The strange craft of the Antelope Valley & Mojave, CA

Beginning with the Rotary Rocket programme, Mojave became a focus for small companies seeking a place to develop space access technologies. Mojave Spaceport has been a test site for several teams in the Ansari X Prize, most notably the Scaled Composites SpaceShipOne, which conducted the first privately funded human sub-orbital flight on June 21, 2004. A full size, 63 ft tall, Atmospheric Test Vehicle (ATV) was built under contract by Scaled Composites for use in hover test flights. The $2.8 million ATV was not intended as an all-up test article, since it had no rocket engine and no heat shielding. The ATV was rolled out of its Mojave hangar on March 1, 1999, bearing an FAA registry of N990RR.

A full size, 63 ft tall, Atmospheric Test Vehicle (ATV) was built under contract by Scaled Composites for use in hover test flights. The $2.8 million ATV was not intended as an all-up test article, since it had no rocket engine and no heat shielding. The ATV was rolled out of its Mojave hangar on March 1, 1999, bearing an FAA registry of N990RR.

The vehicle was to use helicopter-style rotors for landing, rather than wings or parachutes. This concept allowed controlled landings (unlike parachutes), and it was 1/5 the weight of fixed wings. Another advantage was that a helicopter could land almost anywhere, whereas winged space planes such as the Shuttle had to make it back to the runway. The rotor blades were to be powered by peroxide tip rockets and were to be deployed before reentry; some questions were raised about whether the blades would survive until landing.

The vehicle was to use helicopter-style rotors for landing, rather than wings or parachutes. This concept allowed controlled landings (unlike parachutes), and it was 1/5 the weight of fixed wings. Another advantage was that a helicopter could land almost anywhere, whereas winged space planes such as the Shuttle had to make it back to the runway. The rotor blades were to be powered by peroxide tip rockets and were to be deployed before reentry; some questions were raised about whether the blades would survive until landing.

The ATV flew three successful test flights in 1999. The ATV made its first flight on July 28. This flight consisted of three vertical hops totaling 4 min 40 sec in duration and reaching a maximum altitude of 8 ft. The pilots found the flying extremely challenging for a number of reasons. Visibility in the cockpit was so restricted that the pilots nicknamed it the Batcave. The view of the ground was entirely obstructed, so the pilots had to rely on a sonar altimeter to judge ground proximity. The entire craft had a low rotational inertia, and torque from the spinning rotor blades made the body spin, unless counteracted by yaw thrust in the opposite direction.

The ATV flew three successful test flights in 1999. The ATV made its first flight on July 28. This flight consisted of three vertical hops totaling 4 min 40 sec in duration and reaching a maximum altitude of 8 ft. The pilots found the flying extremely challenging for a number of reasons. Visibility in the cockpit was so restricted that the pilots nicknamed it the Batcave. The view of the ground was entirely obstructed, so the pilots had to rely on a sonar altimeter to judge ground proximity. The entire craft had a low rotational inertia, and torque from the spinning rotor blades made the body spin, unless counteracted by yaw thrust in the opposite direction.

The second flight, on September 16, was a continuous hover flight lasting 2 min 30 sec, reaching a maximum altitude of 20 ft. The sustained flight was made possible by the installation of more powerful rotor tip thrusters and an autothrottle. The third and last flight was made on October 12. The ATV flew down the flightline at Mojave Air and Space Port, covering 4,300 ft in its flight and rising to a maximum altitude of 75 ft. The speed was as high as 53 mph. This test revealed some instability in translational flight. A fourth test was planned to simulate a full autorotative descent. The ATV would climb to an altitude 10,000 ft under its own power, before throttling back and returning for a soft landing. At this point, given that further funding was then unlikely, safety considerations prevented the test being attempted.

The second flight, on September 16, was a continuous hover flight lasting 2 min 30 sec, reaching a maximum altitude of 20 ft. The sustained flight was made possible by the installation of more powerful rotor tip thrusters and an autothrottle. The third and last flight was made on October 12. The ATV flew down the flightline at Mojave Air and Space Port, covering 4,300 ft in its flight and rising to a maximum altitude of 75 ft. The speed was as high as 53 mph. This test revealed some instability in translational flight. A fourth test was planned to simulate a full autorotative descent. The ATV would climb to an altitude 10,000 ft under its own power, before throttling back and returning for a soft landing. At this point, given that further funding was then unlikely, safety considerations prevented the test being attempted.

Rotary Rocket failed due to lack of funding, but some have suggested that the design itself was inherently flawed. On one hand, Rotary Rocket demonstrated its technical ability by flight testing of actual hardware. On the other hand, these tests revealed problems. For instance, the ATV demonstrated that a landing of the Rotary Rocket would be tricky, even dangerous. Test pilots have a rating system, the Cooper-Harper rating scale, for vehicles between 1 and 10 that relates to difficulty to pilot. The Roton ATV scored a 10 — the vehicle simulator was found to be practically unflyable by anyone except the Rotary test pilots, and even then there were expected to be short periods where the vehicle was out of control. Other aspects of the flight plan remained unproven. It is not known whether Roton could in practice have developed enough overall performance to reach orbit with a single stage, and return – although on paper this might have been possible. These doubts led some of the aerospace community to dismiss the Rotary Rocket concept as an impossible pipe dream. Whether a flight-article vehicle would have worked successfully remains open to speculation.

Rotary Rocket failed due to lack of funding, but some have suggested that the design itself was inherently flawed. On one hand, Rotary Rocket demonstrated its technical ability by flight testing of actual hardware. On the other hand, these tests revealed problems. For instance, the ATV demonstrated that a landing of the Rotary Rocket would be tricky, even dangerous. Test pilots have a rating system, the Cooper-Harper rating scale, for vehicles between 1 and 10 that relates to difficulty to pilot. The Roton ATV scored a 10 — the vehicle simulator was found to be practically unflyable by anyone except the Rotary test pilots, and even then there were expected to be short periods where the vehicle was out of control. Other aspects of the flight plan remained unproven. It is not known whether Roton could in practice have developed enough overall performance to reach orbit with a single stage, and return – although on paper this might have been possible. These doubts led some of the aerospace community to dismiss the Rotary Rocket concept as an impossible pipe dream. Whether a flight-article vehicle would have worked successfully remains open to speculation.

Meanwhile, visitors to Joe Davies Heritage Airpark may view a collection of aircraft flown, tested, designed, produced or modified at U.S. Air Force Plant 42 in Palmdale, CA

Meanwhile, visitors to Joe Davies Heritage Airpark may view a collection of aircraft flown, tested, designed, produced or modified at U.S. Air Force Plant 42 in Palmdale, CA. Originally known as Palmdale Airport, the U.S. Army Air Corps used the airfield as a base during World War II (1940-1946). Ownership was transferred to Los Angeles County in 1946 for use as a municipal airport, but the Cold War and lack of suitable airspace in the Los Angeles basin created the need for an advanced development facility for the fledgling U.S. Air Force. In 1951, the U.S. Air Force purchased approximately 5,800 acres of land from Los Angeles County and established Plant 42 in Palmdale in 1953 as the premier production flight test installation in the world.

The tail of the Boeing 747 Space Shuttle Carrier 911. This modified and strengthened aircraft was operated by NASA from 1990 to 2012 to transport a Space Shuttle attached to its back from a NASA landing site to the Space Shuttle Facility at the Kennedy Space Centre.

The tail of the Boeing 747 Space Shuttle Carrier 911. This modified and strengthened aircraft was operated by NASA from 1990 to 2012 to transport a Space Shuttle attached to its back from a NASA landing site to the Space Shuttle Facility at the Kennedy Space Centre.

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Space Shuttle Escape System Test Vehicle with markings of the 9 ejection tests conducted 1976 to 1977.

Space Shuttle Escape System Test Vehicle with markings of the 9 ejection tests conducted 1976 to 1977.

The Escape System Test Vehicle was used to test such ejections on 9 occasions between December 1976 and May 1977 by attaching it to a rocket sled, firing it down a rail track and triggering the ejection seats with dummies onboard at Holloman Air Force Base in New Mexico.

The Escape System Test Vehicle was used to test such ejections on 9 occasions between December 1976 and May 1977 by attaching it to a rocket sled, firing it down a rail track and triggering the ejection seats with dummies onboard at Holloman Air Force Base in New Mexico.

This Lockheed C-140 JetStar was flown at the nearby NASA Dryden Flight Research Centre from 1964 to 1989 on various flight research programs. It was fitted with special modifications over the years so that it could simulate the flight characteristics of many different types of aircraft.

This Lockheed C-140 JetStar was flown at the nearby NASA Dryden Flight Research Centre from 1964 to 1989 on various flight research programs. It was fitted with special modifications over the years so that it could simulate the flight characteristics of many different types of aircraft.

Space Shuttle Evacuation Test Sled @ Plant 42.

Space Shuttle Evacuation Test Sled @ Plant 42.