I don’t know if man went to the moon in the sixties

[Glom]

Re "crazy 8", I had assumed he was referring to some kind of aerobatic maneuver. Can't think which one even though I've done a bit of the sport. I do knoc Cuban 8 though.

[Count Zero]

The first probe to hit the Moon (Luna 2, on September 13th, 1959) took an even straighter trajectory and hit the moon just 33.5 hours (less than a day and a half) after launch.

[raven]

Has DAKDAK even replied once beyond the first post?

[Bob B.]

Has DAKDAK even replied once beyond the first post?

Yes... Post #3, 25 minutes after his first post.

[raven]

Ah, my mistake.

[Echnaton]

Still the odds of DAKDAK being a seagull poster are getting shorter every minute.

[BazBear]

Still the odds of DAKDAK being a seagull poster are getting shorter every minute.

I think you're probably right. I have wonder how many seagulls even bother to come back and read the responses to their posts.

[ka9q]

The first probe to hit the Moon (Luna 2, on September 13th, 1959) took an even straighter trajectory and hit the moon just 33.5 hours (less than a day and a half) after launch.

This is fine when you only intend to hit the moon. It's possible to get there even faster; the fastest launch ever conducted, the New Horizons probe to Pluto, crossed the moon's orbit only 10 hours after launch.

But if you want to soft land or decelerate into orbit around the moon, you have to use a less energetic (and more time-consuming) orbit or you'll have a lot of excess velocity to get rid of with your lunar landing or orbit insertion burn.

Apollo's lunar trajectory, besides being designed to provide a free return, was a compromise between the propellant required both for TLI and LOI and the consumables required to sustain the crew in the meantime. You can get there faster (and save consumables) by spending more propellant. Or you can save propellant by taking longer (and using more consumables) but only to a point; if you take too long, you'll never reach the moon at all, but fall back to earth before reaching it.

It's a common misconception that TLI injected Apollo into an earth escape trajectory. It actually went into a highly elliptical earth orbit with an eccentricity of about 0.97. (Escape would be 1.0 or more.) It had its apogee beyond (but not too far beyond) the moon's orbit, meaning it couldn't have taken too much longer than it did or it never would have gotten there at all.

[ka9q]

Re "crazy 8", I had assumed he was referring to some kind of aerobatic maneuver. Can't think which one even though I've done a bit of the sport. I do knoc Cuban 8 though.

Look at the Apollo 8 mission patch; it showed the Earth-Moon-Earth trajectory pretty well.

[Bob B.]

Apollo's lunar trajectory, besides being designed to provide a free return, was a compromise between the propellant required both for TLI and LOI and the consumables required to sustain the crew in the meantime. You can get there faster (and save consumables) by spending more propellant. Or you can save propellant by taking longer (and using more consumables)

Of particular note is the fact that Apollo used fuel cells for electrical power.  Since fuel cells consume reactant (oxygen and hydrogen), they are only practical for short duration missions, otherwise the mass of the reactant required to keep them running the whole time becomes prohibitive.  Long duration missions use solar cells, where sunlight is abundant, or RTGs (radioisotope thermoelectric generators).  The mass of solar cells and RTGs are fixed regardless of the mission duration.

edit spelling

[gwiz]

I've been inside one Apollo CM post-flight, and several Apollo CM boilerplates.  I don't really find them as cramped as they're made out to be by conspiracy theorists.  I'd gladly agree to spend 10 days in one in return for the chance to fly in space and explore another world.

I can confirm this.  I've been in ground training articles for Mercury, Gemini and Apollo.  Gemini was the most cramped, about the same as the front seats of a car, but the Gemini 7 crew managed to put up with it for 14 days.  Apollo was very roomy, you could get out of your seat and move around, which was impossible for Mercury and Gemini.

[raven]

I've been inside one Apollo CM post-flight, and several Apollo CM boilerplates.  I don't really find them as cramped as they're made out to be by conspiracy theorists.  I'd gladly agree to spend 10 days in one in return for the chance to fly in space and explore another world.

I can confirm this.  I've been in ground training articles for Mercury, Gemini and Apollo.  Gemini was the most cramped, about the same as the front seats of a car, but the Gemini 7 crew managed to put up with it for 14 days.  Apollo was very roomy, you could get out of your seat and move around, which was impossible for Mercury and Gemini.

On Gemini 7, Borman got out of his spacesuit. Even in free-fall that's quite a feat for such cramped quarters.
All the extra room of Apollo came at a price, however, with the first cases of space adaptation sickness.

[ApolloGnomon]

Ya know why my post count around here is still in the single digits?

People like DAKDAK. I get really tired of people wandering into various fora and boldly stating wrong things.

[ka9q]

Apollo was very roomy, you could get out of your seat and move around, which was impossible for Mercury and Gemini.

Especially in 0-g; practically every astronaut commented on how much roomier the thing became in space. It was common for one of the astronauts to sleep floating up in the tunnel.

[ka9q]

Of particular note is the fact that Apollo used fuel cells for electrical power.

Yeah, but fuel cells still have a higher mass energy density than batteries. That's why they were used despite their enormously greater complexity and hassles. A few offhand: they operated at hundreds of degrees C with a corrosive KOH electrolyte; they had a fairly tight operating power range: a minimum needed to keep the electrolyte molten as well as a maximum that wasn't enough for peak demands; they were very easily damaged; they required constant monitoring and frequent maintenance, such as purging trace inert gases from the reactant supply; they required a hydrogen supply and a small nitrogen supply as well as the supply of oxygen that would be needed in any event for breathing.

On the other hand, fuel cells produced drinking water that would have to be carried anyway. On the other other hand, they produced so much water that the excess had to be dumped.

I've always thought it interesting that Soyuz has long used a solar panel while the US never seems to use solar power for manned missions except for space stations like Skylab and the ISS. Did the Russians never develop fuel cells? They were a major pacing technology item for NASA in the 60s.