“The total shuttle launch weight [is] 4.5 million lb., of which 85% is propellant, about 14% is vehicle structure and about 1.5% is the payload,” Hale says. “That's pretty typical for orbital space-launch vehicles. The propellant reserve for managing cutoff of the space shuttle was 0.06% of the total load, or about a third of a second of run time on the main engines. That's the reserve you've got to work with.”
Using what he calls “high school physics,” Hale says it takes 1,000 times more kinetic energy to reach orbit than to fly a commercial jetliner. That is significant, because that energy must come out of the system if the spacecraft reenters.
Hale was speaking at a symposium commemorating the 10th anniversary of the Columbia disaster, which tragically demonstrated what can happen if the spacecraft can't protect itself and its crew from that kinetic energy.
To date only SpaceX has managed the physics of getting cargo to the International Space Station (ISS) and bringing it back to Earth. Orbital Sciences Corp. is in the running for the up part of the trip, but has passed on the reentry challenge. Four U.S. companies—Blue Origin, Boeing, Sierra Nevada and SpaceX—are working with NASA to expand commercial capability to deliver astronauts to the space station and bring them home safely.
So far NASA has funded 80-90% of the cost of development across the commercial companies, according to William Gerstenmaier, associate administrator for human exploration and operations. The space agency figures it saved $1 billion getting the SpaceX Falcon 9 developed for orbital missions. The company is now working through its 12-flight, $1.6 billion commercial resupply services contract to deliver cargo to the ISS and return scientific samples and other “down mass” with its Dragon capsule.
Gerstenmaier's mission directorate is spending another $1.1 billion to help Boeing, Sierra Nevada and SpaceX build human-rated commercial spacecraft to deliver crews to the space station on a timetable that is highly dependent on the amount of money Congress appropriates for the task (AW&ST Aug. 6, 2012, p. 22). Blue Origin, endowed by Amazon.com billionaire Jeff Bezos, has stopped taking NASA funds.
That kind of government spending means it remains the largest customer for spacecraft—hardly the truly commercial marketplace NASA is trying to stimulate. But the numbers are going down. Driving the commercial push, Gerstenmaier says, is research on the ISS.
Without NASA's need for commercial cargo and crew transport to cover its share of station support, there is no market. Even with NASA as an anchor tenant, the pace of market growth will not meet the rapid-return-on-investment expectations typical in most corporate boardrooms.
“We've got to be very careful that we don't say tomorrow we're going to find the big eureka in space,” Gerstenmaier says. “I don't think it's going to come. [First are] small, slow steps, and then eventually we'll cross some tipping point [and everyone will wonder] why in the heck weren't we doing research in space all along.”