Re: Scram Success
From: Earl Colby Pottinger (earlcp_at_idirect.com)
Date: 11/22/04
- Next message: Earl Colby Pottinger: "Re: Scram Success"
- Previous message: Earl Colby Pottinger: "Re: Scram Success"
- In reply to: Tkalbfus1: "Re: Scram Success"
- Next in thread: Joann Evans: "Re: Scram Success"
- Messages sorted by: [ date ] [ thread ]
Date: Mon, 22 Nov 2004 12:45:06 -0600
tkalbfus1@aol.com (Tkalbfus1) :
>>This is one of the silliest ideas I've seen in this thread. The scramjet
>>won't reach space at a high velocity because the engines won't work in
>>vacuum.
> Why does it have to? Couldn't it reach the necessary velocity to reach
space
> while still in the atmosphere?
Yes, it can in theory. However Mach 25+ in atmosphere is a tall order and
the massive air resistance vs the slow acelleration of a SCRAM means you are
going to burn a lot of fuel to get there.
> Once the scramjet shuts down, it will still retain some of this velocity
won't it?
Ofcourse.
> Isaac Newton once said that an object in motion will tend to stay in
> motion unless a force acts upon it. the two forces
> in question are air resistance and gravity. Are you saying that those two
> forces will act to bring the ship to a complete halt once the scramjet
shuts
> down, and that the ship will plummet straight down to the ground afterwards?
No, where have I said that ever? However air resistence is NOT a linear
force and at Mach 25 the moment you start to lose thrust as will happen when
you start your climb to thinner air you will find the loss in velocity to be
a major affect.
> Could you not take atmospheric drag and gravity into account and yet
> conclude that they still won't slow the ship down enough to prevent it from
> reaching space?
No, because now you are talking about Mach 27 to Mach 30, the forces on your
airframe are huge. Plus you keep running from the fact about the amount of
time needed to get to those speeds. and the amounts of fuel needed. At this
point even if you can build it you are using way more fuel than any rocket's
total needs to move the same mass to orbit. And you still need a rocket for
a stable orbit.
>>So, you propose to lob a nuclear powered stage out of a suborbital
>>transport and hope the engine works and gets the thing into LEO. If
>>something goes wrong, you've got a "hot" nuclear reactor impacting the
>>earth. Not a good design.
> You don't design the thing to fail, you design it to succeed. You test the
> engine to see it it works before you launch it, and then you launch it.
RULE 1: Murphy rules! There always is a failure possible.
Tested nuclear rockets are 'hot' rockets - no-one want to intergrate a 'hot'
rocket.
Earl Colby Pottinger
-- I make public email sent to me! Hydrogen Peroxide Rockets, OpenBeos, SerialTransfer 3.0, RAMDISK, BoatBuilding, DIY TabletPC. What happened to the time? http://webhome.idirect.com/~earlcp
- Next message: Earl Colby Pottinger: "Re: Scram Success"
- Previous message: Earl Colby Pottinger: "Re: Scram Success"
- In reply to: Tkalbfus1: "Re: Scram Success"
- Next in thread: Joann Evans: "Re: Scram Success"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
