Potential Future use of Nuclear Electric Propulsion in the Outer Solar System
UNKNOWN
Engineering topics
Publications and source records attributed to Casani, John.
UNKNOWN
In March 2010, the Decadal Survey Giant Planets Panel (GPP) requested a short-turnaround study to evaluate the feasibility of a small Fission Power System (FPS) for future unspecified National Aeronautics and Space Administration (NASA) science missions. FPS technology was considered a potential option for power levels that might not be achievable with radioisotope power systems. A study plan was generated and a joint NASA and Department of Energy (DOE) study team was formed. The team developed a set of notional requirements that included 1-kW electrical output, 15-year design life, and 2020 launch availability. After completing a short round of concept screening studies, the team selected a single concept for concentrated study and analysis. The selected concept is a solid block uranium-molybdenum reactor core with heat pipe cooling and distributed thermoelectric power converters directly coupled to aluminum radiator fins. This paper presents the preliminary configuration, mass summary, and proposed development program.
Topics include: INtegrated Science Instrument Module (ISIM) plus Optical Telescope Element (OTE) equals OTIS, Test Assessment Task (TAT) scope, text complexity at JSC, OTIS cryo test timeline, thermal verification overview, optical verification overview, ISIM cryo test configuration at GSFC, ISIM I and T flow, ISIM cryo test timeline, and JSC activities flow.
I first came to the Jet Propulsion Laboratory (JPL) 48 years ago, and was taught that what's most important for project success is bringing good people on board, getting them to come together as a team, making certain that they're all on the same page, and setting up the mechanisms to keep them communicating. That much is true to all successful projects - but, naturally, it is not as simple as it sounds.
The trouble was that the shuttle was still under development when that schedule was set. As time went on, the Shuttle had problems with its high pressure turbines, thermal protection tiles, engines, and more. The early launch dates had to be scrapped. NASA Headquarters told us, "We re going to delay your launch two years to allow more time for the Shuttle development to take place. You can slow your development accordingly." Right off the bat, we looked into the celestial mechanics and how they would affect us. The difficulty in launching a spacecraft to Jupiter changes on a year-to- year basis, in a cyclical pattern that repeats about every ten or twelve years. In order to achieve the velocity needed to get from low earth orbit to Jupiter, an upper stage is required in the Shuttle. For the 1982 launch the upper stage was adequate, but it could not provide the velocity we would need in 1984. This meant we would have to separate the Galileo probe from the Galileo orbiter before launch and put each of them on separate Shuttles with separate upper stages. When we told the folks at Headquarters this, they told us, "Okay we'll give you two Shuttle launches."
NASA's Mars Surveyor Program (MSP) began in 1994 with plans to send spacecraft to Mars every 26 months. Mars Global Surveyor (MGS), a global mapping mission, was launched in 1996 and is currently orbiting Mars. Mars Surveyor '98 consisted of Mars Climate Orbiter (MCO) and Mars Polar Lander (MPL). Lockheed Martin Astronautics (LMA) was the prime contractor for Mars Surveyor '98. The Jet Propulsion Laboratory (JPL), California Institute of Technology, manages the Mars Surveyor Program for NASA's Office of Space Science. MPL was developed under very tight funding constraints. The combined development cost of MPL and MCO, including the cost of the two launch vehicles, was approximately the same as the development cost of the Mars Pathfinder mission, including the cost of its single launch vehicle. The MPL project accepted the challenge to develop effective implementation methodologies consistent with programmatic requirements.
The Mars Climate Orbiter (MCO) was launched on December 11, 1998. The MCO was to arrive at Mars and begin orbit insertion on September 23, 1999. The Mars Orbit Insertion (MOI) burn, a 16-minute maneuver to slow the spacecraft and enable capture into an orbit around Mars, began on schedule. Five minutes into the maneuver, and approximately 49 seconds before the anticipated time for loss of communication, the MCO was occulted by Mars. Thereafter, no contact with the spacecraft could be established. On September 24, 1999, an internal JPL team (the MCO Peer Review Team) was appointed to help investigate the reason for the loss of spacecraft signal. The Peer Review Team's findings are presented in this report.