Orbital Space Place project

I've been reading up on the "Capsule" vs "Something with Wings"
debate. To my mind, as a software engineer who lives wherever
possible by the "Keep It Simple" principle, the "capsule side" make
compelling case.

Along with the inherent simplicity, it seems that a capsule approach
is something that could evolve over time as requirements change.

I'd be interested to hear how people think "Something with Wings" is
going to be more capable etc.

(I expect they'll go "Something with Wings", as I guess the capsule
approach might be perceived as a backwards step).


Byeeeee.
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On Sat, 26 Jul 2003 13:54:05 +1000, in a place far, far away, Brett
O'Callaghan made the phosphor on my
monitor glow in such a way as to indicate that:

(I expect they'll go "Something with Wings", as I guess the capsule
approach might be perceived as a backwards step).

Anything that has to be delivered with a Delta IV or Atlas V is a
backwards step.

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On Sat, 26 Jul 2003 13:54:05 +1000, Brett O'Callaghan
wrote:

I've been reading up on the "Capsule" vs "Something with Wings"
debate. To my mind, as a software engineer who lives wherever
possible by the "Keep It Simple" principle, the "capsule side" make
compelling case.

That it does.

I expect NASA only went with the wings thing to begin with due to
wanting a space ship in the buck rogers fashion.

Along with the inherent simplicity, it seems that a capsule approach
is something that could evolve over time as requirements change.

Making a large capsule to hold quite a few people I would find most
interesting, not that they are doing this of course.

I'd be interested to hear how people think "Something with Wings" is
going to be more capable etc.

All to do with ground range and a softer flight.

As NASA wants this craft to be able to travel the distance so that it
lands on their runway. They also wish a softer flight for their
imaginary injured crew member.

It has been pointed out that the ballistic feature of the capsule and
resulting high Gs are undesirable, even if such a thing happening is
extremely rare.

And well a capsule could handle such a malfunction, when a craft like
the Shuttle could not. As the capsule can handle almost any re-entry
when gravity keeps the heat shield in the right place, but the Shuttle
would soon break up at the wrong angle, when it is always fighting its
natural entry angle.

Also as you no doubt know the capsule has a better protection from
this re-entry heating, when a shock wave forms from this blunt surface
thereby helping out.

Then in a capsule all the G forces go down through your back, which
stops the likes of your eyes trying to pop out. And of course in the
shuttle your falling towards your bum, which gives quite a bumpy ride.

In the capsule you are seated at the right angle for both launch and
re-entry, but on a "plane" you are in the right position going up, but
an undesirable one going down.

And of course the best feature of the capsule is that you can land it
almost anywhere, while with a craft with wings and wheels you are
confined to using runways.

The landing gear is also a wasted item that only goes and eats into
your mass allowance. Not to forget the wings of course, which create
undesirable drag on the way up and are a total dead weigh in space.

In all the best solution for a capsule to meet NASA (unreasonable?)
requirements as best it can is to make use of a parasail, when this at
least can give you some ranging.

(I expect they'll go "Something with Wings", as I guess the capsule
approach might be perceived as a backwards step).

Actually I love what all this is doing for these companies wanting to
build this thing, when they are undecided if they should go with wings
or capsule.

As NASA is giving out huge signs that it wants wings, but everyone
kind of knows that capsules are technically better. So they are worked
up over trying to figure out what NASA would eventually decide on.

I can only feel that if NASA still wants people to believe that their
astronauts still pilot these things, instead of the computer, then
they would go with wings and wheels. And yet if they want the
technically best option, then using a *modern* and *advanced* capsule
it would have it be.

Anyway, this is all kind of pointless, when in 2012 when this thing
gets launched they well be using the space elevator instead. :-]

Cardman.

h (Rand Simberg) wrote:

O'Callaghan made the phosphor on my
(I expect they'll go "Something with Wings", as I guess the capsule
approach might be perceived as a backwards step).
Anything that has to be delivered with a Delta IV or Atlas V is a
backwards step.

Why? If it does the job.

Byeeeee.
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Cardman wrote


And of course the best feature of the capsule is that you can land it
almost anywhere, while with a craft with wings and wheels you are
confined to using runways.

Is there an estimate for how good a CEP one could expect these
days for a capsule with steerable lift like Apollo and Soyuz,
maybe some sort of parasail for final corrections? (Assuming that,
unlike the very scary recent Soyuz landing, things work right.)

They could give a capsule the guidance system of a JDAM satellite guided
munition. These bombs close in on their targets with a high degree of accuracy.
I believe the atmosphere does most of the slowing without the parachute. All
that's required are some landing jets, and the capsule can land right at
kennedy space center. Alternatively, how about ducted fans like the Mollier
flying car is supposed to have? Retractable helicopter blades might also work
in getting the space capsule right where its supposed to go. No Ocean
Splashdown and aircraft carrier recovery is required.

They could give a capsule the guidance system of a JDAM satellite guided
munition.

Don't JDAM's have aerosurfaces for flight control? If so, then this is a
step
away from the "capsule" concept, as such surfaces are dead weight on the way
up.


The JDAMs have flight control fins, not wings. the fins aren't meant to slow
down the JDAM's fall, they are only meant to direct its fall so it lands in the
right spot. Landing jets or rockets can be used to slow down the capsule for a
soft landing once it gets close to the ground. The capsule should be falling at
100 mph or so the capsule should go from 100 mph to 0 with a tollerable
acceleration just before making contact with the ground. This minimizes the
opportunity to air currents to push the capsule off course.

The JDAMs have flight control fins, not wings. the fins aren't meant to slow
down the JDAM's fall, they are only meant to direct its fall so it lands in
the right spot. Landing jets or rockets can be used to slow down the capsule
for a soft landing once it gets close to the ground. The capsule should be
falling at 100 mph or so the capsule should go from 100 mph to 0 with a
tolerable acceleration just before making contact with the ground. This
minimizes the opportunity to air currents to push the capsule off course

Using a JDAM style system to steer a returning capsule is a "-DAM" good
ideal but you are making the actual landing system way to complex. One of
the x planes recently demonstrated a Para wing. The chute deploys into a
working wing. With such a wing a capsule becomes as manageable as winged
vehicle.

On Sun, 27 Jul 2003 21:30:55 GMT, "gmw" wrote:

The JDAMs have flight control fins, not wings. the fins aren't meant to slow
down the JDAM's fall, they are only meant to direct its fall so it lands in
the right spot.

Yes that would be a good idea to get this capsule to land wherever
NASA wants it.

Landing jets or rockets can be used to slow down the capsule
for a soft landing once it gets close to the ground. The capsule should be
falling at 100 mph or so the capsule should go from 100 mph to 0 with a
tolerable acceleration just before making contact with the ground.

Sounds kind of risky to me for a manned craft.

After all if you get a failure in your landing system, then hitting
the ground at 100 mph is a not a good idea.

So at minimum it would need to use very many small rocket engines
(detachable heat shield?), which would still be able to safely land
this thing if more than a few gave out.

Then making sure that your fuel reaches these engines is a key design
point, when again you would get squashed astronauts if your fuel lines
get blocked.

This minimizes the opportunity to air currents to push the capsule off
course

Yes, where if done correctly I would be fully happy with this landing
system, but others may desire to see an emergency parachute as well.

Also lets consider the possibility of it this JDAM system suffered a
guidance failure problem and our capsule was sent off course. As now
we would not be heading towards the nice NASA approved landing pad.

My point here is that having the landing system go from 100 mph to
zero within seconds would not allow the pilot enough time to make sure
that the landing site is suitable.

And so before we start crashing our capsule through someone's barn,
then this system would also need to allow for a manual landing.

Either we could make use of that emergency chute and some manual
control over those rocket engines to head to the landing point, the
computer displays a landing site map to the pilot to allow him to
choose a point, the computer can handle emergency landing on it's own,
or the pilot lands this capsule using the rocket engines alone.

Using a JDAM style system to steer a returning capsule is a "-DAM" good
ideal but you are making the actual landing system way to complex.

The landing system is also very efficient, when those chutes or
para-wings take up important mass.

As if they could get that computer to land this capsule anywhere, then
that would be very impressive. Until the day it screwed up...

And lots of small rocket engines would be quite cheap.

One of
the x planes recently demonstrated a Para wing. The chute deploys into a
working wing. With such a wing a capsule becomes as manageable as winged
vehicle.

Then I hope that they would design it to handle a 5 to 7 ton vehicle
traveling at considerable speed. You can always use a guide chute to
slow the capsule first, as many of these designs do, but that is again
more mass.

Still rocket engines and fuel is a mass thing as well, which I guess
would make me favour the para-wing. And of course for a manned system
you would need backup emergency parachutes.

Going with a JDAM system would be good though, when you don't need
cross range if you could land it right on the button. You may also not
need a para-wing if you use this, when just a chute would do.

Cardman.

On Sun, 27 Jul 2003 21:30:55 GMT, "gmw" wrote:

The JDAMs have flight control fins, not wings. the fins aren't meant to slow
down the JDAM's fall, they are only meant to direct its fall so it lands in
the right spot.

If we're planning on having these fins still on the JDAM when it's
time to direct the ordnance to the target, we'd better not be falling
from a very high altitude. Aerothermodynamics, you know. They're
certainly not suitable for ballistic flight intercontinentally or,
probably, even regionally.

Mary

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