Hacker News Reader

Comment by jackcviers3 | Hacker News Reader

I totally disagree. Ro optic probes are awesome, but their range of activity is extremely limited. They can stay on mission for years at a time in that limited area, but the ground you can cover with several manned missions is currently greater.

We've proven that we can keep humans alive indefinitely in space with the International Space Station. Expanding that practice beyond Earth's orbit can and will go a long way in advancing our understanding of our solar neighborhood.

The initial human explorations of the planets will be more limited than the rover projects. But I think we are getting very close to being able to mount much more significant investigations of our closest neighbors. We just need to choose to go.

View on HN

The ISS is heavily dependent on regular resupply from Earth, is teleoperated from Earth, and depends on large Earth laboratories to analyze air and water samples. We can keep humans alive "indefinitely" there in the same way we could keep people alive indefinitely on the ocean floor; it's an expensive stunt entirely reliant on support operations from the surface that does nothing to advance our ability to explore.

The ISS is way more limited in what it can do because it exists in a vacuum, which inherently limits the size it can reasonably have, and there's zero gravity. The moon has a bit more gravity, but zero atmosphere.

In contrast, there's enough atmosphere available on Mars to make it possible to build larger, pressurized structures and even use aerial flight, and more gravity than on the Moon.

The ISS design is ultimately constrained by cost and fairing size (how big a thing you can fit on your rocket), limits that are far more stringent for the surface of Mars (where the limiting size is set by the descent stage). The fact that it's in vacuum doesn't affect its size at all.

The average surface pressure on Mars is a few millibars; from an engineering perspective it's the same as building pressurized structures in vacuum. If anything, it's more difficult, since your design will have to deal with wind loads and airborne dust.

Bootstrapping scientific facilities in a planet with an unbreathable atmosphere which can only be effectively transversed to and from every 18 months is not an easy thing.

Not to mention the phenomenal effort required to grow food there or transport who knows how much food per person to provide the kinds of safety margins you would want to avoid your first Mars astronauts starving.

An amusing and underappreciated technical obstacle to Mars trips is that food you can subsist on long-term with that kind of unrefrigerated shelf life doesn't exist, even on Earth.

BTW the Earth/Mars synodic period is not 18 months, but 26 months.

How did Reid Stowe manage? He surely could not have relied on frozen food, too much risk of a generator failing.

"In 2010 Stowe completed a more extensive ocean voyage, entitled 1000 Days at Sea: The Mars Ocean Odyssey—a journey that commenced on April 21, 2007, from the 12th St. Pier, Hoboken, New Jersey.[1] Stowe was the principal designer and builder of the Anne, a 70 ft (21.3 m), 60-ton (54,400 kg) gaff-rigged schooner which he sailed on this voyage.[1][2] The purpose of the enterprise was to remain on the open ocean, without resupply or pulling into any harbor, for a period of one thousand days, "

https://en.wikipedia.org/wiki/Reid_Stowe

According to this link, he and his passenger cooked their own food: rice and beans, pasta, salt fish, and dried fruits, with sprouts for vitamins [http://www.marinebuzz.com/2008/02/23/soanya-ahmad-abandons-1...].

The food shelf-life problem is solved if you can rehydrate and cook foods, like this crew did. But a spacecraft has the cooking facilities of an office breakroom — just a microwave and source of hot water. And in that situation, where you need precooked heat-in-bag foods that stay shelf-stable for three years without refrigeration, we don't yet have the technology.

Why can't you include dried pulses and dehydrated other foods? All of those can be cooked in a microwave? Dried pulses are edible for a very long time.

> In contrast, there's enough atmosphere available on Mars to make it possible to build larger, pressurized structures and even use aerial flight, and more gravity than on the Moon.

True, though the atmosphere there brings challenges of its own:

“Every year there are some moderately big dust storms that pop up on Mars and they cover continent-sized areas and last for weeks at a time,” said Michael Smith, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

https://www.nasa.gov/solar-system/the-fact-and-fiction-of-ma...

> In contrast, there's enough atmosphere available on Mars

The martian atmosphere has less than 1% the pressure of Earths: https://en.wikipedia.org/wiki/Atmosphere_of_Mars

So for the purposes of building habitats, it might as well have none.

> and even use aerial flight

Yes, if we are talking about very small, very light robotic probes, that can rotate their blades 10 times faster than what's required on earth.

https://en.wikipedia.org/wiki/Ingenuity_(helicopter)#Mechani...

> but their range of activity is extremely limited.

Not when I compare it with the range of activities a human can do on Mars.

> but the ground you can cover with several manned missions is currently greater.

Wouldn't we able be to build much better robots which would probably be more effective than humans for the same cost it would take to send a manned mission to Mars?

Reply on news.ycombinator.com