Rocket Men

By Larry Niven
Special to SPACE.com
posted: 06:45 am ET
16 June 2000
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The eighth "Access to Space" convention took place April 27 through 29, 2000.

I've been to several of these. I love them. They are people gathered to beat out the details of low-cost access to space...usually to low Earth orbit. Years ago I went home with a cluster of ideas that perfectly shaped a crime story set on the Moon.

I've heard a man promoting leftover Soviet launch rockets.

I've talked to a man who sells half a minute of free fall; he's got a plane that does the paraboloid maneuver. He was all set to sell that to the Apollo 13 producers when NASA stepped in and did it for free.

I've listened in the hospitality suite while a man talked about fullerine (carbon-60). "Somebody must have done certain cheap and obvious experiments! Why can't I find anything on the Net? It's not being reported!" He was furious.

I know half the people who attend. We've all watched each other try to build commercial spacecraft over the years. Mostly we fail.

Two immediate impressions:

This year they're all talking like businessmen.

And it's depressing them.

Now how would I, a professional daydreamer who believes everything a publisher tells me, know when these people are behaving like canny if cynical businessmen? Because I brought Brenda Cooper, that's how. Brenda is a Council member in the tiny town of Longview, Washington. Sure she knows business from bullshit.

"These guys sound intelligent and rational," she says.

Was it thinking in business terms that had them depressed? Maybe not. Some businesses have collapsed in the past year or two.



See Roton in its natural habitat


Two were schemes for tourism in space. They were collecting money to build and run fleets of spacecraft capable of going up and coming down. One was a two stage airplane, to give passengers roughly an hour of free fall in the troposphere. The other was one stage, same purpose. Neither got past paper to anything that flew. For that matter, I didn't love their designs (though loving a rocket ship is easy for me), and I couldn't get my mind around the benefit of building a vehicle to just go up and down.

Then there's Rotary Rocket. We all know Gary Hudson. He was designing Phoenix rockets for 20 years. These were all small one-stage ground-to-orbit ships lofted by an aerospike engine, returning to Earth butt first. Of course butt first. The rocket motor goes back there, and it's always going to be the heaviest part.

Gary's Phoenix designs became DC-X1, an unpiloted X-plane which would have led to a one-stage ground-to-orbit craft, the Delta Clipper. But the Clipper went through some redesign, and then we gave the DC-X1 to NASA and they blew it up immediately. Ultimately the Venture Star beat our design to become X-33. It won't fly because they want it to land facing forward and the butt is too heavy.

Meanwhile, Gary started playing with another concept: rockets at the tips of a helicopter rotor. The long blades make a terrific turbine, delivering fuel and oxidizer fast to the tips. The atmosphere becomes free reaction mass. In vacuum, turn the tips so the rockets point backward. Refuel in orbit, land a helicopter on the Moon.

But no blade material will really stand up to such treatment, not until we can build with some unreasonably strong material such as fullerine tubules. It's perfect for science fiction writers. Meanwhile, as Rotary Rocket, Gary went to a vehicle that uses folded-up blades for landing, with a spinning aerospike motor to put it in orbit. He's tested the landing system. Now he's run out of money, and he's left with a cross between a lighthouse and a helicopter, and it flies like that too, but it has to be dropped.


What's the Pioneer strategy for achieving orbit?


It wasn't all gloom. Mitchell Clapp isn't depressed.

We first saw him as an Air Force officer, and what he wanted to build was an airplane-like rocket that takes off with its hydrogen peroxide (the oxidizer) tank empty. Go up, take a full load of H2O2 from an Air Force tanker, then go to orbit.

When he turned civilian he'd changed the design too, but it still took off like an airplane with one tank empty. The name had become Pioneer Rocketplane. His emphasis is still on a mission that can be run cheaply and scrubbed at any point.

This year he's talking like this. "The way to make a combination rocket and jet is to design the best rocket motor you can. You don't need a good jet. Using ambient air is a miracle anyway, scoop it any way you can, but when you run out of atmosphere you need a rocket." If he's right I could design it myself.

But the point may be that he didn't have pictures. Lots of attendees didn't have pictures.

In previous years I've come home with some beauties. I remember scrambling for posters that showed three proposed variations of X-33. This year, Mitch isn't giving away secrets and Gary isn't either. It would be good to think they've got something to keep secret.


XCOR rocket engine at play


Jeff Greason of XCOR Aerospace isn't depressed.

XCOR are the new businessmen, and at least some of them came straight from the downsized Roton. They want to build whatever someone wants to buy. Maybe rocket motors for someone else's spaceplane. Maybe a replica of the Bell X-1, upgraded by 50 years of aerospace technology; they already have designs for that. But customers for antique warbirds seem more interested in flying a remake of Hitler's armed rocket planes, so it may be they'll build that.

XCOR looks like serious business. They ran a tiny rocket motor in the ballroom of the Holiday Inn, with full approval of the Fire Marshall! They passed out ear plugs first. The rocket is in an open box of clear plastic. They did a demonstration Friday, and it worked fine, and they repeated it Saturday and it worked fine again, on time both times.


Laser propulsion remains big. Tests have pushed us a little further in that direction.

Jordan Kare continues to refine his designs. Originally he wanted to use pulsed defense lasers from SDI (Star Wars) for launches whenever there wasn't a Final War going on. Those didn't get built, so his current vehicle would fly via a noncoherent diode laser. He wants to use it to launch nuclear waste out of the solar system. He's ready to build now.

It still feels like that's long years away.

But TGV Rockets wants to build a reusable medium-payload sounding rocket, low thrust takeoff, carries a crew of one. I'd ride that. My reaction surprised me: I had no interest in the tourist aerospaceplanes, because they weren't ambitious enough. This less ambitious craft would go to the same place, but it has a purpose...something beyond winning the X-Prize, though it would do that.


This year we're thinking like businessmen. That's good, right? Dreamers we've got. We need the Man Who Sold the Moon.


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