landers of the future, however, will require much larger drag devices than any now
in use to slow them down, and those next-generation drag devices will need to be
deployed at higher supersonic speeds to safely land vehicle, crew, and cargo.
The NASA Space Technology Mission Directorate sponsored the Low
Density Supersonic Decelerator (LDSD) project. Managed by JPL in Pasadena,
CA this has undertaken full-scale, stratospheric tests of these breakthrough technologies high above Earth in order to prove their value for future missions to
Mars. Three devices were tested. Two were supersonic inflatable aerodynamic
decelerators in 6 and 8 m (20 and 26 ft) diameter configurations. Both were very
large, durable, balloon-like pressure vessels that inflate around an entry vehicle
in order to slow it from Mach 3.5 or greater down to Mach 2 or lower. Also
developed and tested was a 30.5 m (100 ft) diameter parachute to slow it from
Mach 2 or Mach 1.5 to subsonic speeds. The parachute tests incorporated two
different designs: a disk sail that employed a single, durable piece of fabric, and
a ring sail which was a stronger, paneled variation sewn together in concentric
rings of a high-strength Kevlar material. All three devices will be the largest of
their kind ever flown at speeds several times greater than the speed of sound.
Together, these new drag devices could increase payload delivery to the surface
of Mars from our current capability of 1.5 tonnes (3,307 lb) to 2 to 3 tonnes
(4,409 to 6,614 lb) depending on which inflatable decelerator is used in combination with the parachute. Due to the low pressure of the Martian atmosphere,
the targets for landings have usually been at low elevations in order to maximize
the time available for a parachute to function. The new technologies will increase
the available elevations by 2-3 km (1.24-1.9 mi), thereby increasing the accessible surface area we can explore. The new systems will also improve accuracy,
shrinking the “landing ellipse” from 10 km (6.2 mi) to just 3 km (1.86 mi). All
these factors will increase the capabilities and robustness of robotic and human
explorers on Mars.
To thoroughly test the system in conditions simulating entry into the atmosphere of Mars, the LDSD team flew full scale drag devices at supersonic speeds
high in stratosphere. The investigators conducted design verification tests of parachutes and supersonic inflatable aerodynamic decelerators through 2013, and
supersonic flight tests in 2014 and 2015 from the U.S. Navy Pacific Missile Range
Facility in Kauai, Hawaii. The Supersonic Inflatable Aerodynamic Decelerator
(SIAD) and a supersonic parachute were deployed during the flight test. The SIAD
operated as expected, dramatically slowing the test vehicle. When the parachute
was deployed into the supersonic slipstream, it appeared to blossom to full inflation prior to the emergence of a tear which then propagated and destroyed the
canopy. As a result, the splashdown in the Pacific fractured parts of the structure.
Memory cards with comprehensive test data, including high-speed, high- resolution
imagery recorded in-flight were successfully recovered. Also recovered were the
test vehicle and its components, the supersonic parachute, the ballute which
162 Scientific Flight Types
in use to slow them down, and those next-generation drag devices will need to be
deployed at higher supersonic speeds to safely land vehicle, crew, and cargo.
The NASA Space Technology Mission Directorate sponsored the Low
Density Supersonic Decelerator (LDSD) project. Managed by JPL in Pasadena,
CA this has undertaken full-scale, stratospheric tests of these breakthrough technologies high above Earth in order to prove their value for future missions to
Mars. Three devices were tested. Two were supersonic inflatable aerodynamic
decelerators in 6 and 8 m (20 and 26 ft) diameter configurations. Both were very
large, durable, balloon-like pressure vessels that inflate around an entry vehicle
in order to slow it from Mach 3.5 or greater down to Mach 2 or lower. Also
developed and tested was a 30.5 m (100 ft) diameter parachute to slow it from
Mach 2 or Mach 1.5 to subsonic speeds. The parachute tests incorporated two
different designs: a disk sail that employed a single, durable piece of fabric, and
a ring sail which was a stronger, paneled variation sewn together in concentric
rings of a high-strength Kevlar material. All three devices will be the largest of
their kind ever flown at speeds several times greater than the speed of sound.
Together, these new drag devices could increase payload delivery to the surface
of Mars from our current capability of 1.5 tonnes (3,307 lb) to 2 to 3 tonnes
(4,409 to 6,614 lb) depending on which inflatable decelerator is used in combination with the parachute. Due to the low pressure of the Martian atmosphere,
the targets for landings have usually been at low elevations in order to maximize
the time available for a parachute to function. The new technologies will increase
the available elevations by 2-3 km (1.24-1.9 mi), thereby increasing the accessible surface area we can explore. The new systems will also improve accuracy,
shrinking the “landing ellipse” from 10 km (6.2 mi) to just 3 km (1.86 mi). All
these factors will increase the capabilities and robustness of robotic and human
explorers on Mars.
To thoroughly test the system in conditions simulating entry into the atmosphere of Mars, the LDSD team flew full scale drag devices at supersonic speeds
high in stratosphere. The investigators conducted design verification tests of parachutes and supersonic inflatable aerodynamic decelerators through 2013, and
supersonic flight tests in 2014 and 2015 from the U.S. Navy Pacific Missile Range
Facility in Kauai, Hawaii. The Supersonic Inflatable Aerodynamic Decelerator
(SIAD) and a supersonic parachute were deployed during the flight test. The SIAD
operated as expected, dramatically slowing the test vehicle. When the parachute
was deployed into the supersonic slipstream, it appeared to blossom to full inflation prior to the emergence of a tear which then propagated and destroyed the
canopy. As a result, the splashdown in the Pacific fractured parts of the structure.
Memory cards with comprehensive test data, including high-speed, high- resolution
imagery recorded in-flight were successfully recovered. Also recovered were the
test vehicle and its components, the supersonic parachute, the ballute which
162 Scientific Flight Types