The expenses of space travel have historically been high, mainly because of the expenses of creating a spacecraft that can generate enough energy to overcome the Earth’s gravity. The historical method of accomplishing this task has been through the usage of the multistage rocket, which is enormously expensive. The Apollo Space program, which is the only program to date to take human beings to another celestial body, cost the American taxpayers an amount that is today’s equivalent of roughly 170 billion dollars1. This figures to an average expendeture of about 14.17 billion dollars for each one of Apollo’s 12 missions (including the Apollo I tragedy, in which there was not actually a successful spaceflight). Not surprisingly, NASA began looking for ways to reduce the costs of space travel and would begin research that would lead to the development of America’s space shuttle program. About $145 billion dollars was spent on the space shuttle program from 1981 to 2005, which was far less expensive than the Apollo program and spent an average cost of 1.3 billion dollars per flight2.
But even the costs of the Space Shuttle are far too expensive for any longterm plan to expand the human presence into space. Both NASA and the Private Sector must take on the challenge of finding less expensive modes of travel. This will require both the development of groundbreaking technologies, as well as to capitalize off previous successes. For example, the successful development of the scramjet engine in 2004 could open many possibilities for the development of orbiters that do not need solid rocket boosters. This could allow both NASA and the commercial space travel industry to revisit the successes of the X-15 (which is already seems to be the main method of operation for Virgin Galactic). The X-15 program was able to make 200 flights at a cost of today’s equivalent of 1.5 billion dollars, which figures to 7.5 million dollars per flight. The X-15 was able to achieve 2 flights that were classified as suborbital spaceflights3.
If a company such as Virgin Galactic, or another company that develops space planes, is able to perfect scramjet technology, then it may be able to tremendously reduce the costs of a suborbital spaceflight. Virgin Galactic’s SpaceShipTwo is currently powered by a rocket motor that it has named “RocketMotorTwo.” The Scaled Composites Company, responsible for it’s production, has conducted tests that has satisfied its goals4. The scramjet engine could reduce the costs of low orbit spaceflights due to the elimination of oxidizer expenses. A scramjet can use atmospheric oxygen to provide the same amount of thrust as a conventional rocket motor, by using 1/7th of the amount of oxidizer required by a conventional rocket motor5.
The idea of using gas balloons as an alternative method of ascent to rocket power is nothing new. It has been used on occasion since Captain Joseph Kittinger of the U.S. Air Force made a jump from the gondola of the Excelsior I gas balloon in 1959, and again in 1960 from the Excelsior II balloon. Kittinger set a skydiving altitude record of 31 kilometers, which has yet to be broken6. The Red Bull Stratos Team was seeking to break this record in 2010 until the project was halted by an intellectual property lawsuit. Nonetheless, the program was able to develop a pressurized gondola that resembles the capsules of NASA’s Mercury and Gemini Space programs7 8.
While the costs of helium and the construction of high altitude gondolas should be taken seriously, the idea of space ballooning will not go away in the era of commercial space travel. In fact, it may be further inspired by the recent wave of “homebuilt spacecraft” built by enthusiasts. Luke Geissbühler, and his son Max, made headlines in late 2010 when they sent a modified weather balloon to an altitude of 19 miles9. Several others would make their own attempts and achieve similar results.
It is important to note that Kittinger’s flights and the recent wave of homemade “space balloons” have fallen short of the definitions of outer space by both the Federal Aviation Administration (FAA) and the Fédération Aéronautique Internationale (FAI). However, they are still very important in the development of a strategy to make low cost space travel a sustainable possibility. It can encourage the manufacturing of cost-efficient ballooning materials that are capable of passing the edge-of-space boundaries.
This article was originally written for the SPST300 course at American Military University in January of 2011. Since then, the Red Bull Stratos Project, which is mentioned in this article, has resumed and has successfully completed a test jump from 71,500 ft.
1Glenn Butts and Kent Linton. “The Joint Confidence Level Paradox: A History In Denial,” 2009 NASA Cost Symposium, (Tuesday, April 28th 2009) Online. Available from http://science.ksc.nasa.gov/shuttle/nexgen/Nexgen_Downloads/Butts_NASA’s_Joint_Cost-Schedule_Paradox_-_A_History_of_Denial.pdf
3Sam Dinkin. “X-15 and Today’s Spaceplanes” (Monday, August 9th 2004) Online. Available from http://www.thespacereview.com/article/204/1
4Author Unknown, “Scaled Composites: Projects – RocketMotorTwo Hot-Fire Test Summaries” (Retrieved Friday, January 7th 2011) Online. Available from http://www.scaled.com/projects/rocketmotortwo_hot-fire_test_summaries
5Schafer, Michael D., “FEASIBILITY OF SCRAMJET TECHNOLOGY FOR AN INTERMEDIATE PROPULSIVE STAGE OF AN EXPENDABLE LAUNCH VEHICLE,” Masters Thesis, Naval Postgraduate School Online. Available from http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=€GetTRDoc.pdf&AD=ADA407197
6Judy Rumerman. “Joseph Kittenger,” The U.S. Centennial Flight Commission http://www.centennialofflight.gov/essay/Explorers_Record_Setters_and_Daredevils/Kittinger/EX31.htm (Retrieved January 7th 2011)
7Red Bull Stratos (Retrieved Friday, January 7th 2011) Online. Available at http://www.redbullstratos.com/Science.aspx#CapsuleforAscent
8Jenniger Bogo, “How to Safely Clinb to 120,000 Feet in a Balloon,” Popular Mechanics (August 2nd 2010) Online. Available at http://www.popularmechanics.com/technology/aviation/safety/how-to-safely-climb-to-120000-feet-in-a-balloon
9Bill Hutchinson. “Brooklyn dad Luke Geissbuhler and 7-year-old son Max launch ‘homemade spacecraft’,” New York Daily News (September 30th 2010) Online. Available at http://www.nydailynews.com/ny_local/2010/09/30/2010-09-30_skys_the_limit_for_bklyn_dad_son.html