[X] My Assistant

[PaleBlueDot]

I was browsing around and found some intresting articles about there is some debate whether or not a metal cover for a underground nuke test a few months before Sputnik made it to space or not. Pictures from the test (launch??) give a lower bound of its velocity at 56km/s. the main argument agianst is that it would have blead off the speed in the atmosphere. anyways, kinda cool

http://nuclearweaponarchive.org/Usa/Tests/...ob.html#PascalB

http://nuclearweaponarchive.org/Usa/Tests/Brownlee.html

what do you think?

m

[djellison]

This item might have made it into space - but never into orbit.

Ignoring the fall off of gravity, and ignoring air resistance, getting into orbit is a two fold issue. Getting high, and getting fast.

Say you need 200km and 7500 m/sec

The pot.energy of, say, 1kg @ 200km is 200,000 J
The Kinetic Energy of that 1kg doing 7500 m/s (orbital velocity) is 28,125,000 J

Those are the two things you need to add to something to get it into orbit.

So even if they gave it enough shove to overcome friction, and it survived the massive heating, it might have got into space, but it would never have got into orbit

Doug

[Bob Shaw]

This item might have made it into space - but never into orbit.

Ignoring the fall off of gravity, and ignoring air resistance, getting into orbit is a two fold issue.  Getting high, and getting fast.

Say you need 200km and 7500 m/sec

The pot.energy of, say, 1kg @ 200km is 200,000 J
The Kinetic Energy of that 1kg doing 7500 m/s (orbital velocity)  is 28,125,000 J

Those are the two things you need to add to something to get it into orbit.

So even if they gave it enough shove to overcome friction, and it survived the massive heating, it might have got into space, but it would never have got into orbit

Doug

Doug:

To have an orbit which lasts for more than one pass, you need two impulses, too - one to raise the perigee from sea-level up to something which doesn't intersect the ground (or the atmosphere). Shuttle ETs have gone into orbit several times, but following an orbit which has a perigee below the surface of the Earth (that's why the OMS fires after ET Sep, to circularise the orbit of the shuttle itself).

Bob Shaw

[dvandorn]

...Shuttle ETs have gone into orbit several times, but following an orbit which has a perigee below the surface of the Earth (that's why the OMS fires after ET Sep, to circularise the orbit of the shuttle itself).

That used to be the case. But over the past several years of Shuttle flight operations, more and more of the launches are "SSME direct-to-orbit", in which the entire stack -- orbiter *and* ET -- are placed into a stable (albeit somewhat low) orbit. No OMS burns required during the first orbit to maintain a safe orbit.

This started when the Shuttle needed to get the maximum cargo possible up into the ISS orbit. Adding some SSME delta-V made it possible to get those big components, like Destiny and the solar arrays, up to ISS.

-the other Doug