TCS Daily


Is Space Tourism Ready for Takeoff? Probably Not

By Alexander Tabarrok - November 18, 2004 12:00 AM

Earlier this year SpaceShipOne, flew into space twice in five days, earning it the $10 million Ansari X prize and the plaudits of space boosters everywhere. John Spencer, president of the Space Tourism Society called it "a milestone for humanity" that represents "the kickoff of the space tourist industry." Richard Branson the adventurer and entrepreneur, quickly formed a new "spaceline", Virgin Galactic, promising that flights would be offered in just a few years.[1] An Australian newspaper was perhaps the most optimistic it headlined it's story "Space tourism now a reality."[2]

The vision is enticing but the facts suggest that space tourism is not ready for market. The problem is not the monetary expense, there are enough millionaires with a yearning for adventure to support an industry. The problem is safety. Simply put, rockets remain among the least safe means of transportation ever invented. Since 1980 the United States has launched some 440 orbital launch rockets (not including the Space Shuttle). Nearly five percent of those rockets have experienced total failure, either blowing up or wandering so far from course as to be useless. The space shuttle has a slightly better record of safety -- it was destroyed in two of 113 flights. There are lots of millionaires willing to spend one or two million dollars for a flight into space but how many will risk a two to five percent chance of death?

It is true that we have been "learning by doing" or in this case by learning by exploding. In the 1960s the risk of failure was a stunning 12%. As in other industries, learning by doing reduced the failure rate dramatically over the first units but more slowly thereafter. In the 1970s the failure rate dropped to 5.2% but nearly thirty years later the failure rate for rockets still hovers between four and five percent. We can expect similar slow and steady improvements in the future but there is little reason to expect dramatic improvements in rocket technology. Burt Rutan's SpaceShipOne has some innovations such as a hybrid fuel composed of synthetic rubber and nitrous oxide ("laughing gas") and an ingenious design for reentry which may improve safety. In its first trip, however, a control system failed and in another flight SpaceShipOne rolled 29 times.[3]

If progress continues at the same rate as it has over the past 30 years how long will it take to achieve a level of safety of say a 1 in 10,000 chance of failure? Note that in comparison to other means of travel this is very, very dangerous. Commercial airlines, for example, have a fatality rate of .2 fatalities per 1,000,000 departures or a 1 in 5 million chance.[4]

Figure One shows a logistic curve estimated on the basis of the probability of total failure since 1970. Extrapolating on the basis of the curve we find a 1 in 10,000 rate of failure is not achieved until 2217.[5] Consider instead a 1 in 1000 chance of failure, which would be extremely high even for those who take to bungee jumping; at current rates of progress we will achieve that level of safety only in 2130.

It's possible, of course, that we will dramatically improve our rate of progress in rocket safety. If we were able to double our rate of progress, for example, then we could achieve a level of safety of 1 in 10,000 by 2088. Still a long way off for a level of safety that only thrill seekers will tolerate.

Burt Rutan, the visionary genius behind SpaceShipOne, has suggested that in just 10 to 12 years we might see 100,000 spacefarers per year. Let's suppose that somehow we are able to increase safety to a level of a 1 in 10,000 chance of total failure, about 500 times safer than today's rockets. If each launch carries 10 people that's 10,000 launches a year and on average one of those rockets will fail. In some years, many will fail. The view is great but few people will want to pay the price given these odds.

Rocket power appears to be inherently dangerous and not subject to radical improvement. It's always going to be dangerous to strap 4 million pounds of explosive fuel onto your back in order to get lift.[6] The lesson is that space tourism will have to await a new technology such as a space elevator or other such device not yet available and perhaps not yet even contemplated. Richard Branson should know that SpaceShipOne, like the Space Shuttle before it, is not a spacebus and won't be for a long time.

Alexander Tabarrok is director of research for the Independent Institute, a non-partisan public policy research organization located in Oakland, CA and associate professor of economics at George Mason University. He writes regularly for the blog, Marginal Revolution.

NOTES


[1] Space tourism industry takes off, Tapei Times, Wednesday, Oct 06, 2004,Page 16, http://www.taipeitimes.com/News/feat/archives/2004/10/06/2003205826.

[2] Space tourism now a reality, Melbourne Herald Sun, Australia - Oct 5, 2004.

[3] Watson, Traci. 2004. A lot of ground to be covered before space tourism can fly

USA TODAY 10/28/2004, http://www.usatoday.com/news/nation/2004-10-28-space-travel_x.htm.

[4] See the National Transportation Safety Board date for airlines in 2003, http://www.ntsb.gov/aviation/Table5.htm.

[5] Other methods of estimation, such as estimation based on the number of launches instead of time, probit instead of logit etc. do not produce notable changes in result.

[6] The space shuttle requires just over 4 million pounds of fuel to launch.


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