Comment by slg | Hacker News Reader

Comment by slg | Hacker News Reader

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I just can't imagine them needing this type of vehicle anytime soon. The first car on the moon was unpressurized because the only real benefit to pressurizing the vehicle is if the astronauts don't need to be wearing pressurized suits inside. That would either mean that there are car sized airlocks to travel between or that the astronauts will be traveling long enough distances in the car that it provides a real comfort benefit for them to take off some of their suits. Neither of those is likely to happen on the first trips to Mars.

Even then, this truck doesn't appear particularly light compared to your average vehicle. It also has a ton of added weight from things that would be wasted on Mars like huge acceleration, unnecessary top speed, and the ability to withstand vehicular accidents that would never occur on Mars. Maybe Tesla tries to preserve the look of this car for whatever they may or may not eventually put on Mars, but I doubt it is going to be close to being this car.

Why would a car-size airlock be required? A simple airtight hatch for the car to dock to (similar to a suitport) would work fine.

The first car on the moon was unpressurized because the program was a once-cancelled afterthought designed to fit into a spare cargo bay and unfold, with tight mass constraints. MOLAB was impractical because of the upmass required, not because pressurization wouldn't have been useful.

>Why would a car-size airlock be required? A simple airtight hatch for the car to dock to (similar to a suitport) would work fine.

Fair point. I don't see how that would work on this specific vehicle, but it is certainly works in general.

>The first car on the moon was unpressurized because the program was a once-cancelled afterthought designed to fit into a spare cargo bay and unfold, with tight mass constraints. MOLAB was impractical because of the upmass required, not because pressurization wouldn't have been useful.

A lot of those requirements still stand regarding mass. It isn't a question of whether a pressurized vehicle would be useful on Mars, it is a question of whether its usefulness is enough to justify its weight and this vehicle appears to have a lot of extra weight that would need justification.

This vehicle is probably pretty light if you source the steel and the battery pack from a starship that has landed on mars. Starships have both. The plan isn't to return all of the initial starships because the steel is more useful on mars, and the energy to return them back would be really expensive.

>Neither of those is likely to happen on the first trips to Mars.

It doesn't have to happen on the first trip. They could send the truck to Mars on one of the current rockets and just have it sit there until they're ready to use it. It's an electric vehicle. There's plenty of solar exposure on Mars, they can charge it over the course of weeks if they needed to, even though they don't, and the durability would guarantee that it could serve up there for years. It could literally just sit there and do nothing for the 3-5 years it takes them to build out a basic hab and a dock for it.

If we are ruling it out on the first few trips, then we are probably ruling it out for at least a decade or probably longer. I would bet the Earth version of this truck isn't going to go a decade plus without being redesigned by Tesla.

All your points about the benefits of an electric vehicle apply just as well to something lighter that is specifically and only designed for travel to and on Mars.

What? What makes you say that? SpaceX literally shot Elon Musk's car into space to do nothing but float towards Mars. The entire point is prove that their rockets can shoot something that weighs a metric ton out to Mars safely. They don't want to send something lighter that's only designed for travel to and on Mars. They want to send something from Earth to Mars that proves they can send out the materials and supplies to colonize the planet quickly.

The first two trips are nearly half a decade apart...

Most of the mass that goes with that acceleration is the battery, which also extends the range, and that you do need because superchargers are scarce on Mars. It's also nice to have a rugged vehicle when you don't have body shops.

In general, Musk treats engineering as a scarce resource. If he can use a Tesla vehicle instead of designing a special rover, he will, even if it weighs a little more. Starship can handle more than 100 tons of payload and its successor will do four times that.

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