Orbital Antares User Manual
Page 29
Antares
®
OSP-3
User’s Guide
Section 3.0
– Performance
Release 1.1
July 2013
18
Figure 3.4-6. Antares 122 and 132 Critically Inclined Elliptical Launch Capabilities
3.5. Orbit Insertion Accuracy
Orbit insertion errors for any launch vehicle are primarily driven by impulse errors from terminal stage
propulsion, payload mass, guidance scheme used, and navigational errors. Orbital characterizes apse
errors in terms of altitude errors at the insertion and non-insertion apses. The insertion apse is less de-
pendent on impulse errors and payload mass and typically has a tighter dispersion than the non-insertion
apse. Errors in the non-insertion apse are caused by velocity errors at insertion, and, as a result, are dri-
ven more strongly by impulse errors and payload mass. The distribution of errors between the two apses,
as well as to other orbital parameters, can be greatly affected by the guidance scheme, which can be ad-
justed to place more or less priority on any one of the insertion parameters.
3.5.1. Insertion Accuracies for Antares Configurations 120 and 130
Orbit injection errors for Antares configurations 120 and 130 are strongly driven by total impulse errors
from the CASTOR 30B and 30XL motors, respectively. The actual insertion errors are dependent on the
payload mass and the guidance algorithm. However, insertion apse errors are within ±18 km (10 nmi) and
non-insertion apse errors are within 92.6 km (50 nmi). Lighter payloads going to high altitudes will
experience greater dispersions, particularly on the non-insertion apse.
Inclination dispersions are less than 0.2 degrees. When made a targeting priority, Right Ascension of
Ascending Node (RAAN) dispersions are also less 0.2 degrees.
3.5.2. Insertion Accuracies for Antares Configurations 121 and 131
The enhanced Antares configurations 121 and 131 include a restartable bipropellant third stage. This
stage has sufficient propulsive capability to both improve performance to higher altitude LEO missions as
well as significantly reduce apse altitude errors to within ±15 km (8 nmi) on both apses. Inclination errors