X-37 Variants as Space Taxi?

[sftommy]

With NASA's near-goals apparently set, the Air Force's X-37B appear to be one of our fastest ways to return to manned space flight. With the Atlas V-501 as a launch vehicle, one test flight will happen this week and another scheduled for 2011. One speculation suggested a variant could carry s many as seven astronauts. 2004 Launch cost for an Atlas V was $138m, meaning $20m per seat, anyone know current launch cost?

If successful should these X-37 technologies be shared with private developers for designing variants?

United Launch Alliance's website says they'll broadcast this weeks test launch live.

 

[MelvinOfTheApes]

I actually think that's a great idea, even if we use the X-37 as a kind of "short bus" to haul astronauts the the ISS until we get the next gen space craft ready to roll. Plus, the x-37 makes me feel a little better about our standing since it's not a space capsule, but a ship. It rides and launches like a capsule but it flies and lands like a space ship. If the auto piloting and navigation works as good as they say it's suppossed to, it could be like a Space Marta or Space Metro. I'm onboard with that idea. Just spitballing here.

 

[voyager4d]

The X-37 has many things going for it, and can be used for many cool things.
But I doubt that the current size can be used for human transportation.
Here are some numbers:
Weight: 5,000kg (11,000 pounds)
Length: 8.9m (29ft)
Width(wingspan): 4.5m (14ft)
Height: 2.9m (9ft)
Cargo bay: the size of a pickup truck (can't seam to find exact numbers on this).

It is launched on Altas 5 501 with 5.4m payload fairing (max 8,2 tons to LEO).
So the wingspan and height will be the biggest problems in making bigger versions of X-37.

Anyone know how big a version, it would be possible to launch, on a Atlas 5 HLV (25tons to LEO) or a Falcon 9 heavy (39tons to LEO)?

 

[RVHM]

I don't think so, it's a military spaceplane. It's like asking whether tanks would make good road taxis.

 

[edkyle99]

With NASA's near-goals apparently set, the Air Force's X-37B appear to be one of our fastest ways to return to manned space flight. With the Atlas V-501 as a launch vehicle, one test flight will happen this week and another scheduled for 2011. One speculation suggested a variant could carry s many as seven astronauts. 2004 Launch cost for an Atlas V was $138m, meaning $20m per seat, anyone know current launch cost?

X-37B can haul a 227 kg payload, not enough to carry probably even one astronaut with associated spacesuit, air supply, etc. Scaling X-37 up to carry astronauts would make it too big to fit on an Atlas 5 Medium. It would have to fly on a Heavy something, which means much more money per launch than $138 million.

I very much doubt, BTW, that an Atlas 5 launch only costs $138 million. DoD is paying more than that per average launch to ULA just to maintain the launch infrastructure.

- Ed Kyle

 

[sftommy]

I watched a Russian space entrepreneur complaining about the secrecy of this launch and vehicle, how damaging the secrecy is to world space policy, etc, etc
even now CNN is calling this a mystery space plane

and yet;
This is so much info available on the internet about this project, about so many facets of it; from design, and construction, to launch parameters, to some very clear suggestions about it's mission that it's one of the least secretive of modern day defense projects.

 

[DarkenedOne]

With NASA's near-goals apparently set, the Air Force's X-37B appear to be one of our fastest ways to return to manned space flight. With the Atlas V-501 as a launch vehicle, one test flight will happen this week and another scheduled for 2011. One speculation suggested a variant could carry s many as seven astronauts. 2004 Launch cost for an Atlas V was $138m, meaning $20m per seat, anyone know current launch cost?

X-37B can haul a 227 kg payload, not enough to carry probably even one astronaut with associated spacesuit, air supply, etc. Scaling X-37 up to carry astronauts would make it too big to fit on an Atlas 5 Medium. It would have to fly on a Heavy something, which means much more money per launch than $138 million.

I very much doubt, BTW, that an Atlas 5 launch only costs $138 million. DoD is paying more than that per average launch to ULA just to maintain the launch infrastructure.

- Ed Kyle

As far as scaling the X-37 goes the biggest problem is with the wings. The Atlas V can hail up to 10500 for the version they are using, which means that the Atlas V is only hauling half of its max payload.

If they can design the X-37 to fly without the fairing like the Dream Chaser design than it might work.

In any case I am not sure if space planes are even worth it with all things considered.

The only advantage that space planes have over a capsule design is that they are able to land on an ordinary runway.

The disadvantage is that space planes are an order of magnitude more complex than capsules. Most obviously this leads to higher development and operating expense as we have seen with the shuttle. The increased complexity also leads to a higher chance of failure as we have seen with the shuttle. At the same time you have to factor in all of the weight added by the wings, actuators, and heat shielding for all of the parts etc. The shuttle orbiter, for example, weights 100,000kg even though it only has a 20000kg payload.

Like I said I really do not think that it is really worth it. I think that is the general consensus at NASA too considering that they are going back to the capsule design.

 

[Gravity_Ray]

Although the X37B is a military bird and is designed for military use (I still think its more offensive than just pop up recon), I think the concept of a reusable winged shuttle type space ship is feasible for other applications.

The problem with the shuttle system is that it was designed by committee. The shuttle systems such as the Thermal Protection system (TPS) are very hardy and shouldn’t be discarded because of issues with the shuttle. The problem isn’t the tiles but the fact that the shuttle got so big that it had to be side mounted. This caused most of the problems for the shuttle.

However, if you truly redesign the shuttle and make it smaller say for 6 to 8 people (no cargo) you can still mount it on top of a rocket (say a Saturn V). I think it’s worth at least a consideration rather than throwing out the baby with the bath water. Without cargo there will be a lot of room for people and it can be used for a LEO taxi.

 

[pmn1]

I don't think so, it's a military spaceplane. It's like asking whether tanks would make good road taxis.

Well, I would prefer a tank to a taxi on the roads these days....

 

[sftommy]

I very much doubt, BTW, that an Atlas 5 launch only costs $138 million

Tough to track down current prices, but this years budget for the JUNO Mission has an entry of $190.4M for launch vehicle-which is the Atlas V 551. Could be a 2008 dated cost estimate as it hasn't changed from base-year-2008, my source is pages 153-154 of the NASA_FY_2011_Congressional_Justificaton_Budget_Book_Rev-01

 

[stevekk]

I don't understand how you would even try to fit people in the current X-37 design.

The only real available space would be the cargo hold, squeezed between a couple of highly toxic fuel tanks. The single passenger would probably have to duck under the solar panels as well.

Besides, this thing rides to space inside that 5-meter fairing mounted to the top of the Atlas rocket. Since I assume the X-37 is safely tucked inside that fairing for at least a couple of days before launch (who knows with a 10-15 day turn-around), that means the passenger is stuck in the cargo bay for a while.

I can the development of a completely new space vehicle based on the concepts that have been proved out by the X-37, but please stop talking about putting people inside this thing.

Just think of this vehicle as the next-generation pilot-less drone aircraft. I half expect next year's model (OTV-2) to include a robotic arm to enable it to grab satellites that were deployed by itself, or OTV-1.

 

[sftommy]

but please stop talking about putting people inside this thing.

OK, let's start talk about putting people in a variant of this thing!

The variant would have to be some percentage larger, the forward fuel supply would have to be moved aft. Passenger accommodations would be limited, probably to the pilot(s). The question of G-forces on landing is perhaps the fatal question; this vehicle seems to land much harder than say the shuttle. Wings and launch cowlings are an engineering problem, but not an insurmountable one.

All in all, I would agree the design changes needed will probably make a newer winged craft arise on the NASA drawing boards.

The space shuttle’s too big, the X-37b is too small…

 

[edkyle99]

I very much doubt, BTW, that an Atlas 5 launch only costs $138 million

Tough to track down current prices, but this years budget for the JUNO Mission has an entry of $190.4M for launch vehicle-which is the Atlas V 551. Could be a 2008 dated cost estimate as it hasn't changed from base-year-2008, my source is pages 153-154 of the NASA_FY_2011_Congressional_Justificaton_Budget_Book_Rev-01

Hard to know what's in that price. The Air Force pays ULA hundreds of millions of dollars each year for a "Launch Capability Contract" ($927.7 million in FY2010), for example. Does NASA reimburse USAF for its share of that LCC cost? If so, is it part of the Juno launch price?

Either way, someone (U.S. taxpayers) are paying $927.7 million per year just to keep the program alive. That's $115 million per flight when amortized over the recent-average eight EELV flights per year, just to mow the grass at the launch pad, etc.. The actual launches themselves cost extra.

- Ed Kyle

 

[Booban]

This test flight will demonstrate the feasibility of the reusable space plane concept using modern technologies better than the current manned shuttle. If those tests show that reusability is indeed cost effective, I think it is a no brainer to scale this up to act like a space taxi.

A taxi version for people can be made, a separate one for cargo can be made. It doesn't even need a driver, save money training astronauts for that!

With capsules they are just thrown away. A single reusable space plane perhaps can be used 50 times. Do you think that one reusable space plane should cost more than 50 capsules? It shouldn't be that hard! Its just a matter of low maintenance and high durability.

 

[stevekk]

I have no problem using this to prove out the feasibility of using certain technologies. That's what X vehicles are all about. If the new heat shield works as well or better than the old ceramic tiles, that's exciting. If this vehicle can be ready to launch in 2 weeks or less, after spending 9 months in space, that's an exciting breakthough. Maybe someday, we will find out what type of missions they have designed for this vehicle. I really want a robotic arm included, so it can retrieve stuff from up there, not just add to the existing clutter.

But this is no closer to a shuttle replacement than the Direct designs.

There is no concern about "man-rating" the Atlas V rocket, the aero-dynamics of a larger vehicle would be different (wing size / shape, maybe even location). The tail is V shaped only to fit in the 5-meter fairing. It may be a better design for such a small ship, but does that hold up when it gets scaled up 50 percent ?

 

[bdewoody]

I don't think so, it's a military spaceplane. It's like asking whether tanks would make good road taxis.

It started life as a private venture and there is no evidence that the Air Force plans to use it as a weapon. It's more like a Humvee that can evolve into the highly successful Hummer.

It is a good basic starting point for a small 3 or 4 manned crew taxi to the space station.

 

[vulture4]

The X-37B is a redesignated X-37. It was originally a NASA project, part of the Reusable Launch Vehicle program in the 1990's along with the X-33, X-34, and DC-X. None of these vehicles were intended to be operaitonal. They were designed as technology demonstrators, to test propulsion. structures, aerodynamics, guidance, navigation and control and thermal protection concepts for a new generation of manned space shuttles that would be fully reusable, practical, and safe. In other words, its original mission was to help develop a real "space taxi". Sean O'Keefe and Mike Griffin don't seem to have understood that human spaceflight is much to expensive, and stamped out all NASA work on modern reusable launch vehicles. It's good to see DOD recognize the value of reusable launch vehicles, but it's disappointing to see NASA become essentially irrelevant in the development of advanced launch vehicles.

The X-37B is also a technology demonstrator for a reusable launch system. It makes no sense to talk about its military mission; its mission is simply to develop the technology for an operational reusable spacecraft that will be a transport for launching and retrieving orbital payloads. AS a technology demonstrator, the X-37B was made as small as it reasonably could be and still provide a valid test of the technology. It is too small to carry most DOD payloads, so an operational vehicle will probably be larger. As to the V-tail, the Shuttle vertical fin is in the wake of the fuselage during much of the hypersonic entry and so not very useful. More important is the long control moment with the wings forward and tails aft, which gives it much greater pitch controlability and CG range than the delta-winged shuttle.