Falcon Heavy (RLV) Test Flight

[Full Otto]

I just caught a NOVA episode a few days ago about Hubble
I enjoyed it
http://www.pbs.org/wgbh/nova/space/i...-universe.html

They mentioned toward the end that a new one is in the works that is going to be placed out past Mars I believe

[Krupski]

My father was project manager for the Hubble at Perkin Elmer. Every part that they built that was installed into the main optical assembly had to be tested by his procedures and if passed, installed and tested again as an assembly. The only part of that telescope that was not tested per his procedures was the main mirror. It was NASA that told him not to test it, they were over budget and weeks behind so the money and time saved was more important.

The real reason that the mirror was ground slightly off spec was a fleck of paint came off one of the screw heads that held the measuring device in place. The mirror was ground in a light tight chamber based on light being bounced off it's surface and the reflection time determining the shape. With the exposed screw, the light bounced off the mirror, then off the exposed screw and back onto the mirror and into the measuring device. This added light bounce threw the measure off very slightly, but with the size of the mirror and the size of the telescope it made for a slightly out of focus picture.

The person in charge of the mirror grinding found the exposed screw head, repainted it and told nobody. If he had said something, of if NASA had let my father test the mirror we wouldn't have needed COSTAR.

This is very possibly the first time the truth has been published. My father was sworn to secrecy, and when the Senate held their hearings, his security clearance was raised high enough that congress could not call him and hence NASA kept it quiet that they were the primary reason that a flaw was introduced into an otherwise amazing piece of equipment. As my father is no longer on this earth, I feel it is ok to spill it.

Again, this is first hand information as it was my father who helped build the Hubble and not something I heard or read on the internet.

Wasn't that during Administrator Bolden's "Better-Faster-Cheaper" era?

[Krupski]

I just caught a NOVA episode a few days ago about Hubble
I enjoyed it
http://www.pbs.org/wgbh/nova/space/i...-universe.html

They mentioned toward the end that a new one is in the works that is going to be placed out past Mars I believe

There is the James Webb Telescope (named after the second NASA administrator (served from 1961 to 1968)).

The telescope, when launched, will be placed at a point called "L2" (LaGrange point 2) which is one of several LaGrange locations around earth where the gravity of the earth and sun cancel out and create true zero-G spots where a satellite can orbit the point in a stable manner without using any propellant.

The SOHO (Solar and Heliospheric Observatory) sits at L1 which is between the earth and the sun. The L2 point sits BEHIND the earth. Therefore, the James Webb telescope uses the earth as a huge, permanent sun shield.

LaGrange Points



If all works well, the JWST will be able to see about twice the distance of Hubble, and in more wavelengths.

The primary mirror consists of many individual hexagons made of beryllium (a very light and strong metal) plated in gold (to efficiently reflect infrared radiation to the detectors). The segments are connected to actuators and can be individually focused under computer or manual control. The mirror is 6.5 meters in diameter (21.5 feet) compared with Hubble's 2.4 meters (8 feet).

I think someday NASA should place a HUGE telescope on the moon. Stable platform, no distorting air, constantly rotates giving a 360 degree view of the universe. Only problem would be protecting it from the monthly day and night temperature swings of +250 degrees F to -250 degrees F!

[Krupski]

Screw rockets, build the space elevator

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

Here's a puzzle for everyone:

We all know that several hundred miles above the earth's surface the air pressure is virtually zero (a "vacuum") and would suck any air out of an open container.

So, imagine a hypothetical 100 mile long "pipe", one end on the earth's surface and the other end 100 miles up in "space".

Would the low pressure - virtually a vacuum - suck air up into the pipe and eventually make the entire earth a vacuum?

Please explain your answer.

[imanaknut]

Here's a puzzle for everyone:

We all know that several hundred miles above the earth's surface the air pressure is virtually zero (a "vacuum") and would suck any air out of an open container.

So, imagine a hypothetical 100 mile long "pipe", one end on the earth's surface and the other end 100 miles up in "space".

Would the low pressure - virtually a vacuum - suck air up into the pipe and eventually make the entire earth a vacuum?

Please explain your answer.

Thanks for a great laugh!!! Never thought of the imaginary elevator that way, and a good way to think about it. Very interesting.

[JTHunter]

Here's a puzzle for everyone:

We all know that several hundred miles above the earth's surface the air pressure is virtually zero (a "vacuum") and would suck any air out of an open container.

So, imagine a hypothetical 100 mile long "pipe", one end on the earth's surface and the other end 100 miles up in "space".

Would the low pressure - virtually a vacuum - suck air up into the pipe and eventually make the entire earth a vacuum?

Please explain your answer.

Sorry Krupski but that won't work. The reason there is a "vacuum" in space is because of gravity. Gravity causes matter to coalesce and "atmosphere" is matter - just very light matter. The "gravity well" formed by any planet, in this case Earth, would pull matter towards its bottom. The only way a space elevator could use air pressure to get its payload to space is to pump it in under extremely high pressure at the bottom and force the capsule upwards.
Unfortunately, there probably isn't anything available at this time strong enough to hold that high a pressure that can overcome gravity.

[Full Otto]

I've been working on an idea for a while now



So far the only payoff was reimbursement to my neighbors livestock

[Krupski]

Thanks for a great laugh!!! Never thought of the imaginary elevator that way, and a good way to think about it. Very interesting.

Sorry Krupski but that won't work. The reason there is a "vacuum" in space is because of gravity. Gravity causes matter to coalesce and "atmosphere" is matter - just very light matter. The "gravity well" formed by any planet, in this case Earth, would pull matter towards its bottom. The only way a space elevator could use air pressure to get its payload to space is to pump it in under extremely high pressure at the bottom and force the capsule upwards.
Unfortunately, there probably isn't anything available at this time strong enough to hold that high a pressure that can overcome gravity.

I guess you both missed the point. The "trick" question (which, believe me, DOES stump a lot of people) had to do with whether or not the low pressure at altitude would suck air up from the bottom of the pipe. It wasn't a "space elevator" question.

Anyway, the answer is that nothing would happen because the mass of the air inside the pipe would hold it in place same as the air outside the pipe.

Kinda like putting a straw into a glass of water. Nothing would happen.

[Krupski]

I've been working on an idea for a while now



So far the only payoff was reimbursement to my neighbors livestock

Cool! Made it to orbit yet?

[l921428x]

I guess you both missed the point. The "trick" question (which, believe me, DOES stump a lot of people) had to do with whether or not the low pressure at altitude would suck air up from the bottom of the pipe. It wasn't a "space elevator" question.

Anyway, the answer is that nothing would happen because the mass of the air inside the pipe would hold it in place same as the air outside the pipe.

Kinda like putting a straw into a glass of water. Nothing would happen.

I might be off here but ain't that called gravity?