

So, we have been using that technology since the 1960s, but, as Wikipedia says, liquid hydrogen "has significant handling difficulties." It needs to be a lot colder than liquid oxygen or liquid methane, and it has weird properties like climbing the sides of the tanks. It is also quite good at leaking through the tiniest openings, including pores in metallic walls.

Cold comes free there. Perhaps low gravity helps the fuel flow idiosyncrasies.

The initial Centaur launches created some spectacular explosions during launches. And re-ignition of the engines did not always work, initially. So, making hydrogen propellant and using it on the Moon has some substantial risks.

But, "cold" on the Moon may be more easily done than here on Earth. And it is one of the most efficient rocket propellants. The exhaust gas is pure water, but being non-polluting probably has no value on the Moon.

Perhaps a portion of the water exhaust could be captured.