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The proportions remind me of another somewhat common space-related misconception, which is that rocket launches are big polluters. With each launch emitting ro

The proportions remind me of another somewhat common space-related misconception, which is that rocket launches are big polluters. With each launch emitting roughly as much as a single commercial flight and typically around 100 launches happening globally per year, even a tiny change in the tens of millions of commercial flights per year has a far larger impact on emissions than launches will for the foreseeable future.

TeMPOraL 6y ago
> With each launch emitting roughly as much as a single commercial flight It's one of those "connective" facts that puts so many distinct things into perspective. When I first learned it a few years ago, I became simultaneously very relieved that a rocket launch doesn't really have that big of a carbon footprint, and horrified by how much emissions a single passenger plane can make. It's a lesson about how visuals can be misleading: a plane looks tiny and doesn't really seem to be doing anything, while a rocket is big and rises to heavens on a pillar of flame, propelled by the anger of hell itself - and yet it turns out they're roughly the same, emissions-wise.
gus_massa 6y ago
An easy way to compare the amount of CO2 they release is looking at the size. They only can burn the fuel they carry, and the density of the fuel is similar. The best images I got are https://twitter.com/rocketrundown/status/956079854511972352 https://twitter.com/rocketrundown/status/956079854511972352 https://twitter.com/erdayastronaut/status/1239595527114838018 https://twitter.com/erdayastronaut/status/123959552711483801... To make the calculation more difficult, like the 80% of the volume of a Boeing 747 is room for humans, and like 50% of the volume of a Falcon 9 is room for Oxygen and thrusters.
magicalhippo 6y ago
Some rockets use toxic fuel though, so it's not entirely apples to apples.
- KMag 6y ago
  Some of the propellants (especially the hypergolics) are pretty toxic. However, Soyuz, Long March 5 (and later), Falcon 9, and Delta III (first stage) all use high-grade kerosene (RP-1 or its Russian equivalent) and liquid oxygen. Jet-A isn't too far from high-grade kerosene. Ariane 5 uses liquid hydrogen and liquid oxygen in its first stage. Many of the smaller players use RP-1/LOX, and some of the next-generation rockets will use methane/LOX propellants. Though, the Delta III and Ariane 5 boosters do contain ammonium perchlorate, which is worse for the environment than jet fuel.

TeMPOraL 6y ago

> With each launch emitting roughly as much as a single commercial flight It's one of those "connective" facts that puts so many distinct things into perspective. When I first learned it a few years ago, I became simultaneously very relieved that a rocket launch doesn't really have that big of a carbon footprint, and horrified by how much emissions a single passenger plane can make. It's a lesson about how visuals can be misleading: a plane looks tiny and doesn't really seem to be doing anything, while a rocket is big and rises to heavens on a pillar of flame, propelled by the anger of hell itself - and yet it turns out they're roughly the same, emissions-wise.

gus_massa 6y ago

An easy way to compare the amount of CO2 they release is looking at the size. They only can burn the fuel they carry, and the density of the fuel is similar. The best images I got are https://twitter.com/rocketrundown/status/956079854511972352 https://twitter.com/rocketrundown/status/956079854511972352 https://twitter.com/erdayastronaut/status/1239595527114838018 https://twitter.com/erdayastronaut/status/123959552711483801... To make the calculation more difficult, like the 80% of the volume of a Boeing 747 is room for humans, and like 50% of the volume of a Falcon 9 is room for Oxygen and thrusters.

magicalhippo 6y ago

Some rockets use toxic fuel though, so it's not entirely apples to apples.

KMag 6y ago
Some of the propellants (especially the hypergolics) are pretty toxic. However, Soyuz, Long March 5 (and later), Falcon 9, and Delta III (first stage) all use high-grade kerosene (RP-1 or its Russian equivalent) and liquid oxygen. Jet-A isn't too far from high-grade kerosene. Ariane 5 uses liquid hydrogen and liquid oxygen in its first stage. Many of the smaller players use RP-1/LOX, and some of the next-generation rockets will use methane/LOX propellants. Though, the Delta III and Ariane 5 boosters do contain ammonium perchlorate, which is worse for the environment than jet fuel.