Hayabusa (space probe)

Hayabusa (はやぶさ, the peregrine falcon^? ) was an unmanned space mission carried out by the Japanese Aerospace Exploration Agency to collect samples of material and bring them to Earth for analysis, from a small near-Earth asteroid called (25143) Itokawa (size 0.3 x 0.7 km).

The Hayabusa spacecraft, formerly known as MUSES-C, was launched on May 9, 2003. Upon arrival at Itokawa, the Hayabusa spacecraft launched a small lander called Minerva that Its objective was to study the asteroid's shape, spin, topography, color, composition, density, and history, although it could not be carried out as it was lost in space without touching the surface. The probe arrived in the vicinity of Itokawa on September 12, 2005, initially remaining at a distance of 20 km from the asteroid. Later it approached just 7 km from it. On November 20, the probe landed on the asteroid for 30 minutes. On November 25, in a second descent, the probe took samples of the asteroid's soil.

While other spacecraft, such as the Galileo probe and NEAR Shoemaker, have visited comets before, the Hayabusa mission was the first to bring a sample of an asteroid to Earth for analysis, when he returned on June 13, 2010.

The mission profile

The Hayabusa spacecraft was launched on May 9, 2003 at 04:29:25 UTC with an M-5 rocket from the Uchinoura Space Center (still called at the time the Kagoshima Space Center), named after the spacecraft was changed from the original MUSES-C to Hayabusa, the Japanese word for falcon). The spacecraft has a xenon ion engine that operated almost continuously during the first two years of the mission, slowly approaching the rendezvous with Itokawa in September 2005. The spacecraft did not enter orbit around the asteroid, but remained stationary. in the same heliocentric orbit of the asteroid.

Hayabusa inspected the asteroid's surface initially from a distance of approximately 20 km. The spacecraft then moved near the surface for a series of soft landings and sample collection from two sites. Autonomous optical navigation was employed extensively during this period because communication delay prevents real-time commands. The spacecraft was prepared to fire a tiny projectile at the surface, collecting the resulting dust, although it is still uncertain whether the objectives were achieved. According to the project, the mass of the samples obtained should be approximately one gram, although due to some technical unforeseen events, it is possible that the amount collected is lower.

After a few months near the asteroid, the spacecraft fired its engines to begin its cruise back to Earth. The reentry capsule, which should contain the samples from the Itokawa asteroid, separated from the mother ship at a distance of approximately 300,000 to 400,000 km from Earth, and sailed on a ballistic trajectory, re-entering Earth's atmosphere on June 13, 2010 at a speed of 12,000 meters per second. The capsule experienced maximum decelerations of about 25 g and suffered approximately 30 times more heat than that experienced by the Apollo spacecraft. He landed by parachute in the South Woomera Desert, Australia.

The Minerva mini lander

While Hayabusa's spacecraft remained near the Itokawa asteroid, it deployed a mini-spacecraft weighing only 519 grams called Minerva.

Taking advantage of Itokawa's very low gravity, this vehicle would hop along the asteroid's surface, while sending images from its cameras to Hayabusa. Unfortunately, an error during implementation resulted in a failure of the spacecraft. Due to measurement errors, the probe was lost in space without landing on the asteroid. This type of vehicle has only been included once before, in the failed Soviet Phobos mission to the Mars satellite of the same name, and has never seen real use.

Ship design

The Hayabusa spacecraft had a square-based parallelepiped-shaped main body 1.5 m long and 1.05 m high. The launch mass was 510 kg, including 50 kg of chemical fuel and 65 kg of xenon gas. Two solar panels with a total array area of 12 square meters protruded from the box and a 1.5 m diameter high-gain satellite dish was mounted on top on one of the two gimbal shafts. A cylindrical sampling horn, deployed shortly after launch, protruded from the underside of the ship. The Minerva lander was also mounted on the ship near the bottom of the panel. Hayabusa was powered during the cruise phases by two microwave ion engines, which use a microwave discharge to ionize xenon gas. The ionized plasma is accelerated by high-voltage electrodes through four propeller heads protruding from one side of the craft's body to provide a maximum thrust of 20 Nm through 1 kW of power. Nitrogen tetroxide/hydrazine propulsion system with a maximum thrust of 22 N will be used for the maneuver. The spacecraft is powered by gallium-arsenide solar cells and a 15 A-hr rechargeable nickel-metal hydride (Ni-MH) battery. Communications are via low-gain and optical navigation near the asteroid, a laser ranging (LIDAR) device, and near-IR and weighing about 20 kg, it is inserted into the body of the ship near the Sampling Horn. The capsule has a convex nose covered with a 3 cm thick ablative heat shield to protect the samples from the high velocity (~ 13 km/s) of re-entry. The cost of the Hayabusa spacecraft was approximately 12 million yen (US$100 million).

The lander was equipped with a sample collection device, intended to collect one gram of surface samples taken from landings at 3 different locations. The device consisted of a horn-shaped collection funnel, 40 cm in diameter at the end, which was placed over the sampling area. A pyrotechnic device fired a 10-gram metal projectile through the barrel of the horn at 200 - 300 m/sec. The projectile reached the surface producing a small impact crater on the surface of the asteroid and the fragments of the propelled ejecta were collected with the funnel where some was channeled to a sampling chamber and another to a backup location, backup mode. Before each series of samples, the probe had to drop a small white disk on the surface from about 30 meters high to use as a reference point to ensure that the relative horizontal velocity between the spacecraft and the asteroid surface was zero during The sampling. After taking samples, they would be stored in the reentry capsule for return to Earth.

The scientific importance of the mission

Current scientific knowledge of asteroids is lacking direct samples of them. Hayabusa will solve this problem by bringing back pristine samples from a specific, well-characterized asteroid. "Hayabusa will fill the gap between data from observing real asteroid samples and laboratory analysis of meteorites and "cosmic dust collections," said mission scientist Hajime Yano.

Changes to the mission plan

The Hayabusa mission was modified at various times, before and after launch.

• The spacecraft was originally planned to launch in July 2002 to asteroid Nereus. However, in July 2000, the failure of the Japanese M-5 rocket forced a delay in the launch. As a result, the designated asteroid changed from Nereus to Itokawa.
• Hayabusa also had to deploy a small vehicle designed by NASA and developed by the JPL, called Muses-CN, on the asteroid's surface, but the project was cancelled by NASA in November 2000 due to budgetary problems.
• In 2002, the launch was postponed again from December 2002 to May 2003 for some problems in the manufacture of some components.
• In 2003, while Hayabusa was already on its way to Itokawa, a large solar storm damaged some of the solar cells on board the spacecraft. This electricity reduction reduced the efficiency of the ionic engine by delaying the arrival of Itokawa from June to September 2005. As the spacecraft still had to leave the asteroid in November due to demands due to the celestial mechanics, the time available for the spacecraft to observe Itokawa and the number of landings in the asteroid was reduced from three to two.
• In 2005, two reaction wheels that govern the movement to position the ship failed, the X-axis wheel did it on July 31, and the Y-axis on October 2. After the fault of the latter, the ship was still able to rotate on its X and Y axis with its thrusters. JAXA stated that since the global mapping of Itokawa had been completed, this was not an important problem, but the mission plan was altered. The reaction wheels were manufactured by Ithaco Space Systems, Inc., from New York, which was later acquired by Goodrich.
• On November 4, 2005, the landing 'assay' in Itokawa failed and was rescheduled.
• The original decision to place samples in two different deposits on the asteroid was changed when one of the sites, the Woomera Desert, was found to be too rocky for a safe landing.
• On November 12, 2005, the release of the MINERVA minison ended in a failure, losing itself in space.

The latest events

• On 14 August 2005, Hayabusa I take the first image of Itokawa. The picture showed the asteroid as a point of light, while moving through the star field. Other images were taken on 22 August and 24 August.
• On 28 August there was a maneuvering of the orbit of Hayabusa with the ship's ionic engine.
• On 4 September 2005, the Hayabusa cameras were able to confirm the long form of Itokawa.
• On 11 September 2005, individual hills could be discerned in the asteroid.
• On 12 September 2005, Hayabusa It was only 20 km from Itokawa. [1].
• On 12 November 2005 Hayabusa release MINERVA, losing this in space.
• On 13 June 2010 Hayabusa returns to Earth by re-entering the Australian Central Desert.

Reentry and capsule recovery

The reentry capsule and spacecraft re-entered Earth's atmosphere on June 13, 2010 at 13:51 UTC. The heat shield capsule made a parachute landing in southern outback Australia while the ship separated and incinerated in a large fireball.

Before removing the capsule from the plastic bag that protects it, they must be inspected with an X-ray CT scan to determine their situation. The sample vial is then removed from the reentry capsule. The surface of the container should be cleaned with pure nitrogen gas and carbon dioxide. It is then placed into the bottle opening device. The internal pressure of the container can be determined by a slight deformation of the can with the variation of the pressure of the nitrogen gas in the cleaning chamber. The nitrogen gas pressure will be adjusted to match the internal pressure of the vial to prevent any escape of sample gas when the sample container is opened.

Preliminary analysis of rock samples from the S-type asteroid Itokawa turned out to be of the type of meteorites called chondrites.

The success of the probe mission in solving the mystery of the origin of chondritic meteorites and their asteroidal source (S-type asteroids) has been classified by Science magazine as the second of the 10 greatest scientific discoveries of the year 2011.