Almost half a century after the first orbital launch by the Soviets, and in the wake of another failure of a supposedly "reliable" Russian launcher, Clark Lindsey has a brief, but appropriate rant about our national failure to develop reliable and low-cost access to space, a goal that NASA is not only doing very little about, but, by building yet another horrifically expensive throwaway, actually spending billions to delay.

Not only will it be delayed in the sense that NASA won't be buying commercial services for those launches, or giving more funding to a COTS-like approach that at least attempts to work at the problem, or flying X planes that attempt to whittle away at the technical difficulties, but it will also be delayed in the sense that if it and U.S. commercial alternatives are built, Ares will be set up to compete with the commercial alternatives. That makes it even tougher to get commercial investment.

Ares may be very expensive, there has been NASA talk (proposals/presentations) of using the Ares vehicles for all sorts of other government launches besides ISS/lunar/Mars. I'm not sure whether or not that would be legal, but the suggestions are out there for big science missions, etc. It may not matter how expensive Ares winds up being, in the political sense. Also, the development and operational costs will be there anyway, so they could say the extra launch is cheaper. The Shuttle history offers some warnings.

Is it nonsensical to image a lighter-than-air platform as the first stage of an orbital launch? There would certainly be much less to launch if the platform could achieve sufficient altitude.

A Humungo Hindenburg. I'd like to see it.

D, the real advantage to high altitude balloon launch is that your rocket launches from near vacuum. This means you can use a rocket optimized for vacuum and you get less air resistance (air resistance from the surface can sap 1.5-2 km/s of delta-V).

Otherwise, there's very little change in the delta V needed.

"ELVs Suck" is a nice tagline for a tee shirt

Otherwise, there's very little change in the delta V needed.

Do you know what altitude would effect a significant change? I was thinking of maybe 200,000 feet for a rigid, reusable platform. As said above, a Humungo Hindenberg but of different form and less combustible skin and anti-gravity gas.

I keep saying this, but:

NASA is doing very well indeed at its primary, secondary and tertiary purposes. Primary; to keep mankind out of space for as long as possible. Secondary; to keep bureaucrats in jobs. Tertiary; to keep politicians in jobs by throwing money at various congressional districts, and spreading the pork around as much as possible. Example: shipping booster components around all over the USA, by air, at ruinous expense, instead of keeping all the production together.

Do you know what altitude would effect a significant change? I was thinking of maybe 200,000 feet for a rigid, reusable platform. As said above, a Humungo Hindenberg but of different form and less combustible skin and anti-gravity gas.

Some gratuitous mathematics follows as I figure out very crudely the relative contributions to delta V from the three effects.

The delta V needed for launching from a point that's not rotating (the surface of the Earth is rotating BTW) would be inversely proportional to the square root of the distance from the center of gravity. So given that the Earth is 4,000 miles (crudely) in radius, you would need to be 12,000 miles above the surface (and 16,000 miles above the center of the Earth) to halve your delta V.

In your case, since you are a bit less than 1% further away from center of the Earth, you should expect to see slightly less than 0.5% reduction in escape velocity. I think that would turn out to be around 30-50 m/s reduction in velocities for any destination in Earth orbit or beyond.

In comparison, you should see maybe a 1-2 km/s boost from launching outside of most of Earth's atmosphere, and a signficant boost in the ISP of your rocket engines for firing in near vacuum.

For example, the RS-68 (tuned for sea level launch) has ISP of 365 secs at sea level pressure and 410 secs in vacuum. Apparently, with regen-cooled nozzles, this goes up to 419 secs in vacuum. "Vacuum optimized" and regen cooled gets 430-435 secs apparently (according to the DIRECT people and the Pratt and Whitney engineers they worked with). So you should be able to start at the high end of your ISP (near vacuum does hurt a little, I gather) and in the case of the RS-68, pick up to 5% because you can optimize for vacuum.

As I understand it, the mass ratio (full vehicle to dry weight) is proportional to something which has -(delta V)/ISP as the exponent. So you're effectively getting the equivalent of another 5% reduction in delta V (oh, say 400-500 ,/s) from this ISP improvement.

So to conclude, here are my guesses for delta V reduction (starting with oh, 11-11.5 km/s delta V from sea level to reach low Earth orbit):

• 1-2 km/s from reduced air drag.
  
• 400-500 m/s from improved ISP of the rocket.
  
• 30-50 m/s from being higher up in the gravity well.
  

...you would need to be 12,000 miles above the surface...

Wow. That's as far as I've been from anywhere. :-)

So the altitude of the B52s were of no help, in this regard, to the X-15s when they went for altitude. Unless there are yet other factors involved.

The delta V needed for launching from a point that's not rotating (the surface of the Earth is rotating BTW) would be inversely proportional to the square root of the distance from the center of gravity.

I think you mean the distance above the launch site ( which is not at the center of the Earth).

I think that would turn out to be around 30-50 m/s

A delta v of 30-50 m/s translates into an altitude of 46-127 meters. That's roughly the delta v of the Bell rocket belt or a major league baseball player.

The actual delta v requirement is ~1000 m/s.

Ho, ho, ho. Private space falls over and goes "phutt", and the first response of the privspace zealots is to bitch about NASA, who had fack-all to do with this incident.

Oh, no, I do understand the point--that if it weren't for those facking goddamn morons at NASA, we'd totally have antigravity space elevators by now. Yeah, it's all NASA's fault! Those jerks are changing the laws of physics to make it harder for us!

Actually if you measure the success of private space efforts by the amount of trolls "arguing" against them and their supporters then things have really picked up speed lately. You know it's gotten mainstream when the malevolent retards get involved (as opposed to the well-wishing common eccentric or mild loon ^_^; *everybody points at somebody else*).

On the other hand it might simply be the KOS effect since the troll population multiplied shortly after BS & FV started "spacing out" over there... (no offense intended to BS & FV as I don't think that was their intention).