Discussion Which base to make next?

[Grover]

since ive nearly finished updating my Port Grover, ive been thinking what kind of base to make next. should i do another earth base, closer to the launch path off Wideawake (like an aborted takeoff landing site), or go for a lunar base.

either way, there probably wouldnt be any geo-meshes (like hills, craters etc), but i thnik i could happily do either

what do you think guys?

 

[boby_nadeau]

There's a island near Wideawake To the North-West, you could build a base here, with one runway, some hangar, a control tower and a little village, with tiles !

 

[Spacethingy]

A base on an asteroid/Phobos*/Deimos*.

We need more other moon bases!

*I know about [ame="http://www.orbithangar.com/searchid.php?ID=168"]this one[/ame], but I think it's the only one for these moons.

 

[Urwumpe]

What about Wallops Island?

 

[Wishbone]

Mars... Jezero Crater (#1 in the list of HEM-SAG priorities), or Mawrth Vallis (http://hirise.lpl.arizona.edu/dtm/dtm.php?ID=PSP_005964_2045), or Holden Crater (http://hirise.lpl.arizona.edu/dtm/dtm.php?ID=PSP_007191_1535).

EDIT: If you choose Mawrth or Holden, I will send you a raw mesh of the terrain, which can be skinned with other HiRISE or THEMIS photos. The real limitation is finding a HEM-SAG spot that is sufficiently close to 0 nominal elevation...

 

[Grover]

hmm, a martian landing strip seems nice. though possibly problematic due to the low pressure atmosphere... how long do you think a runway would have to be on Mars (assuming you can get the very heavy concrete over there) to land on. i remember on X-Plane there was a "scenario" where you could fly a "mars plane" , and the runway was HUGE


or perhaps i could just keep to landing pads and cash in on the lower gravity to make hovering easier

 

[Wishbone]

Think we'll need a pad anyway. Have read many times about rocket exhaust fracturing and fluidizing unprepared soil, with the end result - a lander tilting, or engine damage, or lander falling into the newly-made crater. One of the solutions is using an unmanned rover to bulldoze and grade the pad before manned landing...

 

[Fabri91]

Someone actually tried it out, and it turned out that the runway would have had to be approximately 80km long.

 

[Grover]

80Km? the X-plane runway wasnt that long, although it did take a full minute to get to Vr, because i had to get to such a high speed.

and in that case, it makes it 16 times longer than the runway at my earth base... good job runways are mapped to a sphere in Orbiter

 

[Fabri91]

The test was done in Orbiter, with a DG-like spaceplane, maybe this could explain the different results? It was here on the forum, but it was done quite a long while ago I believe.

 

[Grover]

ill trust the figure... enough to not make a runway anyway.

perhaps a mars base is what i want, i never seem to want to go to mars... i prefer Jupiter anyway, going into such a deep gravity well makes navigation of moons incredibly dificult

 

[Wishbone]

Basing off Design reference architecture, there will have to be quite a few markers.

First, to indicate the limits of surface reactor's maximum shielding zone (a wedge), with the reactor itself being 1 km away from the base center.
Second, flag-like markers along the cable from the reactor.
Third, a milepost with fingerposts (Olympus xxx km, Valles Marineris yyy km, Houston TX zzz million km, London... Moscow...).
Fourth, markers for a high-gain dish in a radome, and a cable from it.
Fifth, garbage dump area.

 

[Tommy]

I'd put in a runway. Don't think I'd make it 80km!

Even if vessels need hover assist to use it, a runway can still save fuel. Given a bit of time, and a good Mars base with a reasonable runway I bet someone comes up with a Mars Glider - a DG like craft designed for the thinner atmosphere.

 

[Wishbone]

Here's the milepost (attached).

EDIT: re - runways. If we are going to be realistic, who or what will make the runway? There is currently no way to put a heavy robotic dozer/grader on Mars unless there is a pad done first that could tolerate 20- to 40-tonne lander and its exhaust.

 

[Spacethingy]

Martian runway take-offs are hard.

I tried one in a DGIV... the wheels fell off before I reached take-off speed... :lol:

Couldn't a landing strip be made small, as a kind VSTOL thing, with hover engines used to shorten the stopping distance required? Carefully hovering and steering around with RCS to get over a pad is difficult and fuel heavy. Could runway landings be more efficient, even with a bit of hover assistance?

 

[N_Molson]

Carefully hovering and steering around with RCS to get over a pad is difficult and fuel heavy.

I'm pretty sure that an helicopter pilot wouldn't agree with that. Any one over there ?

 

[Urwumpe]

I think for properly landing on a martian strip without VTOL, you should at least need post-stall and thrust vectoring available to reduce your speed for touchdown.

But VTOL solutions will likely be superior because of many reasons, especially because of the low gravity.

EDIT: as small addition for the discussion: Quickly drop this stupid "It will make a crater" nonsense. Unless you quickly ram the lander into the soil, you will have large technical problems to produce even intentionally a crater.

A Mil Mi-26 helicopter has a maximum take-off weight of 56,000 kg, which means its lift-off force will be about 550 kN. I never heard any report about a landing Mi-26 getting shallowed by the crater that it formed below it. It is about pressure.

If you concentrate 550 kN force on a really tiny spot, you can blow loose soil away and form a steep crater. If you spread the same force over a larger area, you will just create a shallow depression when the top soil is blow away. Even if you hover for a long time over the same spot.

For landing a 50,000 kg lander (landing weight, not maximum weight) on Mars, you just need around 185.55 kN thrust force. You could easily have the force act just on one third of the ground area as the Mi-26, and not get even close to any serious soil damage.

 

[Spacethingy]

I'm pretty sure that an helicopter pilot wouldn't agree with that. Any one over there ?

Yeah, but I'm talking about 60 tonne spaceships, not 1/2 tonne Robinsons... :lol:


Seriously though, could some sort of aircraft carrier capture thing be used? That would make a runway REALLY short...

 

[Urwumpe]

Yeah, but I'm talking about 60 tonne spaceships, not 1/2 tonne Robinsons... :lol:

Shouldn't still be very hard, unless you try aerobatics.

Seriously though, could some sort of aircraft carrier capture thing be used? That would make a runway REALLY short...

Since the landing speed is very high without any powered landing - no. Even there are limits.

 

[Wishbone]

If you are using arrestors, who is going to ship the gadget to Mars and how will it land there in one piece? A variation of chicken and egg problem...

EDIT: re - cratering or , in newspeak, bearing capacity failure. This is too large an unknown to rely on Mi-26 or V-12 data, neither of which blow hot gases under their bellies. We can't simply scale up Spirit or Opportunity or Viking.