Double Asteroid Redirection Test

Last updated

Transformational Solar Array experiment on DART's Roll Out Solar Array (ROSA).png
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. [27]

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 other available solar array technology. [28]

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 operated at the X-band NASA Deep Space Network (NASA DSN) frequencies of 7.2 and 8.4 GHz, and had a gain of 29.8 dBi on downlink and 23.6 dBi on uplink. The fabricated antenna in a flat and compact shape exceeded the given requirements and was tested through environments resulting in a TRL-6 design. [29]

NASA's Evolutionary Xenon Thruster (NEXT) NASA NEXT Ion thruster.712983main NEXT LDT Thrusterhi-res full.jpg
NASA's Evolutionary Xenon Thruster (NEXT)

Ion thruster

DART demonstrated the NEXT gridded ion thruster, a type of solar electric propulsion. [15] [30] It was powered by 22 square metres (240 sq ft) solar arrays to generate the ~3.5 kW needed to power the NASA Evolutionary Xenon Thruster–Commercial (NEXT-C) engine. [31] 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 fueled by the 110 pounds of hydrazine onboard. [32] 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. [33]

Secondary spacecraft

LICIACube CubeSat, a companion satellite of the DART spacecraft LICIACube CubeSat a companion satellite of Dart Spacecraft.jpg
LICIACube CubeSat, a companion satellite of the DART spacecraft

The Italian Space Agency (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 acquired images of the impact and ejecta as it drifted past the asteroid. [34] [35] LICIACube communicated directly with Earth, sending back images of the ejecta after the Dimorphos flyby. [36] [37] LICIACube is equipped with two optical cameras, dubbed LUKE and LEIA. [38]

Effect of the impact on Dimorphos and Didymos

The spacecraft hit Dimorphos in the direction opposite to the asteroid's motion. Following the impact, the instantaneous orbital speed of Dimorphos therefore dropped slightly, which reduced the radius of its orbit around Didymos. The trajectory of Didymos was also modified, but in inverse proportion to the ratio of its mass to the much lower mass of Dimorphos. The actual velocity change and orbital shift depended on the topography and composition of the surface, among other things. The contribution of the recoil momentum from the impact ejecta produces a poorly predictable "momentum enhancement" effect. [39] Before the impact, the momentum transferred by DART to the largest remaining fragment of the asteroid was estimated as up to 3–5 times the incident momentum, depending on how much and how fast material would be ejected from the impact crater. Obtaining accurate measurements of that effect was one of the mission's main goals and will help refine models of future impacts on asteroids. [40]

The DART impact excavated surface/subsurface materials of Dimorphos, leading to the formation of a crater and/or some magnitude of reshaping (i.e., shape change without significant mass loss). Some of the ejecta may eventually hit Didymos's surface. If the kinetic energy delivered to its surface was high enough, reshaping may have also occur in Didymos, given its near-rotational-breakup spin rate. Reshaping on either body would have modified their mutual gravitational field, leading to a reshaping-induced orbital period change, in addition to the impact-induced orbital period change. If left unaccounted for, this could later have led to an erroneous interpretation of the effect of the kinetic deflection technique. [41]

Observations of the impact

Telescopes observing DART's impact Telescopes observing DART's impact.png
Telescopes observing DART's impact
SOAR telescope shows the vast plume of dust and debris blasted from the surface of the asteroid Dimorphos Aftermath of DART Collision with Dimorphos Captured by SOAR Telescope (noirlab2223a).jpg
SOAR telescope shows the vast plume of dust and debris blasted from the surface of the asteroid Dimorphos

DART's companion LICIACube, [42] [36] the Hubble Space Telescope, James Webb Space Telescope, and the Earth-based ATLAS observatory all detected the ejecta plume from the DART impact. [43] [44] On September 26, SOAR observed the visible impact trail to be over 10,000 kilometres (0.026 LD; 6,200 mi) long. [45] Initial estimates of the change in binary orbit period were expected within a week and with the data released by LICIACube. [46] DART's mission science depends on careful Earth-based monitoring of the orbit of Dimorphos over the subsequent days and months. Dimorphos was too small and too close to Didymos for almost any observer to see directly, but its orbital geometry is such that it transits Didymos once each orbit and then passes behind it half an orbit later. Any observer that can detect the Didymos system therefore sees the system dim and brighten again as the two bodies cross.

The impact was planned for a moment when the distance between Didymos and Earth is at a minimum, permitting many telescopes to make observations from many locations. The asteroid was near opposition and visible high in the night sky well into 2023. [47] The change in Dimorphos's orbit around Didymos was detected by optical telescopes watching mutual eclipses of the two bodies through photometry on the Dimorphos-Didymos pair. In addition to radar observations, they confirmed that the impact shortened Dimorphos' orbital period by 32 minutes. [48] Based on the shortened binary orbital period, the instantaneous reduction in Dimorphos' velocity component along its orbital track was determined, which indicated that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than from the impact itself. In this way, the DART kinetic impact was highly effective in deflecting Dimorphos. [10]

Follow-up mission

In a collaborating project, the European Space Agency is developing Hera , a spacecraft that will be launched to Didymos in 2024 [34] [49] [50] and arrive in 2026 [51] [52] to do a detailed reconnaissance and assessment. [50] Hera would carry two CubeSats, Milani and Juventas. [50]

AIDA mission architecture

Double Asteroid Redirection Test
Dart-poster3.jpg
Diagram of the DART spacecraft striking Dimorphos
NamesDART
Mission type Planetary defense mission
Operator NASA  / APL
COSPAR ID 2021-110A
SATCAT no. 49497
Website
Mission duration
10 months and 1 day
Spacecraft properties
Spacecraft
Manufacturer Applied Physics Laboratory
of Johns Hopkins University
Launch mass
  • DART: 610 kilograms (1,340 lb) [1]
  • LICIACube: 14 kilograms (31 lb)
Dimensions
  • DART: 1.8 × 1.9 × 2.6 metres (5 ft 11 in × 6 ft 3 in × 8 ft 6 in)
  • ROSA: 8.5 × 2.4 metres (27.9 × 7.9 ft) (each)
Power6.6 kW
Start of mission
Launch date24 November 2021, 06:21:02 UTC [1]
Rocket Falcon 9 Block 5, B1063.3
Launch site Vandenberg, SLC-4E
Contractor SpaceX
Dimorphos impactor
Impact date26 September 2022, 23:14 UTC [2] [3]
Host spacecraftSecondary spacecraftRemarks
DART LICIACube [53]
  • By the Italian Space Agency
  • 6U CubeSat
  • LUKE (LICIACube Unit Key Explorer) Camera and LEIA (LICIACube Explorer Imaging for Asteroid) Camera
HeraJuventas [54] [55]
  • By GomSpace and GMV
  • 6U CubeSat orbiter
  • Camera, JuRa monostatic low-frequency radar, [56] accelerometers, and gravimeter [57]
  • Will attempt to land on the asteroid surface [55] [57]
Milani [58]
  • By Italy/Czech/Finnish consortium
  • 6U CubeSat orbiter
  • VIS/Near-IR spectrometer, volatile analyzer
  • Will characterize Didymos and Dimorphos surface composition and the dust environment around the system
  • Will perform technology demonstration experiments
SCI

Mission profile

Target asteroid

Pre-impact shape model of Didymos and its satellite Dimorphos, based on photometric light curve and radar data 65803 didymos model.png
Pre-impact shape model of Didymos and its satellite Dimorphos , based on photometric light curve and radar data

The mission's target was Dimorphos in 65803 Didymos system, a binary asteroid system in which one asteroid is orbited by a smaller one. The primary asteroid (Didymos A) is about 780 metres (2,560 ft) in diameter; the asteroid moon Dimorphos (Didymos B) is about 160 metres (520 ft) in diameter in an orbit about 1 kilometre (0.62 mi) from the primary. [15] The mass of the Didymos system is estimated at 528 billion kg, with Dimorphos comprising 4.8 billion kg of that total. [21] Choosing a binary asteroid system is advantageous because changes to Dimorphos's velocity can be measured by observing when Dimorphos subsequently passes in front of its companion, causing a dip in light that can be seen by Earth telescopes. Dimorphos was also chosen due to its appropriate size; it is in the size range of asteroids that one would want to deflect, were they on a collision course with Earth. In addition, the binary system was relatively close to the Earth in 2022, at about 7 million miles (0.075 astronomical units; 29 lunar distances; 11 million kilometers). [61] The Didymos system is not an Earth-crossing asteroid, and there is no possibility that the deflection experiment could create an impact hazard. [62] On 4 October 2022, Didymos made an Earth approach of 10.6 astronomical units (4,100 lunar distances; 1.59 billion kilometres; 990 million miles). [63]

Preflight preparations

DART being encapsulated in the Falcon 9 payload fairing on 16 November 2021 DART inside the payload fairing (KSC-20211116-PH-EGW01 0001).jpg
DART being encapsulated in the Falcon 9 payload fairing on 16 November 2021

Launch preparations for DART began on 20 October 2021, as the spacecraft began fueling at Vandenberg Space Force Base (VSFB) in California. [64] The spacecraft arrived at Vandenberg in early October 2021 after a cross-country drive. DART team members prepared the spacecraft for flight, testing the spacecraft's mechanisms and electrical system, wrapping the final parts in multilayer insulation blankets and practicing the launch sequence from both the launch site and the mission operations center at APL. DART headed to the SpaceX Payload Processing Facility on VSFB on 26 October 2021. Two days later, the team received the green light to fill DART's fuel tank with roughly 50 kilograms (110 lb) of hydrazine propellant for spacecraft maneuvers and attitude control. DART also carried about 60 kilograms (130 lb) of xenon for the NEXT-C ion engine. Engineers loaded the xenon before the spacecraft left APL in early October 2021. [65]

Starting on 10 November 2021, engineers mated the spacecraft to the adapter that stacks on top of the SpaceX Falcon 9 launch vehicle. The Falcon 9 rocket without the payload fairing rolled for a static fire and later came back to the processing facility again where technicians with SpaceX installed the two halves of the fairing around the spacecraft over the course of two days, 16 and 17 November, inside the SpaceX Payload Processing Facility at Vandenberg Space Force Base and the ground teams completed a successful Flight Readiness Review later that week with the fairing then attached to the rocket. [66]

A day before launch, the launch vehicle rolled out of the hangar and onto the launch pad at Vandenberg Space Launch Complex 4 (SLC-4E); from there, it lifted off to begin DART's journey to the Didymos system and it propelled the spacecraft into space. [65]

Launch

DART Launch (NHQ202111230022).jpg
Liftoff of Falcon 9 with DART.
DART-Separation-from-Second-Stage 01.jpg
DART separation from second stage

The DART spacecraft was launched on 24 November 2021, at 06:21:02 UTC.

Early planning suggested that DART was to be deployed into a high-altitude, high-eccentricity Earth orbit designed to avoid the Moon. In such a scenario, DART would use its low-thrust, high-efficiency NEXT ion engine to slowly escape from its high Earth orbit to a slightly inclined near-Earth solar orbit, from which it would maneuver onto a collision trajectory with its target. But because DART was launched as a dedicated Falcon 9 mission, the payload along with Falcon 9's second stage was placed directly on an Earth escape trajectory and into heliocentric orbit when the second stage reignited for a second engine startup or escape burn. Thus, although DART carries a first-of-its-kind electric thruster and plenty of xenon fuel, Falcon 9 did almost all of the work, leaving the spacecraft to perform only a few trajectory-correction burns with simple chemical thrusters as it homed in on Didymos's moon Dimorphos. [67]

Transit

Animation of DART's trajectory .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{} DART * 65803 Didymos * Earth * Sun * 2001 CB21 * 3361 Orpheus Animation of DART trajectory around Sun.gif
Animation of DART's trajectory
  DART ·   65803 Didymos  ·  Earth ·   Sun  ·   2001 CB21  ·   3361 Orpheus

The transit phase before impact lasted about 9 months. During its interplanetary travel, the DART spacecraft made a distant flyby of the 578-metre (1,896-foot) diameter near-Earth asteroid (138971) 2001 CB21 in March 2022. [68] DART passed 0.117 astronomical units (46 lunar distances; 17.5 million kilometres; 10.9 million miles) from 2001 CB21 in its closest approach on 2 March 2022. [69]

DART's DRACO camera opened its aperture door and took its first light image of some stars on 7 December 2021, when it was 2 million miles (0.022 astronomical units; 8.4 lunar distances; 3.2 million kilometres) away from Earth. [70] The stars in DRACO's first light image were used as calibration for the camera's pointing before it could be used to image other targets. [70] On 10 December 2021, DRACO imaged the open cluster Messier 38 for further optical and photometric calibration. [70]

On 27 May 2022, DART observed the bright star Vega with DRACO to test the camera's optics with scattered light. [71] On 1 July and 2 August 2022, DART's DRACO imager observed Jupiter and its moon Europa emerging from behind the planet, as a performance test for the SMART Nav tracking system to prepare for the Dimorphos impact. [72]

Course of the impact

Two months before the impact, on 27 July 2022, the DRACO camera detected the Didymos system from approximately 32 million kilometres (0.21 astronomical units; 83 lunar distances; 20 million miles) away and started refining its trajectory. The LICIACube nanosatellite was released on 11 September 2022, 15 days before the impact. [73] Four hours before impact, some 90,000 kilometres (0.23 LD; 56,000 mi) away, DART began to operate in complete autonomy under control of its SMART Nav guidance system. Three hours before impact, DART performed an inventory of objects near the target. Ninety minutes before the collision, when DART was 38,000 kilometres (0.099 LD; 24,000 mi) away from Dimorphos, the final trajectory was established. [74] When DART was 24,000 kilometres (0.062 LD; 15,000 mi) away Dimorphos became discernible (1.4 pixels) through the DRACO camera which then continued to capture images of the asteroid's surface and transmit them in real-time. [75]

DRACO was the only instrument able to provide a detailed view of Dimorphos' surface. The use of DART's thrusters caused vibrations throughout the spacecraft and solar panels, resulting in blurred images. To ensure sharp images, the last trajectory correction was executed 4 minutes before impact and the thrusters were deactivated afterwards. [75]

Compiled timelapse of DART's final 5.5 minutes until impact

The last full image, transmitted two seconds before impact, has a spatial resolution of about 3 centimeters per pixel. The impact took place on 26 September 2022, at 23:14 UTC. [3]

The head-on impact of the 500 kilograms (1,100 lb) [76] DART spacecraft at 6.6 kilometres per second (4.1 mi/s) [77] likely imparted an energy of about 11 gigajoules, the equivalent of about three tonnes of TNT, [78] and was expected to reduce the orbital velocity of Dimorphos between 1.75 cm/s and 2.54 cm/s, depending on numerous factors such as material porosity. [79] The reduction in Dimorphos's orbital velocity brings it closer to Didymos, resulting in the moon experiencing greater gravitational acceleration and thus a shorter orbital period. [13] [62] [80] The orbital period reduction from the head-on impact serves to facilitate ground-based observations of Dimorphos. An impact to the asteroid's trailing side would instead increase its orbital period towards 12 hours and make it coincide with Earth's day and night cycle, which would limit any single ground-based telescope from observing all orbital phases of Dimorphos nightly. [47]

DART impact and its corresponding plume as seen by using the Mookodi instrument on the SAAO's 1-m Lesedi telescope DART-impact-SAAO-Lesedi-Mookodi.gif
DART impact and its corresponding plume as seen by using the Mookodi instrument on the SAAO's 1-m Lesedi telescope

The measured momentum enhancement factor (called beta) of DART's impact of Dimorphos was 3.6, which means that the impact transferred roughly 3.6 times greater momentum than if the asteroid had simply absorbed the spacecraft and produced no ejecta at all – indicating the ejecta contributed more to moving the asteroid than the spacecraft did. This means one could use either a smaller impactor or shorter lead times for the same deflection. The value of beta depends on various factors, composition, density, porosity, etc. The goal is to use these results and modeling to infer what beta could be for another asteroid by observing its surface and possibly measuring its bulk density. Scientists estimate that DART’s impact displaced over 1,000,000 kilograms (2,200,000 lb) of dusty ejecta into space – enough to fill six or seven rail cars. The tail of ejecta from Dimorphos created by the DART impact is at least 30,000 kilometres (0.078 LD; 19,000 mi) long with a mass of at least 1,000 tonnes (980 long tons; 1,100 short tons), and possibly up to 10 times that much. [81] [82]

Footprint of DART spacecraft over the spot where it impacted asteroid Dimorphos Footprint of DART spacecraft over the spot where it impacted asteroid Dimorphos.jpg
Footprint of DART spacecraft over the spot where it impacted asteroid Dimorphos

The DART impact on the center of Dimorphos decreased the orbital period, previously 11.92 hours, by 33±1 minutes. This large change indicates the recoil from material excavated from the asteroid and ejected into space by the impact (known as ejecta) contributed significant momentum change to the asteroid, beyond that of the DART spacecraft itself. Researchers found the impact caused an instantaneous slowing in Dimorphos' speed along its orbit of about 2.7 millimeters per second — again indicating the recoil from ejecta played a major role in amplifying the momentum change directly imparted to the asteroid by the spacecraft. That momentum change was amplified by a factor of 2.2 to 4.9 (depending on the mass of Dimorphos), indicating the momentum change transferred because of ejecta production significantly exceeded the momentum change from the DART spacecraft alone. [83] While the orbital change was small, the change is in the velocity and over the course of years will accumulate to a large change in position. [84] For a hypothetical Earth-threatening body, even such a tiny change could be sufficient to mitigate or prevent an impact, if applied early enough. As the diameter of Earth is around 13,000 kilometers, a hypothetical asteroid impact could be avoided with as little of a shift as half of that (6,500 kilometers). A 2 cm/s velocity change accumulates to that distance in approximately 10 years.

Dart Impact seen by LICIACube Two LICIACube LUKE images showing the ejecta morphology that were used to reduce the possible axis orientation solutions.webp
Dart Impact seen by LICIACube

By smashing into the asteroid DART made Dimorphos an active asteroid. Scientists had proposed that some active asteroids are the result of impact events, but no one had ever observed the activation of an asteroid. The DART mission activated Dimorphos under precisely known and carefully observed impact conditions, enabling the detailed study of the formation of an active asteroid for the first time. [83] [85] Observations show that Dimorphos lost approximately 1 million kilograms of mass as a result of the collision. [22]

Sequence of operations for impact

Date
(before impact)		Distance from
Dimorphos [86] 		Raw image [lower-alpha 1] Events [2] [88]
27 July 2022
(T-60 days)		38 million kilometers (0.25 astronomical units; 99 lunar distances; 24 million miles)
DART Sets Sights on Asteroid Target Composite of 243 images taken by DRACO on July 27, 2022, detecting Didymos.jpg
The DRACO camera detects the Didymos system.
11 September 2022
23:14 UTC
(T-15 days)		8 million kilometers (0.053 astronomical units; 21 lunar distances; 5.0 million miles)Ejection of LICIACube, which maneuvers to avoid crashing into the asteroid. [73]
26 September 2022
19:14 UTC
(T-4 hours)		89,000 kilometers (0.23 lunar distances; 55,000 miles)Terminal phase—start of autonomous navigation with SMART Nav. DRACO locks onto Didymos since Dimorphos is not visible yet. [3]
22:14 UTC
(T-60 minutes)		22,000 kilometers (0.057 lunar distances; 14,000 miles)
DART-Didymos T-1 h.png
The DRACO camera detects Dimorphos.
22:54 UTC
(T-20 minutes)		7,500 kilometers (4,700 miles)SMART Nav enters precision lock onto Dimorphos and DART begins thrusting toward Dimorphos. [3]
23:10 UTC
(T-4 minutes)		1,500 kilometers (930 miles)
Dart-five-minutes-impact.png
Start of final course correction
23:11 UTC
(T-2 minutes 30 seconds)		920 kilometers (570 miles)
Both dart 0401929889 03770 01 iof imagedisplay-final.png
Last image with both Didymos (lower-left) and Dimorphos entirely in frame is taken
23:12 UTC
(T-2 minutes)		740 kilometers (460 miles)End of final course correction
23:14 UTC
(T-20 seconds)		130 kilometers (81 miles)The photos taken reach the expected spatial resolution.
23:14 UTC
(T-11 seconds)		68 kilometers (42 miles)
All dimorphos dart 0401930040 12262 01 iof imagedisplay-final.png
Last image showing all of Dimorphos by DART
23:14 UTC
(T-3 seconds)		18 kilometers (11 miles)
Dimorphos from DART aprox. 3 sec before impact.jpg
23:14 UTC
(T-2 seconds)		12 kilometers (7.5 miles)
Penultimate image of Dimorphos by DART.png
Final complete image of Dimorphos transmitted. Resolution roughly 3 cm per pixel (~ 30m across).
23:14 UTC
(T-1 second)		6 kilometers (3.7 miles)
Final dart 0401930050 41838 01 iof imagedisplay-final.png
Last partial image taken by DART before impact, transmission of the image was interrupted by the destruction of the spacecraft and all of its transmitting hardware. Resolution per pixel to be determined at a later date by analysis of image and timing.
23:14 UTC
(T-0)		0 kilometers (0 miles)Impact Dimorphos (estimated impact velocity 6 kilometers/second) [89]
23:17 UTC
(T+2 min 45 s) [47] 		56.7 kilometers (35.2 miles)
Liciacube luke l0 1664234221 00000 01 rgb zoom flip.png
Closest approach to Dimorphos by LICIACube.

See also

Notes

  1. ↑ The original raw DRACO images from DART were mirror flipped from reality. The images shown in the sequence of operations are uncorrected and show Didymos and Dimorphos as they appear on the DRACO detector. [87]

Related Research Articles

<span class="mw-page-title-main">Asteroid</span> Minor planets found within the inner Solar System

An asteroid is a minor planet—an object that is neither a true planet nor a comet—that orbits within the inner Solar System. They are rocky, metallic, or icy bodies with no atmosphere. The size and shape of asteroids vary significantly, ranging from small rubble piles under a kilometer across to Ceres, a dwarf planet almost 1000 km in diameter.

<span class="mw-page-title-main">Near-Earth object</span> Small Solar System body with an orbit that can bring it close to Earth

A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun (perihelion) is less than 1.3 times the Earth–Sun distance. This definition applies to the object's orbit around the Sun, rather than its current position, thus an object with such an orbit is considered an NEO even at times when it is far from making a close approach of Earth. If an NEO's orbit crosses the Earth's orbit, and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but about 0.35% are comets.

<span class="mw-page-title-main">Asteroid impact avoidance</span> Methods to prevent destructive asteroid hits

Asteroid impact avoidance comprises the methods by which near-Earth objects (NEO) on a potential collision course with Earth could be diverted away, preventing destructive impact events. An impact by a sufficiently large asteroid or other NEOs would cause, depending on its impact location, massive tsunamis or multiple firestorms, and an impact winter caused by the sunlight-blocking effect of large quantities of pulverized rock dust and other debris placed into the stratosphere. A collision 66 million years ago between the Earth and an object approximately 10 kilometers wide is thought to have produced the Chicxulub crater and triggered the Cretaceous–Paleogene extinction event that is understood by the scientific community to have caused the extinction of all non-avian dinosaurs.

<span class="mw-page-title-main">B612 Foundation</span> Planetary defense nonprofit organization

The B612 Foundation is a private nonprofit foundation headquartered in Mill Valley, California, United States, dedicated to planetary science and planetary defense against asteroids and other near-Earth object (NEO) impacts. It is led mainly by scientists, former astronauts and engineers from the Institute for Advanced Study, Southwest Research Institute, Stanford University, NASA and the space industry.

Don Quijote is a past space mission concept that has been studied from 2005 until 2007 by the European Space Agency, and which would investigate the effects of crashing a spacecraft into an asteroid to test whether a spacecraft could successfully deflect an asteroid on a collision course with Earth. The orbiter was designed to last for seven years. The mission did not proceed beyond initial studies.

<span class="mw-page-title-main">Active asteroid</span> Bodies orbiting within the main asteroid belt which have shown cometary activity

Active asteroids are small Solar System bodies that have asteroid-like orbits but show comet-like visual characteristics. That is, they show a coma, tail, or other visual evidence of mass-loss, but their orbits remain within Jupiter's orbit. These bodies were originally designated main-belt comets (MBCs) in 2006 by astronomers David Jewitt and Henry Hsieh, but this name implies they are necessarily icy in composition like a comet and that they only exist within the main-belt, whereas the growing population of active asteroids shows that this is not always the case.

<span class="mw-page-title-main">65803 Didymos</span> Near-Earth asteroid

65803 Didymos is a sub-kilometer asteroid and binary system that is classified as a potentially hazardous asteroid and near-Earth object of the Apollo group. The asteroid was discovered in 1996 by the Spacewatch survey at Kitt Peak, and its small 160-meter minor-planet moon, named Dimorphos, was discovered in 2003. Due to its binary nature, the asteroid was then named Didymos, the Greek word for 'twin'.

3361 Orpheus is an Apollo asteroid that was discovered on 24 April 1982 by Carlos Torres at Cerro El Roble Astronomical Station. Its eccentric orbit crosses that of Mars and Earth, and approaches Venus as well. From 1900 to 2100 it passes closer than 30 Gm to Venus, 11; Earth, 33; and Mars, 14 times. It passed by Earth at a distance of about 0.03 AU in 1937, 1978, 1982, and 2021, and will do so again in 2025.

The Asteroid Impact and Deflection Assessment (AIDA) missions are a proposed pair of space probes which will study and demonstrate the kinetic effects of crashing an impactor spacecraft into an asteroid moon. The mission is intended to test and validate impact models of whether a spacecraft could successfully deflect an asteroid on a collision course with Earth.

<span class="mw-page-title-main">Patrick Michel</span>

Patrick Michel is a French planetary scientist, Senior Researcher at CNRS, leader of the team TOP of the CNRS and Université Côte d'Azur Lagrange Laboratory at the Côte d'Azur Observatory in Nice (France), and also a Global Fellow of the University of Tokyo.

The Space Safety Programme, formerly the Space Situational Awareness (SSA) programme, is the European Space Agency's (ESA) initiative to monitor hazards from space, determine their risk, make this data available to the appropriate authorities and where possible, mitigate the threat.

<span class="mw-page-title-main">Planetary Defense Coordination Office</span> NASA department for avoiding asteroid impacts

The Planetary Defense Coordination Office (PDCO) is a planetary defense organization established in January 2016 within NASA's Planetary Science Division of the Science Mission Directorate.

<span class="mw-page-title-main">Planetary Missions Program Office</span> Division of NASA responsible for the Discovery, New Frontiers, and Solar System Exploration programs

The Planetary Missions Program Office is a division of NASA headquartered at the Marshall Space Flight Center, formed by the agency's Science Mission Directorate (SMD). Succeeding the Discovery and New Frontiers Program Office, it was established in 2014 to manage the Discovery and New Frontiers programs of low and medium-cost missions by third-party institutions, and the Solar System Exploration program of NASA-led missions that focus on prioritized planetary science objectives. The Discovery and New Frontiers programs were established in 1992 and 2001 respectively, and have launched fourteen primary missions together, along with two missions launched under the administration of the Planetary Missions Program Office. The Solar System Exploration Program was established alongside the office, with three missions planned for launch under the new program.

<span class="mw-page-title-main">Dimorphos</span> Moon of asteroid Didymos

Dimorphos is a natural satellite or moon of the near-Earth asteroid 65803 Didymos, with which it forms a binary system. The moon was discovered on 20 November 2003 by Petr Pravec in collaboration with other astronomers worldwide. Dimorphos has a diameter of 177 meters (581 ft) across its longest extent and it was the target of the Double Asteroid Redirection Test (DART), a NASA space mission that deliberately collided a spacecraft with the moon on 26 September 2022 to alter its orbit around Didymos. Before the impact by DART, Dimorphos had a shape of an oblate spheroid with a surface covered in boulders but virtually no craters. The moon is thought to have formed when Didymos shed its mass due to its rapid rotation, which formed an orbiting ring of debris that conglomerated into a low-density rubble pile that became Dimorphos today.

<span class="mw-page-title-main">LICIACube</span> ASI CubeSat aboard DART spacecraft

Light Italian CubeSat for Imaging of Asteroids is a six-unit CubeSat of the Italian Space Agency (ASI). LICIACube is a part of the Double Asteroid Redirection Test (DART) mission and carries out observational analysis of the Didymos asteroid binary system after DART's impact on Dimorphos. It communicates directly with Earth, sending back images of the ejecta and plume of DART's impact as well as having done asteroidal study during its flyby of the Didymos system from a distance of 56.7 km (35.2 mi), 165 seconds after DART's impact. LICIACube is the first purely Italian autonomous spacecraft in deep space. Data archiving and processing is managed by the Space Science Data Center (SSDC) of the ASI.

NEO-MAPP is a project for studying planetary defence and asteroid exploration.

<i>Hera</i> (space mission) ESA spacecraft which will study the effects of the DART Impactor on the asteroid moon Dimorphos

Hera is a space mission in development at the European Space Agency in its Space Safety program. Its primary objective is to study the Didymos binary asteroid system that was impacted by DART and contribute to validation of the kinetic impact method to deviate a near-Earth asteroid in a colliding trajectory with Earth. It will measure the size and the morphology of the crater created by and momentum transferred by an artificial projectile impacting an asteroid, which will allow measuring the efficiency of the deflection produced by the impact. It will also analyze the expanding debris cloud caused by the impact.

References

  1. 1 2 "DART". NASA Space Science Data Coordinated Archive . Retrieved 9 February 2023.
  2. 1 2 "Double Asteroid Redirection Test Press Kit" (PDF). Johns Hopkins University Applied Physics Laboratory.
  3. 1 2 3 4 Malik, Taliq (23 September 2022). "DART asteroid crash: What time will NASA probe hit Dimorphos on Sept. 26?". Space.com. Retrieved 25 September 2022.
  4. ↑ Chang, Kenneth (27 September 2022). "What NASA's Crash into an Asteroid Looks Like – Astronomers on Earth – and a shoebox-size Italian spacecraft called LICIACube – captured the DART mission's successful strike on Dimorphos". The New York Times . Retrieved 28 September 2022.
  5. ↑ Chang, Kenneth (25 September 2022). "NASA Is About to Crash into an Asteroid. Here's How to Watch – The DART mission has been flying to its target since launching last year. On Monday night, it will connect". The New York Times . Retrieved 26 September 2022.
  6. ↑ "NASA's DART Mission Hits Asteroid in First-Ever Planetary Defense Test". NASA. 27 September 2022.
  7. ↑ Chang, Kenneth (26 September 2022). "NASA Smashes into an Asteroid, Completing a Mission to Save a Future Day". The New York Times . Retrieved 27 September 2022.
  8. ↑ Bardan, Roxana (11 October 2022). "NASA Confirms DART Mission Impact Changed Asteroid's Motion in Space". NASA. Retrieved 11 October 2022.
  9. ↑ Strickland, Ashley (11 October 2022). "The DART mission successfully changed the motion of an asteroid". CNN. Retrieved 11 October 2022.
  10. 1 2 Cheng AF, Agrusa HF, Barbee BW, et al. (1 March 2023). "Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos". Nature. 616 (7957): 457–460. arXiv: 2303.03464 . Bibcode:2023Natur.616..457C. doi:10.1038/s41586-023-05878-z. PMC   10115652 . PMID   36858075. S2CID   257282972.
  11. ↑ Keeter, Bill (7 September 2022). "DART Sets Sights on Asteroid Target". NASA. Retrieved 10 September 2022.; "SpaceX ready for first launch with NASA interplanetary mission". Spaceflight Now. 22 November 2021. Retrieved 24 November 2021.; "DART Launch Moves to Secondary Window". NASA. 17 February 2021. Retrieved 24 November 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .; "Live: NASA to crash spacecraft into asteroid in trial to protect Earth from collisions". ABC News. 26 September 2022. Retrieved 26 September 2022.
  12. ↑ AIDA DART Home page at APL
  13. 1 2 3 "Asteroid Impact & Deflection Assessment (AIDA) study". Archived from the original on 7 June 2015.
  14. 1 2 DART at Applied Physics Laboratory Johns Hopkins University
  15. 1 2 3 Planetary Defense: Double Asteroid Redirection Test (DART) Mission NASA 2017 PD-icon.svg This article incorporates text from this source, which is in the public domain .
  16. ↑ Brown, Geoff; University, Johns Hopkins. "NASA plans to test asteroid deflection technique designed to prevent Earth impact". phys.org.
  17. ↑ Asteroid-deflection mission passes key development milestone 7 September 2018
  18. ↑ "NASA Awards Launch Services Contract for Asteroid Redirect Test Mission". NASA. 12 April 2019. Retrieved 12 April 2019.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  19. ↑ "NASA – Deep Impact's Impactor". nasa.gov. Archived from the original on 23 June 2016.
  20. ↑ "In Depth - Deep Impact (EPOXI)". NASA Solar System Exploration. Retrieved 11 October 2022.
  21. 1 2 "Double Asteroid Redirection Test (DART)". NASA. 28 October 2021. Retrieved 5 November 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  22. 1 2 Witze, Alexandra (1 March 2023). "Asteroid lost 1 million kilograms as a result of the collision with DART spacecraft". Nature. 615 (7951): 195. Bibcode:2023Natur.615..195W. doi:10.1038/d41586-023-00601-4. PMID   36859675. S2CID   257282080 . Retrieved 9 March 2023.
  23. ↑ "DART". dart.jhuapl.edu. Retrieved 20 May 2022.
  24. ↑ Fletcher, Zachary; Ryan, Kyle; Maas, Bryan; Dickman, Joseph; Hammond, Randolph; Bekker, Dmitriy; Nelson, Tyler; Mize, James; Greenberg, Jacob; Hunt, Wendy; Smee, Stephen; Chabot, Nancy; Cheng, Andrew (6 July 2018). Design of the Didymos Reconnaissance and Asteroid Camera for OpNav (DRACO) on the double asteroid redirection test (DART). Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave. Vol. 106981X. Austin, TX: Proceedings of SPIE 10698. doi:10.1117/12.2310136.
  25. ↑ Lakdawalla, Emily (22 September 2022). "DART Impact on Monday!" . Retrieved 26 September 2022– via Patreon.
  26. ↑ Lakdawalla, Emily (23 September 2022). "NASA's DART Mission to Impact Asteroid Monday". Sky & Telescope. Retrieved 26 September 2022.
  27. ↑ Talbert, Tricia (30 June 2017). "Double Asteroid Redirection Test (DART) Mission". NASA. Retrieved 21 January 2018.PD-icon.svg This article incorporates text from this source, which is in the public domain.
  28. ↑ Behind the Scenes: Inspecting DART's Roll-Out Solar Array (ROSA) Technology , retrieved 13 August 2021; "DART has a solar array experiment called transformational solar array on its roll out solar array panel". dart.jhuapl.edu. Archived from the original on 23 December 2019. Retrieved 13 August 2021.
  29. ↑ Bray, Matthew (2020). "A Spiral Radial Line Slot Array Antenna for NASA's Double Asteroid Redirection Test (DART)". 2020 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting. pp. 379–380. doi:10.1109/IEEECONF35879.2020.9330400. ISBN   978-1-7281-6670-4. S2CID   231975847.
  30. ↑ Kantsiper, Brian (2017). "The Double Asteroid Redirection Test (DART) mission electric propulsion trade". 2017 IEEE Aerospace Conference. pp. 1–7. doi:10.1109/AERO.2017.7943736. ISBN   978-1-5090-1613-6. S2CID   43072949.
  31. ↑ Adams, Elena; Oshaughnessy, Daniel; Reinhart, Matthew; John, Jeremy; Congdon, Elizabeth; Gallagher, Daniel; Abel, Elisabeth; Atchison, Justin; Fletcher, Zachary; Chen, Michelle; Heistand, Christopher; Huang, Philip; Smith, Evan; Sibol, Deane; Bekker, Dmitriy; Carrelli, David (2019). "Double Asteroid Redirection Test: The Earth Strikes Back". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742007. ISBN   978-1-5386-6854-2. S2CID   195222414.
  32. ↑ "Impactor Spacecraft". DART. The Johns Hopkins University. Retrieved 24 November 2022.
  33. ↑ NASA's DART Mission Post-Asteroid-Impact News Briefing, 26 September 2022, 8pm EDT, at 27 minutes
  34. 1 2 Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Archived 31 October 2018 at the Wayback Machine Andy Rivkin, The Johns Hopkins University Applied Physics Laboratory, 27 September 2018
  35. ↑ Kretschmar, Peter; Küppers, Michael (20 December 2018). "The CubeSat Revolution" (PDF). ESA. Retrieved 24 January 2019.
  36. 1 2 George Dvorsky (27 September 2022). "First Asteroid Impact Images from DART's Companion Show Tentacle-Like Debris Plume". Gizmodo.
  37. ↑ Cheng, Andy (15 November 2018). "DART Mission Update". ESA. Retrieved 14 January 2019.
  38. ↑ "LICIACube". ASI. Retrieved 26 November 2021.
  39. ↑ WATCH: NASA Asteroid Redirection Test Media Briefing – Livestream , retrieved 20 May 2022
  40. ↑ Rivkin, Andrew S.; Chabot, Nancy L.; Stickle, Angela M.; Thomas, Cristina A.; Richardson, Derek C.; Barnouin, Olivier; Fahnestock, Eugene G.; Ernst, Carolyn M.; Cheng, Andrew F.; Chesley, Steven; Naidu, Shantanu (25 August 2021). "The Double Asteroid Redirection Test (DART): Planetary Defense Investigations and Requirements". The Planetary Science Journal. 2 (5): 173. Bibcode:2021PSJ.....2..173R. doi: 10.3847/PSJ/ac063e . ISSN   2632-3338. S2CID   237301576.
  41. ↑ Nakano, Ryota; Hirabayashi, Masatoshi; Agrusa, Harrison F.; Ferrari, Fabio; Meyer, Alex J.; Michel, Patrick; Raducan, Sabina D.; Sánchez, Paul; Zhang, Yun (5 July 2022). "NASA's Double Asteroid Redirection Test (DART): Mutual Orbital Period Change Due to Reshaping in the Near-Earth Binary Asteroid System (65803) Didymos". The Planetary Science Journal. 3 (7): 148. Bibcode:2022PSJ.....3..148N. doi: 10.3847/PSJ/ac7566 . hdl: 11311/1223308 . ISSN   2632-3338. S2CID   250327233.
  42. ↑ LICIACube Twitter feed
  43. ↑ ATLAS twitter feed
  44. ↑ George Dvorsky (27 September 2022). "Ground Telescopes Capture Jaw-Dropping Views of DART Asteroid Impact". Gizmodo. Telescopes around the world honed in on the historic collision, revealing a surprisingly large and bright impact plume.
  45. ↑ Strickland, Ashley (4 October 2022). "Comet-like debris trail spotted after spacecraft crashes into asteroid". CNN. Retrieved 6 October 2022.
  46. ↑ "DART: Asteroid – eoPortal Directory – Satellite Missions". directory.eoportal.org. Retrieved 24 November 2021.
  47. 1 2 3 Lakdawalla, Emily (22 September 2022). "DART Impact on Monday!". Patreon.
  48. ↑ Nelson, Bill; Saccoccia, Giorgio. "Update on DART Mission to Asteroid Dimorphos (NASA News Conference)". YouTube. Retrieved 11 October 2022.
  49. ↑ Hera mission is approved as ESA receives biggest ever budget Kerry Hebden Room Space Journal 29 November 2019
  50. 1 2 3 Bergin, Chris (7 January 2019). "Hera adds objectives to planetary defense test mission". NASASpaceflight.com. Retrieved 11 January 2019.
  51. ↑ Michel, Patrick; Küppers, Michael; Bagatin, Adriano Campo; Carry, Benoit; Charnoz, Sébastien; Leon, Julia de; Fitzsimmons, Alan; Gordo, Paulo; Green, Simon F.; Hérique, Alain; Juzi, Martin; Karatekin, Özgür; Kohout, Tomas; Lazzarin, Monica; Murdoch, Naomi; Okada, Tatsuaki; Palomba, Ernesto; Pravec, Petr; Snodgrass, Colin; Tortora, Paolo; Tsiganis, Kleomenis; Ulamec, Stephan; Vincent, Jean-Baptiste; Wünnemann, Kai; Zhang, Yun; Raducan, Sabina D.; Dotto, Elisabetta; Chabot, Nancy; Cheng, Andy F.; Rivkin, Andy; Barnouin, Olivier; Ernst, Carolyn; Stickle, Angela; Richardson, Derek C.; Thomas, Cristina; Arakawa, Masahiko; Miyamoto, Hirdy; Nakamura, Akiko; Sugita, Seiji; Yoshikawa, Makoto; Abell, Paul; Asphaug, Erik; Ballouz, Ronald-Louis; Bottke, William F.; Lauretta, Dante S.; Walsh, Kevin J.; Martino, Paolo; Carnelli, Ian (15 July 2022). "The ESA Hera Mission: Detailed Characterization of the DART Impact Outcome and of the Binary Asteroid (65803) Didymos". The Planetary Science Journal. 3 (7): 160. Bibcode:2022PSJ.....3..160M. doi: 10.3847/PSJ/ac6f52 . hdl: 10045/125568 . S2CID   250599919.
  52. ↑ The Juventas CubeSat in Support of ESA's Hera Mission to the Asteroid Didymos. Hannah R. Goldberg, Özgür Karatekin, Birgit Ritter, Alain Herique, Paolo Tortora, Claudiu Prioroc, Borja Garcia Gutierrez, Paolo Martino, Ian Carnelli. 33rd Annual AIAA/USU Conference on Small Satellites.
  53. ↑ Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Archived 2018-10-31 at the Wayback Machine Andy Rivkin, The Johns Hopkins University Applied Physics Laboratory. September 27, 2018.
  54. ↑ A Low Frequency Radar to Fathom Asteroids from Juventas Cubesat on HERA. Alain Herique, Dirk Plettemeier, Wlodek Kofman, Yves Rogez, Christopher Buck, and Hannah Goldberg. EPSC Abstracts. Vol. 13, EPSC-DPS2019-807-2, 2019. EPSC-DPS Joint Meeting 2019.
  55. 1 2 The Juventas CubeSat in Support of ESA's Hera Mission to the Asteroid Didymos Hannah R. Goldberg, Özgür Karatekin, Birgit Ritter, Alain Herique, Paolo Tortora, Claudiu Prioroc, Borja Garcia Gutierrez, Paolo Martino, Ian Carnelli. 33rd Annual AIAA/USU Conference on Small Satellites
  56. ↑ JuRa: the Juventas Radar on Hera to fathom Didymoon Alain Herique, Dirk Plettemeier, Hannah Goldberg, Wlodek Kofman, and the JuRa Team. EPSC Abstracts. Vol.14, EPSC2020-595. doi:10.5194/epsc2020-595.
  57. 1 2 Exploration of the binary asteroid 65803 Didymos by the Hera mission. EPSC Abstracts. Vol. 13, EPSC-DPS2019-583-1, 2019. EPSC-DPS Joint Meeting 2019. 15–20 September 2019.
  58. ↑ "Industry starts work on Europe's Hera planetary defence mission". 15 September 2020. Retrieved 16 June 2021.
  59. ↑ Michel, Patrick; Kueppers, Michael; Sierks, Holger; Carnelli, Ian (26 April 2017). "European component of the AIDA mission to a binary asteroid: Characterization and interpretation of the impact of the DART mission" (PDF). Advances in Space Research (Article). 62 (8) (published 18 December 2017): 2261–2272. doi:10.1016/j.asr.2017.12.020. S2CID   55274187.
  60. ↑ Carnelli, Ian (11 October 2017). "The Hera Mission Study" (PDF). ESA. Retrieved 11 June 2018.
  61. ↑ "Seen the film Armageddon? NASA's aiming to smash an asteroid off course in real life". Australian Broadcasting Corporation (ABC). 23 November 2021. Retrieved 24 September 2022.
  62. 1 2 Michel, P.; Cheng, A.; Carnelli, I.; Rivkin, A.; Galvez, A.; Ulamec, S.; Reed, C.; AIDA Team (8 January 2015). "AIDA: Asteroid impact and deflection assessment mission under study at ESA and NASA". Spacecraft Reconnaissance of Asteroid and Comet Interiors. 1829: 6008. Bibcode:2015LPICo1829.6008M.
  63. ↑ 65803 Didymos (Report). JPL Small-Body Database Browser. NASA / Jet Propulsion Laboratory . Retrieved 30 December 2021– via ssd.jpl.nasa.gov.
  64. ↑ "Spacecraft for asteroid deflection experiment ready for fueling at Vandenberg". Spaceflight Now. 20 October 2021. Retrieved 5 November 2021.
  65. 1 2 "NASA's DART Preps for Launch in First Planetary Defense Test Mission". NASA. 3 November 2021. Retrieved 24 November 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  66. ↑ "NASA's DART Spacecraft Secured in Payload Fairing, Flight Readiness Review Complete – Double Asteroid Redirection Test (DART) Mission". blogs.nasa.gov. 22 November 2021. Retrieved 24 November 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  67. ↑ Atchison, Justin A.; Ozimek, Martin T.; Kantsiper, Brian L.; Cheng, Andrew F. (1 June 2016). "Trajectory options for the DART mission". Acta Astronautica. Special Section: Selected Papers from the International Workshop on Satellite Constellations and Formation Flying 2015. 123: 330–339. Bibcode:2016AcAau.123..330A. doi:10.1016/j.actaastro.2016.03.032. ISSN   0094-5765.
  68. ↑ "Double Asteroid Redirection Test (DART)". NASA Space Science Data Coordinated Archive. NASA. Retrieved 25 September 2022.; Rivkin, Andy (27 September 2018). "Asteroids have been hitting the Earth for billions of years. In 2022, we hit back". DART. Johns Hopkins University Applied Physics Laboratory. Retrieved 25 September 2022.
  69. ↑ "JPL Horizons On-Line Ephemeris for 138971 (2001 CB21) on 2022-Mar-01 to 2022-Mar-03". JPL Horizons On-Line Ephemeris System . Jet Propulsion Laboratory . Retrieved 28 September 2022. Ephemeris Type: Observer. Target Body: 138971 (2001 CB21). Observer Location: 500@-135 (DART Spacecraft).
  70. 1 2 3 Talbert, Tricia (22 December 2021). "NASA's DART Captures One of Night Sky's Brightest Stars". NASA. Retrieved 25 September 2022.
  71. ↑ Talbert, Tricia (17 June 2022). "NASA's DART Captures One of Night Sky's Brightest Stars". NASA. Retrieved 25 September 2022.
  72. ↑ Talbert, Tricia (22 September 2022). "DART Tests Autonomous Navigation System Using Jupiter and Europa". NASA. Retrieved 25 September 2022.
  73. 1 2 Keeter, Bill (14 September 2022). "DART's Small Satellite Companion Takes Flight Ahead of Impact". NASA. Retrieved 25 September 2022.
  74. ↑ "NASA's DART Mission Hits Asteroid in First-Ever Planetary Defense Test". 26 September 2022.
  75. 1 2 Statler, T. "Session 3: DART" (PDF). 7th IAA Planetary Defense Conference. Retrieved 5 November 2022.
  76. ↑ DART: Home page at APL Archived 10 May 2018 at the Wayback Machine DART Spacecraft APL 2017
  77. ↑ "Impactor Spacecraft". NASA. 2021. Retrieved 18 February 2021.PD-icon.svg This article incorporates text from this source, which is in the public domain .; Andone, Dakin (25 July 2017). "NASA unveils plan to test asteroid defense technique". CNN. Retrieved 25 July 2017.
  78. ↑ Soldini, Stefania (21 September 2022). "Can we really deflect an asteroid by crashing into it? Nobody knows, but we are excited to try". The Conversation. Retrieved 23 September 2022.
  79. ↑ Stickle, Angela (2022). "NASA's Double Asteroid Redirection Test Press Kit" (PDF). Johns Hopkins Applied Research Laboratory. Retrieved 5 November 2022.
  80. ↑ "Course corrector". Aerospace America. 28 September 2017. Retrieved 27 September 2022.
  81. ↑ Merzdorf, Jessica (15 December 2022). "Early Results from NASA's DART Mission". NASA. Retrieved 16 December 2022.
  82. ↑ @jeff_foust (15 December 2022). "One other note from the briefing: the tail of ejecta from Dimorphos created by the DART impact is at least 30,000 kilometers long, says Andy Rivkin of JHUAPL, with a mass of at least 1,000 metric tons, and possibly up to 10 times that much" (Tweet) – via Twitter.
  83. 1 2 Furfaro, Emily (28 February 2023). "NASA's DART Data Validates Kinetic Impact as Planetary Defense Method". NASA. Retrieved 9 March 2023.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  84. ↑ "NASA Pushes Through With Asteroid Deflection Mission That Could One Day Save Earth – Inquisitr". inquisitr.com. 5 July 2017. Retrieved 27 September 2022.
  85. ↑ Li, Jian-Yang; Hirabayashi, Masatoshi; Farnham, Tony L.; et al. (1 March 2023). "Ejecta from the DART-produced active asteroid Dimorphos". Nature. 616 (7957): 452–456. arXiv: 2303.01700 . Bibcode:2023Natur.616..452L. doi:10.1038/s41586-023-05811-4. ISSN   1476-4687. PMC   10115637 . PMID   36858074. S2CID   257282549.
  86. ↑ "JPL Horizons On-Line Ephemeris for Dimorphos on 2022-Sep-26". JPL Horizons On-Line Ephemeris System . Jet Propulsion Laboratory . Retrieved 25 September 2022. Ephemeris Type: Observer. Target Body: Dimorphos. Observer Location: 500@-135 (DART Spacecraft).
  87. ↑ Talbert, Tricia (26 September 2022). "DART's Final Images Prior to Impact". NASA. Retrieved 17 December 2022.
  88. ↑ Session 3: DART (PDF). 7th IAA Planetary Defense Conference. 26–30 April 2021.
  89. ↑ "NASA's First Asteroid Deflection Mission Enters Next Design Phase at Johns Hopkins APL". Johns Hopkins University Applied Physics Laboratory. 30 June 2017. Retrieved 28 September 2022.
  90. ↑ "Webb and Hubble Capture Detailed Views of DART Impact". 20 October 2023.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.