BEGIN_DESC
Chapman Uranus Mission
The Canadian Space Agency has decided on a "low cost" basic science mission to one of the least studied and mysterious planets: Uranus. Rather than a Voyager style flyby, they intend to send the first probe to achieve Uranus orbit in order to study the Uranus system for several years. The plan calls for modifying the successful Chapman spacecraft bus to use an RTG power source. However, because the delta-V budget of the Chapman probe is only 2700 m/s, orbital insertion is only possible from an elliptical heliocentric transfer orbit with an apoapsis near Uranus' orbit. Including a Jupiter gravity assist, the transit time of such a trajectory is perhaps 15 or more years. Since the lifetime of the RTG power source is only 18 years, there simply isn't enough time for multiple encounters with inner planets and still allow for a multi-year science mission. Fortunately, the modular design of the Jarvis series of launch vehicles has brought down the launch cost such that a very heavy vehicle can be used where a medium vehicle would have been used formerly. Thus, the massive Jarvis-E is used to accelerate the tiny probe to the tremendous velocity necessary for a direct trans-Jovian insertion.
The mission requires the Jarvis dll version.
Launch is automatic to a 300 x 300 km parking orbit. You should then be approximately in the proper plane to use the third stage to perform the ejection burn to Jupiter. (Delta-V about 6600 m/s) It's okay to complete a full earth orbit if you need more time to setup the plan using your preferred MFD. Plan for a slingshot encounter with Jupiter on about May 22, 2036 with a pass radius of about 2Gm. Arrival at Uranus should occur sometime around 2048 or 2049. This mission takes about an hour or two of real time so have patience!
Once you arrive at Uranus, you will only have enough delta-V to capture to an elliptical orbit; do not expect to reach a circular orbit. Try to leave enough fuel to allow some maneuvering later. Due to Uranus's famous tilt, you will approach a pole such that only high inclination orbits are possible. One idea is to target a 90 deg. equatorial inclination and set a periapsis radius corresponding to the orbital radius of Ariel or Umbriel. Then on orbital insertion, set an apoapsis radius corresponding to the orbit of either Titania or Oberon. This allows your perpendicular orbit to nearly intersect the orbits of two moons at your apoapsis and periapsis. It is then possible to set up a flybys of the moons. If fuel remains, other moons can be targeted. How many can you reach?
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BEGIN_ENVIRONMENT
System Sol
Date MJD 64125.805880
END_ENVIRONMENT
BEGIN_FOCUS
Ship Jarvis_E
END_FOCUS
BEGIN_CAMERA
TARGET Jarvis_E
MODE Extern
POS 4.00 -166.05 71.33
TRACKMODE TargetRelative
FOV 60.00
END_CAMERA
BEGIN_HUD
TYPE Surface
END_HUD
BEGIN_MFD Left
TYPE Orbit
PROJ Ship
FRAME Ecliptic
REF Earth
END_MFD
BEGIN_MFD Right
TYPE Surface
SPDMODE 1
END_MFD
BEGIN_SHIPS
Jarvis_E:JARVIS/Jarvis_E
STATUS Landed Earth
AFCMODE 7
PRPLEVEL 0:1.000000 1:1.000000 2:1.000000
NAVFREQ 0 0 0 0
XPDR 0
FAIRINGON 1
STAGE 0
GLIMIT 5
GTVACC 6
TGT_APOGEE 300000
TGT_PERIGEE 300000
;TGT_INC 30.0
AP 1
MET -180
LAUNCH_SITE 2
PAYLOAD_FILE Jarvis_E\Chapman.ini
END
END_SHIPS
BEGIN_ExtMFD
END
BEGIN_VesselParametersMFD
END
