Lunar Reconnaissance Orbiter: Mapping the Moon 🌕

The LRO is a NASA spacecraft orbiting the Moon, providing scientists accurate, highly-detailed maps of the lunar surface. Short 🧵 The LRO orbits the Moon at an 86 degree inclination, with an aposelene (farthest point from the Moon) of 165 kilometers, and a periselene of just 20 kilometers. Because of this polar orbit, LRO has mapped 98.2% of the lunar surface.

Falcon Heavy: Redefining Spaceflight

The Falcon Heavy is a partially reusable heavy launch vehicle developed by the American aerospace company SpaceX. Falcon Heavy has 2 stages, the first of which is recoverable. A short 🧵 The Falcon Heavy’s first stage is made up of 3 Falcon boosters. Each of these boosters have 9 Merlin 1D engines, putting the Heavy under the power of 27 engines at launch. Falcon Heavy is pushed to space under 5 million pounds of thrust, making it close to the Space Shuttle.

Atlas II: National Security Giant

Atlas II was a 2.5 stage expendable launch vehicle developed by Lockheed Martin. The Atlas II was a very reliable and successful launch system used for national security launches. Short 🧵(1/10) The Atlas II was made up of 2.5 stages. The first (and a half) stage comprised of an RS-56-OSA engine, and with two additional RS-56-OBA booster engines. The second stage was the Centaur II, powered by 2 RL-10A engines. (2/10)

MESSENGER: A Messenger to Mercury

The MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) mission was the first probe that orbited Mercury from 2011 to 2015. The probe was the 7th mission of NASA’s Discovery program. Short 🧵 (1/11) The MESSENGER mission was proposed by NASA in 1998 to explore Mercury. The mission’s objectives were to image the entire surface at a high resolution (>100m), map the minerals on the surface, measure Mercury’s gravity, and determine the materials of Mercury’s poles. (2/11)

Delta IV Heavy: Orange Eye in the Sky

The Delta IV Heavy was a two-stage expendable launch vehicle built by Boeing, later operated by ULA. Delta IV Heavy launched from SLC-37B at Cape Canaveral, and SLC-6 at Vandenberg SFB. 🧵(1/11) The Delta IV Heavy launched many payloads, including reconnaissance satellites for the NRO, the Orion capsule, and the Parker Solar Probe. (2/11)

Delta II: America’s Teal Ride to Space

The Delta II was a two-stage expendable launch vehicle developed by McDonnell Douglas in the 1980s. A Short 🧵1/12 The Delta II had two stages, most of the time. The rocket utilized the Extra Extended Long Tank Thor as the first stage, which had two LR-101-NA-11 verniers and a Rocketdyne RS-27(A) main engine. The rocket could tote either 3, 4, or 9 GEM 40 solid rocket boosters. 2/12

The Titan IV: America’s Heavy Lifter

The Titan IV was a rocket developed by Lockheed Martin to provide assured-capabilities for launches of Space-shuttle class payloads. A short 🧵1/9 The Titan IV consisted of a liquid fuel core stage with the LR87, powered by Aerozine50 and NTO, 2 solid rocket motors, and a second stage that was boosted by the LR91, which ran on Aerozine50 and NTO. It could carry either an Inertial Upper Stage, or a Centaur upper stage. 2/9