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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chrysler SERV | 3/3 | https://en.wikipedia.org/wiki/Chrysler_SERV | reference | science, encyclopedia | 2026-05-05T13:22:17.438809+00:00 | kb-cron |
=== Operational modes === Two basic spacecraft configurations and mission profiles were envisioned. "Mode A" missions flew SERV to a high-altitude parking orbit at 260 nmi (480 km) inclined at 55 degrees, just below the space station's orbit at 270 nmi (500 km). "Mode B" missions flew to a 110 nmi (200 km) low Earth orbit (LEO) inclined at 28.5 degrees, a due-east launch from the Kennedy Space Center. In either case the SERV was paired with a long cargo container in its bay, and optionally combined with a crewed spacecraft on top. The original proposals used a lifting body spaceplane known as MURP to support crewed missions. The MURP was based on the HL-10 design already under study by North American Rockwell as part of their STS efforts. MURP was fitted on top of a cargo container and fairing, which was 114 feet (35 m) long overall. In the second version of the study, Chrysler also added an option that replaced MURP with a "personnel module", based on the Apollo CSM, which was 74 feet (23 m) long when combined with the same cargo container. The original, "SERV-MURP", was 137 ft (42 m) when combined with SERV, while the new configuration, "SERV-PM", was 101 ft (31 m) tall. Both systems included an all-aspect abort of the crewed portion throughout the entire ascent. After considering all four combinations of mode and module, two basic mission profiles were selected as the most efficient. With SERV-PM the high Earth orbit would be used and the PM would maneuver only a short distance to reach the station. With SERV-MURP, the low Earth orbit would be used and the MURP would maneuver the rest of the way on its own. In either case, the SERV could return to Earth immediately and let the PM or MURP land on their own, or more commonly, wait in the parking orbit for a cargo module from an earlier mission to rendezvous with it for return to Earth. Weight and balance considerations limited the return payload. Both configurations delivered 25,000 lb (11,000 kg) of cargo to the space station, although in the PM configuration the overall thrown weights were much lower. If the PM configuration was used with a fairing instead of the capsule, SERV could deliver 112,000 lb (51,000 kg) to LEO, or as much as 125,000 lb (57,000 kg) with an "Extended Nosecone". The Extended Nosecone was a long spike with a high fineness ratio that lowered atmospheric drag by creating shock waves that cleared the vehicle body during ascent. In addition, Chrysler also outlined ways to support 33 ft (10 m) wide loads on the front of SERV. This was the diameter of the S-IC and S-II, the lower stages of the Saturn V. NASA had proposed a wide variety of payloads for the Apollo Applications Program that were based on this diameter that were intended to be launched on the Saturn INT-21. Chrysler demonstrated that they could also be launched on SERV, if weight considerations taken into account. However, these plans were based on the earlier SERV designs with the larger 23 ft (7.0 m) cargo bay. When NASA's loads were adapted to fit to the smaller 15 ft (4.6 m) bay common to all the STS proposals, this option was dropped. SERV was not expected to remain on orbit for extended periods of time, with the longest missions outlined in the report at just under 48 hours. Typically it would return after a small number of orbits brought its ground track close enough to Kennedy, and abort-once-around missions were contemplated. The vehicle was designed to return to a location within four miles (6 km) of the touchdown point using re-entry maneuvering, the rest would be made up during the jet-powered descent.
=== Construction and operations === NASA had partnered with Chrysler to build the NASA-designed Saturn IB, at the Michoud Assembly Facility outside New Orleans. Chrysler proposed building SERVs at Michoud as well, delivering them to KSC on the Bay-class ships used to deliver Boeing's S-IC from the same factory. Since the SERV was wider than the ships, it had to be carried slightly tilted in order to reduce its overall width. Pontoons were then added to the side of the ships to protect the spacecraft from spray. SERVs would be fitted out in the Vehicle Assembly Building (VAB) High Bay, mated with the PM or MURP which were prepared in the Low Bay, and then transported to the LC39 pads on the existing crawler-transporters. The LC39 pads required only minor modifications for SERV use, similar to those needed to launch the Saturn IB. Chrysler proposed building several SERV landing pads between LC39 and the VAB, and a landing strip for the MURP near the existing Space Shuttle landing strip. The SERVs would be returned to the VAB on an enormous flatbed truck. The only other new infrastructure was a set of test stands at the Mississippi Test Operations engine testing complex, near Michoud.
=== Development and construction costs === Re-using much of the existing infrastructure lowered overall program costs; total costs were estimated as $3.565 billion, with each SERV costing $350 million in FY1971 dollars, and being rated for 100 flights over a 10-year service life. This was far less expensive than the two-stage flyback proposals entered by most companies, which had peak development costs on the order of $10 billion.
== Similar designs == SERV was similar to the later McDonnell Douglas DC-X design. The primary difference between the two was that the DC-X was built to a military mission and required much greater re-entry maneuvering capability. Because of this, the airframe was long and skinny, and the spacecraft re-entered nose-first. Tilting this shape relative to the path of motion generates considerably more lift than the blunt base of SERV, but also subjects the airframe to much higher heating loads. More recently, the original SERV layout was used in the Blue Origin Goddard spacecraft. Like the SERV, Goddard did not need the extended crossrange capabilities of a military launcher, and returned to the simpler blunt-base re-entry profile. The similar Kankoh-maru design study also used the same blunt-body VTOL profile.
== See also ==
Douglas SASSTO List of space launch system designs
== Notes ==
== References ==
=== Citations ===
=== Bibliography ===