Inflatable Re-entry Vehicle Experiment (IRVE) Design Overview

Abstract

Inflatable aeroshells offer several advantages over traditional rigid aeroshells for atmospheric entry. Inflatables offer increased payload volume fraction of the launch vehicle shroud and the possibility to deliver more payload mass to the surface for equivalent trajectory constraints. An inflatable's diameter is not constrained by the launch vehicle shroud. The resultant larger drag area can provide deceleration equivalent to a rigid system at higher atmospheric altitudes, thus offering access to higher landing sites. When stowed for launch and cruise, inflatable aeroshells allow access to the payload after the vehicle is integrated for launch and offer direct access to vehicle structure for structural attachment with the launch vehicle. They also offer an opportunity to eliminate system duplication between the cruise stage and entry vehicle. There are however several potential technical challenges for inflatable aeroshells. First and foremost is the fact that they are flexible structures. That flexibility could lead to unpredictable drag performance or an aerostructural dynamic instability. In addition, durability of large inflatable structures may limit their application. They are susceptible to puncture, a potentially catastrophic insult, from many possible sources. Finally, aerothermal heating during planetary entry poses a significant challenge to a thin membrane. NASA Langley Research Center and NASA's Wallop's Flight Facility are jointly developing inflatable aeroshell technology for use on future NASA missions. The technology will be demonstrated in the Inflatable Re-entry Vehicle Experiment (IRVE). This paper will detail the development of the initial IRVE inflatable system to be launched on a Terrier/Orion sounding rocket in the fourth quarter of CY2005. The experiment will demonstrate achievable packaging efficiency of the inflatable aeroshell for launch, inflation, leak performance of the inflatable system throughout the flight regime, structural integrity when exposed to a relevant dynamic pressure and aerodynamic stability of the inflatable system. Structural integrity and structural response of the inflatable will be verified with photogrammetric measurements of the back side of the aeroshell in flight. Aerodynamic stability as well as drag performance will be verified with on board inertial measurements and radar tracking from multiple ground radar stations. The experiment will yield valuable information about zero-g vacuum deployment dynamics of the flexible inflatable structure with both inertial and photographic measurements. In addition to demonstrating inflatable technology, IRVE will validate structural, aerothermal, and trajectory modeling techniques for the inflatable. Structural response determined from photogrammetrics will validate structural models, skin temperature measurements and additional in-depth temperature measurements will validate material thermal performance models, and on board inertial measurements along with radar tracking from multiple ground radar stations will valid...

Low-Density Aerodynamics for the Inflatable Reentry Vehicle Experiment

“…Even though IRVE does not provide a match for interplanetary entry conditions or vehicle size due to the current launch performance and payload volume, IRVE will provide an opportunity to obtain a wealth of data that will contribute significantly to the understanding and the advancement of technology for inflatable decelerators. The IRVE mission and objectives [2] will include demonstration of aeroshell packaging efficiency, materials performance, and methods of construction, inflation, leak performance, structural integrity and aerodynamic stability of the inflatable system, and a trove of data through inertial, radar tracking, photographic, and skin and in-depth temperature measurements. In addition to demonstrating the inflatable aeroshell technology, IRVE will serve [1] to validate structural, aerothermal, and trajectory modeling techniques for inflatables.…”

“…T HE potential benefits of inflatable decelerators for aerocapture is such that they have generated renewed interest in addressing a number of technical challenges associated with their implementation. If these technologies can be validated, then the inflatables will surpass [1][2][3] the capabilities of rigid aeroshells in several respects as follows: increased payload mass and volume fraction, postlaunch vehicle integration payload access, use of mission systems during both the in-transit phase and the entry, descent and landing phases, access to higher altitude landing sites upon entry, and provide a more benign payload thermal environment during entry. Included in the family of aerocapture inflatable decelerators [4] (Fig.…”

“…1) are trailing ballutes, afterbody attached ballutes, and forebody-attached inflatable aeroshells. This paper focuses on the last configuration, which will be used in the inflatable reentry vehicle experiment (IRVE) [1][2][3], described pictorially in Figs. 2-4.…”

Aerodynamic Heating Around Flare-Type Membrane Inflatable Vehicle in Suborbital Reentry Demonstration Flight

“…In general, the use of a deployable aeroshell allows the vehicle to be decelerated at a higher altitude compared with a conventional rigid reentry vehicle. This provides several advantages for the entry, descent, and landing (EDL) approach, such as a lower heat load from aerodynamic heating and reduction in radio-frequency blackout [1][2][3][4][5][6][7][8][9]. Recently, a reentry vehicle with an inflatable aeroshell has also been developed in the Membrane Aeroshell for Atmospheric-entry Capsule (MAAC) project, in cooperation with several universities and JAXA.…”

Aerodecelerator Performance of Flare-Type Membrane Inflatable Vehicle in Suborbital Reentry

“…This technology can provide several advantages, e.g., reduction in aerodynamic heating during atmospheric reentry [1][2][3][4][5][6][7][8][9]. For flare-type thin-membrane aeroshells, several studies of elemental technologies and demonstration flights have been performed as part of the Membrane Aeroshell for Atmospheric-entry Capsule (MAAC) project [10][11][12][13][14].…”