Ares alternatives? "NASA renegades"

How real is this?

http://www.popularmechanics.com/scie...buzz&mag=po p
--
Kulvinder Singh Matharu

Website : www.metalvortex.com
Contact : www.metalvortex.com/contact/

Brain! Brain! What is brain?!

"Kulvinder Singh Matharu" wrote in message
...
How real is this?

http://www.popularmechanics.com/scie...buzz&mag=po p

http://www.directlauncher.com/

How "real" it is, is a matter of opinion. In my opinion, it's a better
option that Ares but a worse option to using EELV's (and any emerging launch
providers in the future) in combination with developing in orbit refueling
depots.

Jeff
--
"Many things that were acceptable in 1958 are no longer acceptable today.
My own standards have changed too." -- Freeman Dyson

"Jeff Findley" writes:

"Kulvinder Singh Matharu" wrote in message
...
How real is this?

http://www.popularmechanics.com/scie...buzz&mag=po p

http://www.directlauncher.com/

How "real" it is, is a matter of opinion. In my opinion, it's a better
option that Ares but a worse option to using EELV's (and any emerging launch
providers in the future) in combination with developing in orbit refueling
depots.

I'm still not getting how you want to get lunar or Mars landers on their
way with EELV's. Sewing 10-15 ton modules together into a Mars lander
seems not exactly easy, especially if alone the heatshield won't fit
under the payload shroud in one piece. Fuel is important, but it's not
everything.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

"Jochem Huhmann" wrote in message
...
"Jeff Findley" writes:

"Kulvinder Singh Matharu" wrote in
message
...
How real is this?

http://www.popularmechanics.com/scie...buzz&mag=po p

http://www.directlauncher.com/

How "real" it is, is a matter of opinion. In my opinion, it's a better
option that Ares but a worse option to using EELV's (and any emerging
launch
providers in the future) in combination with developing in orbit
refueling
depots.

I'm still not getting how you want to get lunar or Mars landers on their
way with EELV's. Sewing 10-15 ton modules together into a Mars lander
seems not exactly easy, especially if alone the heatshield won't fit
under the payload shroud in one piece. Fuel is important, but it's not
everything.

There is no law of physics that says heat shields need to be one piece. The
shuttle, for example, has a few openings in the base of its heat shield for
the landing gear, LOX and LH2 lines to the ET, and etc. Also, a Gemini
capsule was re-flown as part of the MOL program and it had a hatch in it.
It worked just fine too.

Even with Ares V, a Mars mission is going to need to be assembled in LEO
from many launches. The bulk of that mass is fuel and oxidizer for the
engines, so a LEO fuel depot makes a lot of sense to develop.

Jeff
--
"Many things that were acceptable in 1958 are no longer acceptable today.
My own standards have changed too." -- Freeman Dyson

Jochem Huhmann wrote:

I'm still not getting how you want to get lunar or Mars landers on their
way with EELV's. Sewing 10-15 ton modules together into a Mars lander
seems not exactly easy, especially if alone the heatshield won't fit
under the payload shroud in one piece. Fuel is important, but it's not
everything.

Does anyone really think that one could mount a mars expedition without
assembling a huge "space station" for the expedition ship ?

When you consider the biggest thing we've sent to mars so far, do you
really think that you could magically send a cargo ship capable of
landing on mars in one launch ? Do you think we could send a fully
outfitted habitat to the surface of mars ahead of time with a single
launch ?

Having a good launcher will help reduce the number of launches needed to
assemble a mars expedition. (whether set as one ship or as 2 ships, you
still need to send that mass to LEO and assemble it in one or two chunks
before sending it.

"Jeff Findley" writes:

I'm still not getting how you want to get lunar or Mars landers on their
way with EELV's. Sewing 10-15 ton modules together into a Mars lander
seems not exactly easy, especially if alone the heatshield won't fit
under the payload shroud in one piece. Fuel is important, but it's not
everything.

There is no law of physics that says heat shields need to be one piece. The
shuttle, for example, has a few openings in the base of its heat shield for
the landing gear, LOX and LH2 lines to the ET, and etc. Also, a Gemini
capsule was re-flown as part of the MOL program and it had a hatch in it.
It worked just fine too.

There's no law of physics that say heat shields need to be one piece,
right. But assembling such a lander (structure, heatshield and all) from
rather tiny chunks is a nightmare. You can't just easily dock together
things for that. You'll need a crew and do rather delicate work for that
and then you'll need to have even more launches. Look at how many
launches and EVA hours the ISS has needed and then show me how you
assemble a Mars craft this way. And then even without the Shuttle (which
at least has the crew already with it) and without the crew on the
station... no way.

How many launches of EELV's for pieces and assembly crews you're
thinking of here? 100? 200?

Even with Ares V, a Mars mission is going to need to be assembled in LEO
from many launches. The bulk of that mass is fuel and oxidizer for the
engines, so a LEO fuel depot makes a lot of sense to develop.

I have nothing against fuel depots and in-orbit assembly. But I think
that current EELV's are just too small to deliver useful pieces of such
crafts, both mass- and size-wise. 60 to 100 tons of payload and 8 to
10 meters payload diameter makes all of this at least an order of
magnitude easier and this is easily worth a new launcher.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

John Doe writes:

Having a good launcher will help reduce the number of launches needed to
assemble a mars expedition. (whether set as one ship or as 2 ships, you
still need to send that mass to LEO and assemble it in one or two chunks
before sending it.

But if you want to launch that on current EELV's you will deliver at
most 10 to 15 tons of equipment with one launch (since every single
payload will need power and engines and fuel and more). Add to this the
needed crews to assemble non-trivial stuff which you also have to launch
and you end up with dozens or more launches, not two or three. This is
just not practical. You'll have to launch modules that are assembled and
tested on the ground and which don't need any manual work to join them.
You most certainly don't want to assemble a heat-shield for a Mars
lander from a dozen different pieces launched seperately. You probably
even don't want to assemble the structure and tanks and engines and
pressure vessel and airlock and other equipment for a moon lander this
way.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

Jochem Huhmann wrote:

But if you want to launch that on current EELV's you will deliver at
most 10 to 15 tons of equipment with one launch (since every single
payload will need power and engines and fuel and more).


Honest question he

Is it realistic to expect launchers that could scale much beyond the 15
tonnes that we have now ? Someone mentioned 100 tonnes. Is that
realistic with either H2O2 or Kerosene propulsion systems ?

At oe point, wouldn't these become just too big/high and generate way
too much noise/vibration etc ?

John Doe writes:

Honest question he

Is it realistic to expect launchers that could scale much beyond the 15
tonnes that we have now ? Someone mentioned 100 tonnes. Is that
realistic with either H2O2 or Kerosene propulsion systems ?

At oe point, wouldn't these become just too big/high and generate way
too much noise/vibration etc ?

The Saturn V had a payload to LEO of 118 tonnes. Ares V is planned to
have a payload to LEO of 188 tonnes.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

Jochem Huhmann wrote:

The Saturn V had a payload to LEO of 118 tonnes. Ares V is planned to
have a payload to LEO of 188 tonnes.

Ok then. I thought that the Shuttle had some the strongest engines (but
I guess the vehicle itself ate all that power leaving a 15tonne payload).


Ok, so if 120 tonnes is possible and has been done, then I guess it is
quite a realistic payload to expect.