Towed Twin-Fuselage Glider Launch System First Test Flight Successful

One of NASA Armstrong’s DROID small unmanned research aircraft tows the twin-fuselage towed glider into the blue sky on its first test flight. (Credit: Tom Tschida/NASA Armstrong)
One of NASA Armstrong’s DROID small unmanned research aircraft tows the twin-fuselage towed glider into the blue sky on its first test flight. (Credit: Tom Tschida/NASA Armstrong)

EDWARDS, Calif. (NASA PR) — NASA has successfully flight-tested a prototype twin-fuselage towed glider that could lead to rockets being launched from pilotless aircraft at high altitudes – a technology application that could significantly reduce the cost and improve the efficiency of sending small satellites into space. The first flights of the one-third-scale twin fuselage towed glider took place Oct. 21 from NASA’s Armstrong Flight Research Center in California.

The towed glider is an element of the novel rocket-launching concept of the Towed Glider Air-Launch System, or TGALS. NASA Armstrong researchers are developing the project, which is funded as a part of the Space Technology Mission Directorate’s Game Changing Development program.

The 27-foot-wingspan towed glider was towed behind the Dryden Remotely Operated Integrated Drone, or DROID, unmanned aircraft into the blue skies above Edwards Air Force Base. Minutes later the towline was released and the twin fuselage aircraft glided to a perfect landing on the dry lakebed.

Robert “Red”Jensen, who piloted the towed glider, and Gerald Budd, who flew the DROID small UAV that towed the unmanned aircraft skyward, discuss flight procedures prior to takeoff. (Credit: Tom Tschida/NASA Armstrong)
Robert “Red”Jensen, who piloted the towed glider, and Gerald Budd, who flew the DROID small UAV that towed the unmanned aircraft skyward, discuss flight procedures prior to takeoff. (Credit: Tom Tschida/NASA Armstrong)

After reviewing wind conditions and checking the systems of both aircraft, mission managers decided to go for a second flight. As with the first, the glider was towed behind the DROID, leveled out in flight and the glider was released for another free flight to the dry lakebed.

“We had a really good first flight,” said John Kelly, TGALS project manager. “Both aircraft performed well.”

“It flies fantastic,” said Robert “Red” Jensen, who piloted the dual-fuselage glider. “There were no squawks.”

 The one-third scale twin-fuselage towed glider glides in for landing on Rogers Dry Lake after its successful first test flight. (Credit: Tom Tschida/NASA Armstrong)
The one-third scale twin-fuselage towed glider glides in for landing on Rogers Dry Lake after its successful first test flight. (Credit: Tom Tschida/NASA Armstrong)

The goal is to build confidence with the aircraft and with tow operations before the final element – an experimental rocket payload – is mated with the glider and ultimately launched from the glider after its release from the DROID.

Gerald Budd, who for about three years has conceptualized and sought funding for the concept, piloted the DROID during the test flight and was pleased that the project had a successful first test flight.

“It was surreal to watch it fly after all work it took to get here,” Budd said.

If the project continues to succeed, Budd believes the ultimate goal would be to build a relatively inexpensive remotely or optionally piloted glider that will be towed aloft by a transport aircraft. Following release at about 40,000 feet, the glider would launch a booster rocket into an optimal trajectory to place its payload into low Earth orbit.

Small unmanned aircraft technician Derek Abramson and glider pilot Red Jensen, hold back the DROID tow plane while pilot Gerald Budd runs through some last minute checks. (Credit: Tom Tschida/NASA Armstrong)
Small unmanned aircraft technician Derek Abramson and glider pilot Red Jensen, hold back the DROID tow plane while pilot Gerald Budd runs through some last minute checks. (Credit: Tom Tschida/NASA Armstrong)

The glider was built primarily with commercial-off-the-shelf components, but some parts were manufactured at NASA Armstrong’s Fabrication Branch. Assembly was accomplished in NASA Armstrong’s Small Unmanned Aircraft Systems Research Lab, or model shop. In January, flights confirmed that towing and releasing a single-fuselage version of the aircraft by the DROID tow plane functioned as expected. The recent flights confirmed the dual-fuselage version also is airworthy.

TGALS chief engineer Ryan Dibley said using two commercial-off-the-shelf glider halves and joining them together with a center wing structure created challenges. While the center wing section was built in-house and was designed specifically for this mission, the outer wing sections were built for the standard single-fuselage glider without the additional weight.

“One of the concerns was we didn’t know what the outer wing sections were made of, how they were constructed, or what kind of loads they could take,” Dibley said. “We performed a loads test in NASA Armstrong’s Flight Loads Lab where we cleared the structure up to 2 gs to ensure that the wings could handle the loads of the glider itself and then with a partial mass payload. In the near future, we will put a wing back in the loads lab and test it to the loads required to carry the full payload.”

The one-third-scale twin fuselage towed glider rests of the cracked bed of Rogers Dry Lake at Edwards Air Force Base prior to its first flight Oct. 21, 2014 in this photo shot with a 16-mm. fisheye lens. (Credit: Tom Tschida/NASA Armstrong)
The one-third-scale twin fuselage towed glider rests of the cracked bed of Rogers Dry Lake at Edwards Air Force Base prior to its first flight Oct. 21, 2014 in this photo shot with a 16-mm. fisheye lens. (Credit: Tom Tschida/NASA Armstrong)

The system will eventually carry the scale-model Mini Sprite rocket, designed and built by Whittinghill Aerospace of Camarillo, California, under NASA’s Small Business Innovation Research program.

Initial research and development was internally funded at NASA Armstrong through the Center Innovation Fund. Potential U.S. Department of Defense and industry partners are sought for future phases.

David Voracek, NASA Armstrong chief technologist, said he is pleased to see a project that was in the Center Innovation Fund sprout wings and fly in another NASA program.

“I am happy to see that STMD is funding this for the next year under the Game Changing Development Program,” Voracek said. “We need to keep developing innovative technologies here at Armstrong that can be picked up by the NASA mission directorates or industry. I am looking forward to seeing this project continue to fly, especially when we put a rocket on the glider and get a launch off in the next year or so. The whole team came together and made the flight happen. It has been a long time in coming.”

  • Dave Erskine

    Careful modeling and scaled testing…. Stratolauch watch out!
    This and the Nano/cubesat revolution. Balloons, gliders and SSTO Space Planes from many sources… what a time to be around for all this innovation. And without the Big Brag!

  • justchaz

    Dual hull heavy lifter, done. Dual hull heavy lifter as launch platform, done. 40K feet remotely controlled plane, done. All being done daily. So, another entrant into a populated field even if they are just adding remote control? Shouldn’t NASA get out of the way and let the smaller shops build out this low cost market?

  • Anthony Horton

    I must be missing something here, what’s the advantage of tow plane + glider + rocket over the simpler carrier plane + rocket? Are they actually proposing using wave lift to gain altitude for free with the glider after separation from the tow plane?

  • Sam Moore

    It could simply be that it’s easier and cheaper to modify a glider into a specialised launch platform than a large aircraft.

  • B-Sabre

    But there are no large gliders. All of them are 1-2 seater personal recreation craft. You would have to design a glider entirely from scratch.

  • B-Sabre

    As someone noted above, I just don’t see the advantage of this. How is a rocket+glider+tow plane more advantageous than rocket + launch carrier? All you are doing is adding another subsystem to the system, and increasing its unreliability – Now you have the possibility of something going wrong with the glider as well as the rocket and tow-plane.

  • Sam Moore

    There’s no massive twin-hull cargo aircraft either, at least ones that are extant.

  • B-Sabre

    So the only difference between the two is one has power plants and the other doesn’t. I just don’t see the advantage here. You’re still going to need an aircraft as large as or larger than the glider as the tow vehicle. You’re adding a whole lot of structure and unreliability to things and I just don’t see where the advantage comes in.

  • Hmm that twin fuselage glider looks like it was “inspired” by WhiteKnightTwo.

  • According to NASA, the advantage is cost. Building a carrier glider is apparently a lot cheaper than building a WhiteKnightTwo.

    “Budd maintains the Towed Glider Air Launch Concept has the potential to
    realize the operational flexibility of a custom airplane, but without
    the price tag.

    “It’s a real-estate problem,” said Budd. “You’re limited in what you
    can fit underneath an existing aircraft. Launching off the top of a
    carrier aircraft is problematic from a safety perspective. Our approach
    allows for significant payloads to be carried aloft and launched from a
    purpose-built custom aircraft that is less expensive because of the
    simplicity of the airframe, having no propulsion system (engines, fuel,
    etc.), on board,” Budd said.”

    http://www.nasa.gov/centers/dryden/Features/towed_glider_concept.html

    .

  • ‮‮‮

    > Nobody has built heavy-lift gliders since the Second World War.

    Except, you know, Rockwell. (And Energiya)

  • Richard

    Since when did a toy RC plane, become a ‘NASA Armstrong’s DROID small unmanned research aircraft’
    Lets big up and sound amazing for……. flying an RC plane.

  • Hug Doug

    An RC aircraft that that is used to test awesome stuff, like terrain collision avoidance software.

    http://www.nasa.gov/centers/armstrong/multimedia/imagegallery/DROID/index.html#lowerAccordion-set1-slide10

    there’s a lot of research you can do with a smaller aircraft that would be too expensive to put on a larger airplane.

    also, something this size, you can hardly call a toy…

    http://www.nasa.gov/sites/default/files/images/662137main_ED12-0172-012.jpg

  • Dave Erskine

    Please take me off this display feature…. I just only want to comment but dont need to see any others by email.Unsubscribe me… Dave Erskine
    Sent from my iPad

  • Aerospike

    you have to do this yourself in your disqus.com profile.

  • Sam Moore

    There should be an option for it at the bottom of the actual emails.

  • B-Sabre

    Those were less “gliders” than “don’t hit the ground quite as fast.” And I think the Energiya/Buran had a couple of turbojets installed.

    Ok, to be more specific, nobody is making heavy-lift soaring gliders.

  • ‮‮‮

    It was just an unnecessary nitpick, you can safely ignore it. It’s not like anybody is going to modify Shuttle into a towed launch platform. 🙂

  • B-Sabre

    Well, now that you mention it…somebody did some tow-tests of an F-106 behind a C-141 for exactly that sort of mission profile, and I think Burt Rutan just patented something similar. So if you had a shuttle that could get into orbit from high altitude without the external tank and SRBs, you could do it. Now, how do you tow the thing….