A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Policy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Will the investment flood happen?



 
 
Thread Tools Display Modes
  #21  
Old July 13th 03, 05:17 PM
Christopher M. Jones
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

"Joann Evans" wrote:
Richard Schumacher wrote:
A vertical-takeoff vertical-landing rocket ought to be less susceptible to
weather than any airplane, true? It doesn't rely on aerodynamic lift

(except
perhaps very early in the re-entry, when it will be miles above the weather
anyway), so there's none of that nonsense about crosswinds or icing.


As we've seen with Apollo 12, there could be issues with cloud
electrical potentials, though. If the exhaust trail enhances
conductivity to ground, it's a path almost directly there, as opposed to
an HTO that may ascend into the clouds at a shallower angle.

Understand, I think VTVL is the way to go in most cases (espically at
very large payloads) but this has to be considered.


I don't believe that Apollo / Saturn V was specifically
designed to withstand lightning strikes. At least not
at an operational level. Most modern aircraft are, and
many aircraft are struck by lightning in flight without
causing severe (or any) problems for the fligt. I see
little reason why rockets couldn't be made equally
robust.

  #22  
Old July 13th 03, 11:11 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

In article ,
Richard Schumacher wrote:
if it's pouring down rain and shows no signs of stopping -- bearing in
mind that in Northern Europe, one major terminus for intercontinental
runs, this is far from rare :-) -- you have to be able to fly through it.


A vertical-takeoff vertical-landing rocket ought to be less susceptible to
weather than any airplane, true?


In principle, yes. Helicopter landing approaches have far lower weather
minima than fixed-wing landings. Much depends on details, though.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |
  #23  
Old July 14th 03, 05:22 AM
Christopher M. Jones
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

"John Ordover" wrote:
Uh - Fedex routinely delivers overnight, and has same-day service
already (on the sender's end, you have to drop it off at the airport,
because the flight time isn't the problem, it's the ground-time and
sorting. If you go to the airport yourself and put it in the right
bin yourself, no problem getting it across the US the same day).

A flight from CA to NYC -already- takes only a few hours, usually
around 5, plus or minus a little depending on weather, which way
you're going, etc. Paying a higher price to cut the five hours to
2.5, say, or even 2, cutting the delivery time from a same-day ten
hours to a same-day 8 hours, isn't likely to be worth it to anyone
often enough to make the advance in technology worth it.



When FedEx means "sameday" they mean just barely so, since the
flight alone takes several hours.

Also, you're missing an important aspect of the differing
situations, yet again. Next day / sameday is a step up in
cost and speed from ground. It also entails a step up in
handling, both on the ground and by the customers. Taking
another step up in cost and speed to fast package sub-
orbital delivery would also warrant an equivalent step up
in ground operations. Specifically, at that cost level
individual courier services for *each* package would be
a no brainer, as the cost would be less than the shipping.
Similarly, expedited processing would be a sure thing as
well.

The point is, there's no barrier, assuming sub-orbital
rocketplanes are available for the task, to providing
delivery service across the continental US in only a few
hours (not just barely within the same day some of the
time, but within the *work day* most of the time, and
actually within the same day all of the time).

But that's only the tip of the iceberg, because sub-
orbital fast package delivery could deliver anywhere in
the world within the same day, every day. That's an
even more profound jump in capabilities. Though it
would require expedited customs procedures.


If there are billions of dollars at stake because a factory is missing
a part, it's a simple matter to hire a high-speed private jet to get
you what you need. Heck, with that much money at stake, you can -buy-
a private jet.


This supports your argument how? If even a 1 hour speedup is
worth nearly any price they'd pay, then they'd certainly spring
for rocket service if they could get it, even if it only shaved
off the slightest amount of time. If a company can pay
millions of dollars to deliver one package then they can damned
well afford a sub-orbital rocket trip at any conceivable
operating price given today's technology.


That is, in the end, the problem with the Concorde as well. There
simply weren't enough people who wanted to pay between 10 and 20 times
the fare just to cut three hours off a six hour flight.


That's not half of the problem with Concorde. More importantly,
you're comparing apples and oranges. Concorde flies maybe 2 or
3 times faster than regular commercial jets. Whether you fly
the Concorde or a regular jet it still takes hours to cross the
atlantic and it still takes a good day or so for a trip there
or the trip back. With the Concorde you end up with a bit more
time left over for your day, and if you really push it you can
just barely go across the Atlantic and back in one day, but
really it's not much different or terribly faster than a normal
jet. A sub-orbital rocketplane would fly up to 12 times faster
than the Concorde, and that's a quantitative difference large
enough to make a qualitative difference. With a sub-orbital
vehicle, a trans-continental trip would take as much time as an
ordinary commute. It would only take a small amount of a day,
and would leave you with plenty of time for other activities.
A one day round trip would actually leave enough time during
the day to be worthwhile, a weekend trip even more so.

There just might be enough people to buy trips or delivery
services at that level of speed and convenience.

  #24  
Old July 14th 03, 10:56 PM
Joann Evans
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

"Christopher M. Jones" wrote:

"Joann Evans" wrote:
Richard Schumacher wrote:
A vertical-takeoff vertical-landing rocket ought to be less susceptible to
weather than any airplane, true? It doesn't rely on aerodynamic lift

(except
perhaps very early in the re-entry, when it will be miles above the weather
anyway), so there's none of that nonsense about crosswinds or icing.


As we've seen with Apollo 12, there could be issues with cloud
electrical potentials, though. If the exhaust trail enhances
conductivity to ground, it's a path almost directly there, as opposed to
an HTO that may ascend into the clouds at a shallower angle.

Understand, I think VTVL is the way to go in most cases (espically at
very large payloads) but this has to be considered.


I don't believe that Apollo / Saturn V was specifically
designed to withstand lightning strikes. At least not
at an operational level. Most modern aircraft are, and
many aircraft are struck by lightning in flight without
causing severe (or any) problems for the fligt. I see
little reason why rockets couldn't be made equally
robust.


Fortunately, the the Apollo-Saturn stack happened to be sufficently
robust on that occasion, and there may be room for improvement. But the
point is, aircarft generally don't ascend almost vertically, leaving a
potentially conductive trail on the shortest path back to ground. Under
those circumstances, you may *cause* a discharge that otherwise might
not have happened. It's been done deliberately (rockets trailing wires)
for research purposes, many times.

Further complicating the matter (and this is already a consideration
for newer aircraft) is the fact that a VTO commercial launcher is likely
to use assorted composites in its construction (including low-temprature
potrions of its outer surfaces) for weight savings, rather than
conductive metals that could pass the energy around the interior....
  #25  
Old July 16th 03, 01:54 PM
Henry Spencer
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

In article ,
Keith F. Lynch wrote:
That's a somewhat silly concern; we launch almost all our spacecraft
out of somewhere much less than a half hour's flight time for the
rocket out from DC.


Who is "we"? The government itself? What does that prove? We're
discussing privately owned and operated rockets.


Almost all rockets launched from (e.g.) the Cape are privately owned
and operated nowadays.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |
  #27  
Old July 17th 03, 11:45 AM
John Ordover
external usenet poster
 
Posts: n/a
Default Will the investment flood happen?

When FedEx means "sameday" they mean just barely so, since the
flight alone takes several hours.



Not at all. You can drop a package at LAX and pick it up in NYC
about five hours later. That's hardly "barely" same day - if you did
it at 9 LA time, the package would be in NYC five hours later, at 2 LA
time or 11 NY time. Either way, that's good, solid, same-day.

Cut the flight time to 2.5 hours, you're really not making much of an
improvement, and for this you would need to develop and deploy a whole
new system, at the cost of billions?



Also, you're missing an important aspect of the differing
situations, yet again. Next day / sameday is a step up in
cost and speed from ground. It also entails a step up in
handling, both on the ground and by the customers. Taking
another step up in cost and speed to fast package sub-
orbital delivery would also warrant an equivalent step up
in ground operations. Specifically, at that cost level
individual courier services for *each* package would be
a no brainer, as the cost would be less than the shipping.
Similarly, expedited processing would be a sure thing as
well.


But if you only step up the ground operations, which is easier said
than done and also very expensive because the way to do it is to
increase the number of employees who work on each package, you'd cut
the delivery time down substantially without having to deploy new
technolgooy. The extreme example is hiring one person per package,
and having them deliver only that one package each day. That would
cut your delivery time by at least 50%, but is too expensive - except
on those rare occassions when something has to be somewhere at high
speed - in which case you -do- hire one person per package to bring
the missing part, or whatever, to its destination. So a 50% delivery
speed increase involves no new technology, no new flying system.

I mean, just from my own personal experience fed-exing rush blues to
the printer, I drove to the airport (30 mins) and handed it to the
fed-ex operation there. It was at its desintation in Canada 2 hours
later, where someone from the printer picked it up and took 30 mins to
drive to their office, where they called me to tell me they got it.
It was expensive and time consuming for us, but it got done.



The point is, there's no barrier, assuming sub-orbital
rocketplanes are available for the task, to providing
delivery service across the continental US in only a few
hours (not just barely within the same day some of the
time, but within the *work day* most of the time, and
actually within the same day all of the time).


There is no technological barrier. There is a huge economic barrier.
Like I said, same-day service is only a matter of having a person take
the item from door to door personally. I could easily grab a package,
hop on a 7:am flight from LGA to LAX, arrive 3pm LA time and be at my
LA destination by 3 LA time.

So why develop rocket planes for a same-day service that is so rarely
needed, and that already exists?



But that's only the tip of the iceberg, because sub-
orbital fast package delivery could deliver anywhere in
the world within the same day, every day. That's an
even more profound jump in capabilities. Though it
would require expedited customs procedures.


There isn't enough of a market to drive the development.



If there are billions of dollars at stake because a factory is missing
a part, it's a simple matter to hire a high-speed private jet to get
you what you need. Heck, with that much money at stake, you can -buy-
a private jet.


If even a 1 hour speedup is
worth nearly any price they'd pay


Please list for me about 10,000 instances of this happening every day,
because that's about how many ou'd need to make it pay.


There just might be enough people to buy trips or delivery
services at that level of speed and convenience.


There isn't.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ISS an accident waiting to happen ? David Linney Space Station 9 October 1st 03 09:51 AM


All times are GMT +1. The time now is 04:43 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.