Jim Batterson, one of my old friends from college, wrote me about Friday’s SpaceX launch, and his thoughts were so interesting that I asked if he would turn them into a short post. He kindly obliged.
The launch is scheduled for early tomorrow (5:49 a.m. Eastern time, 4:49 a.m. Chicago time), so I’m posting this on Thursday evening to alert you. If you’re a real space aficionado in the U.S., you’ll want to set an alarm.
I asked Jim for his creds to show, and this is what he said:
“Flight control engineer at NASA Langley Research Center from 1978 to retirement in 2008”. I spent several of those years as head of the Dynamics & Control Branch. This is like a university department chair. We did control theory research and design and flight test for a range of aircraft including general aviation aircraft, fighter prototypes, shuttle, next generation launch vehicles, the first micro-air vehicles, and large space structures. My own research was in an area known as “system identification from flight data”.
And so to his post, which I’ve indented:
Just a heads up that there is a planned SpaceX launch of four astronauts headed to the International Space Station scheduled for 0549 EDT Friday morning (0449 Chicago time). This is an instantaneous launch window, which means that if it doesn’t launch at this time, the entire launch will be postponed. NASA live TV coverage will start about four hours before the planned liftoff and is available at the official NASA site or at the YouTube site below:
This launch uses a refurbished crew capsule and a booster rocket from previous SpaceX flights. While the capsule and four-person crew will continue on to the station for a Saturday morning docking, the booster rocket will execute a planned controlled descent back to Earth and land on a barge at sea for further reuse. My former NASA colleagues and I were always nervous about and attentive to each shuttle flight over the years. I remain nervous about these flights, although the current capsule configuration at the top of the rocket provides an escape mode in case of booster failure—something the shuttle system didn’t offer.
Human spaceflight is inherently dangerous: putting enough explosive potential energy to escape Earth’s gravity into the small volume of a rocket. The shuttle system was particularly scary because the crewed vehicle was strapped alongside the fuel tanks with no escape in case of an explosion. The capsule was thus susceptible to impacts from material that might be shed from the external fuel tank or solid-rocket boosters. This design flaw has been corrected with the SpaceX redesign back to a capsule that sits atop the rocket, ahead of the fuel and other components of the launch vehicle—like the earlier Mercury and Apollo capsules. But the escape system still requires a lot of things to happen quickly and correctly. Some of the engineers in my former organization were involved in developing the escape system control laws, and these systems have been tested in situ.
So why does NASA continue to carry out human spaceflight? There are two prongs of space flight and exploration at NASA: robotic and human. The vast majority of pure science is already being in robotic missions, such as the current Mars mission or the recent New Horizons mission to Pluto and beyond. These science missions are supported through ~$7B annually in NASA programs dedicated to planetary science, Earth science, helioscience, and astrophysics. They involve numerous universities, and projects can generally span a decade or more in planning, development, and execution, with data analysis by scientists around the world continuing for another decade.
The second prong, human spaceflight and operations—a separate ~$10B annual budget item—focuses on learning about humans in space in low Earth orbit and on international cooperation. We learn how humans adapt and operate in the weightlessness of space over extended time periods—periods that would be required to fly to another planet. The international crews carry out science experiments, do station and system upkeep and development, and generally learn to live in the always challenging cold vacuum of space.
Human spaceflight is both a science and an engineering project as NASA learns what is needed to keep astronauts both physically and mentally healthy, and then designs, builds, and tests the required infrastructure. Flying in space is heroic, and I have huge respect for the astronauts who train, strap themselves into the vehicles, and endure months on the space station. But it does risk lives both on launch and re-entry. I hope that all of our policy-makers recognize that.
A number of critical cultural policy and management issues were identified in the Rogers Commission investigation into the 1986 Space Shuttle Challenger accident and written about specifically by Commission member and Physics Nobel Prize laureate Richard Feynman in a separate appendix to the Commission report. Feynman’s Appendix F deserves a read by anyone interested in an engineering or political career. While some changes and redesigns of launch vehicles were instituted, I did not see any real change in NASA’s safety culture as a result of either the Challenger or Columbia accidents and subsequent investigations.