Virgil “Gus” Grissom – Commander, Edward White – Command Pilot, Roger Chaffee – Pilot
STS-51 L (January 28, 1986)
Francis R. Scobee – Commander, Michael J. Smith – Pilot, Judith A. Resnik – Mission Specialist 1, Ellison Onizuka – Mission Specialist 2, Ronald E. McNair – Mission Specialist 3, Gregory B. Jarvis – Payload Specialist 1, Sharon Christa McAuliffe – Payload Specialist 2
STS-107 (February 1, 2003)
Rick D. Husband – Commander, William C. McCool – Pilot, Michael P. Anderson – Payload Commander, David M. Brown – Mission Specialist 1, Kalpana Chawla – Mission Specialist 2, Laurel Clark – Mission Specialist 3, Ilan Ramon – Payload Specialist 1
Double Asteroid Redirection Test (DART) is a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEO). It will deliberately crash a space probe into the double asteroid Didymos to test whether the kinetic energy of a spacecraft impact could successfully deflect an asteroid on a collision course with Earth. DART is a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL), administered by NASA’s Planetary Defense Coordination Office, with several NASA laboratories and offices providing technical support. International partners, such as the space agencies of Europe, Italy, and Japan, are contributing to related or subsequent projects. DART was launched on 24 November 2021, at 06:21:02 UTC, with collision slated for 26 September 2022.
DART is an impactor, mass of 610 kg (1,340 lb), that hosts no scientific payload other than a Sun sensor, a star tracker, and a 20 cm (7.9 in) aperture camera (Didymos Reconnaissance and Asteroid Camera for Optical navigation – DRACO) based on Long-Range Reconnaissance Imager (LORRI) onboard New Horizons spacecraft to support autonomous navigation to impact the small asteroid’s moon at its center.
It is estimated that the impact of the 500 kg (1,100 lb) DART at 6.6 km/s (4.1 mi/s) will produce a velocity change on the order of 0.4 mm/s, which leads to a small change in trajectory of the asteroid system, but over time, it leads to a large shift of path. Over a span of millions of kilometers, the cumulative trajectory change would eliminate the risk of a previously-Earth-bound asteroid hitting Earth. The actual velocity change and orbital shift will be measured a few years later by a spacecraft called Hera that would do a detailed reconnaissance and assessment. Hera was approved in November 2019.
DART spacecraft uses the NEXT ion thruster, a type of solar electric propulsion. It will be powered by 22 m2 (240 sq ft) solar arrays to generate the ~3.5-kW needed to power the NASA Evolutionary Xenon Thruster–Commercial (NEXT-C) engine. The spacecraft’s solar arrays use a Roll Out Solar Array (ROSA) design, and this was tested on the International Space Station in June 2017 as part of Expedition 52, delivered to the station by the SpaceX CRS-11 commercial cargo mission.
Using ROSA as the structure, a small portion of the DART solar array is configured to demonstrate Transformational Solar Array technology, which has very-high-efficiency solar cells and reflective concentrators providing three times more power than current solar array technology.
The DART spacecraft is the first spacecraft to use a new type of high gain communication antenna, that is, a Spiral Radial Line Slot Array (RLSA). The antenna operates at the X-band NASA Deep Space Network (NASA DSN) frequencies of 7.2 and 8.4-GHz. The fabricated antenna exceeds the given requirements, agrees well simulations, and has been tested through environments resulting in a TRL-6 design.
The SpaceX South Texas launch site, referred to by SpaceX as Starbase, and also known as the Boca Chica launch site, is a private rocket production facility, test site, and spaceport constructed by SpaceX, located at Boca Chica approximately 32 km (20 mi) east of Brownsville, Texas, on the US Gulf Coast. When conceptualized, its stated purpose was “to provide SpaceX an exclusive launch site that would allow the company to accommodate its launch manifest and meet tight launch windows.” The launch site was originally intended to support launches of the Falcon 9 and Falcon Heavy launch vehicles as well as “a variety of reusable suborbital launch vehicles”, but in early 2018, SpaceX announced a change of plans, stating that the launch site would be used exclusively for SpaceX’s next-generation launch vehicle, Starship. Between 2018 and 2020, the site added significant rocket production and test capacity. SpaceX CEO Elon Musk indicated in 2014 that he expected “commercial astronauts, private astronauts, to be departing from South Texas,” and he foresaw launching spacecraft to Mars from the site.
Between 2012 and 2014, SpaceX considered seven potential locations around the United States for the new commercial launch facility. Generally, for orbital launches an ideal site would have an easterly water overflight path for safety and be located as close to the equator as possible in order to take advantage of the Earth’s rotational speed. For much of this period, a parcel of land adjacent to Boca Chica Beach near Brownsville, Texas, was the leading candidate location, during an extended period while the US Federal Aviation Administration (FAA) conducted an extensive environmental assessment on the use of the Texas location as a launch site. Also during this period, SpaceX began acquiring land in the area, purchasing approximately 41 acres (170,000 m2) and leasing 57 acres (230,000 m2) by July 2014. SpaceX announced in August 2014, that they had selected the location near Brownsville as the location for the new non-governmental launch site, after the final environmental assessment completed and environmental agreements were in place by July 2014. An orbital launch of the Starship would make it SpaceX’s fourth active launch facility, following three launch locations that are leased from the US government.
SpaceX conducted a groundbreaking ceremony on the new launch facility in September 2014, and soil preparation began in October 2015. The first tracking antenna was installed in August 2016, and the first propellant tank arrived in July 2018. In late 2018, construction ramped up considerably, and the site saw the fabrication of the first 9 m-diameter (30 ft) prototype test vehicle, Starhopper, which was tested and flown March–August 2019. Through 2021, additional prototype flight vehicles are being built at the facility for higher-altitude tests. By March 2020, there were over 500 people employed at the facility, with most of the work force involved in 24/7 production operations for the third-generation SpaceX launch vehicle, Starship.
Lucy was launched from Cape Canaveral SLC-41 on 16 October 2021, at 09:34:00.192 UTC on the 401 variant of a United Launch Alliance Atlas V launch vehicle, after which it will gain two gravity assists from Earth; one in 2022, and one in 2024. In 2025, it will fly by the inner main-belt asteroid 52246 Donaldjohanson, which was named after the discoverer of the Lucy hominin fossil. In 2027, it will arrive at the L4 Trojan cloud (the Greek camp of asteroids that orbits about 60° ahead of Jupiter), where it will fly by four Trojans, 3548 Eurybates (with its satellite), 15094 Polymele, 11351 Leucus, and 21900 Orus. After these flybys, Lucy will return to Earth in 2031 for another gravity assist toward the L5 Trojan cloud (the Trojan camp which trails about 60° behind Jupiter), where it will visit the binary Trojan 617 Patroclus with its satellite Menoetius in 2033. The mission may end with the Patroclus–Menoetius flyby, but at that point Lucy will be in a stable, 6-year orbit between the L4 and L5 clouds, and a mission extension will be possible.
Three instruments comprise the payload: a high-resolution visible imager, an optical and near-infrared imaging spectrometer, and a thermal infrared spectrometer. Harold F. Levison of the Southwest Research Institute in Boulder, Colorado is the principal investigator, with Cathy Olkin of Southwest Research Institute as the mission’s deputy principal investigator. NASA’s Goddard Space Flight Center will manage the project.
Exploration of Jupiter Trojans is one of the high-priority goals outlined in the Planetary Science Decadal Survey. Jupiter Trojans have been observed by ground-based telescopes and the Wide-field Infrared Survey Explorer to be “dark with… surfaces that reflect little sunlight”. Jupiter is 5.2 AU (780×106 km; 480×106 mi) from the Sun, or about five times the Earth-Sun distance. The Jupiter Trojans are at a similar distance but can be somewhat farther or closer to the Sun depending on where they are in their orbits. There may be as many Trojans as there are asteroids in the asteroid belt.
On October 16, 2021, our Lucy spacecraft will begin its journey to visit a record-breaking number of asteroids. The 12-year mission starts from NASA’s Kennedy Space Center where it’ll launch aboard a United Launch Alliance Atlas V 401 rocket. From there, Lucy will be the first spacecraft to visit a record number of destinations in independent orbits around the sun – one main belt asteroid and seven of Jupiter’s Trojan Asteroids.
Like the mission’s namesake – the fossilized human ancestor, “Lucy,” whose skeleton provided unique insight into humanity’s evolution – Lucy will revolutionize our knowledge of planetary origins and the formation of the solar system. Lucy’s first launch attempt in its 21-day launch window is scheduled for 5:34 a.m. EDT on October 16.
Lucy is a planned NASA space probe that will complete a 12-year journey to eight different asteroids, visiting a main belt asteroid as well as seven Jupiter trojans, asteroids which share Jupiter’s orbit around the Sun, orbiting either ahead of or behind the planet. All target encounters will be fly-by encounters. The Lucy spacecraft is the centerpiece of a US$981 million mission.
On 4 January 2017, Lucy was chosen, along with the Psyche mission, as NASA’s Discovery Program missions 13 and 14 respectively. The mission is named after the Lucy hominid skeleton, because the study of Trojans could reveal the “fossils of planet formation”: materials that clumped together in the early history of the Solar System to form planets and other bodies. The Australopithecus itself was named after the 1967 Beatles song “Lucy in the Sky with Diamonds”.
Lucy is planned to launch in October 2021 on the 401 variant of a United Launch Alliance Atlas V launch vehicle, after which it will gain two gravity assists from Earth; one in 2022, and one in 2024. In 2025, it will fly by the inner main-belt asteroid 52246 Donaldjohanson, which was named after the discoverer of the Lucy hominid fossil. In 2027, it will arrive at the L4 Trojan cloud (the Greek camp of asteroids that orbits about 60° ahead of Jupiter), where it will fly by four Trojans, 3548 Eurybates (with its satellite), 15094 Polymele, 11351 Leucus, and 21900 Orus. After these flybys, Lucy will return to Earth in 2031 whereupon it will receive another slight gravity assist to take it to the L5 Trojan cloud (the Trojan camp which trails about 60° behind Jupiter), where it will visit the binary Trojan 617 Patroclus with its satellite Menoetius in 2033. The mission may end with the Patroclus–Menoetius flyby, but at that point Lucy will be in a stable, 6-year orbit between the L4 and L5 clouds, and a mission extension will be possible.
Three instruments comprise the payload: a high-resolution visible imager, an optical and near-infrared imaging spectrometer and a thermal infrared spectrometer.
Exploration of Jupiter Trojans is one of the high priority goals outlined in the Planetary Science Decadal Survey. Jupiter Trojans have been observed by ground-based telescopes and the Wide-field Infrared Survey Explorer to be “dark with… surfaces that reflect little sunlight”. Jupiter is 5.2 AU (780×106 km; 480×106 mi) from the Sun, or about five times the Earth-Sun distance. The Jupiter Trojans are at a similar distance but can be somewhat farther or closer to the Sun depending on where they are in their orbits. There may be as many Trojans as there are asteroids in the asteroid belt.
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