NASA needs to refocus its priorities

[Dis]

I'm in the mood to post pictures

ion engine. Great stuff.

http://www.jpl.nasa.gov/technology/features/ion.html

caption:

This image of a xenon ion engine, photographed through a port of
the vacuum chamber where it was being tested at NASA's Jet
Propulsion Laboratory, shows the faint blue glow of charged atoms
being emitted from the engine.

The ion propulsion engine is the first non-chemical propulsion to
be used as the primary means of propelling a spacecraft. The
first flight in NASA's New Millennium Program, Deep Space 1 is
designed to validate 12 new technologies for scientific space
missions of the next century. Another onboard experiment includes
software that tracks celestial bodies so the spacecraft can make
its own navigation decisions without the intervention of ground
controllers. Deep Space 1 will complete most of its mission
objectives within the first two months, but may also do a flyby
of a near-Earth asteroid, 1992 KD, in July 1999. Deep Space 1
will be launched aboard a Boeing Delta 7326 rocket from Launch
Pad 17A, Cape Canaveral Air Station, in October. Delta II rockets
are medium capacity expendable launch vehicles derived from the
Delta family of rockets built and launched since 1960. Since then
there have been more than 245 Delta launches.

[Dis]

more stuff on scramjets.

http://news.bbc.co.uk/1/hi/sci/tech/1528849.stm

Doh!

I found out why I haven't heard much about this. copied:

NASA's fastest jet blew up in its maiden flight. Now, scientists say they know what happened and are ready to try again.

In its maiden test flight last June, a hypersonic plane developed by NASA veered off course and was destroyed. Despite the failure, the agency is now trying to breathe new life into its tests of the craft’s novel jet engine, called a scramjet. NASA expects that future versions of the engine will serve as a low-cost way to get payloads into orbit by lifting space cargoes to nearly stratospheric altitudes before they continue their journeys on rocket power.

[CICSMaster]

Originally posted by Dissident
The engine technology must be developed and tested.

Check out ion engines. They are pretty cool. But we have never actually used one on a large scale ship.

I don't support a manned mission yet. Too dangerous. And there has been talk about psychological effects of such a long mission in cramped quarters. They may go stir crazy.

If you think ION engines are cool, check out VASIMR engines (I hope I spelt that correctly).

[Velociryx]

I disagree that robotic probes are the way to go.

If the central questions are these:

* What effects does long term exposure to the cramped quarters of the ship have on humans

and

* can we build something that will enable humans to make the trip

How will we answer these questions via robots??

-=Vel=-

[Arrian]

The main problems with a manned flight to Mars:

1) The deterioriation of the human body in Zero-G. Muscle atrophy, loss of bone mass, circulatory problems... it's a long and troublesome list. We have not figured out artificial gravity (there are problems with the centrifugal force approach).

2) Radiation. Specifically, Solar Flares. Once they're outside the Earth's magnetic field, the crew would be subjected to the full blast of solar radiation. A medium-large solar flare would probably kill them. NASA is working on the problem, but right now there isn't a solution that I know of. Proper shielding is probably either too heavy (lead) or future technology.

3) Getting enough supplies to/from Mars for the crew to survive and explore. This is a more mundane problem, but still a big one.

Anyway, a manned mission to mars requires a lot more work - and the ISS is the ideal place to test solutions to problem #1. Problem #2... not sure, probably unmanned probes would be best to test solutions for that. #3 is about designing a real spaceship & cramming as much stuff as we can into it.

At the same time, unmanned probes are more cost-effective and thus shouldn't be ignored. Deep Space 1, for instance, is the probe that tested the ion drive pictured above, and that is probably a good choice of propulsion for a Mars mission.

-Arrian

[Dauphin]

Originally posted by Arrian
The main problems with a manned flight to Mars:

1) The deterioriation of the human body in Zero-G. Muscle atrophy, loss of bone mass, circulatory problems... it's a long and troublesome list. We have not figured out artificial gravity (there are problems with the centrifugal force approach).

Which problems with centripetal force are you refering to? Motion sickness?

Two tethered modules spinning at a relatively low speed (~1-2rpm) is not that difficult. The variability in the rate of rotation (by changing the length of the tether also allows acclimatisation between different G forces.

[Arrian]

BC (Sag Dolphin?),

Yeah, motion sickness. I'm no expert, but as I understand it, in order to cut down on that or eliminate it, you would need to increase the length of the tether. That makes for a bigger spacecraft. And doesn't it need to be a little more solid than a tether (when I think tether, I think of a line of rope or something) like a tunnel big enough to get back and forth between the modules? How big would you have to make it in order to generate an acceptable G force (close to 1g) without motion sickness?

-Arrian

[Poppa Bear]

MEN!!!!

The technology that the shuttle uses is definitely outdated and new propulsion systems need to be developed. However I believe that manned exploration is the way to go. Robots are cheaper and safer but a robot will never make the discoveries that a human will.

The only thing that it will take to get humans to the planets is the will and despite the danger I am sure that there are at least thousands who would line up to go.

[Velociryx]

Unmanned missions to probe in advance of human landings definitely have their value, but to answer some of the most vexing questions (how to combat long term-zero-g effects on the human body, etc)....the only way to get valid answer to that stuff is to send 'em up!

Risky? You bet.

But I'll wager that we'll never have a shortage of volunteers....

-=Vel=-

[Dauphin]

Originally posted by Arrian
BC (Sag Dolphin?),

Yeah, motion sickness. I'm no expert, but as I understand it, in order to cut down on that or eliminate it, you would need to increase the length of the tether. That makes for a bigger spacecraft. And doesn't it need to be a little more solid than a tether (when I think tether, I think of a line of rope or something) like a tunnel big enough to get back and forth between the modules? How big would you have to make it in order to generate an acceptable G force (close to 1g) without motion sickness?

-Arrian

From memory, the tether would have to be ~250m long. If all non-essential travel items are kept in the second counterweight module then there is no need to travel between the two during flight. What you keep there could be supplies or equipment exclusively for use at the Mars end.

The tether merely needs to be an extremely stretch resistant and lightweight material.

[Lemmy]

No to manned exploration, the cost to send people out to Mars just isn't worth it. Not now, not while so many things are still uncertain, for example, is it absolutely sure that there is water there to sustain people?
Imagine going there, and then find out that there isn't enough, or no water at all to stay alive.

Manned space flight was possible when going to moon, but farther places will need extensive scouting by robots, before you can risk the resources to send humans there.

[Dis]

and we might not find much more on mars than we did with the moon.

[Lemmy]

From memory, the tether would have to be ~250m long. If all non-essential travel items are kept in the second counterweight module then there is no need to travel between the two during flight. What you keep there could be supplies or equipment exclusively for use at the Mars end.

The tether merely needs to be an extremely stretch resistant and lightweight material.

Travelling would still be possible with 2 smaller modules, that can move along the tether, and act as counterweight for each other, sort of like an elevator.

[Arrian]

BC,

Ok, so I guess the gravity problem could be worked out in the near future, provided there was adequate funding. But what about the radiation issue?

I'm not against a manned flight to Mars. Not at all. I'm just saying that the current manned missions, though they may seem unspectacular... mundane, even, have their purposes.

-Arrian

[Dauphin]

Originally posted by Arrian
Ok, so I guess the gravity problem could be worked out in the near future, provided there was adequate funding. But what about the radiation issue?

I'm not against a manned flight to Mars. Not at all. I'm just saying that the current manned missions, though they may seem unspectacular... mundane, even, have their purposes.

Radiation is the serious problem, and the major one preventing a mission. Last I read, even with the maximum amount of radiation protection, all the astronauts who would travel on a Mars mission would probably die of cancer in the short to medium term.

I see no way around this problem. Radiation sheilding, such as lead, just isn't enough - its too heavy to make a mission possible.

Deflectors, now they may work.... Magnets! We could use magnets!^TM.

Edit - Damn my inability to correct grammar at the first attempt.