2016 : WHAT DO YOU CONSIDER THE MOST INTERESTING RECENT [SCIENTIFIC] NEWS? WHAT MAKES IT IMPORTANT?

As an adolescent in the fifties, along with many others, I dreamt of the Space Age. We knew what the Space Age was supposed to look like: silver, bullet-shaped rockets rising into the sky on a column of flame, and as they return, descending on an identical column of flame, landing gently at the spaceport. Those dreams led me to a degree in astronautical engineering at RPI.

The reality of space flight turned out to very different. We built multistage booster rockets that were thrown away after every launch. Bringing them back turned out to be too hard. Carrying enough fuel to power the landing and managing the very turbulent flow of the rocket exhaust as the vehicle slowly descends on that violent roaring column of flaming gas was too great a challenge. Indeed even the efforts to build vertical take off and landing jet fighters in the fifties also failed for similar reasons.

The disposable launch vehicle made the Space Age too costly for most applications. Getting any mass into orbit cost many thousands of dollars per pound. Imagine what an airline ticket would cost if the airline threw away the aircraft after every flight. The booster vehicle generally costs around a few hundred million dollars, about the cost of a modern jet liner and we only get one use out of it. No other country, like Russia or China, or any company, like Boeing or Lockheed—all of which have huge resources—were able to solve the technical problems of a reusable booster.

The space shuttle was intended to meet this challenge by being reusable. Unfortunately, the cost of refurbishing it after each launch was so great that the cost of a shuttle launch was far greater than a disposable launcher flight. When I worked on mission planning for the space shuttle at SRI in the early seventies the assumption was that the cost of each launch would a be $118 per pound ($657 in current dollars), justifying many applications with each shuttle flying once a month. Instead, the shuttles could only fly a couple of times per year at a cost of $27,000 per pound, meaning most applications were off the table. So space was inaccessible except for those whose needs justified the huge costs either of a shuttle or a single-use booster: the military, telecommunications companies, and some government-funded, very high cost science.

But in the last few weeks of 2015 all that changed as the teams from two different startup rocketry companies, Blue Origin and Space X, made breakthroughs in bringing their launchers back to a vertical landing at the launch site. Both of their rockets were able to control that torrent of flaming gas to bring them to a gentle landing, ready to be prepared for another launch. Provided that they can do this on a regular basis, the economics of space flight have suddenly and fundamentally changed, coming to resemble airline flight with reusable boosters instead of reusable aircraft. It won’t be cheap yet, but many more applications will be possible. And the costs will continue to fall with experience.

While they both solved the very hard problem of controlling the vehicle at slow speed on a column of turbulent gas, the Space X achievement will be more consequential in the near future. The Blue Origin rocket could only fly to an altitude of 60 miles before returning to Earth and is intended mainly for tourism. The Space X vehicle, Falcon 9, could and did launch a second stage that can achieve Earth orbit. And Space X already ferries supplies and may soon be carrying astronauts to the Space Station orbiting the Earth. So the ability to reuse their most expensive component will reduce their launch costs by as much as 90 percent and over time those costs will continue to decline. Boeing and Lockheed should be worried.

Of course, the Blue Origin rocket, New Shepard, will also continue to improve. Their real competition is with Virgin Galactic, which had some difficulties lately—a crash that killed one of the pilots. They are both competing for the space tourism market and (for now) Blue Origin appears to be ahead.

We have turned a corner in space flight. We can dream of a Space Age again. Life in orbit becomes imaginable. Capturing asteroids to mine or human interplanetary exploration both become much more likely. The idea that many of us living today will be able to see the Earth from space is no longer a distant dream.