Spacecraft Landing

How do we develop new landing capabilities for space systems?

Overview

When NASA wants to bring a spacecraft back to Earth, it generally uses a ballistic trajectory. This works well with unmanned satellites, where the precise return point is not critical. The challenge is more difficult when astronauts return from space, as it is important to have them land near recovery ships in the ocean, especially if crew members are injured. Designing reentry for manned spacecraft requires a tricky balance between braking too rapidly and subjecting the crew to crushing deceleration forces and braking too slowly, which can overheat the spacecraft.

Capabilities Used
Positioning, Navigation & Timing (PNT)

Draper develops novel PN&T solutions by combining precision instrumentation, advanced hardware technology, comprehensive algorithm and software development skills, and unique infrastructure and test resources to deploy system solutions. The scope of these efforts generally focuses on guidance, navigation, and control GN&C-related needs, ranging from highly accurate, inertial solutions for (ICBMs) and inertial/stellar solutions for SLBMs, to integrated Inertial Navigation System(INS)/GPS solutions for gun-fired munitions, to multisensor configurations for soldier navigation in GPS-challenged environments. Emerging technologies under development that leverage and advance commercial technology offerings include celestial navigation (compact star cameras), inertial navigation (MEMS, cold atom sensors), precision time transfer (precision optics, chip-scale atomic clocks) and vision-based navigation (cell phone cameras, combinatorial signal processing algorithms).

Image & Data Analytics

Draper combines specific domain expertise and knowledge of how to apply the latest analytics techniques to extract meaningful information from raw data to better understand complex, dynamic processes. Our system design approach encompasses effective organization and processing of large data sets, automated analysis using algorithms and exploitation of results. To facilitate user interaction with these processed data sets, Draper applies advanced techniques to automate understanding and correlation of patterns in the data. Draper’s expertise encompasses machine learning (including deep learning), information fusion from diverse and heterogeneous data sources, optimized coupling of data acquisition and analysis and novel methods for analysis of imagery and video data.

Autonomous Systems

Draper combines mission planning, PN&T, situational awareness, and novel GN&C designs to develop and deploy autonomous platforms for ground, air, sea and undersea needs. These systems range in complexity from human-in-the-loop to systems that operate without any human intervention. The design of these systems generally involves decomposing the mission needs into sets of scenarios that result in trade studies that lead to an optimized solution with key performance requirements.  Draper continues to advance the field of autonomy through research in the areas of mission planning, sensing and perception, mobility, learning, real-time performance evaluation and human trust in autonomous systems.

Human-Centered Solutions

Draper has continued to advance the understanding and application of human-centered engineering to optimize the interaction and capabilities of the human’s ability to better understand, assimilate and convey information for critical decisions and tasks. Through its Human-Centered Solutions capability, Draper enables accomplishment of users’ most critical missions by seamlessly integrating technology into a user’s workflow. This work leverages human-computer interaction through emerging findings in applied psychophysiology and cognitive neuroscience. Draper has deep skills in the design, development, and deployment of systems to support cognition – for users seated at desks, on the move with mobile devices or maneuvering in the cockpit of vehicles – and collaboration across human-human and human-autonomous teams.

Draper’s GENIE system enables NASA to use terrestrial rockets rather than more expensive space launches to test new instruments for landing on planets like Mars.

Draper is building on techniques that it developed for the Apollo missions as it helps NASA address these astronaut safety issues. Draper’s PredGuid successfully guided NASA’s Orion Spacecraft to within half a mile of its intended chute deploy target during its first exploration flight test, far exceeding the required accuracy of 10 miles. PredGuid is a sophisticated predictor-corrector algorithm that extends the capability of Draper’s entry guidance for Apollo. It provides significantly improved landing capability by estimating parameters including aerodynamic and atmospheric properties – increasing the available landing area for a high-speed return by hundreds of kilometers and providing precision accuracy to within 2 kilometers at chute deployment. PredGuid uses the Apollo approach for the final entry into the atmosphere, but it adds the capability to “skip” off the atmosphere to extend downrange capability, thereby allowing Orion to return to a primary landing site at virtually any time of the lunar month and from any lunar orbit.

 

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Draper’s PredGuid successfully guided NASA’s Orion Spacecraft to within half a mile of its intended chute deploy target during its first Exploration Flight Test, far exceeding the required accuracy of 10 miles. Photo credit: NASA

 

The entry guidance validated by Orion also can be used for other atmospheric planetary landings, such as Mars. However, because of the thinner atmosphere, a spacecraft landing on Mars cannot use parachutes and instead requires a propulsive capability. Draper is using its GENIE (Guidance Embedded Navigator Integration Environment) to control terrestrial rockets so that they can fly realistic Mars landing trajectories to demonstrate this ability.

Draper’s solution leverages guidance, navigation and control (GN&C) algorithms developed for the Apollo and Space Shuttle missions, vision-aided navigation expertise and software automation developed for systems like the International Space Station.

 

Technical Contact
Rick Loffi