US Strategic Command, the “own- ticularly on propulsion and vehicle er” of military space operations and control concepts. The service last sum- The Air Force has an urgent need for hypersonic, long-range, the global strike mission, has estab- mer asked US industry to turn in pro- transatmospheric vehicles. lished the requirement for a space- posals and concepts this fall. plane. This fall, the Air Force and USAF wants to build the means to

NASA artist’s conception the Defense Advanced Research attack any target on the globe within Projects Agency began accepting 12 hours of an order to do so. That industry proposals for a project that requirement stems from an April 2003 in 2025 would produce a spaceplane— Air Staff study titled “Long-Range one that may look much like the Global Precision Engagement.” In defunct National Aerospace Plane it, the Air Force—working with the conceptualized in the 1980s. Joint Staff and Office of the Secre- tary of Defense—put strike capa- To Mach 15 bilities into three categories: prompt The new craft, which is described global strike, prompt theater strike, as a Hypersonic Cruise Vehicle (HCV), and persistent area strike. would be capable both of launching USAF believes the products of satellites and deploying weapons. Falcon will fulfill—to a great de- Plans call for it to fly at speeds up to gree—the prompt global strike ele- Mach 15 and carry a mix of weapons ment. The ability to conduct prompt comparable to the load carried by global strike would dissuade or de- one of today’s fighter aircraft. It ter enemies because they would would probably be flown by a crew, know that the US could “hold at risk but it could be flown remotely as or strike high-value targets anytime By John Tirpak, Executive Editor well. and anywhere on the globe,” said “The ability to reach out and touch the study. Such a technology would somebody with great precision ... at also eliminate the need for intra- very long range is ... a very attrac- theater buildup before conducting a tive attribute,” said Brig. Gen. Stephen strike. M. Goldfein, the Air Force’s direc- The study set the following pa- tor of operational capability require- rameters for the prompt global strike ments. “We are looking at what in- capability: dustry can tell us about the art of the Availability on short notice. possible ... with great interest,” Great standoff range with pen- Goldfein said in an August inter- etrating weapons. view. Capacity for 200 strike effects In Search of Spaceplanes Beyond offering the advantage of within 12 hours. extreme speed from point to point, Range of at least 3,400 miles. an orbital or suborbital spaceplane The study authors, despite seeing would also obviate the need to ob- some partial workarounds, urged tain overflight permission from other rapid development of hypersonic countries. vehicles—be they new missiles or USAF wants a system before 2025, aircraft. however. As an interim measure, the “In particular,” the study authors or decades, the Air Force so. The target might be a terrorist ting close enough to an enemy to service is developing a hypersonic wrote, “the development of high su- has wanted spaceplanes— camp, a ballistic missile launch site, conduct operations—a prospect that glide munitions delivery system, personic/hypersonic weapons and craft that can take off from a chemical weapons factory, or a lead- the national leadership no longer will known as the Common Aerospace delivery platforms significantly en- a runway, fly at hypersonic ership target. It also may be deeply accept. Vehicle. It could be fielded within ables global strike from significant Fspeeds through the upper atmosphere, buried. A spaceplane would offer the Moreover, the last few armed con- eight years. The CAV is part of a ranges and reduces the risks associ- reach low Earth orbit, and return in a means to get to a target rapidly, soar flicts have illustrated how the US program dubbed “Falcon” (Force Ap- ated with forward basing.” Addition- conventional fashion. Yet, the prac- high above defenses, and deliver mu- has become highly dependent on plication and Launch from Conti- ally, they said, the reusability of these tical application of the concept kept nitions that would fall at high veloc- space systems for its entire range of nental United States), which also platforms increases their value in a being pushed into the future because ity and plunge far below the Earth’s military operations. The need to ob- includes development of a Small variety of threat scenarios and makes of high development costs, inad- surface. tain cheap, reliable, rapid access to Launch Vehicle to carry the CAV to them more cost effective. equate technology, and the lack of a Fueling the new urgency to pro- space has never been greater. an orbit altitude, from which it would The study concluded that, by 2015, truly pressing mission that would duce an operational spaceplane is “We have an important interest— coast to its “pierce point” location— even stealthy new systems such as demand such an asset. the proliferation of theater ballistic and airmen have always had an im- that is, the point and velocity at which the F/A-22 and F-35 fighters may That is about to change. There now missiles and weapons of mass de- portant interest—in speed,” said Gen. the vehicle enters the atmosphere. lack the range to attack critical tar- is an urgent mission for the capabili- struction, plus the belief that these Gregory S. Martin, head of Air Force Additionally, the SLV would pro- gets deep behind enemy lines in the ties of a spaceplane—or something and other “anti-access” weapons will Materiel Command and former com- vide a quick-reaction launch capa- early hours of a crisis. The ranges of like it. only become more widespread in the mander of US Air Forces in Europe. bility for small satellites. the two fighters in the initial stages USAF needs the ability to swiftly future. In the hands of terrorists or A spaceplane is “an activity that I The Air Force and DARPA are col- of a conflict would “not allow for hit fleeting targets anywhere on Earth states that support them, such weap- think it is important for us to pur- laborating on Falcon and expect sub- penetration beyond approximately shortly after an order is given to do ons could prevent the US from get- sue.” stantial assistance from NASA, par- 400 nautical miles [460 miles] into US Strategic Command, the “own- ticularly on propulsion and vehicle er” of military space operations and control concepts. The service last sum- The Air Force has an urgent need for hypersonic, long-range, the global strike mission, has estab- mer asked US industry to turn in pro- transatmospheric vehicles. lished the requirement for a space- posals and concepts this fall. plane. This fall, the Air Force and USAF wants to build the means to

NASA artist’s conception the Defense Advanced Research attack any target on the globe within Projects Agency began accepting 12 hours of an order to do so. That industry proposals for a project that requirement stems from an April 2003 in 2025 would produce a spaceplane— Air Staff study titled “Long-Range one that may look much like the Global Precision Engagement.” In defunct National Aerospace Plane it, the Air Force—working with the conceptualized in the 1980s. Joint Staff and Office of the Secre- tary of Defense—put strike capa- To Mach 15 bilities into three categories: prompt The new craft, which is described global strike, prompt theater strike, as a Hypersonic Cruise Vehicle (HCV), and persistent area strike. would be capable both of launching USAF believes the products of satellites and deploying weapons. Falcon will fulfill—to a great de- Plans call for it to fly at speeds up to gree—the prompt global strike ele- Mach 15 and carry a mix of weapons ment. The ability to conduct prompt comparable to the load carried by global strike would dissuade or de- one of today’s fighter aircraft. It ter enemies because they would would probably be flown by a crew, know that the US could “hold at risk but it could be flown remotely as or strike high-value targets anytime By John Tirpak, Executive Editor well. and anywhere on the globe,” said “The ability to reach out and touch the study. Such a technology would somebody with great precision ... at also eliminate the need for intra- very long range is ... a very attrac- theater buildup before conducting a tive attribute,” said Brig. Gen. Stephen strike. M. Goldfein, the Air Force’s direc- The study set the following pa- tor of operational capability require- rameters for the prompt global strike ments. “We are looking at what in- capability: dustry can tell us about the art of the Availability on short notice. possible ... with great interest,” Great standoff range with pen- Goldfein said in an August inter- etrating weapons. view. Capacity for 200 strike effects In Search of Spaceplanes Beyond offering the advantage of within 12 hours. extreme speed from point to point, Range of at least 3,400 miles. an orbital or suborbital spaceplane The study authors, despite seeing would also obviate the need to ob- some partial workarounds, urged tain overflight permission from other rapid development of hypersonic countries. vehicles—be they new missiles or USAF wants a system before 2025, aircraft. however. As an interim measure, the “In particular,” the study authors or decades, the Air Force so. The target might be a terrorist ting close enough to an enemy to service is developing a hypersonic wrote, “the development of high su- has wanted spaceplanes— camp, a ballistic missile launch site, conduct operations—a prospect that glide munitions delivery system, personic/hypersonic weapons and craft that can take off from a chemical weapons factory, or a lead- the national leadership no longer will known as the Common Aerospace delivery platforms significantly en- a runway, fly at hypersonic ership target. It also may be deeply accept. Vehicle. It could be fielded within ables global strike from significant Fspeeds through the upper atmosphere, buried. A spaceplane would offer the Moreover, the last few armed con- eight years. The CAV is part of a ranges and reduces the risks associ- reach low Earth orbit, and return in a means to get to a target rapidly, soar flicts have illustrated how the US program dubbed “Falcon” (Force Ap- ated with forward basing.” Addition- conventional fashion. Yet, the prac- high above defenses, and deliver mu- has become highly dependent on plication and Launch from Conti- ally, they said, the reusability of these tical application of the concept kept nitions that would fall at high veloc- space systems for its entire range of nental United States), which also platforms increases their value in a being pushed into the future because ity and plunge far below the Earth’s military operations. The need to ob- includes development of a Small variety of threat scenarios and makes of high development costs, inad- surface. tain cheap, reliable, rapid access to Launch Vehicle to carry the CAV to them more cost effective. equate technology, and the lack of a Fueling the new urgency to pro- space has never been greater. an orbit altitude, from which it would The study concluded that, by 2015, truly pressing mission that would duce an operational spaceplane is “We have an important interest— coast to its “pierce point” location— even stealthy new systems such as demand such an asset. the proliferation of theater ballistic and airmen have always had an im- that is, the point and velocity at which the F/A-22 and F-35 fighters may That is about to change. There now missiles and weapons of mass de- portant interest—in speed,” said Gen. the vehicle enters the atmosphere. lack the range to attack critical tar- is an urgent mission for the capabili- struction, plus the belief that these Gregory S. Martin, head of Air Force Additionally, the SLV would pro- gets deep behind enemy lines in the ties of a spaceplane—or something and other “anti-access” weapons will Materiel Command and former com- vide a quick-reaction launch capa- early hours of a crisis. The ranges of like it. only become more widespread in the mander of US Air Forces in Europe. bility for small satellites. the two fighters in the initial stages USAF needs the ability to swiftly future. In the hands of terrorists or A spaceplane is “an activity that I The Air Force and DARPA are col- of a conflict would “not allow for hit fleeting targets anywhere on Earth states that support them, such weap- think it is important for us to pur- laborating on Falcon and expect sub- penetration beyond approximately shortly after an order is given to do ons could prevent the US from get- sue.” stantial assistance from NASA, par- 400 nautical miles [460 miles] into an adversary’s battlespace without the use of external fuel tanks that

may degrade some aircraft capabili- USAF photo ties,” according to the study. Tank- ers that could refuel the two fighters would not be able to get close, if modern surface-to-air missiles were in the area. The authors projected that some capability independent of forward bases will have to be in hand by 2015, if not sooner. The Falcon program encompasses concepts that are near term—the Common Aerospace Vehicle and Small Launch Vehicle—and far term—the Hypersonic Cruise Ve- hicle. Armed with 1,000 pounds of ord- nance, the CAV hypersonic glide munitions dispenser could strike any- This working scramjet is one of a number of propulsion concepts being explored where on an adversary’s territory. for spaceplanes. Advances in computing power and materials, coupled with a Descending from high altitude and flight program, point to functional manned hypersonic vehicles by 2025. at high speed, it would be extremely effective against hardened or deeply ance, navigation, and control,” said The Falcon program is set up to buried targets. Impact speeds “of the USAFÐDARPA request for pro- use initial CAV and SLV work as approximately 4,000 feet per sec- posal. well as NASA’s work on hypersonic ond” are expected, according to a Plans call for fitting the Common technology in order to develop the USAFÐDARPA summary. Aerospace Vehicle on the Small Hypersonic Cruise Vehicle. This pro- CAV technology has been stud- Launch Vehicle, which should be gram is expected to culminate around ied “since the mid-’90s,” USAF said. able to launch in less than 24 hours 2025. In that time, some workable con- and, with the CAV as its payload, The Hypersonic Cruise Vehicle cepts offered a downrange glide ca- surge to 16 launches in 24 hours. It would be based on US territory. It pability of nearly 3,500 miles. More must lift a 200-to-2,200-pound pay- would be reusable, having aircraft- advanced conceptual versions now load for less than $7,500 per pound. like properties that enable it to take promise ranges of up to 10,350 miles, Today’s benchmark is about $10,000 off from a conventional military run- but these enhanced systems would a pound. way. The system would: require significant technology de- The Air Force expects to have Strike targets 10,350 miles away velopment, “particularly in the ar- workable CAV and SLV systems by within two hours. eas of thermal protection and guid- 2010. Carry a 12,000-pound payload. Engage multiple, diverse, and widely dispersed targets. Be retargetable and recallable.

NASA photo The Hyper-X NASA is about to resume testing of a vehicle that likely will be one of the Falcon program’s key technol- ogy pathfinders. Under a program called Hyper-X, NASA will fly a miniature hyper- sonic vehicle up to Mach 10. The goal is to learn about the environ- ment of very high speed and the performance of hypersonic engines. Such conditions can’t be duplicated in ground-based wind tunnels. The craft itself is called the X-43A. It has a hydrogen-based propulsion system. David Reublish, deputy manager DARPA never gave up on the National Aerospace Plane “dream,” according to of NASA’s Next Generation Launch Director Anthony Tether. Until now, the demands of a NASP—a 1980s concept is Technology Flight Vehicles and Sys- shown—exceeded both the state of the art and funding. tems Program Office, said NASA is

68 AIR FORCE Magazine / December 2003 “almost to the end” of its Hyper-X program, which was intended to be a seven-year technology project. The initial program called for building three X-43A one-time-use vehicles, each about 12 feet long and mounted on a Pegasus booster. NASA uses the vehicles to explore ramjet and scramjet engine technologies at Artist’s conception by Erik Simonsen high Mach numbers. A booster prob- lem caused the first vehicle test flight to fail. NASA scheduled the test flight of the second vehicle for this month. Plans called for it to fly at Mach 7 and then return to Earth. A third vehicle is slated to fly in the spring and reach Mach 10. The actual hy- personic segments of the flights will last only a few seconds, but they will provide mountains of valuable data, said Reublish. Completion of the The Air Force’s “Falcon” program will develop a vehicle, a weapon, and a booster third flight will mark the end of the to make it possible, before 2020, to reach anywhere on the globe in two hours. first phase of Hyper-X. This is an artist’s concept, but the program is real and has multiagency support. Already under construction is the follow-on X-43C, developed in con- weight you add, the cost grows geo- cal) it will be an 80,000-pound, winged junction with the Air Force. Reublish metrically.” reusable vehicle that could carry a said there would again be three ve- The demonstrator will feature en- 16,000-pound payload. The payload hicles. Each X-43C will be about 16 gines of two kinds—the turbine for would consist of an internally carried feet long and, like the A model, will the thick air of the lower atmosphere two-stage rocket that could lift a 110- ride to altitude on the front of a and a scramjet for the thin air of the pound satellite into orbit. Pegasus rocket. The Pegasus will high atmosphere. It will be tricky, In about a year, the US will begin accelerate the X-43C to Mach 5. Then said Reublish, to accurately coordi- construction on Rascal, which would the vehicle will accelerate on its own nate the closing of the turbine inlets fly to about 63,000 feet using four power to Mach 7, where it will cruise. with the opening of the scramjet in- engines and then execute a sharp The first flight of the X-43C is ex- lets. pull-up at supersonic speed. It then pected in about 2007. The project is not yet funded, but would release its payload—a satel- Unlike the X-43A, the X-43C will NASA and the Pentagon will under- lite with an expendable booster. The be fueled by JP-7 aviation gas. “The take it jointly and fully expect to booster would propel the satellite Air Force doesn’t want to build a pursue it. the rest of the way to its desired new infrastructure to support hydro- “NASA has a goal to develop a orbit. Meanwhile, Rascal would re- gen fuel,” Reublish said. Should the shuttle replacement by 2025,” Reub- turn to a runway landing. X-43C work, its derivatives could lish explained. The pace of the pro- Rascal’s four engines will prob- be refueled in flight—at fairly low gram will make it possible to fabri- ably be similar to the F100 power speeds—by standard tankers. cate a test version of a full hypersonic plants found on F-15 and F-16 fight- After completing the X-43C, NASA craft around 2020 and an operational ers. At high temperatures, they will develop a 40-foot-long hyper- model in 2025. The vehicle would would be cooled with water and sonic vehicle called, for now, the weigh about one million pounds, or liquid oxygen sprayed directly into Reusable Combined Cycle Flight one-fifth the weight of the space the inlets. This technique improves Demonstrator. It will be carried aloft shuttle. It would have to be powered thrust but keeps the engines at an by a B-52H bomber. “The B-52 will by hydrogen. acceptable temperature and pro- get it to seven-tenths of Mach, then Because hypersonic vehicles can vides oxygen for combustion. It is release it,” said Reublish. “The craft use the ambient oxygen in the atmo- called mass injection precompressor will accelerate to Mach 10, then sphere to burn fuel, they don’t need cooling and was tried successfully land.” to carry along their own oxygen. in the 1950s. The technique would Reublish explained that such air This factor translates into tremen- let the F100-type engines propel launches are used to cut costs. An dous weight savings. the craft to Mach 6. air-launched craft can have lighter Although both the Air Force and landing gear and smaller fuel tanks, Like an Airplane NASA see some urgency in develop- he said. Development will cost about NASA is also pursuing another ing hypersonic spaceplanes, there are $1 billion. Giving the vehicle the spaceplane that would be airplane- valid cost and technology concerns, ability to launch under its own power like, taking off under its own power said Martin. The AFMC chief sup- would increase the weight and boost from a runway. Called Responsive ports the concept of hypersonic ve- the price tag to about $4 billion, he Access Small Cargo Affordable hicles, but he added, “We have to said, noting, “For every pound of Launch spaceplane (known as Ras- pursue it at the right pace.” ■

AIR FORCE Magazine / December 2003 69