The Business Case for Reusable Launch Vehicles

An anonymous reader writes "Remember the failures of "shuttle replacements" like VentureStar? A Space Review article argues that even if VentureStar succeeded technically, it and other proposed big RLVs would never have made it financially: they cost too much to develop and wouldn't have made it up through increased launches. What's the solution? The author says that suborbital RLVs, like what Carmack, Rutan, and the other X Prize contenders are working on, will create a business cycle that will eventually lead to orbital vehicles."

Comments

What About The Origional RLV?

[MBCook]

I just saw a thing on the shuttle a few days ago that aired on the History Channel. They said that the shuttle was origionaly designed to have an RLV, but it was canceled due to budget concerns. It was supposed to launch with the shuttle on it's back, and would fly up near orbit where the shuttle would detach and fly the rest of the way. The RLV would then land so that it could be used again. It looked sort of like a plane. Has anyone thought about updating the design for this thing and making it?

The best picture I could find was this one on HowStuffWorks.

Where is the "killer app" for suborbital vehicles?

[RocketRick]

While the article does make some good points about the high development costs, technological hurdles, and poor ROI on reusable orbital vehicles, I think that there is very little evidence of any solid business case for reusable sub-orbital vehicles. Just because it's not cost-effective to build and fly ROVs doesn't somehow make RSVs any more logical.

As a development step leading to the next ROV, an RSV may make sense. I am the first to admit that *anything* that gets the public to refocus their attention (and money) on the pursuit of space-related technological goals is a good thing, as it will inevitably drive the aerospace industry to push the engineering envelope in many areas, particularly in materials science (things like new composites, high-temperature ceramics, etc.). Technological advancement is a worthy (and, ultimately, profitable) pursuit.

But, in and of itself, as a "working vehicle", I can't see any suborbital spacecraft making money. There just aren't that many rich "space tourists" around to subsidize this as an industry. Suborbital vehicles are completely useless for the two main "space jobs" that countries and/or companies are willing to pay for: satellite launches and trips to the ISS.

Low Earth Orbit (LEO) is a useful destination. If you can get "stuff" into LEO, later trips can bring more "stuff", and, if you bring enough pieces of another space ship to LEO, you can assemble them there, and can go to other places. In terms of energy, LEO is truly "halfway to anywhere". One of the (rejected for complexity and deadline reasons) proposed Apollo moon landing plans involved assembling a Earth-to-Moon ship in LEO from modules launched over a period of time using multiple smaller launchers.

But, suborbital vehicles, by definition, can't reach LEO. Anything launched sub-orbitally *will* return to Earth, usually sooner, rather than later. There's simply no market for delivery vehicles that always bring their cargo back, and never leave it at the destination!

Bottom line: it may make sense to use an RSV as a technology test-bed as a step on the path to developing an ROV. It makes no sense to develop an RSV as an end in itself.

Re:Business case?

[Anonymous Coward]

...then imagine how much they'll pay for the experience of zero-G sex! Screw the mile-high club, I wanna join the 800-mile high club!

Space Elevator

[mumblestheclown]

Or, we do what we should be doing NOW:

1. Funding to nanotubles.
2. Use remaining shuttle flights to build a space elevator. Low estimates put this at 6 flights - let's conservatively double this to 12.
3. Space elevator by 2015 is a possible reality - financially and technologically.

Roadblocks:

• "rocket culture" at NASA
• "astronaut culture" at NASA
• materials science issues are quickly disappearing
• some probability of catastrophic (not deadly, just catastrophic) failure early on. must be budgeted using real-options analysis.
• 10-20B USD. This can easily be funded without "coalition" help. The US would soon own space like never before, as ESA's rockets would quickly look outdated.
• Defense concerns - the notion that a space elevator is vulnerable to, say, hostile fighter planes.

SPACE ELEVATOR NOW - it's good science, it's good policy.

Re:Space Elevator

[WolfWithoutAClause]

Currently, nanotubes cables are not strong enough to make space elevators, they may never be for all we know. It looks promising but it's premature to start building something without all the ingredients to make the cake rise.

The problem, as I say is the cable. The current state of the art is about 72 GPa threads multiple centimeters long. That's extremely promising. Trouble is, nobody has built a strong rope from those threads yet. Splicing normally loses 20% of the strength; pretty much we need 65 GPa strength to reach orbit- plus a safety factor; but the carbon nanotubes are really slippery right now- sticking or splicing them doesn't seem to work.

The second problem is nearly as bad. The projected cost is maybe $20 billion (for example, nanotubes are thousands of dollars per gram, but you need ~20 tonnes for the initial 'seed' cable).

This means that the cost of putting something up the elevator (which takes a couple of weeks anyway) is projected to be something like $500/kg (bearing in mind that the money would have to be borrowed and repaid, quite a lot of the money is repayments of the loan). That's only slightly better than a rocket can do right now- and incidentally the same nanotube technology probably allows much cheaper/better rockets to be built.

Then there's the radiation problem- the space elevator goes all the way through the Van Allen belts and out the other side. The Van Allen belts are really nasty- the Apollo astronauts got something like 1% of a fatal dose during the few hours they took to go through them, but an elevator goes much, much, much more slowly. That means heavy shielding, but the shielding cuts into the weight that the elevator cable can carry- you're talking about a foot thickness of heavy shielding all around the elevator. So the elevator is mostly only good for freight until you have a really beefy cable (expensive), or unless you can remove the Van Allen Belts (HiVolt is one proposal to do that).

Rockets are antiquated

[ScrewMaster]

Let's not forget that there are a number of potentially viable alternatives to strapping oneself to a controlled chemical explosion and hoping it gets you where you want to go.

The mass-driver concept pioneered by MIT is one that could provide continuous access to near-Earth orbits with clockwork precision. It would be expensive to build and run, but once running would reliably put anything we want into orbit, continuously, twenty-four hours a day.

Another possibility is the laser-launcher. A rocket fueled simply by tanks of water would be heated by a bank of ground-based lasers: the resulting superheated steam would lift the vehicle into the desired orbit. The energy to propel the spacecraft would come from the source powering the lasers, not from any chemical fuel in the vehicle itself. This system would have the advantage of not requiring massive acceleration: laser power could be modulated to provide a comparatively gentle takeoff.

The irrational focus on self-contained launch vehicles is the problem: there are ways to get the required kinetic energy to the vehicle without an on-board fuel supply. Granted, it might take a nuclear power plant or two to run either of the above options, but that's a lot cheaper than building even a single space shuttle, much less developing and flying the current crop of pie-in-the-sky alternatives. Current estimates put the cost of a single space-shuttle launch at 1.5 billion dollars (I suspect that's conservative.)

And hey, when one of these gound-based launching systems isn't boosting spacecraft into orbit, it can be connected to the local power grid to light homes and businesses. Sales of power to the local utilities could be used to help offset launch costs.