A U.S. Air Force space plane and a failed hypersonic glider tested by the Pentagon represent the latest space missions to raise concerns about weapons in space. But while their exact purpose remains murky, they join a host of new space technology tests that could eventually bring the battlefield into space.
Some space technology demonstrations are more obviously space weapons, such as the anti-satellite missile capabilities tested by the U.S. and China in recent years. India has also begun developing its own anti-satellite program which would combine lasers and an exo-atmospheric kill vehicle, as announced at the beginning of 2010.
The U.S. military and others have also long developed and deployed more neutral space assets such as rockets and satellites for military purposes. In that sense, both the Air Force's X-37B robotic space plane and the HTV-2 hypersonic glider prototype of the Defense Advanced Research Projects Agency (DARPA) could represent similarly ambiguous technologies which may or may not lead to weapons.
"Space has been militarized since before NASA was even created," said Joan Johnson-Freese, a space policy analyst at the Naval War College in Newport, RI. Yet she sees weaponization as a different issue from militarization because "so much space technology is dual use" in terms of having both civilian and military purposes, as well as offensive or defensive use.
Such uncertainty regarding space technology can make it tricky for nations to gauge the purpose or intentions behind new prototypes, including the X-37B space plane or the HTV-2 hypersonic glider.
The U.S. military could even be using the cloak of mystery to deliberately bamboozle and confuse rival militaries, according to John Pike, a military and security analyst who runs GlobalSecurity.org. He suggested that the X-37B and HTV-2 projects could represent the tip of a space weapons program hidden within the Pentagon's secret "black budget," or they might be nothing more than smoke and mirrors.
The devil is in the details
Many existing space technologies play dual roles in both military and civilian life.
The Global Positioning Satellite (GPS) system which started out as military-only has since become common in consumer smartphones and car navigation systems. Modern rocketry grew in part from the technology and scientific minds behind Nazi Germany's V-2 rockets of World War II, and continued to evolve alongside ballistic missile technology.
Even something as basic as a satellite image can be used for either military weapons targeting or civilian crop rotation, Johnson-Freese said. Space plane technology can seem equally ambiguous — the Air Force deputy undersecretary of space programs scoffed at the notion of X-37B paving the way for future space weapons.
"The whole issue is further complicated because beyond technologies like lasers, Rods from God, explosives, etc.... virtually any object traveling in space can be a weapon if it can be maneuvered to run into another object," Johnson-Freese told SPACE.com.
Uncertainty matters a great deal for how other nations view the recent U.S. space plane and hypersonic glider tests, regardless of whether or not the technologies lead to future weapons.
"They are testing capabilities that could certainly be useful to the military if it chose to use them in an offensive manner," Johnson-Freese said. "And the military has been silent on intent."
Intrigue and deception
Pike said the current work under way by the U.S. military leaves plenty of room for misinterpretations or even outright deception, which could be a ploy to distract other nations with military space projects.
"One of them could be a deception program and the other could be the spitting image of the real thing," Pike noted. He said that such misdirection could force other nations' militaries to waste money chasing down dead ends.
Both the Air Force space plane and DARPA's hypersonic glider may have a combined budget of several hundred million dollars per year, Pike estimated. He described such spending as "chump change" compared to the Pentagon's black budget spending in recent years of $6 billion to $8 billion annually — and he pointed to decades worth of known space plane programs which had amounted to little.
"I conclude that the hypersonic trans-atmospheric space plane domain is either unusually badly managed even for government programs, or there's a lot of hocus pocus here," Pike said. "I defy anyone to tell the difference between hocus pocus and mismanagement."
Of course, the U.S. military could theoretically make good use of either the X-47B or HTV-2. An operational space plane could launch quickly as a replacement for recon satellites disabled in the opening salvoes of a conflict, and could "play hide and seek" to avoid being shot down easily. Similarly, a hypersonic aircraft or weapon might allow the U.S. to eliminate threats early on without warning.
Walking the line on weapon bans
The double-edged nature of space technologies has also complicated international efforts to ban entire classes of technologies which might serve as space weapons. Instead, there has been interest in "more modest proposals that focus on behavior, rather than what you are allowed to build or test," said Karl Mueller, a political scientist at the RAND Corporation.
Military use of space looks likely to expand, according to the experts. But Mueller explained that the U.S. military's interest in space has less to do with the dazzling futuristic visions of space planes and more to do with "unglamorous" satellites and orbital sensor systems. Such technologies give situational awareness of all the satellites, spacecraft and debris in orbit.
One such example is the $800 million Space Based Space Surveillance satellite slated for launch in July. It carries an optical telescope to help Air Force ground-based radars track the growing orbital traffic of satellites and space debris — a goal which everyone can appreciate.
"That's true whether you're hawkish and enthusiastic about using force in space, or whether you're dovish and want to maintain the sanctuary of space and maximize peaceful spacefaring," Mueller said.