The N-I or N-1 was a derivative of the American Thor-Delta rocket, produced under license in Japan. The N stood for "Nippon" (Japan). It used a Long Tank Thor first stage, a Mitsubishi Heavy Industries-designed LE-3 engine on the second stage,[3][4][5] and three Castor SRMs.[2][6] Seven were launched between 1975 and 1982, before it was replaced by the N-II. Six of the seven launches were successful, however on the fifth flight, there was recontact between the satellite and the third stage, which caused the satellite to fail.
![]() The N-I rocket[1] | |
Function | Carrier rocket |
---|---|
Manufacturer | McDonnell Douglas (design) Mitsubishi Heavy Industries (production) |
Country of origin | United States (design) Japan (production) |
Size | |
Height | 34 metres (112 ft)[1] |
Diameter | 2.44 metres (8.0 ft) |
Mass | 131,330 kilograms (289,530 lb)[1] |
Stages | 2 or 3 |
Capacity | |
Payload to LEO | |
Mass | 1,200 kilograms (2,600 lb)[1] |
Payload to GTO | |
Mass | 360 kilograms (790 lb)[1] |
Associated rockets | |
Family | Delta |
Launch history | |
Status | Retired |
Launch sites | LA-N, Tanegashima |
Total launches | 7 |
Success(es) | 6 |
Partial failure(s) | 1 |
First flight | 9 September 1975 |
Last flight | 3 September 1982 |
Boosters – Castor 2 | |
No. boosters | 3[2] |
Powered by | 1 TX-354-3 |
Maximum thrust | 258.9 kilonewtons (58,200 lbf) |
Specific impulse | 262 sec |
Burn time | 37 seconds |
Propellant | Solid |
First stage – Thor-ELT | |
Powered by | 1 MB-3-3 |
Maximum thrust | 866.7 kilonewtons (194,800 lbf) |
Specific impulse | 290 sec |
Burn time | 270 seconds |
Propellant | RP-1/LOX |
Second stage | |
Powered by | 1 LE-3 |
Maximum thrust | 52.9 kilonewtons (11,900 lbf) |
Specific impulse | 290 sec |
Burn time | 246 seconds |
Propellant | NTO/A-50 |
Third stage (optional) – Star-37N | |
Powered by | 1 solid |
Maximum thrust | 45 kilonewtons (10,000 lbf) |
Specific impulse | 290 sec |
Burn time | 42 seconds |
Propellant | Solid |
On 29 February 1976, the second N-I conducted the only orbital launch to occur on a leap day.[7]
Flight No. | Date / time (UTC) | Rocket, Configuration |
Launch site | Payload | Payload mass | Orbit | Customer | Launch outcome |
---|---|---|---|---|---|---|---|---|
1(F) | 9 September 1975 05:30[8] |
Tanegashima | ETS-1 (JETS-1/Kiku-1)[9] | LEO | Success | |||
2(F) | 29 February 1976 03:30[8] |
Tanegashima | ISS-1 (JISS-1/Ume-1)[10] | LEO | Success | |||
3(F) | 23 February 1977 08:50[8] |
Tanegashima | ETS-2 (Kiku-2)[11] | GTO | Success | |||
3rd stage used | ||||||||
4(F) | 16 February 1978 04:00[8] |
Tanegashima | ISS-2 (JISS-2/Ume-2)[10] | LEO | Success | |||
5(F) | 6 February 1979 08:46[8] |
Tanegashima | ECS-A (Ayame-1)[12] | GTO | Partial failure | |||
3rd stage used; Recontact between satellite and upper stage. | ||||||||
6(F) | 22 February 1980 08:35[8] |
Tanegashima | ECS-B (Ayame-2)[12] | GTO | Success | |||
3rd stage used | ||||||||
9(F) | 3 September 1982 05:00[8] |
Tanegashima | ETS-3 (Kiku-4)[13] | LEO | Success | |||