SEE Expertise: Astrogation

We design trajectories to meet mission needs, and develop launch windows and propellant budgets. We analyze tracking systems and perform error analysis, calculating how well the orbits will be known during operations.

We have been astrogators for many years, navigating satellites around the Earth, in cislunar space, to the Moon, and beyond.

For a satellite mission to accomplish its goals, it must be put into the correct orbit. We design and analyze orbits to meet the mission requirements, and the implement methods to maintain them there. We can help with all sorts of missions, including sun synchronous and other low- Earth orbits; geostationary missions; libration point and other multi-body periodic orbits; heliocentric; and orbits around the Moon, planets, and asteroids.

We also design trajectories to get to these desired orbits. We’ve worked on many types of transfers, around the Earth, in cislunar space, and interplanetary. We’ve analysed rendezvous sequences, highly elliptic transfers, cislunar phasing loops, weak stability boundary trajectories, low thrust, interplanetary transfers, and more.

We also analyze the propulsion system requirements of these trajectories, and develop propellant budgets. We understand how the deterministic maneuvers change depending on many factors, including launch time and date. We also predict the size and timing of statistical maneuvers needed to correct trajectories and orbits, arising from tracking uncertainties and maneuver execution errors.

We also understand how satellites can be tracked, and the effects that the tracking hardware and schedule have on the trajectories. We can analyze the predicted orbit determination errors, and compare alternative tracking schemes to meet trajectory and other mission requirements. We know how to model the uncertainty from orbit estimation, and combined with the maneuver execution uncertainty, we can predict how well requirements will be met.

We also can help assess the constraints of launch vehicles, and the effect of launch windows on trajectories. We have worked with launch providers, making sure that communications and the interfaces are clear.

There is a lot more to astrodynamics than is commonly available, and we’ve found that intuition and experience in one orbit regime doesn’t always apply to other types of orbits. We’ve developed training courses to help teams understand the subtleties that often arise from real, high fidelity trajectory models that don’t show up in the simplified textbook equations.

OUR OTHER AREAS OF EXPERTISE

SATELLITE MISSION ANALYSIS

We model mission orbits and geometry. We perform trade-off and statistical analysis. We develop and validate mission requirements.

TECHNICAL DUE DILIGENCE & REVIEWS

We investigate the feasibility of proposed solutions, and identify gaps. We compare plans with current technology, evaluate development timelines. We investigate dependencies and illuminate risks.

MISSION CONCEPTS & PLANNING

We help develop realistic plans to accomplish the goals of the mission within the technical and budget constraints. We can validate assumptions, and propose alternatives to overcome obstacles.

FLIGHT DYNAMICS & OPERATIONS

We plan orbit maneuvers, and calibrate engines. We perform orbit determination and collision avoidance operations. We plan attitude profiles to meet communication and navigation needs.