15 May 2002
Features - Vehicles (Good)
RVT, The Little Spacecraft That Could
The leading edge of Japanese rocketry
by Carol Pinchefsky
From a conversation with Professor Yoshifumi Inatani
The Institute of Space and Astronautical Science

(as told to Carol Pinchefsky)

Up until the year 2000, the Japanese people spent a lot of time discussing the possibilities of the next hundred years. But since the turn of the century, no one has thought about the future. 'The future' was last year. Now it's time to take another look.

My name is Dr. Yoshifumi Inatani (Ph.D, Aeronautics), and I am a professor of the space system engineering division at ISAS (the Institute of Space and Astronautical Science). ISAS is a university organization here in Japan, not a branch of NASDA (the Japanese National Space Development Agency). NASDA is the equivalent of America's NASA; conversely, we're the 'little league' baseball players of space.

Yoshihiro Naruo (left) and Yoshifumi Inatani standing in front of the reusable RVT-6 rocket
In our research lab outside of Tokyo, we build rockets. After the cancellation of the DC-X project by NASA, ours is the only rocket in the world specifically designed for reusability. While NASDA was suffering launch failures and subsequent recrimination, we were performing our first and second flight series. Not too many people support what we do, but the number is getting larger and larger. Slowly.

In the past aerospace engineers limited their ideas to missile-based rockets; American and European engineers who received their funding from their governments particularly suffered from these prejudices. I was also in this position.

But a grassroots movement gave us a new way to think about space: Instead of modelling space programs after the military, they should instead be based on the aircraft business. I decided we rocket engineers have to change our ideas.

Four million people fly on airplanes each day, more than 1 billion people per year. Eighty per cent of travelers pay money out of their own pocket; 20 per cent fly for business.

According to market research carried out by Professor Patrick Collins, we can expect 1 million Japanese passengers for space tourism per year. The general public would be willing to pay two to three times their monthly salary for a trip to space. We're encouraged by this research. Now we just need to build a rocket based on those requirements.

To carry 1 million passengers each year, we can calculate how many vehicles to build, their size, and how many passengers each ship would take. With those requirements, if a vehicle takes 50 passengers and flies every day, a million people per year can be satisfied using the Japanese Rocket Society's Kankoh-maru design.

We don't have anything like the Kankoh-Maru. We have a different sort of vehicle altogether, much smaller and just experimental, the RVT (Reusable Vehicle Test). We've nicknamed it '100-yen onigiri', because it looks like the triangular rice balls that are eaten like sandwiches here.

The RVT-6 in its hangar at ISAS [larger image]
Our RTV uses a hydrogen-fuelled rocket engine. Liquid hydrogen is difficult to take care of because of its cryogenic characteristics -- it's kept at minus 250 degrees Fahrenheit -- but it's absolutely necessary from a performance point of view: Only liquid hydrogen will get a single-stage vehicle like Kankoh-maru to orbit.

Our current vehicles are small by comparison with rockets that get to orbit, but a small vehicle is cheap and so gives us a good opportunity to test how we launch, land, and turnaround quickly and safely.

Our test environment of a fifteen-second flight is a very precious opportunity for us. Our vehicles rise only a few meters, but from that, we learn. (Currently we're working out some problems on the composite propellant tanks.)

If something happens to a typical ELV (expendable launch vehicle), the mission would be scrapped, the vehicle destroyed and jettisoned into the Pacific Ocean. But for us, the architecture of the flight is totally different. If something goes awry, we can abort the flight and safely rescue the vehicle intact.

It's efficient and economical because it has to be: We have to make maximum use of a repeated flight environment. We have only one craft (though it goes through periodic) upgrades, and if we lose it, we lose everything. We're very fearful of flaws, so we go through many checks to design a flawless vehicle. The system is as sound as we can make it. In case you couldn't tell, ours is not a new vehicle.

One hundred percent of our funding comes from ISAS, and we have had funding for three years' work. Our department receives Y50,000,000 a year. In other words, we build and fly our reusable rockets on less than half a million dollars per year. The X-33 cost the United States $1.3 billion and did not even fly.

(Americans are always developing and investing in new technologies. We've noticed they start their projects quickly -- and give up quickly.)

So how do we do so much with so little? Because we couldn't afford to buy new equipment, the first thing we did is collect existing materials. So we raided our ISAS neighbors' garbage. We used old utility parts, like high-pressure tanks. We collected and rebuilt them, like Frankenstein's monster.

Our ship is one hundred percent automatic. If something mysterious happens, we can send it commands, but if everything is normal, it flies automatically, preprogrammed. Each and every second we check to determine whether the system is sound or not. If something goes wrong, the ship immediately makes an emergency landing.

We call each test a 'flight envelope extension,' not a rocket launch, because we're gradually expanding our flight envelope several meters at a time. We're sending our vehicle to the height of 100 meters in our next flight. Our next test will be an in-flight engine restart. We love danger.

We established a vehicle design target independently from the 'X-Prize' five years ago, but the requirements are much the same. Theirs is to carry three passengers to space and then return to space within two weeks. Our planned vehicle could do that too -- if the passengers are very small children! Unfortunately full-grown adults are another story.

Our test vehicle is unmanned. We hadn't been thinking about manned flight, but the situation is changing. In our original proposal the cost estimate says it would take $US100 million dollars. So just a small amount of funding will take care of suborbital flights.

If funding is properly allocated, and if we can keep our team together, within four years we can build a suborbital vehicle. This program should cost 100 million dollars. Of course, for an orbital flight vehicle, billions of dollars would be necessary.

But manned flight is different. Japan has never carried out manned spaceflight activities in the past. It was more or less taboo to talk about manned flight using a Japanese rocket. Maybe there's no one brave enough to go to space in a Japanese-built expendable launch vehicle. And no wonder -- an ELV is sort of like ammunition in a big gun. One wrong move, and everything is destroyed.

Right now, American engineers are currently working on a replacement for the space shuttle. These shuttles currently carry equipment for the International Space Station, as the United States is not willing to handle tourists. We don't believe this is the best solution. We believe the reusable launch vehicle will be the vehicle of the future. So it is up to us to persuade our community to change their understanding about space.

Unfortunately Japanese space policy currently follows the Western world. Without America, we can't seem to make important decisions concerning space. It's a pity, because Toyota, Honda, and Sony are world economic leaders, and with space tourism, we have a chance to do something new.

What aerospace technology we have is manufactured as subcontractors; for example, the Japanese aircraft community builds equipment for Boeing. I am not satisfied with that. It would be much better for our now-foundering economy if we did our own manufacturing. In order to be competitive, we have to be very ambitious and not be fearful of building new industries. Otherwise, we will always just be subcontractors -- or sub-subcontractors.

So what about the future that Japan was so interested in in 1999? I want to build reusable launch vehicles and apply them to a business model. I've asked our Space Activities Commission to make an investment of ten billion yen over four years. Until we're given those resources, we're going to continue tinkering with our spacecraft and making it better.

Our new prime minister promises to be a revolutionary despite his own party's resistance against him. Will the new prime minister help unearth our aerospace industry and encourage it to grow? Unfortunately, at present he doesn't even know who we are.

What we need is pressure from outside sources. We have to promote our activities and get acceptance. That's our goal for this and next year. That's why we're continuing our test campaign.

We need support from the Japanese public and taxpayers, otherwise the government will never make this idea a reality. If we can't prove the public supports us, our government will never consider our work seriously. But if we have enough support, they can't say no.

Japanese business is famously conservative, and the government does not like change. Because of that, our economy has taken a beating. We can solve our very real financial problems by developing reusable launch vehicles. And this is not just for business today, but business for the future.

If we pattern our operations after the aircraft business -- where we keep a fleet in the air rather than one rocket at a time -- we can expect an annual revenue of more than US$20 billion.

It will take a lot of work to put a great deal of material into space every day, but it gives us a pretty concrete image of the future. I don't know how long it will take, but it's a thoroughly obtainable reality, and we're more than happy to help achieve it.

The future is a totally different world...and if change isn't made, tomorrow does not come.
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Carol Pinchefsky 15 May 2002
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