Space Jump

[Admin]

Speed of sound is 1,236 kilometres per hour approx as it is dependant on air temperature

 

 

[Guest Andys@coffs]

Nah....this is disapointing, I want one from higher up so that the fallee does that red hot meteor like re-entry thing.....

 

Might mean however that the attitudes and approaches at parachuting fraternities if they evolve to do the same thing in time might need to change, no more toss it in the back and go thing.....Hope whatever they use has a better climb rate than an overloaded GA plane with a climb pitched prop that is the only thing breaking the sound barrier at the tip of the prop....

 

 

[Sapphire]

...and his mobile phone so he can ring before dropping in :peepwall:

 

 

 

 

 

At 30,000 feet he'll see a local Pizza Hut and making his order.

 

 

[dazza 38]

I would like to see Felix jump with a wing suit over the top of his space suit. But I guess his arms & legs would get ripped, clean off his torso if he deployed his limbs at the wrong time.

 

 

[Guest Andys@coffs]

Hmmmm sorta like BuzzLightyear then

 

 

 

[turboplanner]

I would to see Felix jump with a wing suit over the top of his space suit. But I guess his arms & legs would get ripped, clean off his torso if he deployed his limbs at the wrong time.

And he'd finish up with eyebrows on his ass

 

.

 

 

[brilin_air]

Hmmmm sorta like BuzzLightyear then[ATTACH=full]19410[/ATTACH]

To infinity and beyond!

 

-Linda

 

 

[Guest Andys@coffs]

To infinity and beyond! -Linda

Well.... to earth at least...I suspect that if he ends up approaching infinity then perhaps some of the engineering prep work they've been doing for however long its been might have some flawed calculations in it...

 

 

[Guest ozzie]

Skydiving......the grounds the limit!

 

 

[Guest ozzie]

Well done, shame about pulling high. Speed of sound, Boom Boom!

 

 

[rdarby]

Apparantly they trained for 4 years for this. It's a massive undertaking, more because it tests next generation space suits. Now how is that capsule getting down?

 

 

[Kyle Communications]

The capsule came down by parachute

 

 

[Guernsey]

Speed of sound is 1,236 kilometres per hour approx as it is dependant on air temperature

Also dependant on air density.

 

Alan.

 

 

[slartibartfast]

Also dependant on air density.Alan.

Nope.

The factors affecting the speed of sound through a gas are temperature, pressure and density. However, pressure and density have equal but opposite effects - thus cancelling each other out.

 

So in an ideal gas, this leaves temperature (or the adiabatic index) as the only variable.

 

Air is not ideal, so humidity also has a small but measurable effect.

 

Here endeth the lesson.

 

This was condensed from the Wikipedia entry.

 

I was sure only fairly sure, so I looked it up.

 

 

[Guest Howard Hughes]

According to one of my university lecturers, "Wikipedia is not research", for the life of me I can't understand why not!

 

 

[Guest Andys@coffs]

And yet I always recall from my RAAF days that the number of aircraft that could exceed Mach were numerous, the number that could exceed Mach at ground level (with a useful fuel load) were few......Somehow I suspect density has a fair bit to do with this.....(as a determinant of, if you can or cant go that fast, but it would seem not a determinant of how fast that actually is....)

 

Re wiki and Uni...correct you cant reference Wiki....but nothings stopping you looking at the wiki references, and reading those and then referencing them where appropriate.....I still found it an entirely useful source at Uni....even if I couldnt formally use it........ If the Wiki article was short on referencing then it probably wasnt of a quality suitable for scholarly use!!!

 

Andy

 

 

[Guernsey]

That's why the Supermarine Swift and the Hawker Hunter did low level runs over the desert when competing for the world air speed record.

 

The air was less dense at higher temperatures.

 

Alan.

 

 

[slartibartfast]

Mach is a relative term. It is the ratio of air speed to the local speed of sound. So if you can do mach 1 at 10,000', then you should be able to do it at sea level.

 

Unless the humidity comes into play (as stated earlier). That might be the reason I guess. More humidity at sea level, less compressibility because the Oxygen and Nitrogen molecules of the air are replaced by lighter water molecules.

 

That was Wiki says anyway. I don't mind citing Wiki. Of course, I never finished school.

 

 

[Guest Andys@coffs]

Mach is a relative term. It is the ratio of air speed to the local speed of sound. So if you can do mach 1 at 10,000', then you should be able to do it at sea level.Unless the humidity comes into play (as stated earlier). That might be the reason I guess. More humidity at sea level, less compressibility because the Oxygen and Nitrogen molecules of the air are replaced by lighter water molecules.

That was Wiki says anyway. I don't mind citing Wiki. Of course, I never finished school.

I wasnt disagreeing with you rather mixing 2 different things:-

 

1) the actual speed of mach might well not have as one of its determinants, density altitude

 

2) whether you could or couldnt get to mach 1 probably did have as a determinant density altitude which is why going mach 1 at altitude is easier than doing so at ground level......

 

To put 2) into context I remeber going on exercise with the F111's to Darwin for a pitchblack exercise. We had Yank aircraft that year as the opposition I think F15's and F16's both of which can exceed Mach. However on finding a F111 they had to catch it....at 200ft doing so was significantly more difficult than it sounds. F111 can exceed Mach at Sea level by a significant amount, I dont recall that either of the others can do so.....or if they can not for very long unless they have a tanker on hand to top up tanks that empty very fast.........and in any event not as fast as the F111 is at sea level.

 

Now the point to this story....One of the aircraft we went on exercise was fresh out of an R4 Service (deepest level of service done which includes a complete repaint of the aircraft.....looks very flash when wheeled out.....) After setting off on exercise and being jumped by F16's it went down low and flat out....F16 last seen somewhere far behind it.......but when it landed the aircrew stunk like roadkill (airconditioning doesnt work so well when the aircraft is >mach at sealevel) and the lovely fresh paint was in a lot of cases .....just gone......friction at >mach at sealevel is severe.....

 

So, what MAch is at sea level apparently apparently doesnt rely on density altitude

 

Whether your ultralight can go that fast apparently does rely on density altitude....

 

Andy

 

 

[dazza 38]

A bit off thread but just to add to above.

 

The F111 at sea level has a max speed (clean) of Mach 1.2.Top speed is 2.5 Mach at around 36 000 Feet.

 

The Panavia Tornado has a max speed (clean) of 1.2 at sea level. Top speed is 2.2 Mach at 30 000.Feet.

 

One resource says the Tornado can do 1.3 Mach at sea level.But it is not proved.

 

Both jets are swing wing, which gives them a massive speed envelope.(stall speed to top speed)

 

 

[Sapphire]

The way I understand it the published speed of sound is based at sea level 20c. Go higher and the speed slows down in the thinning atmosphere till you reach outer space [where dazza flys around] but sound doesn't travel. The mach figure is based on the speed you are flying divided by the published speed of sound. The higher you fly the faster you fly [TAS] given a constant IAS. So your mach number increases. At Oshkosh they had "jet day" and I was at the western end of the strip looking at ultralights. A jet at 100ft decided to head in my direction over the runway and was silent until a fraction of a second passing me.............thats faster than sound demonstrated feet away. In line with the thread title, Mr. Baumgartner is very diciplined and that put the odds in his favour. When his balloon scraped the ground he could have done a "John Wayne" and yelled "Cut the ropes, were going anyways". But this is not the movies and he suceeded on another attempt. Think his luck would run out if he tried it every second weekend.

 

 

[Old Koreelah]

Why don't we use huge balloons to lift space craft up to that height before firing the rockets? Surely, that would be cheaper and repeatable

An interesting idea Mark. The balloon to lift even this light capsule is humongous and difficult to handle. Add a slight breeze and you have disaster. Can't imagine how we'd manage a balloon big enough to lift useful loads in the hundreds of tonnes. Once you get to 30 or so km you then have to launch a heavy rocket in the right direction. It's escape velocity that space flight is all about, not just altitude.

 

An additional problem is that helium is running out. Yes folks, they are not making any more of it and all those party balloons are using up a precious resource. Maybe the space elevator is the solution.

 

 

[eightyknots]

And yet I always recall from my RAAF days that the number of aircraft that could exceed Mach were numerous, the number that could exceed Mach at ground level (with a useful fuel load) were few......Somehow I suspect density has a fair bit to do with this.....(as a determinant of, if you can or cant go that fast, but it would seem not a determinant of how fast that actually is....)Re wiki and Uni...correct you cant reference Wiki....but nothings stopping you looking at the wiki references, and reading those and then referencing them where appropriate.....I still found it an entirely useful source at Uni....even if I couldnt formally use it........ If the Wiki article was short on referencing then it probably wasnt of a quality suitable for scholarly use!!!

 

Andy

Well said; I must say that I have employed a similar method.

 

Mach is a relative term. It is the ratio of air speed to the local speed of sound. So if you can do mach 1 at 10,000', then you should be able to do it at sea level.Unless the humidity comes into play (as stated earlier). That might be the reason I guess. More humidity at sea level, less compressibility because the Oxygen and Nitrogen molecules of the air are replaced by lighter water molecules.

That was Wiki says anyway. I don't mind citing Wiki. Of course, I never finished school.

Good to see you on the Forum Slarti, we haven't see much of you in the last 1-2 years.

 

 

[Sapphire]

A sling shot made from electromagnets seems possible with present technology. Though the acceleration needed to get to escape velocity would turn any astronaut looking like a squashed fly on the wall.

 

 

[flying dog]

Hi guys.

 

I shall try to read all the posts when I can (and get time).

 

Question/s:

 

1 - If people keep breaking the sound barrier, who is the poor person who has to keep fixing it?

 

2 - That person from back in the 60's... (sorry real short term memory failure). Didn't he break the sound barrier?