HUMANKIND has made some giant leaps forward, but we still fall back now and again.
The explosion of the SpaceX Falcon 9 rocket soon after launch is a sobering reminder of the uneven progress of technology.
Rocket science put humans on the moon in 1969, when NASA didn鈥檛 have as much computer power as my six-year-old MacBook. Yet launches still fail with alarming frequency. OK, we鈥檙e a way from 1960, when 13 of the 29 US launches did not reach orbit. But with three major failures in the past eight months, we are far from the reliability sought for human space flight, which Falcon 9 is designed to provide now the US Space Shuttle has been retired.
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Why, despite Apollo鈥檚 success 45 years ago, are we still struggling to reach low Earth orbit?
Astronaut Scott Kelly tweeted his answer after watching the Falcon 9 explosion from the International Space Station: 鈥淪pace is hard.鈥�
No doubt about that. Launches are still risky because so much energy is needed to get into orbit and the conventional options for changing that are limited. The Apollo-era Saturn 1B weighed 590 tonnes and could lift a 21-tonne payload. The 506-tonne Falcon 9 can lift a 13-tonne payload. Efficiency has stalled. Fuel still makes up the bulk of the mass of rockets; you could use a more energetic propellant or cut the structural mass of the rocket to reduce the fuel required, but both create safety issues.
We overestimated the success of Apollo. Rockets and human space flight have not followed the exponential improvement many technologies enjoy because of the limits imposed by propellants and that troublesome gravity. So space is not just hard. It鈥檚 also different. We make computers and electronics in huge volumes, so performance and costs scale tremendously. Not so for rockets.
鈥淩ockets and human space flight haven鈥檛 followed the exponential improvement many technologies enjoy鈥�
Tomorrow鈥檚 rockets should be a bit more efficient than today鈥檚, so future private astronauts may need less than the $30 million they pay now. But to explore space in person, we need better ways to get there. That means looking seriously at alternative propulsion schemes and space elevators rather than focusing only on incremental progress.
This article appeared in print under the headline 鈥淪pace is still hard鈥�
