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Robert A Dillman

Publications and source records attributed to Robert A Dillman.

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

The Design of the Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) Reentry Vehicle (RV)

This discussion will involve the design and architecture of the Low-Earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) Reentry Vehicle (RV). It will describe the structure and modular design of the RV, expounding on its various subsystems, including power and commanding, data handling and recovery, instrumentation, the inflation system, and the aeroshell. The unique launch vehicle architecture for the LOFTID mission, as a massive rideshare payload, required the development of supporting flight systems, including the Payload Adapter Separation System (PASS) and the Reentry Vehicle Payload Adapter Interface Ring (RVPAIR). To do no harm to the primary mission, the LOFTID team also designed and delivered a flightworthy Mass Simulator as risk reduction in the event the RV was not ready in time for the primary mission launch date. Various challenges and design trades will be discussed, along with a brief description of the RV performance in flight.

R J Bodkin↗
NASA NTRS2020

Aerocapture as an Enhancing Option for Ice Giants Missions

Investigation of Uranus and Neptune, via orbiter and atmospheric probes, is required to answer pressing science questions that have been raised in previous Decadal Surveys. As the Ice Giants are the farthest planets from Earth, traditional fully-propulsive orbit insertion missions would require a large amount of propellant, leaving less mass for the scientific payload; additionally, transit time to the planetary bodies near 13-15 years. Aerocapture uses aerodynamic forces generated by flight within a planetary atmosphere to decelerate and achieve orbit insertion. Although, aerocapture has not been used in the past, recent developments in thermal protection systems, guidance and control, and navigation capabilities enable the use of rigid, heritage entry vehicle configurations already flown at other planetary bodies for Ice Giants aerocapture. With the addition of these recent capabilities, aerocapture can robustly deliver spacecraft to Ice Giant orbits, while substantially increasing on-orbit payload mass (more than 40%) and reducing the transit time by 2-5 years (15-30%) relative to fully-propulsive orbit insertion.

Soumyo Dutta↗
NASA NTRS2020

Low Lift-to-Drag Morphing Shape Design

One advantage of the low lift-to-drag (L/D) inflatable vehicle being evaluated for the human Mars Entry, Descent, and Landing Architecture Study (EDLAS) is the lower launch mass compared to the other concepts being considered. Mass reduction is achieved by using a strong but lightweight inflatable structure and by eliminating the need for a backshell. Performance analysis has shown that additional mass savings is achievable using entry guidance technologies that reduce powered descent propellant mass by directly controlling angle of attack and sideslip, rather than the traditional bank angle control approach used by the current state-of-the-art Mars Science Laboratory entry vehicle. Two methods of implementing this guidance scheme are presented, one uses aerodynamic flaps, the other changes or morphs the shape of the inflatable aeroshell during flight. This paper describes both control methods for the EDLAS low-L/D vehicle, including the aerodynamic model of the aerosurfaces and various methods to achieve the morphing shape deflection (internal motors, shifting tori, etc.). Results of trajectory performance simulations for both the aerodynamic flap and morphing designs are also presented along with details of mechanical implementation options available to ground test the system.

Alicia Dwyer Cianciolo↗
NASA NTRSDate not supplied

Tracking and Recovery of the LOFTID RV (Low-Earth Orbit Flight Test of an Inflatable Decelerator Reentry Vehicle)

The LOFTID mission launched from Vandenberg on Nov 10, 2022, and successfully demonstrated the reentry of a 6m diameter inflatable aeroshell from low Earth orbit. This paper will cover the design features implemented to enable recovery of the flight vehicle, and will discuss the splashdown calculations, in-flight tracking, recovery from the ocean, and post-flight inspection of the flight vehicle. To support recovery of the RV and ejected data recorder after splashdown, a recovery ship was pre-positioned near the predicted splashdown ellipse in the Pacific Ocean. The splashdown ellipse was repeatedly updated as launch approached. In-flight tracking included transmission from the RV of GPS data through both the Iridium satellite network and the LoRa direct RF link, along with IR video cameras on the recovery ship and airborne imagery from the SCIFLI Team. Using both the GPS data and the IR imagery, the recovery ship tracked down the RV, and deployed an inflatable boat to approach the RV and attach it to the ship’s crane, after which the RV was hoisted on board and secured in its GSE recovery stand. The ship then tracked down the ejected data recorder, which was also broadcasting its GPS data, and pulled it from the water. Once the ship returned to port, the RV was hoisted ashore for additional inspection, removal of the data recorders, and repackaging for shipment back to NASA Langley.

Robert A Dillman↗