Apollo lunar rover11/19/2023 The combined original and copied fields created the first full 525-line interlaced frame and the signal was then sent to Houston. It then fed that field, and an appropriately time-delayed copy of the first field, to the NTSC field interlace switch (encoder). An analog disk recorder, based on the Ampex HS-100 model, was used to record the first field from the camera. The monitor had persistent phosphors, that acted as a primitive framebuffer. The conversion process started when the signal was sent to the RCA converter's high-quality 10-inch video monitor where a conventional RCA TK-22 television camera – using the NTSC broadcast standard of 525 scanned lines interlaced at 30 fps – merely re-photographed its screen. The other raw SSTV signal branch was sent to the RCA scan converter where it would be processed into an NTSC broadcast television signal. One signal branch was sent unprocessed to a fourteen-track analog data tape recorder where it was recorded onto fourteen-inch diameter reels of one-inch-wide analog magnetic data tapes at 3.04 meters per second. When the Apollo TV camera radioed its images, the ground stations received its raw unconverted SSTV signal and split it into two branches. NASA selected a scan converter manufactured by RCA to convert the black-and-white SSTV signals from the Apollo 7, 8, 9, and 11 missions. Since the camera's scan rate was much lower than the approximately 30 fps for NTSC video, the television standard used in North America at the time, a real-time scan conversion was needed to be able to show its images on a regular TV set. It was understood at the time that motion fidelity from such a slow-scan television system (SSTV) would be less than standard commercial television systems, but deemed sufficient considering that astronauts would not be moving quickly in orbit, or even on the Lunar surface. RCA was given the contract to manufacture such a camera. The video standard for the Block I CM meant that the analog video standard for early Apollo missions was set as follows: monochrome signal, with 320 active scan lines, and progressively scanned at 10 frames per second (fps). Both analog and digital transmission techniques were studied, but the early digital systems still used more bandwidth than an analog approach: 20 MHz for the digital system, compared to 500 kHz for the analog system. NASA decided on initial specifications for TV on the Apollo command module (CM) in 1962. RCA command module TV camera Development Apollo 7 slow-scan TV, transmitted by the RCA command module TV camera Afterwards, the camera would be detached from its mount in the MESA, mounted on a tripod and carried away from the LM to show the EVA's progress or, mounted on a Lunar Roving Vehicle (LRV), where it could be remotely controlled from Mission Control on Earth. Positioning the camera in the MESA made it possible to telecast the astronauts' first steps as they climbed down the LM's ladder at the start of a mission's first moonwalk/EVA. For each lunar landing mission, a camera was also placed inside the Apollo Lunar Module (LM) descent stage's modularized equipment stowage assembly (MESA). Starting with Apollo 7, a camera was carried on every Apollo command module (CM) except Apollo 9. All of these cameras required signal processing back on Earth to make the frame rate and color encoding compatible with analog broadcast television standards. Starting with the Apollo 15 mission, a more robust, damage-resistant camera was used on the lunar surface. The cameras all used image pickup tubes that were initially fragile, as one was irreparably damaged during the live broadcast of the Apollo 12 mission's first moonwalk. The color camera ran at the North American standard 30 fps. A color camera – using a field-sequential color system – flew on the Apollo 10 mission in May 1969, and every mission after that. Originally, these slow-scan television (SSTV) cameras, running at 10 frames per second (fps), produced only black-and-white pictures and first flew on the Apollo 7 mission in October 1968. Two companies made these various camera systems: RCA and Westinghouse. These cameras varied in design, with image quality improving significantly with each successive model. The Apollo program used several television cameras in its space missions in the late 1960s and 1970s some of these Apollo TV cameras were also used on the later Skylab and Apollo–Soyuz Test Project missions. Notice how the camera is stowed upside-down on its top, due to that being its only flat surface. Udvar-Hazy Center Virginia US Apollo Lunar Television Camera, as it was mounted on the side of the Apollo 11 Lunar Module when it telecasted Neil Armstrong's "One small step". Apollo Portable RCA TV camera at Steven F.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |