The Space Congress® Proceedings 1988 (25th) Heritage - Dedication - Vision Apr 1st, 8:00 AM STS 30, 34 And 44- A Rebirth Of The Planetary Missions Ed Bangsund Director of Space Systems Planning Boeing Aerospace Company Seattle, Washington Robert Knutson Planning Staff Administrator Boeing Aerospace Company Seattle, Washington Follow this and additional works at: https://commons.erau.edu/space-congress-proceedings Scholarly Commons Citation Bangsund, Ed and Knutson, Robert, "STS 30, 34 And 44- A Rebirth Of The Planetary Missions" (1988). The Space Congress® Proceedings. 5. https://commons.erau.edu/space-congress-proceedings/proceedings-1988-25th/session-10/5 This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. STS 30, 34 AND 44 - A REBIRTH OF THE PLANETARY MISSIONS Ed Bangsund Robert Knutson Director of Space Systems Planning Planning Staff Administrator Boeing Aerospace Company Boeing Aerospace Company Seattle, Washington Seattle, Washington before it takes up its final flight path to Jupiter. ABSTRACT This new type of trajectory has been dubbed VEEGA, for Venus-Earth-Earth Gravity Assist, No American planetary probe has been launched with arrival at Jupiter to occur six years later since the twin Voyager spacecraft in 1979- in November 1995. The scientific objectives However, within eighteen months beginning of the Galileo mission are investigation of (1) in April 1989, three interplanetary probes will chemical composition and physical state of be shot into deep space from Shuttle cargo Jupiter's atmosphere, (2) chemical composition bays using the Inertial Upper Stage (IUS) as and physical state of the Jovian satellites, and an upper stage booster. In 1986 NASA made (3) the structure and physical dynamics of the the decision to cancel the use of Centaur as Jovian magnetosphere. an upper stage for the Space Shuttle. This action was one of the results of the tragic The third and final mission is Ulysses (presently Challenger accident in January 1986. With scheduled on STS-44 for October 5, 1990). increased safety concerns, it was decided not This mission involves a spacecraft being placed to risk using cryogenic propellant in the Shuttles on a trajectory around the sun normal to the payload bay. As a result of that decision a plane of the ecliptic. The trajectory of Ulysses search for a new upper stage to launch the will involve a fly-by of the planet Jupiter to three planetary spacecraft, stranded without obtain a gravity assist to change its orbit plane a launch system, began. This paper briefly to a solar polar orbit. The primary mission describes the search for a new upper stage objectives include investigation of properties and the resulting decisions, but focuses primarily of the solar corona, solar wind, heliocentric on the methods the selected IUS will fly those magnetic field, cosmic rays, and electromagnetic missions and what they mean in terms of phenomena as a function of the solar latitude. scientific knowledge to all of us. BACKGROUND The first of the three planetary missions to be launched by the Space Shuttle and IUS is The Inertial Upper Stage (IUS) is a two-stage, the Magellan mission (presently scheduled on solid rocket propelled, three axis controlled, STS 30 for April 27, 1989). Upon arrival at inertially navigated upper stage that can provide the planet Venus 15 months after launch, the 5,000 Ibs. of payload to geosynchronous orbit spacecraft will use its own solid rocket motor or boost various planetary orbits to escape to achieve an elliptical polar orbit and then velocities dependent upon their mass. The map the carbon dioxide and sulfuric acid cloud generic IUS vehicle can be configured to be obscured planet surface with its Synthetic used on the Shuttle, Titan 34D, or Titan 4 boost Aperture Radar (SAR). vehicles. The basic generic vehicle includes: stage structure; solid rocket motors and the The Galileo mission (presently scheduled on reaction control subsystem for propulsion; STS 34 for November 2, 1989) involves placing avionics for telemetry, tracking and command, an orbiter around the planet Jupiter as well guidance, navigation and control, data as a probe which will descend into the Jovian management, and thrust vector control; electrical atmosphere. The spacecraft will follow an power sources and electrical cabling; destruct entirely new trajectory to Jupiter that involves hardware; and airborne software. The IUS vehicle a flight to Venus, a gravity assist by that planet, also provides the interface between the and then two gravity-assist flights past Earth spacecraft and the launch vehicle (figure 1). 10-8 - SPACECRAFT INTERFACE PLANE • EQUIPMENT SUPPORT SECTION THRUST VECTOR CONTROL POTENTIOMETER" SOLID ROCKET MOTOR EXTENDIBLE EXIT CON NOZZLE SOLID ROCKET MOTOR INTERSTAGE STRUCTURE • CONTROL SYSTEM Figure 1. Inertial Upper Stage (IUS) implementation of an intensive four-month UPPER STAGE SELECTION NASA effort to investigate alternative launch vehicle capabilities for the near-term NASA The Challenger accident resulted in an extensive planetary missions — Magellan, Galileo, and re-examination and evaluation by NASA of Ulysses. A joint task team was formed and the Failure Modes and Effects Analysis (FMEA) concluded that the two-stage IUS system was and Critical Items List (CIL) for all elements the only known alternative which was currently of the Space Transportation System (STS) and in production, had been integrated into the the upper stages it carried to Earth orbit. Shuttle, had satisfactorily passed all the required Included were the Shuttle/Centaur, a high safety reviews in its required flight configuration, performance, liquid oxygen (02) - liquid hydrogen had successfully flown, and could achieve the (H^) upper stage being developed for future planetary missions' performance and schedule NASA and USAF high energy missions. requirements. The NASA studies showed that the On November 4, 1986 these findings, and other Shuttle/Centaur system as implemented did results of this four-month study were presented not meet STS design criteria. After a detailed to the administrator. Direction was received study of the program options and impacts, it to proceed to implement the Shuttle/IUS based was concluded that cancellation of the alternative by immediately procuring three Shuttle/Centaur program would provide lower IUS two-stage vehicles and one PAM-S for the safety risks for future Shuttle flights and less Magellan, Galileo and Ulysses planetary missions. impact to NASA's resources and other programs. In order to meet the required launch dates for These findings were presented to NASA's the planetary missions three IUS vehicles were administrator in June 1986 for his concurrence re-allocated from the IUS production program and the decision to cancel immediately followed. currently underway. The missions, to which these lUSs had been assigned were not scheduled The decision to terminate the Shuttle/Centaur in the near time frame and could await a program resulted in the immediate replacement production order, figure 2. 10-9 1988 1989 1990 V o rr OoO Mission IU9SJ7^% f I IUS-21 n OoO Mission I 'X^f ...... llUS-22 rt NASA/TDRS-F I iilvia! SMAB Processing f IUS-20 ] X Planetary 0 • Ulysses [lUS-17| o • Magellan I IUS-18 rt • Galileo Qus-ig Figure 2. Replacement IUS Vehicle Buy THE MAGELLAN MISSION 70 to 90 percent of the planet's surface, and thus fulfill its nominal mission. Additional After launch, the Shuttle will ascend to a parking science data expected is surface temperature orbit altitude of 137 nmi inclined at 31 degrees. data returned by passively sensing heat emissions The spacecraft, IUS and Airborne Support from the radiometry experiment, altimetry Equipment configuration that will be installed data with 30-meter resolution, and gravity in the Shuttle is illustrated in figure 3. Total data, obtained by measuring minute deviations weight of this cargo element is approximately in the orbit of the Magellan spacecraft each 49,000 Ibs. After separation from the Shuttle time it circles the planet. Very small variations is accomplished, the IUS will ignite its first in the density of the planet beneath the stage rocket for about two and a half minutes spacecraft will be enough to cause the orbital and its second stage rocket for one and three changes. In turn, these density variations will quarter minutes with only a 150 second coast provide details about the subsurface composition period between the two stage firings. and construction of Venus at that location. This series of subtle changes bears great The launch will use IUS-18, which is a basic implications for the dynamics of Venus' interior IUS two-stage vehicle with very little and the possible effects on the Venusian surface. modification. This IUS had previously been assigned to a Tracking and Data Relay Satellite Thus, the surface data from the radar, altimetry, mission. The IUS will inject Magellan into the and radiometry experiments, combined with transfer orbit that is illustrated in figure 4. the subsurface information from the gravity At injection, the 3475 kg spacecraft will require experiment, will furnish scientists with the a 03 of 7.12 km^/sec^ and will arrive at Venus information to construct a truly global picture in July of 1990. of Venus' geologic history. Upon completion of the Venus Orbit Insertion The highest and most dramatic continent-sized maneuver with its onboard rocket, Magellan highland region on Venus is Ishtar Terra, based will orbit Venus every three hours and nine on topography measurements by the Pioneer minutes. One mapping cycle will take 243 days Venus Orbiter. Ishtar is named for the Assyrian and during that cycle will acquire imaging, goddess of love and war and is about the size radiometry, altimetry, and gravity data from of the continental United States.