provides one alternative for enlarging the drag area with a low-mass design. Russia Such an inflatable shield/aerobrake was designed for the penetrators of Mars 96 mission. Since the mission failed due to the launcher malfunction, the NPO Lavochkin and DASA/ESA have designed a mission for Earth orbit. The Inflatable Reentry and Descent Technology (IRDT) demonstrator was launched on Soyuz-Fregat on 8 February 2000. The inflatable shield was designed as a cone with two stages of inflation. Although the second stage of the shield failed to inflate, the demonstrator survived the orbital reentry and was recovered.Inflatable Reentry and Descent Technology (IRDT) Factsheet, ESA, September, 2005 The subsequent missions flown on the Volna rocket failed due to launcher failure. NASA IRVE NASA launched an inflatable heat shield experimental spacecraft on 17 August 2009 with the successful first test flight of the Inflatable Re-entry Vehicle Experiment (IRVE). The heat shield had been vacuum-packed into a payload shroud and launched on a Black Brant 9 sounding rocket from NASA's Wallops Flight Facility on Wallops Island, Virginia. "Nitrogen inflated the heat shield, made of several layers of silicone-coated [Kevlar] fabric, to a mushroom shape in space several minutes after liftoff." The rocket apogee was at an altitude of where it began its descent to supersonic speed. Less than a minute later the shield was released from its cover to inflate at an altitude of . The inflation of the shield took less than 90 seconds. NASA HIAD Following the success of the initial IRVE experiments, NASA developed the concept into the more ambitious Hypersonic Inflatable Aerodynamic Decelerator (HIAD). The current design is shaped like a shallow cone, with the structure built up as a stack of circular inflated tubes of gradually increasing major diameter. The forward (convex) face of the cone is covered with a flexible thermal protection system robust enough to withstand the stresses of atmospheric entry (or reentry). In 2012, a HIAD was tested as Inflatable Reentry Vehicle Experiment 3 (IRVE-3) using a sub-orbital sounding rocket, and worked. See also Low-Density Supersonic Decelerator, a NASA project with tests in 2014 & 2015 of a 6m diameter SIAD-R. LOFTID A inflatable reentry vehicle, Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID), was launched in Nov 2022, inflated in orbit, reentered faster than Mach 25, and was successfully recovered on November 10. Entry vehicle design considerations There are four critical parameters considered when designing