DART MISSION

WHAT IS DART Mission

DART (Double Asteroid Redirection Test) was the first-ever mission dedicated to investigating and demonstrating one method of asteroid deflection by changing an asteroid's motion in space through kinetic impact.

OBJECTIVES OF DART MISSION

An unmanned spacecraft, launched 10 months ago, collided with an asteroid — which itself was moving at an astounding pace — at 15,000 kmph, destroying itself. By doing so, NASA’s DART (Double Asteroid Redirection Test) has come very close to hitting its mark. The objective of the mission is to ensure that asteroids capable of reaching the earth’s surface and causing loss of life. So, kudos are clearly in order to the fine people at NASA and Johns Hopkins University, who pulled off the feat that will almost certainly save lives one day.

 

TARGETS OF DARTS MISSION

DART's target is the binary asteroid system Didymos, which means "twin" in Greek. Didymos is the ideal candidate for humankind's first planetary defense experiment, although it is not on a path to collide with Earth and therefore poses no actual threat to the planet.

 BRIEFLY ABOUT DART MISSION

Double Asteroid Redirection Test (DART) was a NASA space mission aimed at testing a method of planetery defence against near earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through a transfer of momentum by hitting the asteroid head on and attempting to slow it. The asteroid selected for the test poses no actual threat to Earth. The probe was launched from Earth in November 2021, and on 26 September 2022, intentionally crashed into Dimorphos, the minor-planet moon of the asteroid Didymos. Initial estimates of the change in the binary orbit period are expected by the first week of October.

The system is composed of two asteroids: the larger asteroid Didymos (diameter: 780 meters, 0.48 miles), and the smaller moonlet asteroid, Dimorphos (diameter: 160 meters, 525 feet), which orbits the larger asteroid. Currently, the orbital period of Dimorphos around Didymos is 11 hours and 55 minutes, and the separation between the centers of the two asteroids is 1.18 kilometers (0.73 miles). The DART spacecraft will impact Dimorphos nearly head-on, shortening the time it takes the small asteroid moonlet to orbit Didymos by several minutes.

 

 

EQUIPMENT USED IN THE DART MISSION

Spacecraft

The DART spacecraft was an impactor with a mass of 610 kg (1,340 lb) that hosted no scientific payload and had only sensors for navigation.

Camera

DRACO camera

DART's navigation sensors included a sun sensor, a star tracker called SMART Nav software (Small-body Maneuvering Autonomous Real Time Navigation),and a 20 cm (7.9 in) aperture camera called Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO). DRACO was based on the Long Range Reconnaissance Imager (LORRI) onboard New Horizons spacecraft, and supported autonomous navigation to impact the asteroid's moon at its center. The instrument had a mass of 8.66 kg (19.1 lb). The detector used in the camera is a CMOS Image sensor measuring 2,560 × 2,160 pixels. Fed into an onboard computer with software descended from anti-missile technology, the DRACO images helped DART autonomously guide itself to its crash.

Solar arrays

The spacecraft's solar arrays used a Roll Out Solar Array (ROSA) design, that was tested on the International Space Station (ISS) in June 2017 as part of Expedition 52. Using ROSA as the structure, a small portion of the DART solar array was configured to demonstrate Transformational Solar Array technology, which has very-high-efficiency SolAero Inverted Metamorphic (IMM) solar cells and reflective concentrators providing three times more power than current other solar array technology.

Antenna

The DART spacecraft was the first spacecraft to use a new type of high-gain communication antenna, a Spiral Radial Line Slot Array (RLSA). The circularly-polarized antenna operates at the X-band NASA Deep Space Network   (NASA DSN) frequencies of 7.2 and 8.4 GHz, and has a gain of 29.8 dBi on downlink and 23.6 dBi on uplink. The fabricated antenna in a flat and compact shape exceeds the given requirements and has been tested through environments resulting in a TRL-6 design.

NASA's Evolutionary Xenon Thruster 

Ion thruster

DART spacecraft used the NEXT gridded ion thruster, a type of solar electric propulsion. It was 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. Early tests of the ion thruster revealed a reset mode that induced higher current (100 A) in the spacecraft structure than expected (25 A). It was decided not to use the ion thruster further as the mission could be accomplished without it, using conventional thrusters. However, the ion thrusters remained available if needed to deal with contingencies, and had DART missed its target, the ion system could have returned DART to Dimorphos two years later.

 Secondary spacecraft

Secondary DART spacecraft

The Italian Space Ageency (ASI) contributed a secondary spacecraft called LICIAcube (Light Italian CubeSat for Imaging of Asteroids), a small Cubesat that piggybacked with DART and separated on 11 September 2022, 15 days before impact. It will try to acquire images of the impact and ejecta as it drifts past the asteroid. LICIACube is equipped with two optical cameras dubbed LUKE and LEIA.

CONCLUSION 

The 1,260-pound DART spacecraft crashed into Dimorphos—which is about 525 feet wide—at a speed of roughly 14,000 miles per hour, aiming to change the asteroid’s orbit by a tiny amount that will be measured over the next few weeks, according to NASA and Johns Hopkins University, which built the spacecraft for the U.S. space agency.

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That's all for now, meet you in the next one

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