Initial Cassini Propulsion System In-Flight Characterization

Barber, Todd J.; Cowley, Richard

doi:10.2514/6.2002-4152

Cited by 25 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Cassini propulsion module subsystem is comprised of two separate propulsion systems: a bipropellant system with the main-engine assembly (MEA) and a monopropellant, reaction-control system (RCS) [2]. The locations of the main engines and RCS thruster pods are shown in Figure 1.…”

Section: Cassini Propulsion Systemsmentioning

confidence: 99%

Ensuring Cassini's end-of-mission propellant margins

Sturm

Barber

Roth

2015

2015 IEEE Aerospace Conference

View full text Add to dashboard Cite

The Cassini spacecraft is in its final years. On September 15, 2017, Cassini will plunge deep into Saturn's atmosphere never to reemerge; thus concluding its second extended mission and 13 years in orbit around the ringed planet. As of October 2014, the spacecraft is four years in to its sevenyear, second extended mission, the Cassini Solstice Mission (CSM). With three years left and only 2.5% of its loaded bipropellant and 37% of its loaded monopropellant remaining, the Cassini project actively manages the predicted end-ofmission propellant margins to maintain a high confidence in the spacecraft's ability to complete the CSM as designed.Accurate spacecraft navigation, rigorous remaining-propellant estimation, and frequent future propellant consumption prediction have resulted in efficient propellant use and a probability of sufficient propellant margin greater than 99%.

show abstract

Section: Cassini Propulsion Systemsmentioning

confidence: 99%

Ensuring Cassini's end-of-mission propellant margins

Sturm

Barber

Roth

2015

2015 IEEE Aerospace Conference

View full text Add to dashboard Cite

show abstract

“…The pre-launch mission design called for the PMS system to be characterized 30 days prior to the SOI Burn maneuver, so that the OP FP could be disabled. Leak mitigation measures were also added to the PMS plumbing: Two high-pressure helium latch valves (LV10 & LV11), a pyroisolation ladder upstream of the regulators (PV10-PV15), plus several filters as depicted in Figure 11 (Barber, 2002;Leeds et al, 1996):…”

Section: Occurrence Of Waived Failure In Flight: Leaking Prime Pms Rementioning

confidence: 99%

Resolving the Difficulties Encountered by JPL Interplanetary Robotic Spacecraft in Flight

Morgan¹

2012

Advances in Spacecraft Systems and Orbit Determination

View full text Add to dashboard Cite

“…The monopropellant propulsion system for Cassini is of the blow-down type, consisting of a single hydrazine tank and sixteen (eight primary and eight backup) hydrazine thrusters with a thrust range of 0.5 to 1.0 N, and a helium recharge tank. 5 Fig. 2.b depicts one of Cassini 's 1-N (0.2-lbf) monopropellant hydrazine thrusters.…”

Section: Monopropellant Hydrazine Propulsion Systemmentioning

confidence: 99%

A Flight-Calibrated Methodology for Determination of Cassini Thruster On-Times for Reaction Wheel Biases

Sarani

2010

AIAA Guidance, Navigation, and Control Conference

View full text Add to dashboard Cite

This paper describes a methodology for accurate and flight-calibrated determination of the on-times of the Cassini spacecraft Reaction Control System (RCS) thrusters, without any form of dynamic simulation, for the reaction wheel biases. The hydrazine usage and the ΔV vector in body frame are also computed from the respective thruster on-times. The Cassini spacecraft, the largest and most complex interplanetary spacecraft ever built, continues to undertake ambitious and unique scientific observations of planet Saturn, Titan, Enceladus, and other moons of Saturn. In order to maintain a stable attitude during the course of its mission, this three-axis stabilized spacecraft uses two different control systems: the RCS and the reaction wheel assembly control system. The RCS is used to execute a commanded spacecraft slew, to maintain three-axis attitude control, control spacecraft's attitude while performing science observations with coarse pointing requirements, e.g. during targeted low-altitude Titan and Enceladus flybys, bias the momentum of reaction wheels, and to perform RCS-based orbit trim maneuvers. The use of RCS often imparts undesired ΔV on the spacecraft. The Cassini navigation team requires accurate predictions of the ΔV in spacecraft coordinates and inertial frame resulting from slews using RCS thrusters and more importantly from reaction wheel bias events. It is crucial for the Cassini spacecraft attitude control and navigation teams to be able to, quickly but accurately, predict the hydrazine usage and ΔV for various reaction wheel bias events without actually having to spend time and resources simulating the event in flight software-based dynamic simulation or hardware-in-the-loop simulation environments. The methodology described in this paper, and the ground software developed thereof, are designed to provide just that. This methodology assumes a priori knowledge of thrust magnitudes and thruster pulse rise and tail-off time constants for eight individual attitude control thrusters, the spacecraft's wet mass and its center of mass location, and a few other key parameters.

show abstract

Initial Cassini Propulsion System In-Flight Characterization

Cited by 25 publications

References 0 publications

Ensuring Cassini's end-of-mission propellant margins

Ensuring Cassini's end-of-mission propellant margins

Resolving the Difficulties Encountered by JPL Interplanetary Robotic Spacecraft in Flight

A Flight-Calibrated Methodology for Determination of Cassini Thruster On-Times for Reaction Wheel Biases

Contact Info

Product

Resources

About