Mission Description

The Dawn Mission

• Launch from Earth July 7, 2006 0:0:0 (fixed)
  • launch declination limited to be between + or - 27 degrees EME2000 frame,
  • launch vehicle: Fit to Boeing Delta II 2925-9.5 foot fairing performance data,
  • Adapter mass 0.01 kg
  • launch contingency 0%
  • Forced coast days 0 to 15
  • Forced coast days 23 to 36
• Mars Flyby near March 15, 2009 (free)
  • Minimum flyby altitude allowed is 500 km at Mars.
• Intermediate Rendezvous with Vesta
  • Arrive: 27 September, 2011 (fixed)
  • Depart: 1 May, 2012  (fixed)
  • Vesta operations mass drop: 12 kg.
• Ceres Rendezvous July 24, 2015 (fixed)
• Engine: Single Dawn Tu (number 35)
  • Duty cycle: Continuous 95%, plus
  • Seven days forced coasting every year between Earth and Vesta
  • Four days forced coasting every year between Vesta and Ceres
• RCS system propellant expenditure (modeled as periodic mass drops)
  • 0.64 kg every 150 days from Earth to Vesta
  • 0.33 kg every 150 days from Vesta departure to Ceres arrival
• Solar array number 21 111704Am, Po=9.0 kW
• Spacecraft power models:      
  • (5) 111704L1 From day 0 to day 2771.7
  • (6) 111704L2m From Day 2771.7 to end
• Solar array power degradation model: (2) 061004T summer 04 baseline
  • Degradation Epoch: 2453923.5 JED
• Total Xenon propellant constraint: P=385 kg.
• Objective function: final mass.
• Gravitating bodies: Earth, Moon, Venus, Mars, Jupiter, Saturn, Sun
• Originally modeled using Mystic.

Additional Mission Options

A. Earth – Yen – Sauer Rendezvous

• Propulsion System SEP
• Launch Date 2012 (free)
• Yen Rendezvous 2018 (free)
• Sauer Rendezvous 2025 (free)
• Solar Array ASPA 1
• Engine NSTAR Engine G (1 engine)
• P0 11 kW
• Duty Cycle 100%
• Launch Vehicle Delta 7326-9.5
• Originally modeled in MALTO?

B. Earth – Vesta – Ceres

• Propulsion System: SEP, Solar Array ASPA 1,Engine NSTAR Engine G, (1 Engine), Duty Cycle 100%, P0 = 11 kW
• Launch Date, any time in 2010: Jan 1 2006 ≤ tlaunch ≤ Dec 31 2006
• Stay time at Vesta no less than 60 days, tvesta_stay ≥ 60 days
• Arrival at Ceres before Jan 1 2013, tceres_arrival ≤ Jan 1 2013
• Mass Drop at Vesta 0 (fixed)
• Launch Vehicle Delta II 7326-9.5, .V infinity magnitude and direction are free to be optimized.
• Originally modeled in Copernicus

Input/Output files

Copernicus20060318.zip (download)

MALTO4_4.zip (download)

Mysticv9_0_0.zip (download)

All Reference Case 15:  Multiple Asteroid Rendezvous Files (download zip)