Space travel is hazardous to the brain

In article 56f83368-2648-40a6-b535-
, says...

Fred's point is you don't know what you're talking about when it comes
to Mars, but I see you snipped all of that to evade his point.

As to air launch, a big upper stage(s) is still needed. *This is why the
payload of such an air launched vehicle is severely limited if you
constrain the carrier aircraft to existing aircraft.

Stratolauncher needs to build a huge, new, carrier aircraft because of
this. *It's not yet clear if this approach will be better than, say, the
VTVL approach being pursued by SpaceX.

Jeff

I have posted about air launch here forever, although a large carrier
aircraft is needed, they found a affordable way to build it.

Don't count your chickens before they're hatched!

The carrier aircraft has yet to fly even once, so its development costs
are unknown at this time. Once it flies, it's operational costs still
won't be known until it's actually operated.

On mars a LARGE transhab type ballon of say kevlar, should slow a
manned descent capsule just fine. even at high rate of entry.

This is utter b.s.

You've not done the math to take into account Mars' extremely thin
atmosphere. Your inflatable would need to be absolutely huge. Besides,
a transhab inflatable is not designed for the sort of thing you're
proposing, so you're wrong about that as well.

You needent land a huge manned vehicle, and controlled dipping of
probes in the atmospehere have been used in the past to obtain a lower
orbit with minimal fuel consumption. The large transit vehicle would
return to earth less passengers for the next outgoing trip after
refurb. The return from mars ship would already be in mars orbit for
later use. The mars base would already be established by remote
controlled vehcles, and the habitats buried for radiation protection

Something like this out of the box plan could cut transit time
dramatically, and cutting time minimises radiation exposure and
consumables. Plus it should also lessen hazards of life threatening
breakdowns

You're talking out of your a$$. You don't know squat about orbital
mechanics, let alone aerobraking. Where is your cite for this crap?

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article 337a8385-e45d-425d-ba28-68bf5a8acdc3
@c16g2000yqi.googlegroups.com, says...
obviously transit time must be cut using a nuclear rocket.

It's not obvious that transit time must be cut in the first place. Your
starting assumption is garbage.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

In article f4e47ad3-31c8-4c85-a905-c3f27bc9c666
@x3g2000yqo.googlegroups.com, says...
the booster will not need to push the payloadfrom sea level to release
altitude and all the fuel can be from the ground and nothing has to go
to orbit, plus airliner operations are routine

You're showing your complete ignorance of orbital mechanics again.

It's the velocity it takes to get to LEO that's prohibitive, not the
altitude. If you could do the math, you'd know this.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

obviously transit time must be cut using a nuclear rocket.

It's not obvious that transit time must be cut in the first place. *Your
starting assumption is garbage.

Jeff
--


6 months each way means a large radiation exposure for the crew, a
large food water and consumbales needed, lots of spare parts too.....
bigger chance of breakdowns endangering the mission. plus 6 months
each way probably means a couple of years on mars for the crew. or a
ground time of a week

cut transit time to a month or 6 weeks makes everything easier.

picture this 2 transit vehicles are built....

vehicle A the return from mars one is sent unmanned a couple years
before humans depart earth, and arrives successfully in mars orbit.
being unmanned it can take a slow coast trip to mars saving nuclear
fuel for the return run

after vehicle A is safely in mars orbit vehicle B leaves earth on a
fast track to mars, it accelerates the entire way to mars. the main
vehicle has a small rugged capsule for descent. small with transhab or
other unique re entry capsule.

the capsule plunges into mars atmosphere, the large transit vehicle
declerates as long as necessary and returns to earth taking however
long it needs unmanned, for reuse.

the capsule is targeted at the robotically built base. saving valuable
time when the crew arrives. the base includes a return to orbit
capsule, so after mars time the crew blasts off, docks with vehicle A
thats already in orbit waiting for it.... Accelerates the entire way
to earth, a small capsule returns the crew, vehicle A decelerates and
returns to earth orbit eventually

Mars ground time could be a month or as long as you cared to spend.
But a first mission time could spend a month on mars and perhaps 2
months transit each way. So figure round trip 6 months and the transit
vehicles could be refurbished for reuse.

The only disposable parts are the descent capsules the 2 transit
vehicles get refurbed for reuse

Total mission time 6 months, reusability, safer for crew since return
system will already be at mars before astronauts leave earth....

By building the mars base robotically it not only saves astronaut
ground time, but it could be overbuilt with enough supplies for 5
years on mars in case the return ship had problems

On Jan 4, 9:04*am, Jeff Findley wrote:
In article f4e47ad3-31c8-4c85-a905-c3f27bc9c666
@x3g2000yqo.googlegroups.com, says...

the booster will not need to push the payloadfrom sea level to release
altitude and all the fuel can be from the ground and nothing has to go
to orbit, *plus airliner operations are routine

You're showing your complete ignorance of orbital mechanics again.

It's the velocity it takes to get to LEO that's prohibitive, not the
altitude. *If you could do the math, you'd know this.

Jeff


Never the less stratolauncher is being built today. So your stating
they are wasting their time and money? Just for the heck of it?

: bob haller
: 6 months each way means a large radiation exposure for the crew, a
: large food water and consumbales needed, lots of spare parts too.....
: bigger chance of breakdowns endangering the mission. plus 6 months
: each way probably means a couple of years on mars for the crew. or a
: ground time of a week
:
: cut transit time to a month or 6 weeks makes everything easier.

You've just replaced one problem (deal with slow transit with shielding,
food, parts, etc) with a more difficult problem (come up with new drive
tech, and/or take truly *immense* amounts of fuel with you).

: after vehicle A is safely in mars orbit vehicle B leaves earth on a
: fast track to mars, it accelerates the entire way to mars.

And necessarily zips right past it, since if you took a whole month of
accelerating, reaching average speeds 12 times faster than before, the
only way to stop would be lithobreaking. No puny martian atmosphere
would do doodly squat to your velocity by then. Of course, if you
accelerate half way and decelerate the rest, you might have a chance,
but again, aerobraking on mars is only minimally more clever than
aerobraking on the moon. *Most* of your mars-approach delta-v *has*
to come from somewhere else, if you're going to be bopping past as 12
times energy-efficient transit velocities.

: Mars ground time could be a month or as long as you cared to spend.

Now you've placed even *worse* constraints on the propulsion tech that
needs to be invented, since if you ignore arrival and departure windows
entirely, you'll be returning with earth in horrid orbital positions,
needing even *more* delta-v to accomplish it, and if you insist on
similar transit times regardless, the propulsion tech required becomes
*truly* phenomenal.

You've made it exceedingly clear you have no idea how little
aerobraking matters on mars at these speeds, and what it implies to
"accelerate all the way", or the implications of ignoring orbital
positions when planning transits.

Therefore, in short, your proposal reeks.

Pravda - well, Pravda - Pravda said: "Zhil-bil korol kogda-to, pree
nyom blokha zhila"... It stinks. But Izvestia! Izvestia said: "Ya
idoo kuda sam czar idyot peshkom!"... It stinks.
--- Tom Lehrer, "Lobachevsky"

"bob haller" wrote in message
...

On Jan 4, 9:04 am, Jeff Findley wrote:
In article f4e47ad3-31c8-4c85-a905-c3f27bc9c666
@x3g2000yqo.googlegroups.com, says...

the booster will not need to push the payloadfrom sea level to release
altitude and all the fuel can be from the ground and nothing has to go
to orbit, plus airliner operations are routine

You're showing your complete ignorance of orbital mechanics again.

It's the velocity it takes to get to LEO that's prohibitive, not the
altitude. If you could do the math, you'd know this.

Jeff


Never the less stratolauncher is being built today. So your stating
they are wasting their time and money? Just for the heck of it?



I can't speak for Jeff, but personally, I find Stratolauncher a poor idea.
It solves a few issues, but I don't think the win is worth it.

It's not a place I'd invest my money. But then again, it's not my money.



--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article 1b4666f1-32d5-454d-afd1-99015e9e9ce0
@i1g2000vbp.googlegroups.com, says...

On Jan 4, 9:04*am, Jeff Findley wrote:
In article f4e47ad3-31c8-4c85-a905-c3f27bc9c666
@x3g2000yqo.googlegroups.com, says...

the booster will not need to push the payloadfrom sea level to release
altitude and all the fuel can be from the ground and nothing has to go
to orbit, *plus airliner operations are routine

You're showing your complete ignorance of orbital mechanics again.

It's the velocity it takes to get to LEO that's prohibitive, not the
altitude. *If you could do the math, you'd know this.


Never the less stratolauncher is being built today. So your stating
they are wasting their time and money? Just for the heck of it?

I never said that. I said that it's not clear how the Stratolauncher
approach (large carrier aircraft as a first stage) will compare to the
SpaceX approach (reusable VTVL rocket powered first stage). Neither has
flown operationally (Grasshopper is a prototype, not the flight
version).

Only time will tell if one approach is better than another. For the
time being, I'll support both approaches since competition is always a
good thing. But I do have my favorite approach, which I've made clear
over the years.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

: bob haller
: Never the less stratolauncher is being built today. So your stating
: they are wasting their time and money? Just for the heck of it?

No. He's saying you are totally ignorant of why it can be a good idea,
and therefore are making overblown claims about its benefits.

"bob haller" wrote in message
...


Fred's point is you don't know what you're talking about when it comes
to Mars, but I see you snipped all of that to evade his point.

As to air launch, a big upper stage(s) is still needed. This is why the
payload of such an air launched vehicle is severely limited if you
constrain the carrier aircraft to existing aircraft.

Stratolauncher needs to build a huge, new, carrier aircraft because of
this. It's not yet clear if this approach will be better than, say, the
VTVL approach being pursued by SpaceX.

Jeff

I have posted about air launch here forever, although a large carrier
aircraft is needed, they found a affordable way to build it.

Build AND operate it. And prove that it's worth the cost. It does gain you
some flexibility, but again I'm not convinced it's worth it.

But again, not my money.


On mars a LARGE transhab type ballon of say kevlar, should slow a
manned descent capsule just fine. even at high rate of entry.


This is true. Lithobraking (sic) would work on Mars, just like on the Moon.
Unfortunately it would be just as fatal.

I mean you do realize why NASA went with the skycrane approach for
Curiosity?

You needent land a huge manned vehicle, and controlled dipping of
probes in the atmospehere have been used in the past to obtain a lower
orbit with minimal fuel consumption. The large transit vehicle would
return to earth less passengers for the next outgoing trip after
refurb. The return from mars ship would already be in mars orbit for
later use. The mars base would already be established by remote
controlled vehcles, and the habitats buried for radiation protection


Controlled dipping... yes. On planets with dense atmosphere.



Something like this out of the box plan could cut transit time
dramatically, and cutting time minimises radiation exposure and
consumables. Plus it should also lessen hazards of life threatening
breakdowns



--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net