ShuttleA. How realistic is it? Anything better?

[TMac3000]

My proposal is called Shuttle-B. The only changes from the A would be more realistic thrust, and a heat-shielded aerodynamic hull for re-entry. This would require nixing the gimbal engines altoether, which would reduce mass.

And of course, a more complicated virtual cockpit. I mean Dragonfly-level detail.

 

[Andy44]

My proposal is called Shuttle-B. The only changes from the A would be more realistic thrust, and a heat-shielded aerodynamic hull for re-entry. This would require nixing the gimbal engines altoether, which would reduce mass.

What are going to use it for? The thrust of Shuttle A is already realistic; it's the Isp that is unrealistic. A heatshield for a realistic Moon freighter makes no sense since it won't be able to take off from Earth after one re-entry and landing.

 

[Ghostrider]

I see the Shuttle-A as a LEO-Moon workhorse, it may be used on bodies with low-density or no atmosphere but why Earth? We've got DGs for Earth and any dense atmosphere bodies. The good thing about the Shuttle-A is that it's mostly a skeletal chassis with a pressurized cabin, engines, tanks and lots of places to attach stuff to. In the Orbiterverse there are orbital stations to which it can dock, refuel and depart again, it doesn't need to make Earthfall except in an emergency and in this case, why not just put the heatshield on the cabin, separate and re-enter in it? The vehicle would be a total loss after a reentry anyway (if it could realistically survive it) because of structural stresses.

 

[Clavius0712]

My proposal is called Shuttle-B. The only changes from the A would be more realistic thrust, and a heat-shielded aerodynamic hull for re-entry.

As the others have said, forget the heat-shield. The Shuttle-B or whatever you want to call it should be a space tug - a workhorse for transits between orbiting space stations and the surfaces of airless moons. We don't need another Delta-Glider wannabe.

I just want the Shuttle-A with more realism (no atmospheric flights, realistic engine performance) and some easy way of landing the thing on a pad whilst still flying it manually (i.e. descent-rate hold or similar).

 

[Andy44]

Exactly. In fact, as someone else mentioned, why should a LEO-Moon ship even land on the Moon? Eliminate the landing gear and related structure, as well as the need to configure thrusters for a landing (hovers, gimbaled aux pods, etc.) and just go from LEO to LLO and let another vehicle handle ferrying stuff up and down from Luna-LLO. This is the old Heinleinian (among others) idea of a segmented transportation system between Earth and other bodies, and it's the one my addons are based on.

But the Shuttle A is a type of lunar space shuttle that can go beyond LLO and deliver things on a trans-Earth trajectory, so it has to be able to land on the Moon and then some. That's what makes it fun to fly.

For a real challenge, try the following: Launch a Shuttle A from a Lunar surface base, and do a trans-Earth injection (TEI) burn. Then, before leaving the Moon's SOI, jettison one or more of your payload modules and try to make them hit an exact spot on the Earth, say the Gulf of Mexico or the Med. Sea. Then do a burn to return to a closed Lunar orbit and return to your launch site. If the payload reenters and parachutes anywhere near your target site, good job! It'd be more than I've been able to accomplish!

 

[TMac3000]

We've got DGs for Earth and any dense atmosphere bodies.

Okay, but the DG is about the size of a typical medium bomber. Imagine if these craft were real: who wants to sit in a cockpit for four days during a lunar hop? I mean, *man* that is a *long* time without taking a leak.

Although it's not depicted in the sim, the Shuttle-A is supposed to have full crew support for long missions, like a galley, a place to excercise, bunks and so forth. It is much better suited for interplanetary travel than the DG, which is a good craft, but basically a theoretical replacement for the STS.

As for landing on Earth or other planets with full atmospheres, dropping cargo into the ocean from LEO is one thing, but people? You need to land to deliver those.

In short, the Shuttle-A is a full-blown interplanetary vessel, and needs to be able to go anywhere it wants (within reason) in the solar system, including Earth.

To be fair:
1) The Apollo Astronauts sat in a tiny capsule for three days, even though it presumably didn't have full facilities

2) The Space Shuttle stays up for days, but has good enough crew support for what it does.

 

[Andy44]

This is a thread about a more realistic Shuttle A. Realistic means it's not an Earth-landing interplanetary vehicle. What is your point? Do you want realistic or pure fantasy? Which?

 

[Hielor]

Okay, but the DG is about the size of a typical medium bomber. Imagine if these craft were real: who wants to sit in a cockpit for four days during a lunar hop? I mean, *man* that is a *long* time without taking a leak.

Check out the door in the back of the DG...it's a bathroom.

As for landing on Earth or other planets with full atmospheres, dropping cargo into the ocean from LEO is one thing, but people? You need to land to deliver those.

Err, okay, but that landing will be done by a specialized lander craft, not the interplanetary tug. Having the heatshield and related infrastructure is just a waste of mass.

In short, the Shuttle-A is a full-blown interplanetary vessel, and needs to be able to go anywhere it wants (within reason) in the solar system, including Earth.

I thought you said that you wanted this to be realistic? If it's going to be realistic, then it certainly won't be able to go anywhere in the solar system in a reasonable amount of time, and certainly not if it's lugging around all the extra weight of a heat shield.

To be fair:
1) The Apollo Astronauts sat in a tiny capsule for three days, even though it presumably didn't have full facilities

"Presumably?"

 

[Andy44]

Check out the door in the back of the DG...it's a bathroom.

Yes, and after a few days that radiation symbol takes on a special meaning.

 

[Hielor]

Yes, and after a few days that radiation symbol takes on a special meaning.

Hey, but then you save energy on lighting, because you're glowing...

 

[MattNW]

If you decide to have a go at it, would it be possible to have a "descent hold" autopilot? Even a manual "descent rate" text entry box would do. I just need some way of precisely telling the ship how many m/s to descend at so I can do all those beautiful pad landings I've mastered with the XR2.

Don't need all that fancy software. Wait until you are at a reasonable altitude reduce your rate of descent to near 0 then hit the "Hold Altitude" AP. Once you become stabilized turn it off and reduce hover thrust a little with the {.} key on your number pad. Adjust your rate of descent using RCS for small corrections and hover thrust for large. If you also use the level horizon AP you can use the small amount of tilt available with it turned on to control the ship like a helicopter.

 

[Andy44]

Arrive MFD gives you the "descent hold" feature and calls it "antigravity" mode. It's very easy to use, as described above.

The problem with using altitude hold and then backing off the hover throttle is that your mass is constantly dereasing as you burn off fuel and your descent rate constantly decreases. This makes it hard to descend on a steady slope.

 

[Hielor]

Attached is a quick-and-dirty edit of the Shuttle-A mesh to give an impression of what I was thinking of. Obviously if I were actually going to make this I would spend more time on it--as it is, this took me like 15 minutes in Wings.
T
Sorry for the messed-up normals...apparently the msh2obj tool doesn't actually connect any of the elements together, so every polygon is separate.

 

[Sky Captain]

There is no need to make Shuttle A capable of entering Earth atmosphere. For that we have a XR5 Vanguard cargo spaceplane. Just take of from the Moon go to LEO, rendezvous with XR5, transfer the cargo and head back to Moon while XR5 delivers stuff to surface.

 

[Clavius0712]

I'm glad to see this thread still has some life.

FYI, I have now created three scenarios in the Jupiter system, circa 2061, as follows:

1 ShuttleA Callisto to Europa
2 ShuttleA Europa to Ganymede
3 ShuttleA Ganymede to Callisto

All the flights use relatively little Dv and take a mere three or four days of flight time. There are PreludeII bases at each destination and I've added bases to the config files where the PreludeII models are, so I can navigate to them and land on the solitary landing pad of each base. Each flight follows on from the previous one, assuming a few days at each base waiting for a launch window.

I plan to do the same for Saturn soon but am having great fun with these scenarios using the stock ShuttleA.

If anyone wants these scenarios, let me know and I'll post them along with a list of the addons I'm using (for instance, level 8 Jovian moon textures - which really make a difference).

Now if we had a ShuttleA that was really credible, these scenarios would be even better.

By the way, someone said Saturn is a more suitable destination for Earth colonies than Jupiter, because it has a shallower gravity well. I'm not so sure. For instance, a steep gravity well is ideal for orbit insertion manoevres. Pretty much anything thrown from Earth towards Jupiter has a good chance of ending up in orbit around it with just a little braking for orbit insertion. A trip to Saturn would presumably require more braking at the end because it has less gravitational pull to capture a passing spacecraft.

Thanks once again to all contributors.

 

[PhantomCruiser]

Hey I'd like to take a run at those scenarios, sounds like a load of fun. Do you drop-off any cargo containers at each base, or do you just simulate loading and unloading?
I've put an "arm" on my Shuttle-A for cargo manipulation in orbit, and ofter run around with that inflatable module on the nose so I can do EVA's to one station or another.

I like the look of the -B that Heilor has put together too. You guys amaze me, wish I could code so I could help out.

 

[Andy44]

Attached is a quick-and-dirty edit of the Shuttle-A mesh to give an impression of what I was thinking of. Obviously if I were actually going to make this I would spend more time on it--as it is, this took me like 15 minutes in Wings.
T
Sorry for the messed-up normals...apparently the msh2obj tool doesn't actually connect any of the elements together, so every polygon is separate.

That looks okay, I think, but the tail now lacks the mass to balance the crew module. Since cargo is detachable and fuel tanks get empty, putting them back there isn't quite right, either. One silution would be to vary the thrust of the aft jet pods to match the current mass distribution of the vehicle, a la Dragonfly, but that means more ccomplicated coding.

 

[Hielor]

That looks okay, I think, but the tail now lacks the mass to balance the crew module. Since cargo is detachable and fuel tanks get empty, putting them back there isn't quite right, either. One silution would be to vary the thrust of the aft jet pods to match the current mass distribution of the vehicle, a la Dragonfly, but that means more ccomplicated coding.

Yeah, that would be the plan (varying the thrust), and considering the fairly complicated autopilots already proposed, I don't think a simple torque-balancing would be very difficult at all

 

[Clavius0712]

Hey I'd like to take a run at those scenarios, sounds like a load of fun. Do you drop-off any cargo containers at each base, or do you just simulate loading and unloading?

I'm pretty new to Orbiter and have only just started using the ShuttleA as I didn't think it made sense to have a winged craft for Jupiter-based scenarios. Consequently I have just been flying the ShuttleA unloaded. I have looked in the documentation for it and can't find how you're supposed to add payload modules. Do you just edit them into the .scn file?

If you still want the scenarios let me know how you'd like me to get them to you.

 

[PhantomCruiser]

I sent you a PM with my e-mail address (or you could post them here). There is a trick to getting the cargo containers to appear. You can 'spawn' them with the scenario editor, but they are invisible (or at least mine are). I've got to save it, exit, then come back to it, and then I can see them. I found out about here on the site somewhere.