Mission typeCommunication
OperatorSKY Perfect JSAT Group
COSPAR ID1996-007A [1]
SATCAT no.23781
Mission duration10 years (planned)
Spacecraft properties
SpacecraftN-STAR b
BusSSL 1300
ManufacturerSpace Systems/Loral
Launch mass3,400 kg (7,500 lb) [2]
BOL mass2,050 kg (4,520 lb)
Dry mass1,617 kg (3,565 lb)
Start of mission
Launch date5 February 1996, 07:19:38 UTC[1]
RocketAriane 44P H10-3
Launch siteCentre Spatial Guyanais, ELA-2
Orbital parameters
Reference systemGeocentric orbit
RegimeGeostationary orbit
Band6 C-band
11 Ka-band
8 Ku-band
1 S-band[3]
Coverage areaJapan

N-STAR b, was a geostationary communications satellite originally ordered by a consortium including NTT DoCoMo and JSAT Corporation, and later fully acquired by JSAT, which was merged into SKY Perfect JSAT Group. It was designed and manufactured by Space Systems/Loral on the SSL 1300 platform.[2] It had a launch weight of 3,400 kg (7,500 lb), and a 10-year design life.[2] Its payload is composed of 6 C-band, 11 Ka-band, 8 Ku-band and 1 S-band transponders.


N-Star was created as a joint venture between JSAT, Nippon Telegraph and Telephone (NTT), NTT Communications and NTT DoCoMo for the supply of these latter two WIDESTAR satellite telephone and data packet service.[4] JSAT would handle the satellite side of business and NTT DoCoMo would operate the payload.[5][6]

Two identical satellites were ordered on 1992 from Space Systems Loral, N-STAR a and N-STAR b, for 1995 and 1996 on orbit delivery.[7][8] They would be "switchboards in the sky" having S-band, C-band, Ka-band and Ku-band payload.[9]

N-STAR a was successfully launched aboard an Ariane 44P on 29 August 1995. Its twin, N-STAR b, launched on 5 February 1996, also aboard an Ariane 44P.[2][9] The satellite telephone service was operational in March 1996. In March 2000, the packet communications service was introduced.[10] In March 2000, JSAT received the NTT Communications interest in the N-STAR a and N-STAR b.[11][12]

In August 2003, the JSAT acquired the NTT DoCoMo interest on N-STAR a and N-STAR b, whom then leased them back.[13][14]

See also


  1. ^ a b "Display: N-STAR B 1996-006A". NASA. 10 February 2021. Retrieved 18 March 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ a b c d Krebs, Gunter (11 December 2017). "N-Star a, b". Gunter's Space Page. Retrieved 18 March 2021.
  3. ^ "Communications in Japan 1999" (PDF). General Planning and Policy Division, Minister's Secretariat (Page 132) (Whitepaper) (1999 ed.). Ministry of Posts and Telecommunications of Japan. Retrieved 18 March 2021.
  4. ^ "FORM 20-F/A AMENDMENT NO.1 TO FORM 20-F" (PDF). NTT DoCoMo. 8 February 2002. Retrieved 2 August 2016.
  5. ^ "FORM 20-F/A AMENDMENT NO.1 TO FORM 20-F" (PDF). NTT DoCoMo. 10 July 2002. Retrieved 2 August 2016.
  6. ^ "FORM 20-F/A AMENDMENT NO.1 TO FORM 20-F" (PDF). NTT DoCoMo. 8 February 2002. pp. 33–34. Retrieved 18 March 2021.
  7. ^ "N-Star". Global Security. Retrieved 2 August 2016.
  8. ^ "Awards & Launch History - 1300 Bus Satellites". SSL (company). Archived from the original on 12 August 2015. Retrieved 20 August 2016.
  9. ^ a b "N-Star a and b". SSL (company). Archived from the original on 14 September 2016. Retrieved 18 August 2016.
  10. ^ Yamamoto, Kazuichi; Furukawa, Makoto; Satoh, Hijin; Nishi, Yasuki; Kouji, Horikawa (September 2010). "Overview of WIDESTAR II Mobile Satellite Communications System and Service" (PDF). NTT DoCoMo Technical Journal. 12 (2). NTT DoCoMo: 37–42. Retrieved 2 August 2016.
  11. ^ "Who we are?". SKY Perfect JSAT Group. 3 August 2012. Retrieved 2 August 2016.
  12. ^ "History". SKY Perfect JSAT Holdings Inc. Retrieved 18 March 2021.
  13. ^ "NTT DoCoMo to Transfer Satellite Assets to JSAT and Acquire JSAT Common Stock". NTT DoCoMo. 31 July 2003. Retrieved 2 August 2016.
  14. ^ "FORM 20-F/A AMENDMENT NO.1 TO FORM 20-F" (PDF). NTT DoCoMo. 28 June 2004. Retrieved 2 August 2016.