NASA - National Aeronautics and Space Administration

As a ‘wind-tunnel in the sky’ this is a means of conducting rapid and inexpensive sub-orbital re-entry experiments in support of novel probe design, flight dynamics, control system development, and instrument and sensor verification.

Benefit
It is of great importance to the exploration program to have a capability of testing a variety of different technologies for future flight application. The advantages of the sounding rocket platform include elimination of crew safety concerns (e.g., STS and ISS) and a rapidity with which new experiments can be incorporated. A very high altitude sounding rocket may provide as much as 40 minutes of microgravity, and atmospheric entry velocities approaching that of earth orbit entry.

Image right: Superstable probe: Initial flight verification for SCRAMP configuration.

For entry applications, the potential utility is as follows:

Hypersonic decelerators - this would include the initial testing of attached and trailing ballutes as well as other concepts (deployed flexible decelerators; linear aerobrake designs)

IVHM - Integrated Vehicle Health Management systems for both ascent and re-entry sub-systems.

Advanced control methodologies - for improving the landing footprint of CEVs, Mars and other planetary probes.

Scramjet developments - an initial flight experiment with a ‘Busemann duct’ was conducted with some success, suggesting focused experiments in duct flow physics with fuel injection are possible.

Advanced probe design - for the development of dynamically stable re-entry systems (e.g., SCRAMP). This is particularly important for future SAMPLE RETURN missions.

Research Overview
Our in-house expertise draws upon a diverse, multi-disciplinary team of psychologists and engineers. We apply a variety of task analytic, experimental, and modeling techniques to characterize interface requirements and test potential solutions.

Right: Image from waverider aft-camera at apogee (image of terminator from pre-dawn launch).

Recent research and development projects include:

• Haptic Interfaces for Teleoperations
  We are developing human factors guidelines for effective haptic (force reflecting) manual interfaces for multi-sensory virtual simulation and teleoperation displays. Major program goals include: 1) the design of a novel, very high performance, 3 DOF force reflecting manual interface device; and 2) examination of operator perception and manual task mechanical linkage.
• Spatial Auditory Displays
  We have developed and validated technologies to synthesize spatially localized sounds. By applying real-time transformation, any acoustic source (voice, warning tones) can be localized to a point in 3D space. Sounds can be displayed via speakers or headphones. These technologies have been tested in a number of aerospace environments (including ATC, aircraft flight deck, and mission control). We have demonstrated consistent improvements in situational awareness and speech intelligibility with these advanced acoustic displays. Several patents have been awarded or are pending.
• Space Perception in Virtual Environments
  We are assessing the acquisition of situational awareness via immersive (virtual environment) and non-immersive (desktop) interface displays, and are developing a model to predict the degree of interface fidelity required for specific visualization tasks. Our findings have been published in PRESENCE, the journal of virtual environment research.

Background
The flight series was born of the perceived difficulty of performing small scale flight experiments. It was intended to complement ground facilities such as ballistic ranges (this was conceived as an ‘atmospheric scale’ ballistic range), arc-jets, and more traditional hypersonic test facilities.

Image right: Hypersonic waverider flight test development article.

By using the stable of NASA sounding rockets, and developing a simple means of deploying multiple experiments above the atmosphere, Mach 8-12 may be readily achieved.

Three flights have been conducted with over 15 independent re-entry experiments. Experiments have ranged from advanced low L/D probes (‘super’ stable configurations; transpiration cooling systems testing, deployed drag devices) to high L/D flight articles (simple waveriders; control systems development for future planetary entry concepts).

SOAREX I: Comprehensive Success
Flight using a land range, radial ejection of 11 experiments and autonomous on-board data-storage. performance via psychophysical and target acquisition experiment. A patent has been award for our 3 DOF parallel All experiments were recovered using unique retrieval systems.

SOAREX II: Success
Flight using a water range, first design of multiple-axial experiment ejection, linear aerobrake system test.

SOAREX III: Comprehensive Success
First waverider system test, redundant IMU sensors, use of multiple cameras on payload to confirm ejection and subsequent stabilization.

SOAREX IV: Launch in late 2004
Multiple high L/D test articles; first test of deployable aerobrake technology, water recovery system test.

SOAREX Launch systems:
Multiple Reentry Experiments

SOAREX Trajectories
Altitude vs. velocity plots show different ballistic and lifting entry trajectories compared to a typical STS trajectory. Sounding rocket platforms can provide very high altitude ejection of experiments, and 10-30 minutes of microgravity during freefall.

Experimental modular data system packages have been developed which help to efficiently incorporate future experiments. The high L/D test articles (waveriders) have been equipped with redundant IMU sensors, video cameras, pressure and temperature sensors (for boundary layer transition flight data). There are both terrestrial and planetary applications.