Ares 1-X Launch (2009 Nov 2)

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Expand view Topic review: Ares 1-X Launch (2009 Nov 2)

Re: Ares 1-X Launch (2009 Nov 2)

by Star*Hopper » Wed Nov 04, 2009 11:15 pm

Chris Peterson wrote:
jerbil wrote:Do people still use ft-lbs on your side of the pond?
"...

But most Americans know that switching to proper units would just be a Commie plot to destroy the youth of our nation!"
I've been saying for 30-some years - we'll switch to your "proper units" just's soon as you get 'em standardized.

~*

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Wed Nov 04, 2009 5:32 pm

Chris Peterson wrote:
jerbil wrote:Do people still use ft-lbs on your side of the pond?
Sadly, some do. In the space program, it is part of our special patented system for crashing billion dollar probes into planets.
http://en.wikipedia.org/wiki/Mars_Climate_Orbiter

<<The Mars Climate Orbiter was intended to enter orbit at an altitude of 140.5–150 km (460,000-500,000 ft.) above Mars. However, a navigation error caused the spacecraft to reach as low as 57 km (190,000 ft.). The spacecraft was destroyed by atmospheric stresses and friction at this low altitude. The navigation error arose because a NASA subcontractor, Lockheed Martin, used imperial units (pound-seconds) instead of the metric system.>>
http://en.wikipedia.org/wiki/Gimli_Glider

<<On 23 July 1983, Air Canada Flight 143, a Boeing 767-200 jet, ran completely out of fuel at 41,000 feet (12,500 m) altitude, about halfway through its flight from Montreal to Edmonton via Ottawa. The crew was able to glide the aircraft safely to an emergency landing at Gimli Industrial Park Airport, a former airbase at Gimli, Manitoba. Fuel loading was miscalculated through misunderstanding of the recently adopted metric system which replaced the Imperial system.>>
Chris Peterson wrote:
The units used on the chart Neufer posted are almost nauseating. ft-lbs is bad enough, but slugs/ft^3 is really awful.
Image
Chris Peterson wrote:It would be nearly impossible to use this information constructively without doing a lot of conversions, which each one a chance for things to go wrong. But most Americans know that switching to proper units would just be a Commie plot to destroy the youth of our nation!
  • <<The grain (Symbol: gr) is equal to 0.06479891 grams (Symbol: g). Medical errors in the US are sometimes attributed to the confusion between grains and grams. A patient received phenobarbital 0.5 grams instead of 0.5 grains (0.03 grams) after the prescriber misread the prescription>>

Re: Ares 1-X Launch (2009 Nov 2)

by Chris Peterson » Wed Nov 04, 2009 4:52 pm

jerbil wrote:Do people still use ft-lbs on your side of the pond?
Sadly, some do. In the space program, it is part of our special patented system for crashing billion dollar probes into planets.

The units used on the chart Neufer posted are almost nauseating. ft-lbs is bad enough, but slugs/ft^3 is really awful. It would be nearly impossible to use this information constructively without doing a lot of conversions, which each one a chance for things to go wrong.

But most Americans know that switching to proper units would just be a Commie plot to destroy the youth of our nation!

Re: Ares 1-X Launch (2009 Nov 2)

by jerbil » Wed Nov 04, 2009 4:36 pm

Do people still use ft-lbs on your side of the pond?

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Wed Nov 04, 2009 1:51 pm

silent lurker wrote:Its my understanding that the image was taken as the vehicle reached "Max Q," the point of maximum aerodynamic pressure on the vehicle which, if I recall correctly, corresponds to it passing Mach 1 and going supersonic. Most of the time we see this supersonic shock condensation cone only on high performance jet aircraft breaking the sound barrier. Its less common to see it on a rocket.
No doubt this is a Mach ~0.85 transonic shock collar but it has little to do with "Max Q."
http://en.wikipedia.org/wiki/Prandtl%E2%80%93Glauert_singularity wrote:
The Prandtl–Glauert singularity or P.G. singularity is sometimes referred to as a vapor cone, shock collar, or shock egg. The point at which a sudden drop in air pressure occurs is generally accepted as the cause of the visible condensation cloud that often surrounds an aircraft traveling at transonic speeds, though there remains some debate. These condensation clouds, also known as "shock collars" or "shock eggs," are frequently seen during Space Shuttle launches around 25 to 33 seconds after launch when the vehicle is traveling at transonic speeds.
"Max Q" generally occurs when the vehicle is hypersonic but there is still significant air density
such that the dynamic pressure (density x velocity squared) is greatest.

The space shuttle breaks the sound barrier at an altitude of about 20,000 feet
but reaches "Max Q" only at about 35,000 feet at Mach 1.35.

Image

Re: Ares 1-X Launch (2009 Nov 2)

by silent lurker » Wed Nov 04, 2009 4:43 am

Its my understanding that the image was taken as the vehicle reached "Max Q," the point of maximum aerodynamic pressure on the vehicle which, if I recall correctly, corresponds to it passing Mach 1 and going supersonic. Most of the time we see this supersonic shock condensation cone only on high performance jet aircraft breaking the sound barrier. Its less common to see it on a rocket.

Re: Ares 1-X Launch (2009 Nov 2)

by geckzilla » Wed Nov 04, 2009 2:56 am

I'm glad you guys have practical applications for math.

Re: Ares 1-X Launch (2009 Nov 2)

by apodman » Tue Nov 03, 2009 10:10 pm

Accelerating on a level road perpendicular to the Earth's gravity, (not up into the yonder nor down into free fall), our friend Pythagoras would have to handle 1.06 g (1 g vertical and .35 g horizontal) to accelerate like the Ares or 1.18 g (1 g vertical and .63 g horizontal) to accelerate like the Shuttle.

Re: Ares 1-X Launch (2009 Nov 2)

by SkyGazerGPS » Tue Nov 03, 2009 9:48 pm

neufer,
Actually, in a 1st order approx, I only experience 0.35 g's since, Prius does 0-60 MPH in 8 secs (with 300 ft-lbs torque).
SkyGazerGPS

--------------------------------------------------------------------------------------
neufer wrote:
apodman wrote:
neufer wrote:0.63 g's : Shuttle
0.35 g's : Ares 1-X
Don't forget he has to handle 1.63 or 1.35 g's when you add 1 for gravity.
Not in a Prius.
http://www.youtube.com/watch?v=4z88U915uq8

Re: Ares 1-X Launch (2009 Nov 2)

by apodman » Tue Nov 03, 2009 9:05 pm

Yes, in free fall you may omit the gravity term. But I was thinking of the +y direction again. Keep looking up.

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Tue Nov 03, 2009 8:56 pm

apodman wrote:
neufer wrote:0.63 g's : Shuttle
0.35 g's : Ares 1-X
Don't forget he has to handle 1.63 or 1.35 g's when you add 1 for gravity.
Not in a Prius.
http://www.youtube.com/watch?v=4z88U915uq8

Re: Ares 1-X Launch (2009 Nov 2)

by apodman » Tue Nov 03, 2009 8:42 pm

neufer wrote:0.63 g's : Shuttle
0.35 g's : Ares 1-X
Don't forget he has to handle 1.63 or 1.35 g's when you add 1 for gravity.

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Tue Nov 03, 2009 7:46 pm

ovatlantis wrote:The thrust to weight ratio and thus acceleration of Ares 1-X is almost the same as the shuttle.
Using this chart I calculate that the initial accelerations are:

[list]0.63 g's : Shuttle
0.35 g's : Ares 1-X
[/list]
[Personally, I don't think that SkyGazerGPS could handle 0.63 g's. :wink: ]

Re: Ares 1-X Launch (2009 Nov 2)

by ovatlantis » Tue Nov 03, 2009 6:02 pm

The thrust to weight ratio and thus acceleration of Ares 1-X is almost the same as the shuttle.

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Tue Nov 03, 2009 5:43 pm

SkyGazerGPS wrote:Yesterdaze post about my Prius acceleration was tongue-in-cheek and referred to the words used in the description of the Ares 1-X launch:
The tremendous thrust of the Ares 1-X can bring the massive rocket from a standing start to a vertical speed of over 100 kilometers per hour in under eight seconds...

Clearly, 62 MPH was passed long before 8 seconds :D
100 kilometers per hour = 62 MPH

Re: Ares 1-X Launch (2009 Nov 2)

by SkyGazerGPS » Tue Nov 03, 2009 5:11 pm

Yesterdaze post about my Prius acceleration was tongue-in-cheek and referred to the words used in the description of the Ares 1-X launch:
The tremendous thrust of the Ares 1-X can bring the massive rocket from a standing start to a vertical speed of over 100 kilometers per hour in under eight seconds...
Clearly, 62 MPH was passed long before 8 seconds :D
-Rich

Re: Ares 1-X Launch (2009 Nov 2)

by Star*Hopper » Tue Nov 03, 2009 1:33 am

SkyGazerGPS wrote:My Prius can do 62MPH in under 8 seconds... granted, not vertically :D
SURE it will!! Vertical isn't a one-way street, y'know.
(Think Grand Canyon....& brake failure.)

:mrgreen:
~*

Re: Ares 1-X Launch (2009 Nov 2)

by DonAVP » Mon Nov 02, 2009 10:53 pm

I was at the cape last week and saw the launch. I was at Coco Beach about 20 miles south of the launch pad. It took close to 30 seconds for the sound to reach me. It was not loud like distant thunder. The rocket arched over quickly after launch. The sonic cloud in the photo was there less than a second. I think that is when the rocket hit mach one. That was about five or six second after the launch.

From want I understand this is the same solid rocket booster that are on the shuttle. The next stage (which did not fire) is a liquid rocket and above that is a capsule for manned flight only bigger than the Apollo. Very exiting to see a launch. :D

Re: Ares 1-X Launch (2009 Nov 2)

by tblaxland » Mon Nov 02, 2009 10:30 pm

I also have a nitpick with the caption:
Pictured above, the Ares 1-X blasts into space...
Ares I-X did not get to space (nor was it planned to). The apogee was only approx 46 km and the most common definition of the boundary of space is 100 km.

Re: Ares 1-X Launch (2009 Nov 2)

by apodman » Mon Nov 02, 2009 9:37 pm

SkyGazerGPS wrote:My Prius can do 62MPH in under 8 seconds... granted, not vertically :D
You might be edged out in the payload specs as well. And I'll bet the Ares would accelerate faster without a full tank.

Re: Ares 1-X Launch (2009 Nov 2)

by SkyGazerGPS » Mon Nov 02, 2009 9:33 pm

My Prius can do 62MPH in under 8 seconds... granted, not vertically :D

Re: Ares 1-X Launch (2009 Nov 2)

by neufer » Mon Nov 02, 2009 8:57 pm

iamlucky13 wrote:
ovatlantis wrote:The caption is correct. Launch Pads 39A and B are the only ones at the Kennedy Space Center. Unmanned rocket launches take place from neighboring Cape Canaveral Air Force Station.
Precisely. Atlas V, Delta IV and Delta II, and previously Titan IV all fly from the Air Force Station.
http://en.wikipedia.org/wiki/File:Cape_ ... ad_39B.jpg
Image

Re: Ares 1-X Launch (2009 Nov 2)

by Chris Peterson » Mon Nov 02, 2009 7:23 pm

ovatlantis wrote:The caption is correct. Launch Pads 39A and B are the only ones at the Kennedy Space Center. Unmanned rocket launches take place from neighboring Cape Canaveral Air Force Station.
Thanks. I do vaguely recall that distinction. I've been to KSC for unmanned launches, and the difference is not obvious, since you normally enter via KSC and there is no obvious transition to the Air Force Station when you travel to different launch pads.

Re: Ares 1-X Launch (2009 Nov 2)

by iamlucky13 » Mon Nov 02, 2009 7:15 pm

ovatlantis wrote:The caption is correct. Launch Pads 39A and B are the only ones at the Kennedy Space Center. Unmanned rocket launches take place from neighboring Cape Canaveral Air Force Station.
Precisely. Atlas V, Delta IV and Delta II, and previously Titan IV all fly from the Air Force Station.

I've got to say, that is one of the neatest vapor cones I've ever seen.

Re: Ares 1-X Launch (2009 Nov 2)

by ovatlantis » Mon Nov 02, 2009 6:45 pm

The caption is correct. Launch Pads 39A and B are the only ones at the Kennedy Space Center. Unmanned rocket launches take place from neighboring Cape Canaveral Air Force Station.

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