Kounotori 6

Kounotori 6 (こうのとり6号機), also known as HTV-6, was the sixth flight of the H-II Transfer Vehicle, an uncrewed cargo spacecraft launched to resupply the International Space Station. It was launched at 13:26:47 UTC on 9 December 2016 aboard H-IIB launch vehicle from Tanegashima Space Center.

Kounotori 6
The SSRMS (Canadarm2) grapples Kounotori 6
spacecraft, prior to berthing on 13 December 2016.
Mission typeISS resupply
OperatorJAXA
COSPAR ID2016-076A Edit this at Wikidata
SATCAT no.41881
Mission duration58 days
Spacecraft properties
SpacecraftKounotori 6
Spacecraft typeHTV
ManufacturerMitsubishi Heavy Industries
Launch mass16400 kg
Dry mass10500 kg
Payload mass5900 kg
Dimensions9.8 metre of long,
4.4 metre of diameter
Start of mission
Launch date9 December 2016, 13:26:47 UTC
RocketH-IIB No. 6
Launch siteTanegashima, Yoshinobu 2
ContractorMitsubishi Heavy Industries
End of mission
Disposaldeorbited
Decay date5 February 2017, 15:06 UTC
Orbital parameters
Reference systemGeocentric orbit
RegimeLow Earth orbit
Inclination51.66°
Berthing at ISS
Berthing portHarmony
RMS capture13 December 2016, 10:37 UTC
Berthing date13 December 2016, 13:57 UTC
Unberthing date27 January 2017, 10:59 UTC
RMS release27 January 2017, 15:45 UTC
Cargo
Mass5900 kg
Pressurised4000 kg
Unpressurised1900 kg
 

Spacecraft

Major changes from previous Kounotori include:[1][2]

  • Built-in payloads to demonstrate new technologies: SFINKS and KITE, described below.
  • Reduction of primary batteries to 6 from the previous 7.
  • Reduction of solar cell panels to 48 from previous 49.
  • Omission of some of navigation/position lights which were Earth-side when approaching to ISS.
  • Strengthened EP (Exposed Pallet) maximum payload to 1900 kg from the previous 1600 kg to carry Lithium-ion batteries.

SFINKS (Solar Cell Film Array Sheet for Next Generation on Kounotori Six) will test thin film solar cells in space.[3]

Kounotori Integrated Tether Experiment

KITE (Kounotori Integrated Tether Experiment) was an experimental electrodynamic tether (EDT).[4][5] The tether was equipped with a 20 kg end-mass, and would have been 700 m long when deployed,[4][6][7] Unfortunately deployment failed, but useful data was still gathered from some of the instruments.[8] A maximum current of 10 mA was planned to run through the tether.[4] Kounotori's ISS rendezvous sensor would have been utilized to measure how the end-mass moves during the test.[4] The EDT experiment was scheduled following Kounotori 6's departure from the ISS, with a planned duration of one week.[4] After the experiment, the tether would have been separated before the spacecraft proceeds with the de-orbit maneuvers. The main objective of this experiment were the orbital demonstration of both extending an uncoated bare-tether, and driving electric currents through the EDT.[5] These two technologies will contribute to gaining capabilities to remove space debris.[5][9][10][11]

Cargo

Kounotori 6 carries about 5900 kg of cargo (including the support structure weight), consisting of 3900 kg in PLC (Pressurized Logistics Carrier) and 1900 kg in ULC (Unpressurized Logistics Carrier).[12]

Cargo in the pressurized compartment includes 30 bags filled with potable water (600 liters),[13][14] food, crew commodities, CDRA Bed (Carbon Dioxide Removal Assembly), TPF (Two-Phase Flow) experiment unit, PS-TEPC (Position-Sensitive Tissue Equivalent Proportional Chamber) radiation measurement instrument, ExHAM (Exposed Experiment Handrail Attachment Mechanism), HDTV-EF2 high-definition and 4K camera, new J-SSOD (JEM Small Satellite Orbital Deployer), and CubeSats (AOBA-Velox III, TuPOD which comprises two TubeSats (Tancredo-1 and OSNSAT), EGG, ITF-2, STARS-C, FREEDOM, WASEDA-SAT3).[15][16][12] Cargo by NanoRacks includes TechEdSat-5,[17] CubeRider,[18] RTcMISS,[19] NREP-P DM7,[20][21] four Lemur-2.[22] Additionally, the Blue SPHERES satellite of the MIT Space Systems Laboratory is being returned to the ISS for continued autonomous systems research.[23]

Cargo in the unpressurized compartment consists of six lithium-ion batteries and their associated adapter plates to replace existing nickel-hydrogen batteries of the International Space Station. Since each of the new lithium-ion battery has a capability equivalent to two of the current nickel-hydrogen batteries, the six new batteries will replace twelve old batteries, out of the 48 existing batteries of the ISS.[13]

On departure from the ISS, Kounotori 6 carries 9 out of the 12 replaced old batteries which will be disposed of by destructive reentry into Earth's atmosphere. The 3 remaining old batteries stay on the ISS.[14]

Operation

Launch

On 26 July 2016, the launch was scheduled for 30 September 2016,[24] but on 10 August 2016, postponement was announced due to the leak from piping.[25]

The H-IIB launch vehicle carrying Kounotori 6 lifted off at 13:26:47 UTC on 9 December 2016, and 15 minutes 11 seconds later, Kounotori 6 was released into initial 200 × 300 km orbit.[26][27]

SFINKS experiment payload began the data collection at 14:16, on 9 December 2016, but it stopped unexpectedly after 509 seconds.[28]

After a series of orbital manoeuvres, Kounotori 6 arrived to the proximity of ISS and captured by SSRMS (Canadarm2) at 10:39 (10:37 according to NASA), on 13 December 2016.[29][30] Kounotori was bolted to the CBM (Common Berthing Mechanism) of the Harmony nadir port by 13:48 UTC.[31]

Operation while berthed to ISS

Berthing operation completed at 18:24, on 13 December 2016 UTC,[32] and the hatch opened at 19:44 UTC.[33]

Since 07:44, 14 December 2016, Exposed Pallet (EP) was extracted from Unpressurised Logistics Carrier (ULC) of Kounotori 6 by SSRMS and transferred to Payload and ORU Accommodation (POA).[34][35] After a combination of two Extra-Vehicular Activities and robotic operations, the lithium-ion battery units and adapter plates were installed. The Exposed Pallet carrying old Nickel-hydrogen battery units was returned to Kounotori 6's Unpresurised Logistics Carrier on 23 January 2017.[36]

Departure from the ISS and re-entry to the Earth atmosphere

SSRMS grappled and detached Kounotori 6 from the CBM of Harmony nadir port at 10:59, 27 January 2017,[37] and Kounotori 6 was released at 15:45, on 27 January 2017.[38]

Following the undocking after moving to a safe distance from ISS, the Kounotori 6 was to demonstrate the "Kounotori Integrated Tether Experiment" (KITE) using electrodynamic tether to demonstrate space debris removal technology.[39] This experiment was planned for seven days before reentry to the Earth's atmosphere.[37] On 31 January 2017, media reported some problems in extending the tether, bringing to doubt the experiment's success.[40]

A series of deorbit manoeuvres were performed at 08:42, 10:12, and 14:42 UTC, on 5 February 2017.[41][42][43] Kounotori 6 reentered to Earth atmosphere over southern Pacific Ocean around 15:06 UTC, on 5 February 2017.

References

External links

Images