Hayabusa (space probe)
A model of the Hayabusa space probe taking soil samples. The four nozzles of the ion thrusters can be seen on the left side of the board.
|Mission goal||Asteroid (25143) Itokawa|
|Takeoff mass||510 kg|
|Course of the mission|
|Start date||May 9, 2003|
|End date||June 13, 2010|
Hayabusa ( Japanese 小 惑星 探査 機 「は や ぶ さ」 (MUSES-C) , shōwakusei tansaki "Hayabusa" (Muses-C) , German "Asteroid probe ' Peregrine Falcon ' (Muses-C)", called "Muses-C" before the start ) was a space probe of the Japanese space agency JAXA , which was launched on May 9, 2003 to the asteroid (25143) Itokawa . On September 12, 2005, the probe reached its destination and took soil samples there . After a return flight that was delayed by three years due to various technical problems, the detached return capsule with the sample and the probe entered the earth's atmosphere on June 13, 2010 at around 13:56 UTC (23:30 local time) via Australia. It was the first sample returned from the surface of an asteroid by spacecraft. In 2014 the probe of the follow-up mission Hayabusa 2 started .
Hayabusa hit the asteroid (25143) Itokawa (formerly known as 1998 SF 36 ) in September 2005 . The originally planned arrival date was June 2005, but due to major solar storms , some of the probe's solar cells were damaged, so that the ion thrusters received less power and thus could deliver less thrust. The probe was the first Japanese space probe with ion thrusters. Pivoting into orbit around the asteroid was not planned. Instead, the probe remained in a position near the asteroid. After mapping from a height of 20 km, the probe approached the asteroid several times. At first it was still uncertain whether the attempted removal of around one gram of soil material was successful. Even so, the probe returned the sample container to Earth. To take samples, Hayabusa had a funnel-shaped opening that served as a dust collector . When the funnel touched the ground, a small projectile was fired at the surface and the sample container was briefly opened. Some of the material thrown up should be collected in this way. Shortly before the actual ground contact, a so-called target marker was placed on the surface, which the space probe used for navigation. It also had 877,590 names that were submitted to JAXA via the Internet in 2002. The return flight to earth was delayed due to various problems with the attitude control, the hydrazine engines and the data transmission. That is why the first possible start date for the return, at the beginning of December 2005, could not be used. The probe was only able to return to earth with its ion propulsion system when it was the next chance to return by rail, and reached it on June 13, 2010, where the return capsule was detached and landed in Australia.
Originally the mission was supposed to take place with the participation of the USA , which wanted to contribute a small nanorover called Muses-CN . However, the rover was canceled for financial reasons. Instead, Hayabusa carried a small, only 591 g heavy Japanese landing probe called Minerva (abbreviation for Micro / Nano Experimental Robot Vehicle for Asteroid ), which was equipped with three cameras and solar cells. The lander should have been set down on the surface during the first attempt at sampling, in order to continue to “hop” and take pictures because of the very low gravity of the asteroid. Since the probe was only suspended due to a timing error when Hayabusa was already moving upwards away from the asteroid after approaching the surface, Minerva exceeded the escape speed necessary to overcome the asteroid's gravity and went into space after about 14 hours of radio contact lost.
- Hayabusa was successfully launched on May 9, 2003 from the Japanese Uchinoura Space Center in Kagoshima on an MV launcher.
- At the end of 2003 the probe got caught in strong solar winds, which damaged the solar cell surfaces and delayed arrival for three months due to the reduced thrust of the ion thrusters.
- On May 19, 2004, Hayabusa performed a swing-by maneuver on Earth. The flyby altitude was 3,700 km.
- On July 31, 2005, one (X-axis) of three gyroscopes on board the spacecraft required for position control and alignment went out of service.
- On August 14, 2005, Hayabusa's first picture of Itokawa was published. The photo was taken by a start tracker and showed a moving point of light that was mistaken for the asteroid. Additional pictures were taken between August 22nd and August 24th.
- On August 28, 2005 the ion thrusters were switched off and chemical thrusters were now used for position correction purposes.
- On September 4, 2005, Hayabusa's cameras took the first pictures of Itokawa, showing the shape of the asteroid.
- On September 12, 2005, Hayabusa reached a position about 20 km from Itokawa in which the space probe "remained". JAXA called this position the "Gate Position". The chemical thrusters fired for the last time at 1:17 UTC to compensate for the relative speed of the probe and the asteroid. Now Hayabusa was in an orbit that was almost the same as the orbit of the celestial body - the differential speed was 0.25 mm / s.
- On September 30, 2005, Hayabusa switched to the "home position" with the help of its chemical thrusters, which was about 7 km away from the asteroid.
- On October 2, 2005, the second (Y-axis) of the three gyroscopes failed. From now on the attitude control was carried out with the remaining gyroscope (Z-axis) and two chemical thrusters.
- On November 2, 2005, JAXA held a press conference during which the first high-resolution images of Itokawa were presented. The planned surface locations for taking samples were also shown and the dates for the sampling attempts were given.
- On November 4, the first test approach to the asteroid was canceled.
- On November 12, during the second approach, the Minerva lander was launched at a height of around 200 m. The launch took place while the mother probe was in an upward movement, so that Minerva was lost in space. A target marker was also exposed during this approach .
- The first sampling started on November 19th. A target marker was released at 19:55 UTC at a height of 40 meters and reached the surface of the asteroid about 6.5 minutes later. The probe then followed the target marker in fully automatic mode at a speed of about 2-3 cm / s, communication with the earth ceased as planned at a height of 17 meters, since contact with the probe from a ground station was blocked at this time was handed over to another. According to the initial reports, the approach was nominally up to a height of about ten meters, after which the probe went into safe mode and began to rotate slowly. The overheating of the electronics of the probe near the sunlit surface, which has a temperature of around 100 ° C, was named as a possible cause. When contact with Hayabusa was restored, the probe was sent away from the surface. Hayabusa then moved away to an altitude of about 100 km from Itokawa. However, after the data stored on board the probe had been downloaded and evaluated, it was found that Hayabusa had apparently actually landed on the asteroid and stayed there for about 30 minutes. However, since the landing did not take place in a scheduled mode, no samples were likely to be taken.
- The second landing took place on November 26, 2005. This time, according to the first reports, the sampling mechanism worked properly. It was not yet certain whether material was taken, but the JAXA assumed that the sample had been taken successfully. In addition, there were problems with one of the attitude control thrusters, possibly a fuel leak from contact with the asteroid surface. In order to stop the loss of fuel, Hayabusa was initially put into safe mode .
- Due to a lack of connection to the probe and the discharge of the batteries, the start window on December 14, 2005 was not used. It was still unclear whether samples were taken successfully.
- On January 23, 2006, JAXA received the first, as yet unmodulated signal from Hayabusa since the beginning of December 2005. Over the next few weeks, the probe was brought under control and stable communication was established.
- On April 25, 2007, Hayabusa returned to Earth with the help of its ion thrusters, which, as forecast at that time, was reached in 2010. At the time, it was unclear whether the probe would survive this unplanned long flight.
- The engines were switched off on October 24, 2007 and the probe was aligned with its axis of rotation to the sun . From now on she flew unpowered on a Hohmannbahn towards Erdbahn. The engines had been in operation for 31,000 hours by then and still had enough thrust and fuel. The orbit maneuver was only continued in February 2009.
- In May 2008, the return capsule was checked for functionality one last time and finally sealed. On June 2, 2008, Hayabusa was 1.5 AU from the Sun and behind the Sun when viewed from Earth.
- On February 4th, 2009 JAXA announced the successful ignition of the engines. The probe was to be accelerated further up to March 2010; the return was planned for June 2010.
- On November 4, 2009 it was found that engine D had shut down automatically due to problems. It was not possible to reactivate the engine. Engine C was also switched off during this time, but was functional.
- In the course of the return flight, four orbit correction maneuvers took place from May 4, 2010 (distance to earth: 16.6 million km) in order to adjust the orbit of the probe to earth and the landing area.
- Despite numerous failures of components (e.g. two gyroscopes were out of order, only four of the eleven lithium-ion batteries were still functional, the chemical fuel was exhausted and the antenna alignment mechanism blocked), the space probe was able to be returned to Earth and separated on May 13 June, 2010 at 10:51 UTC from the 20 kg re-entry capsule with the sample. The probe burned up over South Australia and could be followed by several observation stations, while the return capsule landed on parachute in the Woomera Prohibited Area in South Australia and was located an hour later by helicopter. Here the apparently intact capsule was recovered the next day and sealed until the samples were examined.
- Due to the success of the mission, JAXA voted in autumn 2010 for a follow-up mission Hayabusa 2 , which started successfully on December 3, 2014 and reached the asteroid (162173) Ryugu after a four-year flight.
- Takeoff weight: 510 kg, of which:
- Empty weight: 380 kg
- Propellants: 60 kg xenon as a support mass for the ion drive and 70 kg chemical fuel
- Dimensions: 1.0 m × 1.6 m × 1.1 m
- Energy: gallium arsenide - solar cells with 2.6 kW power in Erdentfernung from the sun
- Weight return capsule: 20 kg
- Communication: X-band
The images of the probe, which Itokawa reached in September 2005, show the surface of the asteroid with a resolution of less than one meter. What is striking is the almost complete absence of impact craters , which dominate the surfaces of other asteroids that have been explored by space probes , such as (243) Ida or (433) Eros . Some areas on Itokawa are covered by regolith and boulders of various sizes, while elsewhere bare rock is apparently exposed. The mean density of Itokawa could be determined by Hayabusa to be 2.3 ± 0.3 g / cm³. This is a little less than would have been expected for compact silicate rock. These observations suggest that the asteroid is a porous "rubble pile" held together only by the force of gravity .
The return container, which was carefully examined under high-purity conditions, contained a number of small particles, according to JAXA, which were subsequently examined. The research confirmed that the particles definitely came from the Itokawa.
The follow-up mission Hayabusa 2 was successfully launched on December 3, 2014 at 04:22 UTC with an H-IIA rocket . The start was postponed by two days due to weather conditions. The target is the asteroid (162173) Ryugu. Hayabusa 2 reached it in 2018, is expected to examine it and bring a soil sample back to Earth in December 2020.
More missions on asteroids
- Galileo 1991 in (951) Gaspra and 1993 in (243) Ida
- NEAR 1997 in (253) Mathilde and 2000–2001 in (433) Eros
- Deep Space 1 1999 at (9969) Braille
- Stardust 2002 with (5535) Annefrank and 2004 with Wild 2
- Dawn to (4) Vesta (arrival August 2011) and (1) Ceres (arrival February 2015)
- Rosetta flyby at (2867) Šteins on September 5, 2008
- Rosetta flyby at (21) Lutetia on July 10, 2010
- Mission website (Japanese, English)
- Hayabusa in the NSSDCA Master Catalog (English)
- Profile of the Hayabusa mission at JAXA ( Memento from December 3, 2016 in the Internet Archive )
- Bernd Leitenberger: Hayabusa
- JAXA: Recovery of the return capsule in the WPA (English, with pictures)
- Site to the target marker (English)
- FlugRevue February 2010, p. 76, Back with half strength - hope and fear with Japan's asteroid probe
- Hayabusa performed the Star Tracker imaging of Itokawa! JAXA, August 15, 2005, accessed June 14, 2010 .
- Hayabusa's navigation camera photographed the "Itokawa". JAXA, August 26, 2005, accessed June 14, 2010 .
- Hayabusa successfully captured Itokawa Shape for the first time in Space. JAXA, September 5, 2005, accessed June 14, 2010 .
- Hayabusa arrives Itokawa. JAXA, September 12, 2005, accessed June 14, 2010 .
- Hayabusa arrives at Home Position, and Current Status of Hayabusa Spacecraft. JAXA, October 4, 2005, accessed June 14, 2010 .
- anxiously Awaiting the Fruits of Our Labor. JAX, accessed April 7, 2013 .
- Emily Lakdawalla: Hayabusa Update: Hayabusa is alive; the target marker was placed successfully; another try in a few days. (No longer available online.) November 20, 2005, archived from the original on June 15, 2010 ; accessed on June 14, 2010 (English).
- Firing ion engine and starting second phase orbit maneuver to return to Earth. JAXA, February 4, 2009, accessed June 14, 2010 .
- Asteroid Explorer "HAYABUSA" Ion Engine Anomaly. JAXA, November 9, 2009, accessed June 14, 2010 .
- Asteroid Explorer "HAYABUSA" (MUSES-C) Capsule reentry plan. JAXA, June 12, 2009, accessed June 14, 2010 .
- Message from DLR on arrival
- Small particles found in the sample container of the HAYABUSA. JAXA, July 5, 2009, accessed July 23, 2010 .
- Particles brought back by Hayabusa identified as from Itokawa. JAXA, November 16, 2010, accessed November 16, 2010 .
- Landing device "Mascot": German jumping probe to asteroid launched. In: Spiegel Online . December 3, 2014, accessed June 9, 2018 .