3.3 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chrysler SERV | 2/3 | https://en.wikipedia.org/wiki/Chrysler_SERV | reference | science, encyclopedia | 2026-05-05T13:22:17.438809+00:00 | kb-cron |
=== Vehicle design === SERV consisted of a large conical body with a rounded base that Chrysler referred to as a "modified Apollo design". The resemblance is due to the fact that both vehicles used blunt body re-entry profiles, which lessen heating load during re-entry by creating a very large shock wave in front of a rounded surface. Tilting the vehicle in relation to the direction of motion changes the pattern of the shock waves, producing lift that can be used to maneuver the spacecraft - in the case of SERV, up to about 100 NM on either side of its ballistic path. To aid lift generation, SERV was "stepped", with the lower portion of the cone angled in at about 30 degrees, and the upper portion closer to 45 degrees. SERV was 96 feet (29 m) across at the widest point, and 83 feet (25 m) tall. Gross lift off weight was just over 6,000,000 lb (2,700,000 kg), about the same as the Saturn V's 6,200,000 lb (2,800,000 kg) but more than the Shuttle's 4,500,000 lb (2,000,000 kg). The majority of the SERV airframe consisted of steel composite honeycomb. The base was covered with screw-on ablative heat shield panels, which allowed for easy replacement between missions. The upper portions of the airframe, which received dramatically lower heating loads, were covered with metal shingles covering a quartz insulation below. Four landing legs extended from the bottom, their "foot" forming their portion of heat shield surface when retracted. A twelve module LH2/LOX aerospike engine was arranged around the rim of the base, covered by movable metal shields. During the ascent the shields would move out from the body to adjust for decreasing air pressure, forming a large altitude compensating nozzle. The module was fed from a set of four cross-linked turbopumps that in normal operations would run at 75% of their design capacity, if one turbopump failed then throttling up the remaining 3 to 100% would allow full power to be maintained. The engine as a whole would provide 7,454,000 lbf (25.8 MN) of thrust, about the same as the S-IC, the first stage of the Saturn V. Also arranged around the base were forty 20,000 lbf (89 kN) jet engines, which were fired just prior to touchdown in order to slow the descent. Movable doors above the engines opened for feed air. Two RL-10's provided de-orbit thrust, so the main engine did not have to be restarted in space. Even on-orbit maneuvering, which was not extensive for the SERV (see below), was provided by small LOX/LH2 engines instead of thrusters using different fuels. A series of conical tanks around the outside rim of the craft, just above the engines, stored the LOX. LH2 was stored in much larger tanks closer to the center of the craft. Much smaller spherical tanks, located in the gaps below the rounded end of the LOX tanks, held the JP-4 used to feed the jet engines. Orbital maneuvering and de-orbit engines were clustered around the top of the spacecraft, fed by their own tanks interspersed between the LH2. This arrangement of tanks left a large open space in the middle of the craft, 15 by 60 feet (18 m), which served as the cargo hold.